In situ cross-linking encapsulation has been demonstrated to be an efficient strategy for enhancing the humidity stability of perovskite solar cells(PSCs).In this study,a novel cross-linkable fullerene derivative,name...In situ cross-linking encapsulation has been demonstrated to be an efficient strategy for enhancing the humidity stability of perovskite solar cells(PSCs).In this study,a novel cross-linkable fullerene derivative,namely1-(p-benzoate-(p-methylvinylbenzene)-indolino[2,3][60]fullerene(FPPS),was readily synthesized from commercially available building blocks in two steps.This FPPS was employed as an interfacial modifier on perovskite surfaces in inverted planar p-i-n PSCs.Owing to the fast interfacial charge extraction and efficient trap passivation,PSCs based on the cross-linked FPPS(C-FPPS)exhibited excellent performance.The PSCs had a top-performing power conversion efficiency(PCE)of 17.82%with negligible hysteresis,compared to the control devices without C-PFFS(16.99%).Moreover,the strong water resistance of the C-FPPS interfacial layer distinctly enhances the ambient stability of PSC devices,exhibiting a t80(the time required to reach 80%of the initial PCE)of 300 h under high-humidity conditions.This significantly surpasses the control devices,whose t80 was only 130 h.These results demonstrate that cross-linkable fullerene derivatives can be promising interfacial materials for designing high-efficiency,hysteresis-free,air-stable PSCs.展开更多
Cross-linkable hole transport materials(x-HTMs)play a crucial role in solving the issue of interlayer mixing of solution-processed organic light-emitting diodes(OLEDs).However,issues such as energy level mismatch and ...Cross-linkable hole transport materials(x-HTMs)play a crucial role in solving the issue of interlayer mixing of solution-processed organic light-emitting diodes(OLEDs).However,issues such as energy level mismatch and low hole mobility hinder the application of x-HTMs in deep-blue OLEDs.In particular,thermally activated delayed fluorescent(TADF)emitters require HTMs with high triplet energies(E T)to ensure high exciton utilization efficiency.Here,two star-shaped cross-linkable HTMs 5-(9H-carbazol-9-yl)-N^(1),N^(3)-di(p-tolyl)-N^(1),N^(3)-bis(4-vinylphenyl)benzene-1,3-diamine(m-V-CzDPA)and N^(1),N^(1)-diphenyl-N^(3),N^(5)-di(p-tolyl)-N^(3),N^(5)-bis(4-vinylphenyl)benzene-1,3,5-triamine(m-V-DPADPA)were designed and synthesized.Owing to their aromatic torsion structures,m-V-CzDPA and m-V-DPADPA possessed high E Ts of 2.89 and 2.87 eV,respectively,which can effectively confine triplet excitons in the emitting layer(EML).The carrier diffusion coefficients of their x-HTMs,x-m-CzDPA and x-m-DPADPA,which were obtained via carrier diffusion imaging characterization were 0.54 and 0.44 cm^(2) s^(-1),respectively,thus indicating outstanding intrinsic hole transport capacity,with hole mobilities of 4.30×10^(-4) and 1.39×10^(-4) cm^(2) V^(-1) s^(-1),respectively.Solution-processed deep-blue TADF-OLEDs employing x-m-CzDPA as the HTM achieved a maximum current efficiency/maximum external quantum efficiency of 5.25 cd A^(-1)/18.06%,with CIE coordinates of(0.162,0.042).This is the first time that x-HTMs have served as efficient deep-blue TADF-OLEDs via a solution process,which also meets the latest BT.2020 standard(CIE_(y)≤0.046).展开更多
The retrospective study by Edwar et al reinforces the role of therapeutic penetrating keratoplasty(PK)as a vital intervention in severe,treatment-resistant infectious keratitis.In advanced cases—often complicated by ...The retrospective study by Edwar et al reinforces the role of therapeutic penetrating keratoplasty(PK)as a vital intervention in severe,treatment-resistant infectious keratitis.In advanced cases—often complicated by trauma,delayed presentation,and corneal perforation—PK restores globe integrity and provides limited visual recovery.However,its application is constrained by graft-related complications and donor shortages,particularly in low-resource settings.These limitations highlight the need for earlier,globe-sparing strategies to prevent progression and reduce surgical demand.Photoactivated chromophore for infectious keratitis-corneal collagen cross-linking(PACK-CXL)has emerged as a promising adjunct or alternative.With both antimicrobial and tissue-stabilizing effects,PACK-CXL may control infection and preserve corneal structure in earlier stages.A layered treatment framework that incorporates PACK-CXL as an initial intervention and reserves PK for refractory cases may help improve clinical outcomes.Further studies are needed to define their best use in practice.展开更多
Based on the characteristics of laser-induced surface ignition,energetic photosensitive films show promising potential to meet the ignition requirements of various energetic materials(EMs).In this study,DATNBI/ferric ...Based on the characteristics of laser-induced surface ignition,energetic photosensitive films show promising potential to meet the ignition requirements of various energetic materials(EMs).In this study,DATNBI/ferric alginate(DI/FeA),DI/cobalt alginate(DI/CoA),and DI/nickel alginate(DI/Ni A)films are fabricated by employing sodium alginate(SA)with a three-dimensional network structure as the film matrix,via ionic cross-linking of SA with Fe^(3+),Co^(2+),and Ni^(2+)ions.The study demonstrates that the ionic cross-linking enhances the hydrophobic performance of the films,with the water contact angle increasing from 82.1??to 123.5??.Concurrently,the films'near-infrared(NIR)light absorption improved.Furthermore,transition metal ions facilitate accelerated electron transfer,thereby catalyzing the thermal decomposition of DATNBI.Under 1064 nm laser irradiation,the DI/Fe A film exhibits exceptional combustion performance,with an ignition delay time as low as 76 ms.It successfully acts as an NIR laser ignition medium to initiate the self-sustained combustion of CL-20.This study demonstrates the synergistic realization of enhanced hydrophobicity,improved photosensitivity,and promoted catalytic decomposition through microstructural design of the material,providing new insights for the design of additive-free EMs in laser ignition applications.展开更多
The solution-processed method for organic light-emitting diodes(OLEDs)offers the benefits of cost-effectiveness and enhanced material utilization.In the multilayer architecture of solution-processed OLEDs(SOLEDs),the ...The solution-processed method for organic light-emitting diodes(OLEDs)offers the benefits of cost-effectiveness and enhanced material utilization.In the multilayer architecture of solution-processed OLEDs(SOLEDs),the role of hole-transport materials(HTMs)is pivotal for cascade hole injection.However,commercial HTMs such as poly-(9,9-dioctylfluorene-alt-N-(4-sec-butylphenyl)-diphenylamine)(TFB)are hampered by incompatible energy levels and redissolution with overlayer solvent,prompting the exploration of cross-linkable HTMs(X-HTMs)for better performance.In this study,we have developed two novel small-molecule X-HTMs,N^(1),N^(1)′-((perfluoropropane-2,2-diyl)bis(4,1-phenylene))bis(N^(4),N^(4)-diphenyl-N^(1)-(4-vinylphenyl)benzene-1,4-diamine)(FTPA-V)and N,N′-((perfluoropropane-2,2-diyl)bis-(4,1-phenylene))bis(9-phenyl-N-(4-vinylphenyl)-9H-carbazol-3-amine)(FPCz-V),which incorporate thermally cross-linkable vinyl groups and electron-rich trifluoromethyl units.The X-HTMs enhance interfacial contact through superior film formation and solvent resistance,along with optimal energy levels.The application of X-HTMs significantly enhances the efficiencies and longevities of blue,green,and red SOLEDs.Specially,blue SOLED incorporating FPCz-V exhibits unprecedented lifetime(LT95)extending to over 150 h,setting a new record for blue SOLEDs.The electrochemistry stability,high bond dissociation energy,and triplet energy levels of X-HTMs can effectively minimize exciton annihilation and prolong the lifetime.These findings underscore the potential of X-HTM optimization to propel the development of stable solution-processed luminescent technologies.展开更多
How to obtain organic electro-optic materials with large electro-optic coefficients,high glass transition temperature,and good optical transparency remains a challenge in this field.To solve this problem,we introduce ...How to obtain organic electro-optic materials with large electro-optic coefficients,high glass transition temperature,and good optical transparency remains a challenge in this field.To solve this problem,we introduce groups that can undergo Huisgen cycloaddition reactions into the donor and electron bridge of chromophores with large hyperpolarizability using tetrahydroquinoline as the donor.Binary cross-linkable chromophores TLD1-2 with CF_(3)-TCF as the acceptor and chromophores TLD3-4 with 5Fph-TCF as the acceptor were synthesized.After poling and crosslinking,the T_(g)of TLD1/TLD2 and TLD3/TLD4 were raised to 152 and 174°C,respectively.The electro-optical coefficients of chromophores TLD1/TLD2 and TLD3/TLD4 were as high as 312 pm/V and 287 pm/V,respectively.The long-term alignment stability test showed that after being left at 85℃ for 500 h,the cross-linked film TLD3/TLD4 can still maintain more than 98%of the original electro-optical coefficient value,which is higher than that of TLD1/TLD2(93%).The chromophore TLD3-4 exhibited much blue-shifted maximum absorption wavelengths(~40 nm)compared to TLD1-2 which was beneficial for reducing optical loss in the device.The combination of high electro-optic coefficient,strong stability,and excellent optical transparency makes the TLD series of binary cross-linked materials very promising for practical high-performance electro-optic devices.展开更多
AIM:To investigate the response of the anterior and posterior corneal surface in femtosecond laser-assisted convex stromal lenticule addition keratoplasty(SLAK)combined with cross-linking(CXL)for treating keratoconus ...AIM:To investigate the response of the anterior and posterior corneal surface in femtosecond laser-assisted convex stromal lenticule addition keratoplasty(SLAK)combined with cross-linking(CXL)for treating keratoconus at the first 3mo of follow-up.METHODS:In this prospective observational study,20 eyes of 20 keratoconus patients who underwent SLAK combined with CXL were included.The morphological indices in keratometry and elevation data were recorded from the Sirius at baseline and 1 and 3mo postoperatively.The mean values of maximum keratometry(K_(max)),flat keratometry(K_(1)),and steep keratometry(K_(2))at the central,3-mm,5-mm,and 7-mm areas were measured from the curvature map.The changes in anterior and posterior corneal elevation under the best-fit sphere(BFS)radius at seven points horizontally of the center,3-mm,5-mm,and 7-mm area from the center at both nasal(N)and temporal(T)side were measured from elevation map.RESULTS:For the front corneal curvature,K_(1),and K_(2) at 3-mm,5-mm,and 7-mm of the anterior corneal surface increased significantly 1mo postoperatively(all P<0.05)and remained unchanged until 3mo(P>0.05).For the back corneal curvature,K_(1) and K_(2) along the 3-mm back meridian significantly decreased after month 1(P=0.002,0.077,respectively).Posterior K_(2)-readings along the 5-mm and 7-mm did not change after surgery(P>0.05).Anterior BFS decreased 1mo(P<0.001)postoperatively but remained unchanged until 3mo after SLAK(P>0.05).There was no change in posterior BFS before and after the surgery(P>0.05).Anterior elevation at N5,N3,central,and T5 points and posterior elevation at central and T7 points shifted backward 1mo postoperatively(all P<0.05)and remained stable until 3mo(P>0.05).CONCLUSION:The myopic SLAK combined with CXL is an economical alternative for stabilizing the corneal surface in severe keraoconus.“Pseudoprogression”occurs in the early phase postoperatively,but it is not an indicator of keratoconus progression.展开更多
Polymer binders possess significant potential in alleviating the volume expansion issues of silicon-based anodes,yet remain challenging due to insufficient interfacial interactions with individual components(Si,C,and ...Polymer binders possess significant potential in alleviating the volume expansion issues of silicon-based anodes,yet remain challenging due to insufficient interfacial interactions with individual components(Si,C,and Cu)of the anode.Herein,we report the synthesis of a stable three-dimensional network structure of the PAA-PEA(polyacrylic acid-polyether amines)polymer binder through intermolecular physicochemical dual cross-linking.By incorporating polar functional groups,the binder molecules not only form strong C-O-Si,N-Si,O=C-O-C,and O=C-O-Cu covalent bonds but also enhance non-covalent interactions with Si,C,and Cu,thereby improving adhesion between the binder and each interface of the anode.Furthermore,weak hydrogen bonds,acting as"sacrificial bonds",dissipate energy and disperse accumulated stress,improving the material flexibility.Due to the high mechanical stability of the framework,which combines both rigidity and flexibility and the coupling effect at the three interfaces,the movement and separation of electrode components are effectively restrained,significantly enhancing the cycling stability of silicon-graphite anodes.The PAA-PEA 2000 electrode exhibits a capacity retention of 78% after 500 cycles at a current density of 0.2 A g^(-1).This work provides insights into the mechanism of binders and guides the design of polymer binders for high-performance Si-based electrodes.展开更多
AIM:To compare simultaneous corneal collagen cross-linking(CXL)with intracorneal ring segment(ICRS)implantation versus successive ICRS followed by CXL and detect the impact of the timing of CXL after ICRS implantation...AIM:To compare simultaneous corneal collagen cross-linking(CXL)with intracorneal ring segment(ICRS)implantation versus successive ICRS followed by CXL and detect the impact of the timing of CXL after ICRS implantation in the successive method.METHODS:This is a retrospective study of the records of three groups of patients.Group 1 of 28 patients were operated on with simultaneous ICRS implantation and CXL,group 2 of 32 patients had ICRS implantation followed by CXL after 1mo,and group 3 of 38 patients had ICRS implantation followed by CXL after 3mo.The three groups had follow-up visits after 6,12,and 24mo.RESULTS:The preoperative data,age,and gender differences among 3 groups revealed no significant differences.The postoperative spherical equivalent and best-corrected visual acuity were improved significantly in all groups compared to the baseline,which were more evident in groups 1 and 2.The differences between preoperative and postoperative mean values of mean of K readings(Km)and maximum K reading(Kmax)at 6mo were 4.66 and 4.1 D in group 1,4.43 and 4.64 D in group 2,but 3.2 and 3.4 D in group 3,respectively.The spherical aberrations and the vertical coma showed significant postoperative changes in all groups,and trefoil showed nonsignificant changes.CONCLUSION:Simultaneous and sequential ICRS implantation and CXL at 1mo has similar Km and Kmax better postoperative changes than when both surgeries were done at three-month intervals.展开更多
Highly transparent,durable,and flexible liquid-repellent coatings are urgently needed in the realm of transparent materials,such as car windows,optical lenses,solar panels,and flexible screen materials.However,it has ...Highly transparent,durable,and flexible liquid-repellent coatings are urgently needed in the realm of transparent materials,such as car windows,optical lenses,solar panels,and flexible screen materials.However,it has been difficult to strike a balance between the robustness and flexibility of coatings constructed by a single cross-linked network design.To overcome the conundrum,this innovative approach effectively combines two distinct cross-linked networks with unique functions,thus overcoming the challenge.Through a tightly interwoven structure comprised of added crosslinking sites,the coating achieves improved liquid repellency(WCA>100°,OSA<10°),increased durability(withstands 2,000 cycles of cotton wear),enhanced flexibility(endures 5,000 cycles of bending with a bending radius of 1 mm),and maintains high transparency(over 98%in the range of 410 nm to 760 nm).Additionally,the coating with remarkable adhesion can be applied to multiple substrates,enabling large-scale preparation and easy cycling coating,thus expanding its potential applications.The architecture of this fluoride-free dual cross-linked network not only advances liquid-repellent surfaces but also provides valuable insights for the development of eco-friendly materials in the future.展开更多
Aging is a persistent topic of interest,with skin aging as its most visible manifestation,characterized by a reduction in intact collagen and elastic fibers in the dermis.Hyaluronic acid,a vital component of the extra...Aging is a persistent topic of interest,with skin aging as its most visible manifestation,characterized by a reduction in intact collagen and elastic fibers in the dermis.Hyaluronic acid,a vital component of the extracellular matrix present in the skin,has become a mainstream method for skin rejuvenation through injections.However,the rapid degradation of pure hyaluronic acid,combined with insufficient maintenance duration and often limited therapeutic effects,presents significant challenges for injectable treatments.Additionally,low patient compliance due to discomfort from needles penetrating the dermal layer further complicates its use.In this review,we summarize and compare existing interventions for skin aging,focusing on strategies to prolong the degradation cycle of hyaluronic acid,including variations in cross-linking modalities and injection techniques.We conclude that the injection of cross-linked modified hyaluronic acid via microneedles represents a promising approach to extend the degradation cycle,offering valuable insights for current therapeutic strategies.展开更多
In this study,a novel cost-effective methodology was developed to enhance the gas barrier properties and permselectivity of unfilled natural rubber(NR)/polybutadiene rubber(BR)composites through the construction of a ...In this study,a novel cost-effective methodology was developed to enhance the gas barrier properties and permselectivity of unfilled natural rubber(NR)/polybutadiene rubber(BR)composites through the construction of a heterogeneous structure using pre-vulcanized powder rubber to replace traditional fillers.The matrix material is composed of a blend of NR and BR,which is widely used in tire manufacturing.By incorporating pre-vulcanized trans-1,4-poly(isoprene-co-butadiene)(TBIR)rubber powder(pVTPR)with different cross-linking densities and contents,significant improvements in the gas barrier properties and CO_(2)permselectivity of the NR/BR/pVTPR composites were observed.The results indicated that compared to NR/BR/TBIR composites prepared through direct blending of NR,BR,and TBIR,the NR/BR/pVTPR composites exhibited markedly superior gas barrier properties.Increasing the cross-linking density of pVTPR resulted in progressive enhancement of the gas barrier properties of the NR/BR/pVTPR composite.For example,the addition of 20 phr pVTPR with a cross-linking density of 346 mol/m^(3)resulted in a 79%improvement in the oxygen barrier property of NR/BR/pVTPR compared to NR/BR,achieving a value of 5.47×10^(-14)cm^(3)·cm·cm^(-2)·s^(-1)·Pa^(-1).Similarly,the nitrogen barrier property improved by 76%compared to NR/BR,reaching 2.4×10^(-14)cm^(3)·cm·cm^(-2)·s^(-1)·Pa^(-1),which is 28%higher than the conventional inner liner material brominated butyl rubber(BIIR,PN2=3.32×10^(-14)cm^(3)·cm·cm^(-2)·s^(-1)·Pa^(-1)).Owing to its low cost,exceptional gas barrier properties,superior adhesion to various tire components,and co-vulcanization capabilities,the NR/BR/pVTPR composite has emerged as a promising alternative to butyl rubber in the inner liner of tires.Furthermore,by fine-tuning the cross-linking density of pVTPR,the high-gas-barrier NR/BR/pVTPR composites also demonstrated remarkable CO_(2)permselectivity,with a CO_(2)/N2 selectivity of 61.4 and a CO_(2)/O_(2)selectivity of 26.12.This innovation provides a novel strategy for CO_(2)capture and separation,with potential applications in future environmental and industrial processes.The multifunctional NR/BR/pVTPR composite,with its superior gas barrier properties and CO_(2)permselectivity,is expected to contribute to the development of safer,greener,and more cost-effective transportation solutions.展开更多
Selective hydrogenation of furfural to furfuryl alcohol is a great challenge in the hydrogenation field due to thermodynamic preference for hydrogenation of C=C over C=O.Herein,a novel Al_(2)O_(3)/C-u hybrid catalyst,...Selective hydrogenation of furfural to furfuryl alcohol is a great challenge in the hydrogenation field due to thermodynamic preference for hydrogenation of C=C over C=O.Herein,a novel Al_(2)O_(3)/C-u hybrid catalyst,composed of N-modified dendritic carbon networks supporting Al_(2)O_(3)nanoparticles,was successfully prepared via carbonizing the freeze-dried gel from spontaneous cross-linking of alginate,Al3+and urea.The obtained carbon-supported Al_(2)O_(3)hybrid catalyst has a high ratio (31%) of Al species in pentahedral-coordinated state.The introduction of urea enhances the surface N content,the ratio of pyrrolic N,and specific surface area of catalyst,leading to improved adsorption capacity of C=O and the accessibility of active sites.In the furfural hydrogenation reaction with isopropyl alcohol as hydrogen donor,Al_(2)O_(3)/C-u catalyst achieved a 90%conversion of furfural with 98.0% selectivity to furfuryl alcohol,outperforming that of commercial γ-Al_(2)O_(3).Moreover,Al_(2)O_(3)/C-u demonstrates excellent catalytic stability in the recycling tests attributed to the synergistic effect of abundant weak Lewis acid sites and the anchoring effect of the carbon network on Al_(2)O_(3)nanoparticles.This work provides an innovative and facile strategy for fabrication of carbon-supported Al_(2)O_(3)hybrid catalysts with rich AlVspecies,serving as a high selective hydrogenation catalyst through MPV reaction route.展开更多
LiMnxFe1-xPO_(4) is a promising cathode candidate due to its high security and the availability of a high 4.1 V operating voltage and high energy density.However,the poor electrochemical kinetics and structural instab...LiMnxFe1-xPO_(4) is a promising cathode candidate due to its high security and the availability of a high 4.1 V operating voltage and high energy density.However,the poor electrochemical kinetics and structural instability currently hinder its broader application.Herein,inspired by the hydrogen-bonded cross-linking and steric hindrance effect between short-chain polymer molecules(polyethylene glycol-400,PEG-400),the pomegranate-type LiMn_(0.5)Fe_(0.5)PO_(4)-0.5@C(P-LMFP@C)cathode materials with 3D ion/electron dual-conductive network structure were constructed through ball mill-assisted spray-drying method.The intermolecular effects of PEG-400 promote the spheroidization and uniform PEG coating of LMFP precursor,which prevents agglomeration during sintering.The 3D ion/electron dual-conductive network structure in P-LMFP@C accelerates the Li^(+)transport kinetics,improving the rate performance and cycling stability.As a result,the designed P-LMFP@C has remarkable electrochemical behavior,boasting excellent capacity retention(98%after 100 cycles at the 1C rate)and rate capability(91 mAh·g^(-1)at 20C).Such strategy introduces a novel window for designing high-performance olivine cathodes and offers compatibility with a range of energy storage materials for diverse applications.展开更多
The performance of cross-linked magnetic chitosan, coated with magnetic fluids and cross-linked with ePichlorohydrin, was investigated for the adsorption of Copper （Ⅱ） from aqueous solutions. Infrared spectra of ch...The performance of cross-linked magnetic chitosan, coated with magnetic fluids and cross-linked with ePichlorohydrin, was investigated for the adsorption of Copper （Ⅱ） from aqueous solutions. Infrared spectra of chitosan before and after modification showed that the coating and cross-linking are effective. Experiments were performed at different pH of solution and contact time, and appropriate conditions for the adsorption of Cu（Ⅱ） were determined. Experimental equilibrium data were correlated with Langmuir and Freundlich isotherms for determination of the adsorption potential. The results showed that the Langmuir isotherm was better compared with the Freundlich isotherm, and the uptake of Cu（Ⅱ） was 78.13 mg·g^- 1. The kinetics of adsorption corresponded with the first-order Langergren rate equation, and Langergren rate constants were determined.展开更多
Performance characteristics of partially hydrolyzed polyacrylamide （HPAM） and cross- linked polymer （CLP, Cr^3＋ as the cross linker） solutions have been investigated. A Brookfield viscometer, rheometer, dynamic l...Performance characteristics of partially hydrolyzed polyacrylamide （HPAM） and cross- linked polymer （CLP, Cr^3＋ as the cross linker） solutions have been investigated. A Brookfield viscometer, rheometer, dynamic light scattering system, and core flow device have been used to measure the viscosity, viscoelasticity, polymer coil dimensions, molecular configuration, flow characteristics, and profile modification. The results show that, under conditions of high salinity and low HPAM and Cr^3＋ concentrations, cross-linking mainly occurred between different chains of the same HPAM molecule in the presence of Cr^3＋, and a cross-linked polymer （CLP） system with a local network structure was formed. Compared with an HPAM solution of the same concentration, the apparent viscosity of the CLP solution increased slightly or remained almost unchanged, but its viscoelasticity （namely storage modulus, loss modulus, and first normal stress difference） increased, and the resistance coefficient and residual resistance coefficient increased significantly. This indicates that the CLP solution exhibits a strong capability to divert the sequentially injected polymer flood from high-permeability zones to low- permeability zones in a reservoir. Under the same HPAM concentration conditions, the dimensions of polymer coils in the CLP solution increased slightly compared with the dimensions of polymer coils in HPAM solution, which were smaller than the rock pores, indicating that the cross-linked polymer solution was well adapted to reservoir rocks. Core flood experiments show that at the same cost of reagent, the oil recovery by CLP injection （HPAM-1, Cr^3＋ as the cross linker） is 3.1% to 5.2% higher than that by HPAM- 2 injection.展开更多
Ethanol perm-selective PDMS/PVDF composite membranes were prepared by curing polydimethylsiloxane (PDMS) with various cross-linking reagents,such as tetraethoxylsilane(TEOS),γ-aminopropyltriethoxylsilane(APTEOS), phe...Ethanol perm-selective PDMS/PVDF composite membranes were prepared by curing polydimethylsiloxane (PDMS) with various cross-linking reagents,such as tetraethoxylsilane(TEOS),γ-aminopropyltriethoxylsilane(APTEOS), phenyltrimethoxylsilane(PTMOS) and octyltrimethoxylsilane(OTMOS) as well.The cross-linking density and surface properties of the PDMS active layer were adjusted by varying cross-linking reagents.The pervaporation performance of PDMS membranes cured with different cross-linking reagents was investig...展开更多
Membrane fouling is always the biggest problem in the practice of membrane separation technologies,which strongly impacts their applicability,separation efficiency,cost effectiveness,and service lifespan.Herein,a simp...Membrane fouling is always the biggest problem in the practice of membrane separation technologies,which strongly impacts their applicability,separation efficiency,cost effectiveness,and service lifespan.Herein,a simple but effective 3D modification approach was designed for permanently functionalizing polymeric membranes by directly cross-linking polyvinyl alcohol(PVA)under gamma-ray irradiation at room temperature without any additives.After the modification,a PVA layer was constructed on the membrane surface and the pore inner surface of polyvinylidene fluoride(PVDF)membranes.This endowed them with good hydrophilicity,low adsorption of protein model foulants,and easy recoverability properties.In addition,the pore size and distribution were customized by controlling the PVA concentration,which enhanced the rejection ability of the resultant membranes and converted them from microfiltration to ultrafiltration.The crosslinked PVA layer was equipped with the resultant membranes with good resistance to chemical cleaning by acidic,alkaline,and oxidative reagents,which could greatly prolong the membrane service lifetime.Furthermore,this approach was demonstrated as a universal method to modify PVDF membranes with other hydrophilic macromolecular modifiers,including polyethylene glycol,sodium alginate,and polyvinyl pyrrolidone.This modification of the membranes effectively endowed them with good hydrophilicity and antifouling properties,as expected.展开更多
AIM: To evaluate the effect of Collagen cross-linking on the prevention of melting in rabbit corneas after alkali burn. METHODS: Twenty New Zealand white rabbits were randomly divided into model control group and coll...AIM: To evaluate the effect of Collagen cross-linking on the prevention of melting in rabbit corneas after alkali burn. METHODS: Twenty New Zealand white rabbits were randomly divided into model control group and collagen cross-linking treatment group. The second group of rabbits received collagen cross linked treatment. Both groups were applied with antibiotic eye drops to prevent infection. The corneas were evaluated for melting, opacity, pathological and immunohistochemistry, record the changes when 28 days after the animals were killed. RESULTS: In the control group, 6 out of 8 rabbits showed corneal melting after injury (14 +/- 4) days, while two corneal perforated. In collagen cross-linking treatment group, one rabbit showed corneal melting after injury 23 days, without corneal perforation; corneal dissolution rate between the two groups was significantly different (P <0.05). Pathological examination suggested that in the treatment group, mild corneal edema, mild damage to collagen fibers, inflammatory cell infiltration was significantly less than the control group. Immunohistochemistry showed that corneal collagen fibers arranged in neat rows in the control group. CONCLUSION: Collagen cross-linking treatment not only can prevent and delay the corneal melting after alkali burn, but also can reduce the destruction of corneal collagen fibers and infiltration of inflammatory cells in the corneal tissue.展开更多
A new type of crown ether cross-linked chitosan was synthesized by the reaction of chitosan with 4,4′-dibromodibenzo-18-crown-6 (Br-DBC). Its token structure was analyzed with FT-IR and NMR and the adsorption behavio...A new type of crown ether cross-linked chitosan was synthesized by the reaction of chitosan with 4,4′-dibromodibenzo-18-crown-6 (Br-DBC). Its token structure was analyzed with FT-IR and NMR and the adsorption behaviors for lead and cadmium in environmental water samples by FAAS were studied. In addition the best analysis conditions were discussed and the adsorption mechanism was explained. As the enrichment factor is above 100, both recoveries are 94%–106%, the detection limits of lead and cadmium are 0.5μg·L?1 and 0.04 μg·L?1 and the relatively standard deviations of lead and cadmium are 3.1% and 2.8% respectively, this new method was successfully applied to the determination of environmental water samples. This method is fast and simple and it greatly enhances the determination ability of FAAS for lead and cadmium.展开更多
基金the National Natural Science Foundation of China(Nos.21721001,51572231 and 51502252)the Natural Science Foundation of Fujian Province of China(No.2016J01264)。
文摘In situ cross-linking encapsulation has been demonstrated to be an efficient strategy for enhancing the humidity stability of perovskite solar cells(PSCs).In this study,a novel cross-linkable fullerene derivative,namely1-(p-benzoate-(p-methylvinylbenzene)-indolino[2,3][60]fullerene(FPPS),was readily synthesized from commercially available building blocks in two steps.This FPPS was employed as an interfacial modifier on perovskite surfaces in inverted planar p-i-n PSCs.Owing to the fast interfacial charge extraction and efficient trap passivation,PSCs based on the cross-linked FPPS(C-FPPS)exhibited excellent performance.The PSCs had a top-performing power conversion efficiency(PCE)of 17.82%with negligible hysteresis,compared to the control devices without C-PFFS(16.99%).Moreover,the strong water resistance of the C-FPPS interfacial layer distinctly enhances the ambient stability of PSC devices,exhibiting a t80(the time required to reach 80%of the initial PCE)of 300 h under high-humidity conditions.This significantly surpasses the control devices,whose t80 was only 130 h.These results demonstrate that cross-linkable fullerene derivatives can be promising interfacial materials for designing high-efficiency,hysteresis-free,air-stable PSCs.
基金supported by the National Key Research and Development Program of China(2021YFB3602702)the National Natural Science Foundation of China(52173180).
文摘Cross-linkable hole transport materials(x-HTMs)play a crucial role in solving the issue of interlayer mixing of solution-processed organic light-emitting diodes(OLEDs).However,issues such as energy level mismatch and low hole mobility hinder the application of x-HTMs in deep-blue OLEDs.In particular,thermally activated delayed fluorescent(TADF)emitters require HTMs with high triplet energies(E T)to ensure high exciton utilization efficiency.Here,two star-shaped cross-linkable HTMs 5-(9H-carbazol-9-yl)-N^(1),N^(3)-di(p-tolyl)-N^(1),N^(3)-bis(4-vinylphenyl)benzene-1,3-diamine(m-V-CzDPA)and N^(1),N^(1)-diphenyl-N^(3),N^(5)-di(p-tolyl)-N^(3),N^(5)-bis(4-vinylphenyl)benzene-1,3,5-triamine(m-V-DPADPA)were designed and synthesized.Owing to their aromatic torsion structures,m-V-CzDPA and m-V-DPADPA possessed high E Ts of 2.89 and 2.87 eV,respectively,which can effectively confine triplet excitons in the emitting layer(EML).The carrier diffusion coefficients of their x-HTMs,x-m-CzDPA and x-m-DPADPA,which were obtained via carrier diffusion imaging characterization were 0.54 and 0.44 cm^(2) s^(-1),respectively,thus indicating outstanding intrinsic hole transport capacity,with hole mobilities of 4.30×10^(-4) and 1.39×10^(-4) cm^(2) V^(-1) s^(-1),respectively.Solution-processed deep-blue TADF-OLEDs employing x-m-CzDPA as the HTM achieved a maximum current efficiency/maximum external quantum efficiency of 5.25 cd A^(-1)/18.06%,with CIE coordinates of(0.162,0.042).This is the first time that x-HTMs have served as efficient deep-blue TADF-OLEDs via a solution process,which also meets the latest BT.2020 standard(CIE_(y)≤0.046).
文摘The retrospective study by Edwar et al reinforces the role of therapeutic penetrating keratoplasty(PK)as a vital intervention in severe,treatment-resistant infectious keratitis.In advanced cases—often complicated by trauma,delayed presentation,and corneal perforation—PK restores globe integrity and provides limited visual recovery.However,its application is constrained by graft-related complications and donor shortages,particularly in low-resource settings.These limitations highlight the need for earlier,globe-sparing strategies to prevent progression and reduce surgical demand.Photoactivated chromophore for infectious keratitis-corneal collagen cross-linking(PACK-CXL)has emerged as a promising adjunct or alternative.With both antimicrobial and tissue-stabilizing effects,PACK-CXL may control infection and preserve corneal structure in earlier stages.A layered treatment framework that incorporates PACK-CXL as an initial intervention and reserves PK for refractory cases may help improve clinical outcomes.Further studies are needed to define their best use in practice.
基金supported by Research Fund of SWUST for PhD(Grant No.22zx7175)Sichuan Science and Technology Program(Grant No.2024NSFSC1097)。
文摘Based on the characteristics of laser-induced surface ignition,energetic photosensitive films show promising potential to meet the ignition requirements of various energetic materials(EMs).In this study,DATNBI/ferric alginate(DI/FeA),DI/cobalt alginate(DI/CoA),and DI/nickel alginate(DI/Ni A)films are fabricated by employing sodium alginate(SA)with a three-dimensional network structure as the film matrix,via ionic cross-linking of SA with Fe^(3+),Co^(2+),and Ni^(2+)ions.The study demonstrates that the ionic cross-linking enhances the hydrophobic performance of the films,with the water contact angle increasing from 82.1??to 123.5??.Concurrently,the films'near-infrared(NIR)light absorption improved.Furthermore,transition metal ions facilitate accelerated electron transfer,thereby catalyzing the thermal decomposition of DATNBI.Under 1064 nm laser irradiation,the DI/Fe A film exhibits exceptional combustion performance,with an ignition delay time as low as 76 ms.It successfully acts as an NIR laser ignition medium to initiate the self-sustained combustion of CL-20.This study demonstrates the synergistic realization of enhanced hydrophobicity,improved photosensitivity,and promoted catalytic decomposition through microstructural design of the material,providing new insights for the design of additive-free EMs in laser ignition applications.
基金supported by the National Natural Science Foundation of China(22275003)Shenzhen Fundamental Research Program(JCYJ20200109140425347)+4 种基金the Development and Reform Commission of Shenzhen Municipality(XMHT20200106002)the Key-Area Research and Development Program of Guangdong Province(2019B010924003)Guangdong Basic and Applied Basic Research Foundation(2020B1515120030)provided by Guangdong Key Laboratory of Flexible Optoelectronic Materials and DevicesGuangdong International Science and Technology Cooperation Base of Optoelectronic Materials and Device Technology。
文摘The solution-processed method for organic light-emitting diodes(OLEDs)offers the benefits of cost-effectiveness and enhanced material utilization.In the multilayer architecture of solution-processed OLEDs(SOLEDs),the role of hole-transport materials(HTMs)is pivotal for cascade hole injection.However,commercial HTMs such as poly-(9,9-dioctylfluorene-alt-N-(4-sec-butylphenyl)-diphenylamine)(TFB)are hampered by incompatible energy levels and redissolution with overlayer solvent,prompting the exploration of cross-linkable HTMs(X-HTMs)for better performance.In this study,we have developed two novel small-molecule X-HTMs,N^(1),N^(1)′-((perfluoropropane-2,2-diyl)bis(4,1-phenylene))bis(N^(4),N^(4)-diphenyl-N^(1)-(4-vinylphenyl)benzene-1,4-diamine)(FTPA-V)and N,N′-((perfluoropropane-2,2-diyl)bis-(4,1-phenylene))bis(9-phenyl-N-(4-vinylphenyl)-9H-carbazol-3-amine)(FPCz-V),which incorporate thermally cross-linkable vinyl groups and electron-rich trifluoromethyl units.The X-HTMs enhance interfacial contact through superior film formation and solvent resistance,along with optimal energy levels.The application of X-HTMs significantly enhances the efficiencies and longevities of blue,green,and red SOLEDs.Specially,blue SOLED incorporating FPCz-V exhibits unprecedented lifetime(LT95)extending to over 150 h,setting a new record for blue SOLEDs.The electrochemistry stability,high bond dissociation energy,and triplet energy levels of X-HTMs can effectively minimize exciton annihilation and prolong the lifetime.These findings underscore the potential of X-HTM optimization to propel the development of stable solution-processed luminescent technologies.
基金supported by the Guangzhou Municipal Science and Technology Project(No.202102010426)the National Natural Science Foundation of China(Nos.21805049 and 22074025)Engineering Research Centre of Photonic Design Software,Ministry of Education,China(No.62175267).
文摘How to obtain organic electro-optic materials with large electro-optic coefficients,high glass transition temperature,and good optical transparency remains a challenge in this field.To solve this problem,we introduce groups that can undergo Huisgen cycloaddition reactions into the donor and electron bridge of chromophores with large hyperpolarizability using tetrahydroquinoline as the donor.Binary cross-linkable chromophores TLD1-2 with CF_(3)-TCF as the acceptor and chromophores TLD3-4 with 5Fph-TCF as the acceptor were synthesized.After poling and crosslinking,the T_(g)of TLD1/TLD2 and TLD3/TLD4 were raised to 152 and 174°C,respectively.The electro-optical coefficients of chromophores TLD1/TLD2 and TLD3/TLD4 were as high as 312 pm/V and 287 pm/V,respectively.The long-term alignment stability test showed that after being left at 85℃ for 500 h,the cross-linked film TLD3/TLD4 can still maintain more than 98%of the original electro-optical coefficient value,which is higher than that of TLD1/TLD2(93%).The chromophore TLD3-4 exhibited much blue-shifted maximum absorption wavelengths(~40 nm)compared to TLD1-2 which was beneficial for reducing optical loss in the device.The combination of high electro-optic coefficient,strong stability,and excellent optical transparency makes the TLD series of binary cross-linked materials very promising for practical high-performance electro-optic devices.
基金Supported by the Social Development Grant of Shaanxi Province(No.2022SF-404)the Science and Technology Program of Xi’an,China(No.23YXYJ0010,No.23YXYJ0037)+1 种基金the Research Project of Xi’an Health Commission(No.2024ms05)the Technology Innovation Supporting Program of Shaanxi(No.2024RS-CXTD-11).
文摘AIM:To investigate the response of the anterior and posterior corneal surface in femtosecond laser-assisted convex stromal lenticule addition keratoplasty(SLAK)combined with cross-linking(CXL)for treating keratoconus at the first 3mo of follow-up.METHODS:In this prospective observational study,20 eyes of 20 keratoconus patients who underwent SLAK combined with CXL were included.The morphological indices in keratometry and elevation data were recorded from the Sirius at baseline and 1 and 3mo postoperatively.The mean values of maximum keratometry(K_(max)),flat keratometry(K_(1)),and steep keratometry(K_(2))at the central,3-mm,5-mm,and 7-mm areas were measured from the curvature map.The changes in anterior and posterior corneal elevation under the best-fit sphere(BFS)radius at seven points horizontally of the center,3-mm,5-mm,and 7-mm area from the center at both nasal(N)and temporal(T)side were measured from elevation map.RESULTS:For the front corneal curvature,K_(1),and K_(2) at 3-mm,5-mm,and 7-mm of the anterior corneal surface increased significantly 1mo postoperatively(all P<0.05)and remained unchanged until 3mo(P>0.05).For the back corneal curvature,K_(1) and K_(2) along the 3-mm back meridian significantly decreased after month 1(P=0.002,0.077,respectively).Posterior K_(2)-readings along the 5-mm and 7-mm did not change after surgery(P>0.05).Anterior BFS decreased 1mo(P<0.001)postoperatively but remained unchanged until 3mo after SLAK(P>0.05).There was no change in posterior BFS before and after the surgery(P>0.05).Anterior elevation at N5,N3,central,and T5 points and posterior elevation at central and T7 points shifted backward 1mo postoperatively(all P<0.05)and remained stable until 3mo(P>0.05).CONCLUSION:The myopic SLAK combined with CXL is an economical alternative for stabilizing the corneal surface in severe keraoconus.“Pseudoprogression”occurs in the early phase postoperatively,but it is not an indicator of keratoconus progression.
基金financial support from the National Natural Science Foundation of China[grant number 21878299]。
文摘Polymer binders possess significant potential in alleviating the volume expansion issues of silicon-based anodes,yet remain challenging due to insufficient interfacial interactions with individual components(Si,C,and Cu)of the anode.Herein,we report the synthesis of a stable three-dimensional network structure of the PAA-PEA(polyacrylic acid-polyether amines)polymer binder through intermolecular physicochemical dual cross-linking.By incorporating polar functional groups,the binder molecules not only form strong C-O-Si,N-Si,O=C-O-C,and O=C-O-Cu covalent bonds but also enhance non-covalent interactions with Si,C,and Cu,thereby improving adhesion between the binder and each interface of the anode.Furthermore,weak hydrogen bonds,acting as"sacrificial bonds",dissipate energy and disperse accumulated stress,improving the material flexibility.Due to the high mechanical stability of the framework,which combines both rigidity and flexibility and the coupling effect at the three interfaces,the movement and separation of electrode components are effectively restrained,significantly enhancing the cycling stability of silicon-graphite anodes.The PAA-PEA 2000 electrode exhibits a capacity retention of 78% after 500 cycles at a current density of 0.2 A g^(-1).This work provides insights into the mechanism of binders and guides the design of polymer binders for high-performance Si-based electrodes.
文摘AIM:To compare simultaneous corneal collagen cross-linking(CXL)with intracorneal ring segment(ICRS)implantation versus successive ICRS followed by CXL and detect the impact of the timing of CXL after ICRS implantation in the successive method.METHODS:This is a retrospective study of the records of three groups of patients.Group 1 of 28 patients were operated on with simultaneous ICRS implantation and CXL,group 2 of 32 patients had ICRS implantation followed by CXL after 1mo,and group 3 of 38 patients had ICRS implantation followed by CXL after 3mo.The three groups had follow-up visits after 6,12,and 24mo.RESULTS:The preoperative data,age,and gender differences among 3 groups revealed no significant differences.The postoperative spherical equivalent and best-corrected visual acuity were improved significantly in all groups compared to the baseline,which were more evident in groups 1 and 2.The differences between preoperative and postoperative mean values of mean of K readings(Km)and maximum K reading(Kmax)at 6mo were 4.66 and 4.1 D in group 1,4.43 and 4.64 D in group 2,but 3.2 and 3.4 D in group 3,respectively.The spherical aberrations and the vertical coma showed significant postoperative changes in all groups,and trefoil showed nonsignificant changes.CONCLUSION:Simultaneous and sequential ICRS implantation and CXL at 1mo has similar Km and Kmax better postoperative changes than when both surgeries were done at three-month intervals.
基金financially supported by the National Natu-ral Science Foundation of China(Nos.22375047,22378068,and 22075046)the Natural Science Foundation of Fujian Province(No.2022J01568)+2 种基金the National Key Research and Development Program of China(Nos.2022YFB3804905 and 2022YFB3804900)China Postdoctoral Science Foundation(No.2023M743437)start-up funding from Wenzhou Institute,University of Chinese Academy of Sciences(No.WIUCASQD2019002).
文摘Highly transparent,durable,and flexible liquid-repellent coatings are urgently needed in the realm of transparent materials,such as car windows,optical lenses,solar panels,and flexible screen materials.However,it has been difficult to strike a balance between the robustness and flexibility of coatings constructed by a single cross-linked network design.To overcome the conundrum,this innovative approach effectively combines two distinct cross-linked networks with unique functions,thus overcoming the challenge.Through a tightly interwoven structure comprised of added crosslinking sites,the coating achieves improved liquid repellency(WCA>100°,OSA<10°),increased durability(withstands 2,000 cycles of cotton wear),enhanced flexibility(endures 5,000 cycles of bending with a bending radius of 1 mm),and maintains high transparency(over 98%in the range of 410 nm to 760 nm).Additionally,the coating with remarkable adhesion can be applied to multiple substrates,enabling large-scale preparation and easy cycling coating,thus expanding its potential applications.The architecture of this fluoride-free dual cross-linked network not only advances liquid-repellent surfaces but also provides valuable insights for the development of eco-friendly materials in the future.
基金financial support from several corporate sponsors.Contributions were made by the National Natural Science Foundation of China(Grant No.32071332)Shenzhen Science and Technology Innovation Project(Grant No.JCYJ20210324095802006)+2 种基金Ningbo Bureau of Science and Technology(Grant No.2023Z187)TransEasy Medical Tech.Co.,Ltd.(Grant No.2021114)Shenzhen University MedTech Innovation Fund(2023YG027).
文摘Aging is a persistent topic of interest,with skin aging as its most visible manifestation,characterized by a reduction in intact collagen and elastic fibers in the dermis.Hyaluronic acid,a vital component of the extracellular matrix present in the skin,has become a mainstream method for skin rejuvenation through injections.However,the rapid degradation of pure hyaluronic acid,combined with insufficient maintenance duration and often limited therapeutic effects,presents significant challenges for injectable treatments.Additionally,low patient compliance due to discomfort from needles penetrating the dermal layer further complicates its use.In this review,we summarize and compare existing interventions for skin aging,focusing on strategies to prolong the degradation cycle of hyaluronic acid,including variations in cross-linking modalities and injection techniques.We conclude that the injection of cross-linked modified hyaluronic acid via microneedles represents a promising approach to extend the degradation cycle,offering valuable insights for current therapeutic strategies.
基金supported by the National Key Research and Development Program of China (No. 2022YFB3704700(2022YFB3704702))the National Natural Science Foundation of China (No. 52473096)+1 种基金Major Scientific and Technological Innovation Project of Shandong Province (No. 2021CXGC010901)Taishan Scholar Program
文摘In this study,a novel cost-effective methodology was developed to enhance the gas barrier properties and permselectivity of unfilled natural rubber(NR)/polybutadiene rubber(BR)composites through the construction of a heterogeneous structure using pre-vulcanized powder rubber to replace traditional fillers.The matrix material is composed of a blend of NR and BR,which is widely used in tire manufacturing.By incorporating pre-vulcanized trans-1,4-poly(isoprene-co-butadiene)(TBIR)rubber powder(pVTPR)with different cross-linking densities and contents,significant improvements in the gas barrier properties and CO_(2)permselectivity of the NR/BR/pVTPR composites were observed.The results indicated that compared to NR/BR/TBIR composites prepared through direct blending of NR,BR,and TBIR,the NR/BR/pVTPR composites exhibited markedly superior gas barrier properties.Increasing the cross-linking density of pVTPR resulted in progressive enhancement of the gas barrier properties of the NR/BR/pVTPR composite.For example,the addition of 20 phr pVTPR with a cross-linking density of 346 mol/m^(3)resulted in a 79%improvement in the oxygen barrier property of NR/BR/pVTPR compared to NR/BR,achieving a value of 5.47×10^(-14)cm^(3)·cm·cm^(-2)·s^(-1)·Pa^(-1).Similarly,the nitrogen barrier property improved by 76%compared to NR/BR,reaching 2.4×10^(-14)cm^(3)·cm·cm^(-2)·s^(-1)·Pa^(-1),which is 28%higher than the conventional inner liner material brominated butyl rubber(BIIR,PN2=3.32×10^(-14)cm^(3)·cm·cm^(-2)·s^(-1)·Pa^(-1)).Owing to its low cost,exceptional gas barrier properties,superior adhesion to various tire components,and co-vulcanization capabilities,the NR/BR/pVTPR composite has emerged as a promising alternative to butyl rubber in the inner liner of tires.Furthermore,by fine-tuning the cross-linking density of pVTPR,the high-gas-barrier NR/BR/pVTPR composites also demonstrated remarkable CO_(2)permselectivity,with a CO_(2)/N2 selectivity of 61.4 and a CO_(2)/O_(2)selectivity of 26.12.This innovation provides a novel strategy for CO_(2)capture and separation,with potential applications in future environmental and industrial processes.The multifunctional NR/BR/pVTPR composite,with its superior gas barrier properties and CO_(2)permselectivity,is expected to contribute to the development of safer,greener,and more cost-effective transportation solutions.
基金China Postdoctoral Science Foundation (2023M733451)Dalian Innovation Team in Key Areas(2020RT06)Engineering Research Center for Key Aromatic Compounds and LiaoNing Key Laboratory,Liaoning Provincial Natural Science Foundation (Doctoral Research Start-up Fund 2024-BSBA-37)。
文摘Selective hydrogenation of furfural to furfuryl alcohol is a great challenge in the hydrogenation field due to thermodynamic preference for hydrogenation of C=C over C=O.Herein,a novel Al_(2)O_(3)/C-u hybrid catalyst,composed of N-modified dendritic carbon networks supporting Al_(2)O_(3)nanoparticles,was successfully prepared via carbonizing the freeze-dried gel from spontaneous cross-linking of alginate,Al3+and urea.The obtained carbon-supported Al_(2)O_(3)hybrid catalyst has a high ratio (31%) of Al species in pentahedral-coordinated state.The introduction of urea enhances the surface N content,the ratio of pyrrolic N,and specific surface area of catalyst,leading to improved adsorption capacity of C=O and the accessibility of active sites.In the furfural hydrogenation reaction with isopropyl alcohol as hydrogen donor,Al_(2)O_(3)/C-u catalyst achieved a 90%conversion of furfural with 98.0% selectivity to furfuryl alcohol,outperforming that of commercial γ-Al_(2)O_(3).Moreover,Al_(2)O_(3)/C-u demonstrates excellent catalytic stability in the recycling tests attributed to the synergistic effect of abundant weak Lewis acid sites and the anchoring effect of the carbon network on Al_(2)O_(3)nanoparticles.This work provides an innovative and facile strategy for fabrication of carbon-supported Al_(2)O_(3)hybrid catalysts with rich AlVspecies,serving as a high selective hydrogenation catalyst through MPV reaction route.
基金supported by the Key Technologies R&D Program of Xiamen(No.3502Z20231057)Industry Leading Key Projects of Fujian Province(No.2022H0057)+2 种基金the National Natural Science Foundation of China(No.21975212)High-Level Talent Start-Up Foundation of Xiamen Institute of Technology for financial support(No.YKJ23017R)Graduate Science and Technology Innovation Program of Xiamen University of Technology(No.YKJCX2023194).
文摘LiMnxFe1-xPO_(4) is a promising cathode candidate due to its high security and the availability of a high 4.1 V operating voltage and high energy density.However,the poor electrochemical kinetics and structural instability currently hinder its broader application.Herein,inspired by the hydrogen-bonded cross-linking and steric hindrance effect between short-chain polymer molecules(polyethylene glycol-400,PEG-400),the pomegranate-type LiMn_(0.5)Fe_(0.5)PO_(4)-0.5@C(P-LMFP@C)cathode materials with 3D ion/electron dual-conductive network structure were constructed through ball mill-assisted spray-drying method.The intermolecular effects of PEG-400 promote the spheroidization and uniform PEG coating of LMFP precursor,which prevents agglomeration during sintering.The 3D ion/electron dual-conductive network structure in P-LMFP@C accelerates the Li^(+)transport kinetics,improving the rate performance and cycling stability.As a result,the designed P-LMFP@C has remarkable electrochemical behavior,boasting excellent capacity retention(98%after 100 cycles at the 1C rate)and rate capability(91 mAh·g^(-1)at 20C).Such strategy introduces a novel window for designing high-performance olivine cathodes and offers compatibility with a range of energy storage materials for diverse applications.
文摘The performance of cross-linked magnetic chitosan, coated with magnetic fluids and cross-linked with ePichlorohydrin, was investigated for the adsorption of Copper （Ⅱ） from aqueous solutions. Infrared spectra of chitosan before and after modification showed that the coating and cross-linking are effective. Experiments were performed at different pH of solution and contact time, and appropriate conditions for the adsorption of Cu（Ⅱ） were determined. Experimental equilibrium data were correlated with Langmuir and Freundlich isotherms for determination of the adsorption potential. The results showed that the Langmuir isotherm was better compared with the Freundlich isotherm, and the uptake of Cu（Ⅱ） was 78.13 mg·g^- 1. The kinetics of adsorption corresponded with the first-order Langergren rate equation, and Langergren rate constants were determined.
基金financial support from the National Key Technology R&D Program in the 12th Five Year Plan of PetroChina (No: 2011ZX05010-003-02)the National Key Technology R&D Program in the 12th Five Year Plan of CNOOC (No: 2011ZX05024-04-05-03)
文摘Performance characteristics of partially hydrolyzed polyacrylamide （HPAM） and cross- linked polymer （CLP, Cr^3＋ as the cross linker） solutions have been investigated. A Brookfield viscometer, rheometer, dynamic light scattering system, and core flow device have been used to measure the viscosity, viscoelasticity, polymer coil dimensions, molecular configuration, flow characteristics, and profile modification. The results show that, under conditions of high salinity and low HPAM and Cr^3＋ concentrations, cross-linking mainly occurred between different chains of the same HPAM molecule in the presence of Cr^3＋, and a cross-linked polymer （CLP） system with a local network structure was formed. Compared with an HPAM solution of the same concentration, the apparent viscosity of the CLP solution increased slightly or remained almost unchanged, but its viscoelasticity （namely storage modulus, loss modulus, and first normal stress difference） increased, and the resistance coefficient and residual resistance coefficient increased significantly. This indicates that the CLP solution exhibits a strong capability to divert the sequentially injected polymer flood from high-permeability zones to low- permeability zones in a reservoir. Under the same HPAM concentration conditions, the dimensions of polymer coils in the CLP solution increased slightly compared with the dimensions of polymer coils in HPAM solution, which were smaller than the rock pores, indicating that the cross-linked polymer solution was well adapted to reservoir rocks. Core flood experiments show that at the same cost of reagent, the oil recovery by CLP injection （HPAM-1, Cr^3＋ as the cross linker） is 3.1% to 5.2% higher than that by HPAM- 2 injection.
基金supported by the Major State Basic Research Program of China(No.2009CB623404)National NaturalScience Foundation of China(Nos.20736003,20676067)+2 种基金National High Technology Research and Development Programof China(No.2007AA06Z317)Foundation of Ministry of Education of China(No.20070003130)Foundation of theState Key Laboratory of Chemical Engineering(SKL-ChE-08A01).
文摘Ethanol perm-selective PDMS/PVDF composite membranes were prepared by curing polydimethylsiloxane (PDMS) with various cross-linking reagents,such as tetraethoxylsilane(TEOS),γ-aminopropyltriethoxylsilane(APTEOS), phenyltrimethoxylsilane(PTMOS) and octyltrimethoxylsilane(OTMOS) as well.The cross-linking density and surface properties of the PDMS active layer were adjusted by varying cross-linking reagents.The pervaporation performance of PDMS membranes cured with different cross-linking reagents was investig...
基金This work was supported by the National Natural Science Foundation of China(Nos.11875313,12075153,and 11575277).
文摘Membrane fouling is always the biggest problem in the practice of membrane separation technologies,which strongly impacts their applicability,separation efficiency,cost effectiveness,and service lifespan.Herein,a simple but effective 3D modification approach was designed for permanently functionalizing polymeric membranes by directly cross-linking polyvinyl alcohol(PVA)under gamma-ray irradiation at room temperature without any additives.After the modification,a PVA layer was constructed on the membrane surface and the pore inner surface of polyvinylidene fluoride(PVDF)membranes.This endowed them with good hydrophilicity,low adsorption of protein model foulants,and easy recoverability properties.In addition,the pore size and distribution were customized by controlling the PVA concentration,which enhanced the rejection ability of the resultant membranes and converted them from microfiltration to ultrafiltration.The crosslinked PVA layer was equipped with the resultant membranes with good resistance to chemical cleaning by acidic,alkaline,and oxidative reagents,which could greatly prolong the membrane service lifetime.Furthermore,this approach was demonstrated as a universal method to modify PVDF membranes with other hydrophilic macromolecular modifiers,including polyethylene glycol,sodium alginate,and polyvinyl pyrrolidone.This modification of the membranes effectively endowed them with good hydrophilicity and antifouling properties,as expected.
文摘AIM: To evaluate the effect of Collagen cross-linking on the prevention of melting in rabbit corneas after alkali burn. METHODS: Twenty New Zealand white rabbits were randomly divided into model control group and collagen cross-linking treatment group. The second group of rabbits received collagen cross linked treatment. Both groups were applied with antibiotic eye drops to prevent infection. The corneas were evaluated for melting, opacity, pathological and immunohistochemistry, record the changes when 28 days after the animals were killed. RESULTS: In the control group, 6 out of 8 rabbits showed corneal melting after injury (14 +/- 4) days, while two corneal perforated. In collagen cross-linking treatment group, one rabbit showed corneal melting after injury 23 days, without corneal perforation; corneal dissolution rate between the two groups was significantly different (P <0.05). Pathological examination suggested that in the treatment group, mild corneal edema, mild damage to collagen fibers, inflammatory cell infiltration was significantly less than the control group. Immunohistochemistry showed that corneal collagen fibers arranged in neat rows in the control group. CONCLUSION: Collagen cross-linking treatment not only can prevent and delay the corneal melting after alkali burn, but also can reduce the destruction of corneal collagen fibers and infiltration of inflammatory cells in the corneal tissue.
文摘A new type of crown ether cross-linked chitosan was synthesized by the reaction of chitosan with 4,4′-dibromodibenzo-18-crown-6 (Br-DBC). Its token structure was analyzed with FT-IR and NMR and the adsorption behaviors for lead and cadmium in environmental water samples by FAAS were studied. In addition the best analysis conditions were discussed and the adsorption mechanism was explained. As the enrichment factor is above 100, both recoveries are 94%–106%, the detection limits of lead and cadmium are 0.5μg·L?1 and 0.04 μg·L?1 and the relatively standard deviations of lead and cadmium are 3.1% and 2.8% respectively, this new method was successfully applied to the determination of environmental water samples. This method is fast and simple and it greatly enhances the determination ability of FAAS for lead and cadmium.
