Polypiperazine-amide membranes were modified with poly(ethyleneimine)(PEI) by self-assembled method,through which PEI molecules were fixed on the membrane surface by ionic interaction. In the experiments,the PEI conce...Polypiperazine-amide membranes were modified with poly(ethyleneimine)(PEI) by self-assembled method,through which PEI molecules were fixed on the membrane surface by ionic interaction. In the experiments,the PEI concentration ranged from 50 to 2000 mg·L-1while the depositing time was fixed at 20 min. The results showed that low PEI concentration resulted in a slight increase of pure water flux, which was attributed to the enhanced membrane surface hydrophilicity. The PEI adsorption on membrane surface had less effect on the rejections to neutral PEG and sucrose, but improved the rejections to divalent cationic ions and methylene blue as the result of reversion of the membrane surface charge from negative to positive according to the XPS analysis and zeta potential measurements. The membrane modified at PEI = 1500 mg·L-1exhibited high rejection to methylene blue(MB) and is potential to be applied in the treatment of effluents containing positively charged dyes.展开更多
The self-assembled nanoparticles(SAN)formed during the decoction process of traditional Chinese medicine(TCM)exhibit non-uniform particle sizes and a tendency for aggregation.Our group found that the p H-driven method...The self-assembled nanoparticles(SAN)formed during the decoction process of traditional Chinese medicine(TCM)exhibit non-uniform particle sizes and a tendency for aggregation.Our group found that the p H-driven method can improve the self-assembly phenomenon of Herpetospermum caudigerum Wall.,and the SAN exhibited uniform particle size and demonstrated good stability.In this paper,we analyzed the interactions between the main active compound,herpetrione(Her),and its main carrier,Herpetospermum caudigerum Wall.polysaccharide(HCWP),along with their self-assembly mechanisms under different p H values.The binding constants of Her and HCWP increase with rising p H,leading to the formation of Her-HCWP SAN with a smaller particle size,higher zeta potential,and improved thermal stability.While the contributions of hydrogen bonding and electrostatic attraction to the formation of Her-HCWP SAN increase with rising p H,the hydrophobic force consistently plays a dominant role.This study enhances our scientific understanding of the self-assembly phenomenon of TCM improved by p H driven method.展开更多
Self-assembled monolayers(SAMs)are widely used as hole transport materials in inverted perovskite solar cells,offering low parasitic absorption and suitability for semitransparent and tandem solar cells.While SAMs hav...Self-assembled monolayers(SAMs)are widely used as hole transport materials in inverted perovskite solar cells,offering low parasitic absorption and suitability for semitransparent and tandem solar cells.While SAMs have shown to be promising in small-area devices(≤1 cm^(2)),their application in larger areas has been limited by a lack of knowledge regarding alternative deposition methods beyond the common spin-coating approach.Here,we compare spin-coating and upscalable methods such as thermal evaporation and spray-coating for[2-(9H-carbazol-9-yl)ethyl]phosphonic acid(2PACz),one of the most common carbazole-based SAMs.The impact of these deposition methods on the device performance is investigated,revealing that the spray-coating technique yields higher device performance.Furthermore,our work provides guidelines for the deposition of SAM materials for the fabrication of perovskite solar modules.In addition,we provide an extensive characterization of 2PACz films focusing on thermal evaporation and spray-coating methods,which allow for thicker 2PACz deposition.It is found that the optimal 2PACz deposition conditions corresponding to the highest device performances do not always correlate with the monolayer characteristics.展开更多
We demonstrate surface enhanced Raman scattering （SERS） detection of self-assembled nano silver film using a low-cost electrolysis strategy at a proper voltage and silver nitrate concentration in electrolyte. The co...We demonstrate surface enhanced Raman scattering （SERS） detection of self-assembled nano silver film using a low-cost electrolysis strategy at a proper voltage and silver nitrate concentration in electrolyte. The concentration dependence of SERS from crystal violet （CV） molecules adsorbed to silver film was systematically studied. Importantly, the SERS surface enhancement factor of such nano silver film was 603, which was measured by a portable Raman spectrometer. The minimum concentration of detectable CV molecules can be as low as 10^-11 mol/L. The nano silver film prepared by this electrolysis method is an active, stable, cost-effective, and reusable SERS substrate.展开更多
The NiOx,due to its excellent semiconductor properties,ease of large-area deposition,and tunable optoelectronic characteristics,shows great potential in industrial large-area perovskite technologies.However,NiO_(x)-ba...The NiOx,due to its excellent semiconductor properties,ease of large-area deposition,and tunable optoelectronic characteristics,shows great potential in industrial large-area perovskite technologies.However,NiO_(x)-based perovskite solar cells(PSCs)are limited by interfacial photocatalytic chemical reactions and energy level mismatch.Thus,phosphate-based self-assembled monolayers(SAMs)have been widely developed for delicate interfacial modification;however,they suffer from severe issues such as self-aggregation and high cost.Herein,a low-cost carboxylate-based SAM(pyrenebutyric acid,PyBA)was used to modify NiO_(x),achieving an improved surface chemical environment and interfacial properties,such as an increased Ni^(3+)/Ni2^(+)ratio,a reduced proportion of high-valence Ni^(≥3+),and better-aligned hole transport interface energy level.The introduction of PyBA also results in larger grain size,higher uniformity,and enhanced photoluminescence(PL)from the bottom of the perovskite,yielding a significant increase in efficiency from an initial 22.48%to 25.14%,while increasing the open-circuit voltage(VOC)from 1.077 to 1.192 V.Additionally,a perovskite module with an aperture area of 21 cm^(2)achieved an efficiency of 22.28%,demonstrating the excellent scalability of the PyBA treatment.Moreover,the well-modified buried interface combined with the chemical inertness and structural rigidity of pyrene ensures excellent ultraviolet(UV)stability(the target module maintained 92%of the initial efficiency after 200 h and the control device only retained 40%).展开更多
A new type of amphiphiles bearingmacrocycle such as cucurbit[7]uril(CB[7])spontaneously forms a nanomaterial in water,specifically vesicles(tACB[7]vesicles)with a positive surface charge,verified through various analy...A new type of amphiphiles bearingmacrocycle such as cucurbit[7]uril(CB[7])spontaneously forms a nanomaterial in water,specifically vesicles(tACB[7]vesicles)with a positive surface charge,verified through various analytical techniques including TIRF,DLS and TEM.Functional validation not only reveals the accessibility of the CB[7]portal on these vesicles allowing CB[7]-based host-vip interactions with various functional vip molecules such as fluorescein isothiocyanate conjugated adamantylammonium and spermine(FITC-AdA and FITC-SPM,respectively)using confocal laser scanning microscopy,but also showcases the effective internalization of tACB[7]vesicles into cancer cells with the anticancer drug oxaliplatin(OxPt),as a vip to CB[7],through in vitro cell experiments.Hence,this study provides a blueprint to impart amphiphilic properties to CB[7]through synthetic design and highlights the potential of CB[7]derivatives as a new class of unconventional amphiphiles self-assembling into functional nanomaterials for advanced drug delivery.展开更多
A significant challenge in developing block copolymer photonic crystals is constructing low-symmetric ordered phases,which are essential for achieving a complete photonic band gap.Here,we propose a promising strategy ...A significant challenge in developing block copolymer photonic crystals is constructing low-symmetric ordered phases,which are essential for achieving a complete photonic band gap.Here,we propose a promising strategy to create low-symmetric ordered morphologies by incorporating shape-anisotropic rod-like side chains into block copolymers.Using dissipative particle dynamics simulations,we demonstrate that block copolymers with longer rod-like side chains can self-assemble into a hexagonally packed columnar phase characterized by a low-symmetric rectangular cross-section.Photonic band structure calculations reveal that this low-symmetric columnar phase can exhibit a complete photonic band gap,with the gap size dependent on the aspect ratio of the rectangular cross-sections of the columns.Our findings suggest an effective approach to constructing low-symmetric photonic crystals through the self-assembly of block copolymers with shape-anisotropic segments.展开更多
The optimization of hole transport layer(HTL)is crucial for achieving high efficiency and stability in inverted perovskite solar cells(PSCs)due to its role in facilitating hole transport and passivating the perovskite...The optimization of hole transport layer(HTL)is crucial for achieving high efficiency and stability in inverted perovskite solar cells(PSCs)due to its role in facilitating hole transport and passivating the perovskite bottom interface.While self-assembled monolayers(SAMs)are commonly used for this purpose,the inherent limitations of a single SAM,such as fixed energy levels and rigid structure,restrict their adaptability for different perovskite components and further efficiency enhancement.Here,we demonstrate a stepwise deposition method for SAM-based HTLs to address this issue.We regulated the energy level gradient by depositing two SAMs with distinct energy levels,while the interactions between the phosphate groups in the SAMs and perovskite effectively reduce defect density at the bottom interface of the perovskite film.The as-fabricated PSCs achieved enhanced efficiency and stability with PCEs of 25.7% and 24.0% for rigid and flexible PSCs,respectively;these devices maintain 90% of their initial PCE after 500 h of maximum power point tracking,and retain 98% of their initial PCE after 4,000 bending cycles,representing one of the most stable flexible PSCs reported to date.展开更多
Inflammatory skin disorders(ISDs),characterized by severe inflammation and impaired skin barrier functions,often requires persistent treatment due to chronic and relapsing natures.To address these issues,we developed ...Inflammatory skin disorders(ISDs),characterized by severe inflammation and impaired skin barrier functions,often requires persistent treatment due to chronic and relapsing natures.To address these issues,we developed a small-molecular self-assembled nanodrug(ECN)that is composed of natural epigallocatechin-3-gallate(EGCG)self-assembled with tripeptide collagen(CTP).By formulating a transdermal enhancer(cationic dendrimer)with ECN,the resulted dendrimers/ECN nanocomplex(DECN)can effectively penetrate into the skin layer,resulting in effective anti-inflammatory response and repair of skin-barrier functions.In animal models of ISDs,including atopic dermatitis(AD)and psoriasis,DECN showed remarkable skin penetration,with high level of drug deposition in the epidermaldermal layer.By using a commercially available spray pump,DECN nanoparticles can be further translated into a spray formulation,which contributes to alleviating visible symptoms,skin lesions,and inflammatory progression of psoriasis and AD.This all-in-one spray nano-formulation offers an effective,safe,and convenient way for ISDs treatment.展开更多
Inverted p-i-n perovskite solar cells(PSCs)based on self-assembled monolayers(SAMs)as hole-selective layers(HSLs)have produced potential record efficiencies of more than 26%by tuning work function,dipole,and passivati...Inverted p-i-n perovskite solar cells(PSCs)based on self-assembled monolayers(SAMs)as hole-selective layers(HSLs)have produced potential record efficiencies of more than 26%by tuning work function,dipole,and passivation defects.However,the stability of the SAM molecules,the stability of the molecular anchoring conformation,and the impact on the stability of subsequent PSCs have not been clearly elucidated.In this review,we systematically discussed the intrinsic connection between the molecular conformation(including anchoring groups,spacer groups,and terminal groups)and the stability of SAMs.Sequentially,the research progress of SAMs as HSLs in improving the stability of PSCs is summarized,including photostability,thermal stability,ion migration,and residual stress.Finally,we look forward to the shortcomings and possible challenges of using SAMs as HSLs for inverted PSCs.展开更多
Spatial confinement of block copolymers can induce frustrations,which can further be utilized to regulate self-assembled structures,thus providing an efficient route for fabricating novel structures.We studied the sel...Spatial confinement of block copolymers can induce frustrations,which can further be utilized to regulate self-assembled structures,thus providing an efficient route for fabricating novel structures.We studied the self-assembly of AB di-block copolymers(di-BCPs)confined in Janus spherical nanocavities using simulations,and explained the structure formation mechanisms.In the case of a strongly selective cavity wall,all the lamella-forming,gyroid-forming,and cylinder-forming di-BCPs can form interfacial frustration-induced Janus concentric perforated lamellar nanoparticles,whose outermost is a Janus spherical shell and the internal is a sphere with concentric perforated lamellar structure.In particular,Janus concentric perforated lamellar nanoparticles with holes distributed only near the equatorial plane were obtained in both lamella-forming and gyroid-forming di-BCPs,directly reflecting the effect of interfacial frustration.The minority-block domain of the cylider-forming di-BCPs may form hemispherical perforated lamellar structures with holes distributed in parallel layers with a specific orientation.For symmetric di-BCPs,both the A and B domains in each nanoparticle are continuous,interchangeable,and have rotational symmetry.While for gyroid-forming and cylinder-forming di-BCPs,only the majority-block domains are continuous in each nanoparticle,and holes in the minority-block domains usually have rotational symmetry.In the case of a weakly selective cavity wall,the inhomogeneity of the cavity wall results in structures having a specific orientation(such as flower-like and branched structures in gyroid-forming and cylinder-forming di-BCPs)and a perforated wetting layer with uniformly distributed holes.The novel nanoparticles obtained may have potential applications in nanotechnology as functional nanostructures or nanoparticles.展开更多
Directly correlating the morphology and composition of interfacial water is vital not only for studying water icing under critical conditions but also for understanding the role of protein–water interac-tions in bio-...Directly correlating the morphology and composition of interfacial water is vital not only for studying water icing under critical conditions but also for understanding the role of protein–water interac-tions in bio-relevant systems.In this study,we present a model system to study two-dimensional(2D)water layers under ambient conditions by using self-assembled monolayers(SAMs)supporting the physisorp-tion of the Cytochrome C(Cyt C)protein layer.We observed that the 2D island-like water layers were uniformly distributed on the SAMs as characterized by atomic force microscopy,and their composition was confirmed by nano-atomic force microscopy-infrared spectroscopy and Raman spectroscopy.In addition,these 2D flakes could grow under high-humidity conditions or melt upon the introduction of a heat source.The formation of these flakes is attributed to the activation energy for water desorption from the Cyt C being nearly twofold high than that from the SAMs.Our results provide a new and effective method for further understanding the water–protein interactions.展开更多
Antimicrobial resistance(AMR)is a growing public health crisis that requires innovative solutions.Emerging multidrug resistant(MDR)Salmonella typhimurium has raised concern for its effect on pathogenic infection and m...Antimicrobial resistance(AMR)is a growing public health crisis that requires innovative solutions.Emerging multidrug resistant(MDR)Salmonella typhimurium has raised concern for its effect on pathogenic infection and mortality in humans caused by enteric diseases.To combat these MDR Salmonella typhimurium pathogens,highly effective and broad-spectrum antibiotics such as flufenicol(FFC)need to be evaluated for their potent antibacterial activity against Salmonella typhimurium.However,the low solubility and low oral bioavailability of flufenicol need to be addressed to better combat AMR.In this work,we develop a novel nano-formulation,flufenicol nano-micelles(FTPPM),which are based on d-α-tocopherol polyethylene glycol 1,000 succinate(TPGS)/poloxamer 188(P188),for the targeted treatment of biofilms formed by drug-resistant Salmonella typhimurium in the intestine.Herein,FTPPM were prepared via a thin film hydration method.The preparation process for the mixed micelles is simple and convenient compared with other existing nanodrug delivery systems,which can further decrease production costs.The optimized FTPPM demonstrated outstanding stability and sustained release.An evaluation of the in vivo anti-drug-resistant Salmonella typhimurium efficacy demonstrated that FTPPM showed a stronger efficacy(68.17%)than did florfenicol-loaded TPGS polymer micelles(FTPM),flufenicol active pharmaceutical ingredients(FFC-API),and flufenicol commercially available medicine(FFC-CAM),and also exhibited outstanding biocompatibility.Notably,FTPPM also inhibited drug-resistant Salmonella typhimurium from forming biofilms.More importantly,FTPPM effectively restored intestinal flora disorders induced by drug-resistant Salmonella typhimurium in mice.In summary,FTPPM significantly improved the solubility and oral bioavailability of florfenicol,enhancing its efficacy against drug-resistant Salmonella typhimurium both in vitro and in vivo.FTPPM represent a promising drug-resistant Salmonella typhimurium treatment for curbing bacterial resistance via oral administration.展开更多
Self-assembled monolayers(SAMs)have been commonly employed as hole-selective layers(HSLs)in inverted(p-i-n)perovskite solar cells(PSCs),and typically only a single-component SAM is applied,which plays limited role in ...Self-assembled monolayers(SAMs)have been commonly employed as hole-selective layers(HSLs)in inverted(p-i-n)perovskite solar cells(PSCs),and typically only a single-component SAM is applied,which plays limited role in selective hole transport.Herein,we synthesize a novel SAM,(4-(3,11-dibro mo-7H-dibenzo[c,g]carbazol-7-yl)butyl)phosphonic acid(Br-4PADBC),and apply it as a complementary component to the commonly used[2-(3,6-dimeth oxy-9H-carbazol-9-yl)ethyl]phosphonic acid(MeO-2PACz)SAM,accomplishing boosted hole transport in inverted PSCs.A series of characterizations and theoretical calculations are employed to unravel the roles of each components within the binary SAM(bi-SAM).The involvements of the non-planar dibenzo[c,g]carbazole unit and electron-withdrawing Br atoms induce larger dipole moment of Br-4PADBC than MeO-2PACz,resulting in much deeper work function of ITO and consequently improved alignment with the valence band energy level of perovskite.Besides,the introduced Br atoms improve the quality of perovskite crystals and help passivate defects of perovskite.On the other hand,the existence of the conventional MeO-2PACz SAM ensures the considerable conductivity of the bi-SAM and thus efficient hole extraction from the perovskite layer.As a result,inverted PSC devices based on bi-SAM HSL deliver a decent power conversion efficiency(PCE)of 24.52%as well as dramatically improved thermal and operational stabilities.展开更多
Self-assembled monolayers(SAMs),owing to their amphiphilic nature,tend to aggregate,which impedes the formation of a dense and uniform SAM on the substrate.Additionally,the weak adsorption ability of SAMs on the indiu...Self-assembled monolayers(SAMs),owing to their amphiphilic nature,tend to aggregate,which impedes the formation of a dense and uniform SAM on the substrate.Additionally,the weak adsorption ability of SAMs on the indium tin oxide(ITO)surface and the desorption of hydroxyl(OH)from the ITO surface induced by polar solvents can lead to the formation of vacancies.Herein,a dimethylacridine-based SAM is incorporated into the perovskite precursor solution.This SAM can be extruded from the precursor solution and enriched on the bottom surface of the perovskite,filling the vacancies and in situ forming a mixed SAM with MeO-2PACz as a hole-selective layer(HSL).The in situ formed mixed SAM optimizes the energy level alignment between the HSL and the perovskite,facilitating hole extraction and alleviating the residual strain of the perovskite film.Consequently,the perovskite solar cells(PSCs),based on the mixed SAM,achieve a power conversion efficiency(PCE)of 25.69%and exhibit excellent operational stability.When this approach is applied to 1.78 eV bandgap PSC devices,it yields a PCE of 20.08%.This work presents a unique strategy for fabricating both high-quality perovskite films and superior buried interfaces,which is also applicable to wide-bandgap PSCs.展开更多
Recently,stimuli-responsive nanocarriers capable of precision drug release have garnered significant attention in the field of drug delivery.Here,an in-situ dynamic covalent self-assembled(DCS)strategy was utilized to...Recently,stimuli-responsive nanocarriers capable of precision drug release have garnered significant attention in the field of drug delivery.Here,an in-situ dynamic covalent self-assembled(DCS)strategy was utilized to develop a co-delivery system.This assembly was based on a thiol-disulfide-exchange reaction,producing disulfide macrocycles in an oxidizing aerial environment.These macrocycles encapsulated the anti-cancer drug(paclitaxel,PTX)on the surface of gold nanoparticles,which served as photothermal therapy agents during the self-assembly.In the DCS process,the kinetic control over the concentration of each building unit within the reaction system led to the formation of a stable co-delivery nanosystem with optimal drug-loading efficiency.Notably,the high glutathione(GSH)concentrations in tumor cells caused the disulfide macrocycles in nanostructures to break,resulting in drug release.The stimuli-responsive performances of the prepared nanosystems were determined by observing the molecular structures and drug release.The results revealed that the self-assembled nanosystem exhibited GSH-triggered drug release and good photothermal conversion capability under near-infrared light.Moreover,the in vitro and in vivo results revealed that conjugating the targeting molecule of cRGD with co-delivery nanosystem enhanced its biocompatibility,chemo-photothermal anti-cancer effect.Overall,our findings indicated that in-situ DCS strategy enhanced the control over drug loading during the construction of the co-delivery system,paving a way for the development of more functional carriers in nanomedicine.展开更多
In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to ...In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method.展开更多
Marine thin plates are susceptible to welding deformation owing to their low structural stiffness.Therefore,the efficient and accurate prediction of welding deformation is essential for improving welding quality.The t...Marine thin plates are susceptible to welding deformation owing to their low structural stiffness.Therefore,the efficient and accurate prediction of welding deformation is essential for improving welding quality.The traditional thermal elastic-plastic finite element method(TEP-FEM)can accurately predict welding deformation.However,its efficiency is low because of the complex nonlinear transient computation,making it difficult to meet the needs of rapid engineering evaluation.To address this challenge,this study proposes an efficient prediction method for welding deformation in marine thin plate butt welds.This method is based on the coupled temperature gradient-thermal strain method(TG-TSM)that integrates inherent strain theory with a shell element finite element model.The proposed method first extracts the distribution pattern and characteristic value of welding-induced inherent strain through TEP-FEM analysis.This strain is then converted into the equivalent thermal load applied to the shell element model for rapid computation.The proposed method-particularly,the gradual temperature gradient-thermal strain method(GTG-TSM)-achieved improved computational efficiency and consistent precision.Furthermore,the proposed method required much less computation time than the traditional TEP-FEM.Thus,this study lays the foundation for future prediction of welding deformation in more complex marine thin plates.展开更多
Self-assembled monolayers （SAMs） of （3-mercaptopropy） trimethoxysilane （3-MtrF） chemisorbed on silver surfaces were chemically ＂modified by 1-octadecanethiol to form self-assembled mixed-monolayers （SAMM） and...Self-assembled monolayers （SAMs） of （3-mercaptopropy） trimethoxysilane （3-MtrF） chemisorbed on silver surfaces were chemically ＂modified by 1-octadecanethiol to form self-assembled mixed-monolayers （SAMM） and the co-polymer of N-vinylcarbazole and methyl methacrylate ester （to form complex selfassembled film （CSAF））. The oxidation resistance of these barriers on silver surfaces and some influential factors concerned processes were analyzed by electrochemical impedance spectroscopy （EIS） in a 10% NaOH aqueous solution at oxidation potential. X-ray diffraction （XRD） spectroscopy shows that the oxidation occurring on the silver surface may be restrained effectively due to the coating barrier, and CSAF（Ⅱ） is the best one. Studies also reveal that oxide processes of bare silver and a series of modified silver electrodes in a 10% NaOH aqueous solution are of more than two relaxation time constants.展开更多
Self assembled monolayers （SAMs） of 1-tetradecylphosphonic acids （TDPA, CH3（CH2）13P（O）（OH）2 ） were formed on the 2024 aluminum alloy surface in TDPA-containing ethanol-water solutions with different water co...Self assembled monolayers （SAMs） of 1-tetradecylphosphonic acids （TDPA, CH3（CH2）13P（O）（OH）2 ） were formed on the 2024 aluminum alloy surface in TDPA-containing ethanol-water solutions with different water content. The adsorption and corrosion protection properties of the SAMs for 2024 alloy in 0.1 mol/L H2SO4 solution were examined and characterized by potentiodynamic polarization, electrochemical impedance spectrum （EIS）, Fourier transformed infrared spectroscopy （FTIR）, Auger electron spectra （AES） and atomic force microscopy （AFM）. FTIR and AES results show that the TDPA molecules were successfully adsorbed on the 2024 aluminum alloy surface, and the density of the SAMs increased with the increasing water content in the assembly solution. The results of electrochemical studies and corrosion morphologies observed by AFM show that a 4 h modification resulted in maximal inhibition efficiency, and the higher the water content in the assembly solution is, the better the inhibition performance of the SAMs can be achieved. The effect of water content in TDPA solutions on the performance of the SAMs is related to the hydration reaction of the metal surface.展开更多
基金Support by the National High Technology Research and Development Program of China(863 Program)(2012AA03A608)the Open Foundation of Zhejiang Provincial Top Key Academic Discipline of Applied Chemistry and Eco-Dyeing&Finishing Engineering(YR2012012)
文摘Polypiperazine-amide membranes were modified with poly(ethyleneimine)(PEI) by self-assembled method,through which PEI molecules were fixed on the membrane surface by ionic interaction. In the experiments,the PEI concentration ranged from 50 to 2000 mg·L-1while the depositing time was fixed at 20 min. The results showed that low PEI concentration resulted in a slight increase of pure water flux, which was attributed to the enhanced membrane surface hydrophilicity. The PEI adsorption on membrane surface had less effect on the rejections to neutral PEG and sucrose, but improved the rejections to divalent cationic ions and methylene blue as the result of reversion of the membrane surface charge from negative to positive according to the XPS analysis and zeta potential measurements. The membrane modified at PEI = 1500 mg·L-1exhibited high rejection to methylene blue(MB) and is potential to be applied in the treatment of effluents containing positively charged dyes.
基金supported by the National Natural Science Foundation of China(Nos.81873092,82174074)。
文摘The self-assembled nanoparticles(SAN)formed during the decoction process of traditional Chinese medicine(TCM)exhibit non-uniform particle sizes and a tendency for aggregation.Our group found that the p H-driven method can improve the self-assembly phenomenon of Herpetospermum caudigerum Wall.,and the SAN exhibited uniform particle size and demonstrated good stability.In this paper,we analyzed the interactions between the main active compound,herpetrione(Her),and its main carrier,Herpetospermum caudigerum Wall.polysaccharide(HCWP),along with their self-assembly mechanisms under different p H values.The binding constants of Her and HCWP increase with rising p H,leading to the formation of Her-HCWP SAN with a smaller particle size,higher zeta potential,and improved thermal stability.While the contributions of hydrogen bonding and electrostatic attraction to the formation of Her-HCWP SAN increase with rising p H,the hydrophobic force consistently plays a dominant role.This study enhances our scientific understanding of the self-assembly phenomenon of TCM improved by p H driven method.
基金supported by funding from the Energy Materials and Surface Sciences Unit of the Okinawa Institute of Science and Technology Graduate University,the OIST R&D Cluster Research Program,the OIST Proof of Concept(POC)Program,the JSPS KAKENHI Grant Number JP21F21754 and Alexander von Humboldt Foundation。
文摘Self-assembled monolayers(SAMs)are widely used as hole transport materials in inverted perovskite solar cells,offering low parasitic absorption and suitability for semitransparent and tandem solar cells.While SAMs have shown to be promising in small-area devices(≤1 cm^(2)),their application in larger areas has been limited by a lack of knowledge regarding alternative deposition methods beyond the common spin-coating approach.Here,we compare spin-coating and upscalable methods such as thermal evaporation and spray-coating for[2-(9H-carbazol-9-yl)ethyl]phosphonic acid(2PACz),one of the most common carbazole-based SAMs.The impact of these deposition methods on the device performance is investigated,revealing that the spray-coating technique yields higher device performance.Furthermore,our work provides guidelines for the deposition of SAM materials for the fabrication of perovskite solar modules.In addition,we provide an extensive characterization of 2PACz films focusing on thermal evaporation and spray-coating methods,which allow for thicker 2PACz deposition.It is found that the optimal 2PACz deposition conditions corresponding to the highest device performances do not always correlate with the monolayer characteristics.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.10864001）, the Natural Science Foundation of Yunnan Province （No.2008ZC159M）, and No.8 Middle-Aged and Young Academic Talent Reserve Project of Yunnan Province （No.2005PY01-51）.
文摘We demonstrate surface enhanced Raman scattering （SERS） detection of self-assembled nano silver film using a low-cost electrolysis strategy at a proper voltage and silver nitrate concentration in electrolyte. The concentration dependence of SERS from crystal violet （CV） molecules adsorbed to silver film was systematically studied. Importantly, the SERS surface enhancement factor of such nano silver film was 603, which was measured by a portable Raman spectrometer. The minimum concentration of detectable CV molecules can be as low as 10^-11 mol/L. The nano silver film prepared by this electrolysis method is an active, stable, cost-effective, and reusable SERS substrate.
基金Y.Zhan acknowledges funding support from the National Key Research and Development Program of China(2022YFE0137400)the National Natural Science Foundation of China(62274040)+5 种基金A.Yu acknowledges funding support from the National Natural Science Foundation of China(62304046)the National Key Research and Development Program of China(2022YFB2802802)the Key Laboratory of Rare Earths,Ganjiang Innovation Academy,Chinese Academy of SciencesX.Zhang acknowledges funding from the China Postdoctoral Science Foundation(GZC20230463)X.Li acknowledges funding from the China Postdoctoral Science Foundation(GZC20230461)We also acknowledge support from the Shanghai Science and Technology Innovation Action Plan 2023 Special Project for Supporting Carbon Peak Carbon Neutrality Project(23DZ1200400).
文摘The NiOx,due to its excellent semiconductor properties,ease of large-area deposition,and tunable optoelectronic characteristics,shows great potential in industrial large-area perovskite technologies.However,NiO_(x)-based perovskite solar cells(PSCs)are limited by interfacial photocatalytic chemical reactions and energy level mismatch.Thus,phosphate-based self-assembled monolayers(SAMs)have been widely developed for delicate interfacial modification;however,they suffer from severe issues such as self-aggregation and high cost.Herein,a low-cost carboxylate-based SAM(pyrenebutyric acid,PyBA)was used to modify NiO_(x),achieving an improved surface chemical environment and interfacial properties,such as an increased Ni^(3+)/Ni2^(+)ratio,a reduced proportion of high-valence Ni^(≥3+),and better-aligned hole transport interface energy level.The introduction of PyBA also results in larger grain size,higher uniformity,and enhanced photoluminescence(PL)from the bottom of the perovskite,yielding a significant increase in efficiency from an initial 22.48%to 25.14%,while increasing the open-circuit voltage(VOC)from 1.077 to 1.192 V.Additionally,a perovskite module with an aperture area of 21 cm^(2)achieved an efficiency of 22.28%,demonstrating the excellent scalability of the PyBA treatment.Moreover,the well-modified buried interface combined with the chemical inertness and structural rigidity of pyrene ensures excellent ultraviolet(UV)stability(the target module maintained 92%of the initial efficiency after 200 h and the control device only retained 40%).
基金supported by the National Research Foundation of Korea[NRF-2023–00211758].
文摘A new type of amphiphiles bearingmacrocycle such as cucurbit[7]uril(CB[7])spontaneously forms a nanomaterial in water,specifically vesicles(tACB[7]vesicles)with a positive surface charge,verified through various analytical techniques including TIRF,DLS and TEM.Functional validation not only reveals the accessibility of the CB[7]portal on these vesicles allowing CB[7]-based host-vip interactions with various functional vip molecules such as fluorescein isothiocyanate conjugated adamantylammonium and spermine(FITC-AdA and FITC-SPM,respectively)using confocal laser scanning microscopy,but also showcases the effective internalization of tACB[7]vesicles into cancer cells with the anticancer drug oxaliplatin(OxPt),as a vip to CB[7],through in vitro cell experiments.Hence,this study provides a blueprint to impart amphiphilic properties to CB[7]through synthetic design and highlights the potential of CB[7]derivatives as a new class of unconventional amphiphiles self-assembling into functional nanomaterials for advanced drug delivery.
基金financially supported by the National Key R&D Program of China(No.2022YFB3707300)the National Natural Science Foundation of China(Nos.22133002,22373089)the support from the Excellent Youth Foundation of Henan Scientific Committee(No.242300421032).
文摘A significant challenge in developing block copolymer photonic crystals is constructing low-symmetric ordered phases,which are essential for achieving a complete photonic band gap.Here,we propose a promising strategy to create low-symmetric ordered morphologies by incorporating shape-anisotropic rod-like side chains into block copolymers.Using dissipative particle dynamics simulations,we demonstrate that block copolymers with longer rod-like side chains can self-assemble into a hexagonally packed columnar phase characterized by a low-symmetric rectangular cross-section.Photonic band structure calculations reveal that this low-symmetric columnar phase can exhibit a complete photonic band gap,with the gap size dependent on the aspect ratio of the rectangular cross-sections of the columns.Our findings suggest an effective approach to constructing low-symmetric photonic crystals through the self-assembly of block copolymers with shape-anisotropic segments.
基金supported by the National Natural Science Foundation of China(22305119,12204234)the Natural Science Foundation of Jiangsu Province(BK20220878)+3 种基金the Fundamental Research Funds for the Central Universities(NS2023059)the China Postdoctoral Science Foundation(2022TQ0157,2023M741695)the Liaoning University Talent Introduction Research Startup Project(d295000048)the Center for Microscopy and Analysis of Nanjing University of Aeronautics and Astronautics for characterization support。
文摘The optimization of hole transport layer(HTL)is crucial for achieving high efficiency and stability in inverted perovskite solar cells(PSCs)due to its role in facilitating hole transport and passivating the perovskite bottom interface.While self-assembled monolayers(SAMs)are commonly used for this purpose,the inherent limitations of a single SAM,such as fixed energy levels and rigid structure,restrict their adaptability for different perovskite components and further efficiency enhancement.Here,we demonstrate a stepwise deposition method for SAM-based HTLs to address this issue.We regulated the energy level gradient by depositing two SAMs with distinct energy levels,while the interactions between the phosphate groups in the SAMs and perovskite effectively reduce defect density at the bottom interface of the perovskite film.The as-fabricated PSCs achieved enhanced efficiency and stability with PCEs of 25.7% and 24.0% for rigid and flexible PSCs,respectively;these devices maintain 90% of their initial PCE after 500 h of maximum power point tracking,and retain 98% of their initial PCE after 4,000 bending cycles,representing one of the most stable flexible PSCs reported to date.
基金supported by National Natural Science Foundation of China(32261143727,82073779,32000992)National Key Research and Development Program of China(2018YFA0901800)Natural Science Foundation of Zhejiang Province(Natural Science Foundation of Zhejiang Province Distinguished Young Scholar Program,LR21H300002)。
文摘Inflammatory skin disorders(ISDs),characterized by severe inflammation and impaired skin barrier functions,often requires persistent treatment due to chronic and relapsing natures.To address these issues,we developed a small-molecular self-assembled nanodrug(ECN)that is composed of natural epigallocatechin-3-gallate(EGCG)self-assembled with tripeptide collagen(CTP).By formulating a transdermal enhancer(cationic dendrimer)with ECN,the resulted dendrimers/ECN nanocomplex(DECN)can effectively penetrate into the skin layer,resulting in effective anti-inflammatory response and repair of skin-barrier functions.In animal models of ISDs,including atopic dermatitis(AD)and psoriasis,DECN showed remarkable skin penetration,with high level of drug deposition in the epidermaldermal layer.By using a commercially available spray pump,DECN nanoparticles can be further translated into a spray formulation,which contributes to alleviating visible symptoms,skin lesions,and inflammatory progression of psoriasis and AD.This all-in-one spray nano-formulation offers an effective,safe,and convenient way for ISDs treatment.
基金supported by the Natural Science Foundation of China(22425903,U24A20568,61705102,62288102,22409091,22409090 and 62205142)the National Key R&D Program of China(2023YFB4204500)the Jiangsu Provincial Departments of Science and Technology(BE2022023,BK20220010,BZ2023060,BK20240561,and BK20240562)。
文摘Inverted p-i-n perovskite solar cells(PSCs)based on self-assembled monolayers(SAMs)as hole-selective layers(HSLs)have produced potential record efficiencies of more than 26%by tuning work function,dipole,and passivation defects.However,the stability of the SAM molecules,the stability of the molecular anchoring conformation,and the impact on the stability of subsequent PSCs have not been clearly elucidated.In this review,we systematically discussed the intrinsic connection between the molecular conformation(including anchoring groups,spacer groups,and terminal groups)and the stability of SAMs.Sequentially,the research progress of SAMs as HSLs in improving the stability of PSCs is summarized,including photostability,thermal stability,ion migration,and residual stress.Finally,we look forward to the shortcomings and possible challenges of using SAMs as HSLs for inverted PSCs.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.22173051,21829301,21774066)College Discipline Innovation and Intelligence Introduction Program(111 Project(B16027)+1 种基金the International Cooperation Base(2016D01025)Tianjin International Joint Research and Development Center。
文摘Spatial confinement of block copolymers can induce frustrations,which can further be utilized to regulate self-assembled structures,thus providing an efficient route for fabricating novel structures.We studied the self-assembly of AB di-block copolymers(di-BCPs)confined in Janus spherical nanocavities using simulations,and explained the structure formation mechanisms.In the case of a strongly selective cavity wall,all the lamella-forming,gyroid-forming,and cylinder-forming di-BCPs can form interfacial frustration-induced Janus concentric perforated lamellar nanoparticles,whose outermost is a Janus spherical shell and the internal is a sphere with concentric perforated lamellar structure.In particular,Janus concentric perforated lamellar nanoparticles with holes distributed only near the equatorial plane were obtained in both lamella-forming and gyroid-forming di-BCPs,directly reflecting the effect of interfacial frustration.The minority-block domain of the cylider-forming di-BCPs may form hemispherical perforated lamellar structures with holes distributed in parallel layers with a specific orientation.For symmetric di-BCPs,both the A and B domains in each nanoparticle are continuous,interchangeable,and have rotational symmetry.While for gyroid-forming and cylinder-forming di-BCPs,only the majority-block domains are continuous in each nanoparticle,and holes in the minority-block domains usually have rotational symmetry.In the case of a weakly selective cavity wall,the inhomogeneity of the cavity wall results in structures having a specific orientation(such as flower-like and branched structures in gyroid-forming and cylinder-forming di-BCPs)and a perforated wetting layer with uniformly distributed holes.The novel nanoparticles obtained may have potential applications in nanotechnology as functional nanostructures or nanoparticles.
基金supported by the National Natural Science Foundation of China(22273045,52488101 and 22472043)Ningbo Youth Science and Technology Innovation Leading Talent(2023QL041)Tsinghua University Independent Scientific Research Plan for Young Investigator,Tsinghua University Dushi Program,and Initiative Scientific Research Program。
文摘Directly correlating the morphology and composition of interfacial water is vital not only for studying water icing under critical conditions but also for understanding the role of protein–water interac-tions in bio-relevant systems.In this study,we present a model system to study two-dimensional(2D)water layers under ambient conditions by using self-assembled monolayers(SAMs)supporting the physisorp-tion of the Cytochrome C(Cyt C)protein layer.We observed that the 2D island-like water layers were uniformly distributed on the SAMs as characterized by atomic force microscopy,and their composition was confirmed by nano-atomic force microscopy-infrared spectroscopy and Raman spectroscopy.In addition,these 2D flakes could grow under high-humidity conditions or melt upon the introduction of a heat source.The formation of these flakes is attributed to the activation energy for water desorption from the Cyt C being nearly twofold high than that from the SAMs.Our results provide a new and effective method for further understanding the water–protein interactions.
基金supported by the grants from the National Key Research and Development Program of China(Grant No.:2024YFE0106300)the Key Projects of Natural Science Foundation of Anhui Provincial Department of Education,China(Grant No.:2023AH051017)+2 种基金the Outstanding Youth Scientific Research Foundation of the Anhui Education Department,China(Grant No.:2024AH030019)the National Natural Science Foundation of China(Grant No.:32302923)Natural Science Foundation of Anhui Province,China(Grant No.:2208085MC79).
文摘Antimicrobial resistance(AMR)is a growing public health crisis that requires innovative solutions.Emerging multidrug resistant(MDR)Salmonella typhimurium has raised concern for its effect on pathogenic infection and mortality in humans caused by enteric diseases.To combat these MDR Salmonella typhimurium pathogens,highly effective and broad-spectrum antibiotics such as flufenicol(FFC)need to be evaluated for their potent antibacterial activity against Salmonella typhimurium.However,the low solubility and low oral bioavailability of flufenicol need to be addressed to better combat AMR.In this work,we develop a novel nano-formulation,flufenicol nano-micelles(FTPPM),which are based on d-α-tocopherol polyethylene glycol 1,000 succinate(TPGS)/poloxamer 188(P188),for the targeted treatment of biofilms formed by drug-resistant Salmonella typhimurium in the intestine.Herein,FTPPM were prepared via a thin film hydration method.The preparation process for the mixed micelles is simple and convenient compared with other existing nanodrug delivery systems,which can further decrease production costs.The optimized FTPPM demonstrated outstanding stability and sustained release.An evaluation of the in vivo anti-drug-resistant Salmonella typhimurium efficacy demonstrated that FTPPM showed a stronger efficacy(68.17%)than did florfenicol-loaded TPGS polymer micelles(FTPM),flufenicol active pharmaceutical ingredients(FFC-API),and flufenicol commercially available medicine(FFC-CAM),and also exhibited outstanding biocompatibility.Notably,FTPPM also inhibited drug-resistant Salmonella typhimurium from forming biofilms.More importantly,FTPPM effectively restored intestinal flora disorders induced by drug-resistant Salmonella typhimurium in mice.In summary,FTPPM significantly improved the solubility and oral bioavailability of florfenicol,enhancing its efficacy against drug-resistant Salmonella typhimurium both in vitro and in vivo.FTPPM represent a promising drug-resistant Salmonella typhimurium treatment for curbing bacterial resistance via oral administration.
基金the National Natural Science Foundation of China(51925206,U1932214,52302052)the National Natural Science Foundation of China(52322318)+6 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0450301)the Fundamental Research Funds for the Central Universities(WK2060000051,20720220009)the National Key Research and Development Program of China(No.2023YFB3809700)the Innovation and Technology Fund(GHP/100/20SZ,GHP/102/20GD,MRP/040/21X,ITS/147/22FP)the Research Grants Council of Hong Kong Grant(N_City U102/23,C4005-22Y,C1055-23G,11306521)the Green Tech Fund(GTF202020164)the Science Technology and Innovation Committee of Shenzhen Municipality(SGDX20210823104002015,JCYJ20220818101018038)。
文摘Self-assembled monolayers(SAMs)have been commonly employed as hole-selective layers(HSLs)in inverted(p-i-n)perovskite solar cells(PSCs),and typically only a single-component SAM is applied,which plays limited role in selective hole transport.Herein,we synthesize a novel SAM,(4-(3,11-dibro mo-7H-dibenzo[c,g]carbazol-7-yl)butyl)phosphonic acid(Br-4PADBC),and apply it as a complementary component to the commonly used[2-(3,6-dimeth oxy-9H-carbazol-9-yl)ethyl]phosphonic acid(MeO-2PACz)SAM,accomplishing boosted hole transport in inverted PSCs.A series of characterizations and theoretical calculations are employed to unravel the roles of each components within the binary SAM(bi-SAM).The involvements of the non-planar dibenzo[c,g]carbazole unit and electron-withdrawing Br atoms induce larger dipole moment of Br-4PADBC than MeO-2PACz,resulting in much deeper work function of ITO and consequently improved alignment with the valence band energy level of perovskite.Besides,the introduced Br atoms improve the quality of perovskite crystals and help passivate defects of perovskite.On the other hand,the existence of the conventional MeO-2PACz SAM ensures the considerable conductivity of the bi-SAM and thus efficient hole extraction from the perovskite layer.As a result,inverted PSC devices based on bi-SAM HSL deliver a decent power conversion efficiency(PCE)of 24.52%as well as dramatically improved thermal and operational stabilities.
基金supported by the Young Cross Team Project of CAS(No.JCTD-2021-14)the National Natural Science Foundation of China(51925206)Gusu Innovation and Entrepreneur Leading Talents(ZXL2022466)。
文摘Self-assembled monolayers(SAMs),owing to their amphiphilic nature,tend to aggregate,which impedes the formation of a dense and uniform SAM on the substrate.Additionally,the weak adsorption ability of SAMs on the indium tin oxide(ITO)surface and the desorption of hydroxyl(OH)from the ITO surface induced by polar solvents can lead to the formation of vacancies.Herein,a dimethylacridine-based SAM is incorporated into the perovskite precursor solution.This SAM can be extruded from the precursor solution and enriched on the bottom surface of the perovskite,filling the vacancies and in situ forming a mixed SAM with MeO-2PACz as a hole-selective layer(HSL).The in situ formed mixed SAM optimizes the energy level alignment between the HSL and the perovskite,facilitating hole extraction and alleviating the residual strain of the perovskite film.Consequently,the perovskite solar cells(PSCs),based on the mixed SAM,achieve a power conversion efficiency(PCE)of 25.69%and exhibit excellent operational stability.When this approach is applied to 1.78 eV bandgap PSC devices,it yields a PCE of 20.08%.This work presents a unique strategy for fabricating both high-quality perovskite films and superior buried interfaces,which is also applicable to wide-bandgap PSCs.
基金supported by the National Natural Science Foundation of China(Nos.82202274,82072032,22161016,32025021,12374390,52002380 and 31971292),the National Science and Technology Major Project(No.2023ZD0500902)the Fellowship of China Postdoctoral Science Foundation(No.2023M743559)+2 种基金the Member of Youth Innovation Promotion Association Foundation of CAS,China(No.2023310)the Key Scientific and Technological Special Project of Ningbo City(No.2023Z209)the Natural Science Foundation of Zhejiang Province(No.LQ23H180003)。
文摘Recently,stimuli-responsive nanocarriers capable of precision drug release have garnered significant attention in the field of drug delivery.Here,an in-situ dynamic covalent self-assembled(DCS)strategy was utilized to develop a co-delivery system.This assembly was based on a thiol-disulfide-exchange reaction,producing disulfide macrocycles in an oxidizing aerial environment.These macrocycles encapsulated the anti-cancer drug(paclitaxel,PTX)on the surface of gold nanoparticles,which served as photothermal therapy agents during the self-assembly.In the DCS process,the kinetic control over the concentration of each building unit within the reaction system led to the formation of a stable co-delivery nanosystem with optimal drug-loading efficiency.Notably,the high glutathione(GSH)concentrations in tumor cells caused the disulfide macrocycles in nanostructures to break,resulting in drug release.The stimuli-responsive performances of the prepared nanosystems were determined by observing the molecular structures and drug release.The results revealed that the self-assembled nanosystem exhibited GSH-triggered drug release and good photothermal conversion capability under near-infrared light.Moreover,the in vitro and in vivo results revealed that conjugating the targeting molecule of cRGD with co-delivery nanosystem enhanced its biocompatibility,chemo-photothermal anti-cancer effect.Overall,our findings indicated that in-situ DCS strategy enhanced the control over drug loading during the construction of the co-delivery system,paving a way for the development of more functional carriers in nanomedicine.
基金Supported in part by Natural Science Foundation of Guangxi(2023GXNSFAA026246)in part by the Central Government's Guide to Local Science and Technology Development Fund(GuikeZY23055044)in part by the National Natural Science Foundation of China(62363003)。
文摘In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method.
基金Supported by the National Natural Science Foundation of China under Grant No.51975138the High-Tech Ship Scientific Research Project from the Ministry of Industry and Information Technology under Grant No.CJ05N20the National Defense Basic Research Project under Grant No.JCKY2023604C006.
文摘Marine thin plates are susceptible to welding deformation owing to their low structural stiffness.Therefore,the efficient and accurate prediction of welding deformation is essential for improving welding quality.The traditional thermal elastic-plastic finite element method(TEP-FEM)can accurately predict welding deformation.However,its efficiency is low because of the complex nonlinear transient computation,making it difficult to meet the needs of rapid engineering evaluation.To address this challenge,this study proposes an efficient prediction method for welding deformation in marine thin plate butt welds.This method is based on the coupled temperature gradient-thermal strain method(TG-TSM)that integrates inherent strain theory with a shell element finite element model.The proposed method first extracts the distribution pattern and characteristic value of welding-induced inherent strain through TEP-FEM analysis.This strain is then converted into the equivalent thermal load applied to the shell element model for rapid computation.The proposed method-particularly,the gradual temperature gradient-thermal strain method(GTG-TSM)-achieved improved computational efficiency and consistent precision.Furthermore,the proposed method required much less computation time than the traditional TEP-FEM.Thus,this study lays the foundation for future prediction of welding deformation in more complex marine thin plates.
基金The National Natural Science Foundation of China(Nos.60371027,60171005).
文摘Self-assembled monolayers （SAMs） of （3-mercaptopropy） trimethoxysilane （3-MtrF） chemisorbed on silver surfaces were chemically ＂modified by 1-octadecanethiol to form self-assembled mixed-monolayers （SAMM） and the co-polymer of N-vinylcarbazole and methyl methacrylate ester （to form complex selfassembled film （CSAF））. The oxidation resistance of these barriers on silver surfaces and some influential factors concerned processes were analyzed by electrochemical impedance spectroscopy （EIS） in a 10% NaOH aqueous solution at oxidation potential. X-ray diffraction （XRD） spectroscopy shows that the oxidation occurring on the silver surface may be restrained effectively due to the coating barrier, and CSAF（Ⅱ） is the best one. Studies also reveal that oxide processes of bare silver and a series of modified silver electrodes in a 10% NaOH aqueous solution are of more than two relaxation time constants.
基金Project(Q20120110)supported by Youth Foundation of Hubei Provincial Education Bureau,ChinaProject(2009CDB347)supported by the Hubei Provincial Natural Science Foundation,ChinaProject(51001045)supported by the National Natural Science Foundation of China
文摘Self assembled monolayers （SAMs） of 1-tetradecylphosphonic acids （TDPA, CH3（CH2）13P（O）（OH）2 ） were formed on the 2024 aluminum alloy surface in TDPA-containing ethanol-water solutions with different water content. The adsorption and corrosion protection properties of the SAMs for 2024 alloy in 0.1 mol/L H2SO4 solution were examined and characterized by potentiodynamic polarization, electrochemical impedance spectrum （EIS）, Fourier transformed infrared spectroscopy （FTIR）, Auger electron spectra （AES） and atomic force microscopy （AFM）. FTIR and AES results show that the TDPA molecules were successfully adsorbed on the 2024 aluminum alloy surface, and the density of the SAMs increased with the increasing water content in the assembly solution. The results of electrochemical studies and corrosion morphologies observed by AFM show that a 4 h modification resulted in maximal inhibition efficiency, and the higher the water content in the assembly solution is, the better the inhibition performance of the SAMs can be achieved. The effect of water content in TDPA solutions on the performance of the SAMs is related to the hydration reaction of the metal surface.
