Temperature-sensitive hydrogel—poly(N-isopropyl acrylamide) (PNIPA) was prepared and applied to protein refolding. PNIPA gel disks and gel particles were synthesized by the solution polymerization and inverse suspens...Temperature-sensitive hydrogel—poly(N-isopropyl acrylamide) (PNIPA) was prepared and applied to protein refolding. PNIPA gel disks and gel particles were synthesized by the solution polymerization and inverse suspension polymerization respectively. The swelling kinetics of the gels was also studied. With these prepared PNIPA gels, the model protein lysozyme was renatured. Within 24h, PNIPA gel disks improved the yield of lysozyme activity by 49.3% from 3375.2U·mg^-1 to 5038.8U·mg^-1. With the addition of faster response PNIPA gel beads, the total lysozyme activity recovery was about 68.98% in 3h, as compared with 42.03% by simple batch dilution. The novel refolding system with PNIPA enables efficient refolding especially at high protein concentrations. Discussion about the mechanism revealed that when PNIPA gels were added into the refolding buffer, the hydrophobic interactions between denatured proteins and polymer gels could prevent the aggregation of refolding intermediates, thus enhanced the protein renaturation.展开更多
In this study,the hydrogels composites with coatings based on a temperature-sensitive linear copolymer of N-tert-butylacrylamide(NTBA)and acrylamide(AAm)on cotton fabrics have been developed.The cotton fabrics were co...In this study,the hydrogels composites with coatings based on a temperature-sensitive linear copolymer of N-tert-butylacrylamide(NTBA)and acrylamide(AAm)on cotton fabrics have been developed.The cotton fabrics were coated using aqueous solution of the linear copolymer,1,2,3,4-butanetertracarboxylic acid(BTCA)as a cross-linker and sodium hypophosphite(SHP)as a catalyst,followed by drying and curing.The effects of cross-linking reaction conditions in coating process on water-impermeable ability of coated cotton fabrics were investigated in detail.The results indicate that the coated fabrics have temperature sensitivity.The coatings of poly(NTBA-co-AAm)hydrogels were bonded on the surface of the cotton fabrics,as verified by SEM and optical microscopy,which gave the water-impermeable ability to the hydrogels composites.Moreover,the hydrogels formed in the coating process also identified that - COOH of BTCA reacted with -NH2 in the linear polymer and formed three-dimensional network hydrogels.FTIR and XPS were used to characterize the cross-linking reaction of - COOH of BTCA and - OH of cellulose.展开更多
The swelling behavior of a temperature-sensitive poly-N-isopropylacrylamide(PNIPAM) hydrogel circular cylinder is studied subjected to combined extension-torsion and varied temperature. In this regard, a semi-analytic...The swelling behavior of a temperature-sensitive poly-N-isopropylacrylamide(PNIPAM) hydrogel circular cylinder is studied subjected to combined extension-torsion and varied temperature. In this regard, a semi-analytical solution is proposed for general combined loading. A finite element(FE) analysis is conducted, subjecting a hydrogel cylinder to the combined extension-torsion and the varied temperature to evaluate the validity and accuracy of the solution. A user-defined UHYPER subroutine is developed and verified under free and constrained swelling conditions. The FE results illustrate excellent agreement with the semi-analytical solution. Due to the complexity of the problem, some compositions and applied loading factors are analyzed. It is revealed that for larger cross-linked density and larger ending temperature, the cylinder yields higher stresses and smaller radial swelling deformation. Besides, the radial and hoop stresses increase by applying larger twist and axial stretch. The hoop stresses intersect at approximately R/Rout = 0.58, where the hoop stress vanishes. Besides, the axial force has direct and inverse relationships with the axial stretch and the twist, respectively. However, the resultant torsional moment behavior is complex, and the position of the maximum point varies significantly by altering the axial stretch and the twist.展开更多
A kind of novel copolymer hydrogel of poly（N, N-dimethylaminoethyl methacrylate-co-N-isopropylacrylamide） （poly[DMAEMA/NIPAAm]） was synthesized by the initiation of K2S2O8, N, N＇-methylene-bis（acrylamide） （Bis...A kind of novel copolymer hydrogel of poly（N, N-dimethylaminoethyl methacrylate-co-N-isopropylacrylamide） （poly[DMAEMA/NIPAAm]） was synthesized by the initiation of K2S2O8, N, N＇-methylene-bis（acrylamide） （Bis） was used as the crosslinker. The effects of monomer content, pH and temperature on swelling ratio of the hydrogel were investigated; the thermo-sensitivity in deionized water and in physiological saline was determined. It showed that the swelling ratio of the hydrogel could be changed by changing the temperature or pH alternately. Both swelling ratio and LCST （Lower Critical Solution Temperature） of the hydrogel decreased with the increase of NIPAAm in the co-polymer content.展开更多
Nanoscale zero-valent iron(n ZVI) particles supported on a porous, semi-interpenetrating(semi-IPN), temperature-sensitive composite hydrogel(PNIPAm-PHEMA). n ZVI@PNIPAmPHEMA, was successfully synthesized and character...Nanoscale zero-valent iron(n ZVI) particles supported on a porous, semi-interpenetrating(semi-IPN), temperature-sensitive composite hydrogel(PNIPAm-PHEMA). n ZVI@PNIPAmPHEMA, was successfully synthesized and characterized by FT-IR, SEM, EDS, XRD and the weighing method. The loading of nZVI was 0.1548 ± 0.0015 g/g and the particle size was30–100 nm. NZVI was uniformly dispersed on the pore walls inside the PNIPAm-PHEMA.Because of the well-dispersed n ZVI, the highly porous structure, and the synergistic effect of PNIPAm-PHEMA, nZVI@PNIPAm-PHEMA showed excellent reductive activity and wide p H applicability. 95% of 4-NP in 100 m L of 400 mg/L 4-NP solution with initial p H 3.0–9.0 could be completely reduced into 4-AP by about 0.0548 g of fresh supported n ZVI at 18–25 °C under stirring(110 r/min) within 45 min reaction time. A greater than 99% 4-NP degradation ratio was obtained when the initial p H was 5.0–9.0. The reduction of 4-NP by nZVI@PNIPAm-PHEMA was in agreement with the pseudo-first-order kinetics model with Kobsvalues of 0.0885–0.101 min-1.NZVI@PNIPAm-PHEMA was able to be recycled, and about 85% degradation ratio of 4-NP was obtained after its sixth reuse cycle. According to the temperature sensitivity of PNIPAmPHEMA, n ZVI@PNIPAm-PHEMA exhibited very good storage stability, and about 88.9%degradation ratio of 4-NP was obtained after its storage for 30 days. The hybrid reducer was highly efficient for the reduction of 2-NP, 3-NP, 2-chloro-4-nitrophenol and 2-chloro-4-nitrophenol. Our results suggest that PNIPAm-PHEMA could be a good potential carrier, with n ZVI@PNIPAm-PHEMA having potential value in the application of reductive degradation of nitrophenol pollutants.展开更多
Atherosclerosis remains a major cause of morbidity and mortality worldwide.Intraplaque neovascularization critically promotes atherosclerotic progression and instability.Vascular endothelial growth factor A(VEGFA)stim...Atherosclerosis remains a major cause of morbidity and mortality worldwide.Intraplaque neovascularization critically promotes atherosclerotic progression and instability.Vascular endothelial growth factor A(VEGFA)stimulates aberrant microvessel growth in plaques by inducing endothelial cell proliferation and migration.Pigment epithelium-derived factor(PEDF)potently inhibits VEGFA-dependent neovascularization.This study introduces a thermosensitive hydrogel(PFSgel)developed from poloxamer 407(F127)and sodium alginate(SA)to deliver PEDF locally to atherosclerotic lesions.The PFSgel demonstrated a suitable liquid-solid transition at body temperature(37°C),then forming a stable 3D network structure after SA gelling with the Ca2+in the physiological environment which contributed to the character of controlled release.Rheological analysis confirmed its phase transition temperature of 28.7°C and notable self-healing properties,making it ideal for dynamic vascular environments.In vitro experiments showed that PFSgel could suppress VEGFA-induced endothelial cells’proliferation and migration through modulation of CD31 and MMP-2/MMP-9 signaling.Notably,in vivo degradation test validated the controlled release pattern of PFSgel.In Apoedeficient atherosclerotic mice,ultrasound-guided PFSgel injection onto the abdominal aorta enabled gradual in situ release of encapsulated PEDF.This effectively reduced plaque burden,neovascularization,and luminal stenosis,even with exogenous VEGFA administration.Histological analyses confirmed reduced lipid deposition,plaque area,and neovascularization within plaques.Overall,this novel in situforming PEDF delivery platform enables targeted suppression of pathological neovascularization via CD31 and MMP-2/MMP-9 pathways,representing a promising approach to stabilize high-risk plaques by intervening against VEGFA-dependent neovascularization.展开更多
Flexible hydrogels have shown promise as strain sensors in medical monitoring,human motion detection and intelligent robotics.For a hydrogel strain sensor,certain challenges need to be urgently addressed for practical...Flexible hydrogels have shown promise as strain sensors in medical monitoring,human motion detection and intelligent robotics.For a hydrogel strain sensor,certain challenges need to be urgently addressed for practical applications,such as the damage caused by external effects,leading to equipment failure,and the inability to perceive ambient temperature,resulting in single functionality.Herein,a stretchable,self-healing and dual temperature-strain sensitive hydrogel,with a physically-crosslinked network,is designed by constructing multiple dynamic reversible bonds.Graphene oxide(GO)and iron ions(Fe^(3+))act as dynamic bridges in the cross-linked network and are mediated by the covalent and hydrogen bonding,rendering excellent stretchability to the hydrogel.The reversible features of coordination interactions and hydrogen interactions endow excellent recoverability and self-healing properties.Moreover,the incorporated N-isopropyl acrylamide(NIPAM)provides excellent temperature responsiveness to the hydrogel,facilitating the detection of external temperature changes.Meanwhile,the hydrogels exhibited strain-sensitivity,with a wide working range of 1%-300%,fast response and electrical stability,which can be used as flexible sensors to monitor body motions,e.g.,speaking and the bending of finger,wrist,elbow and knee.Overall,the hydrogel possesses dual sensory capabilities,combining external temperature and strain,for potential applications in wearable multifunctional sensing devices.展开更多
Post-traumatic stress disorder(PTSD)is a psychiatric disease that seriously affects brain function.Currently,selective serotonin reuptake inhibitors(SSRIs)are used to treat PTSD clinically but have decreased efficienc...Post-traumatic stress disorder(PTSD)is a psychiatric disease that seriously affects brain function.Currently,selective serotonin reuptake inhibitors(SSRIs)are used to treat PTSD clinically but have decreased efficiency and increased side effects.In this study,nasal cannabidiol inclusion complex temperature-sensitive hydrogels(CBD TSGs)were prepared and evaluated to treat PTSD.Mice model of PTSD was established with conditional fear box.CBD TSGs could significantly improve the spontaneous behavior,exploratory spirit and alleviate tension in open field box,relieve anxiety and tension in elevated plus maze,and reduce the freezing time.Hematoxylin and eosin and c-FOS immunohistochemistry slides showed that the main injured brain areas in PTSD were the prefrontal cortex,amygdala,and hippocampus CA1.CBD TSGs could reduce the level of tumor necrosis factor-a caused by PTSD.Western blot analysis showed that CBD TSGs increased the expression of the 5-HT1 A receptor.Intranasal administration of CBD TSGs was more efficient and had more obvious brain targeting effects than oral administration,as evidenced by the pharmacokinetics and brain tissue distribution of CBD TSGs.Overall,nasal CBD TSGs are safe and effective and have controlled release.There are a novel promising option for the clinical treatment of PTSD.展开更多
Semi-interpenetrating （semi-IPNs） hydrogels containing biocompatible silk sericin （SS） and poly（N-isopropylacrylamide）（PNIPAM） were prepared as novel cellular matrices. Their maximum swelling degree and basic ...Semi-interpenetrating （semi-IPNs） hydrogels containing biocompatible silk sericin （SS） and poly（N-isopropylacrylamide）（PNIPAM） were prepared as novel cellular matrices. Their maximum swelling degree and basic characteristics for biomedical applications such as mouse ？broblasts （L929） cell proliferation and desorption were investigated. The results showed that the incorporation of high hydrophilic SS into PNIPAM hydrogel increased the maximum swelling degree of the semi-IPNs hydrogels, and the adhesion and growth of the L929 on semi-IPNs hydrogels were at least comparable to, or even better than, that on conventional PNIPAM hydrogel. In addition, L929 cells were found to detach from the hydrogels surface naturally by controlling environmental temperature. These results suggest great potential of semi-IPNs hydrogels in tissue engineering.展开更多
Insulin is an essential and versatile protein taking part in the control of blood glucose levels and protein anabolism.However,under prolonged storage or high temperature stress,insulin tends to unfold and aggregate i...Insulin is an essential and versatile protein taking part in the control of blood glucose levels and protein anabolism.However,under prolonged storage or high temperature stress,insulin tends to unfold and aggregate into toxic amyloid fibrils,leading to loss of physiological function.Inspired by natural chaperones,a series of temperature-sensitive polycaprolactone-based micelles were designed to prevent insulin from deactivation.The micelles were fabricated through the self-assembly of amphiphilic copolymers of methoxy poly(ethylene glycol)-poly(4-diethylformamide caprolactone-co-caprolactone)(mPEG_(17)-P(DECL-co-CL)),which had a regular spherical morphology with particle sizes of about 100 nm.In addition,the lower critical solution temperature(LCST)of the micelles could be tuned to 9 and 29℃by changing the ratio of DECL to CL.Benefiting from the temperature-sensitivity of DECL segment,the binding ability of micelles to insulin could be modulated by changing the temperature.Above LCST,micelles effectively inhibited insulin aggregation and protected it from thermal inactivation due to the strong binding ability between the hydrophobic segment DECL and insulin.Below LCST,DECL segment returned to hydrophilic and bound weakly with insulin,leading to the release of insulin and assisting in its recovery of secondary structure.Thus,these temperature-sensitive micelles provided an effective strategy for insulin protection.展开更多
A temperature-sensitive mud cake remover(G315)was developed using ethyl lactate as the primary component.Based on this,a temperature-sensitive acidic completion fluid(CF-G315)was formulated.Core evaluation tests,mud c...A temperature-sensitive mud cake remover(G315)was developed using ethyl lactate as the primary component.Based on this,a temperature-sensitive acidic completion fluid(CF-G315)was formulated.Core evaluation tests,mud cake dissolution tests and corrosion tests were conducted to analyze the mud cake removal performance of G315,the removal efficiency of CF-G315,and its ability to modify the near-wellbore reservoirs,corrosion to casing and hydrolysis performance.Results indicate that ethyl lactate in G315 exhibits weak acidity at room temperature and decomposes into lactic acid under high temperatures.The lactic acid reacts with the calcium carbonate in the mud cake,generating bubbles that dislodge the mud cake and form soluble salts that are subsequently removed by fluid flow,thereby ensuring effective mud cake clearance.CF-G315 removes mud cake efficiently and enhances near-wellbore reservoir permeability.It demonstrates low corrosivity and environmental compatibility,contributing to equipment safety,simplified operational procedures and reduced operational risks.CF-G315 is promising for application in scenarios such as horizontal wells,open-hole completions and gravel pack completions.展开更多
To get a sort of new scaffold material for soft tissue reconstruction,we have prepared XLHA-PNIPAAm and XLHA-MC injectable hydrogels through blending crosslinked HA(XLHA) and two temperature-sensitive materials differ...To get a sort of new scaffold material for soft tissue reconstruction,we have prepared XLHA-PNIPAAm and XLHA-MC injectable hydrogels through blending crosslinked HA(XLHA) and two temperature-sensitive materials differed in degradation poly(N-isopropylacrylamide)(PNIPAAm) and methylcellulose(MC),respectively.We tested the injectablility,enzymatic biodegradability,temperature-sensitivity,structure cytotoxicity and hemolysis of the two injectable hydrogels.Our research has successfully obtained the preparation condition of XLHA-PNIPAAm injectable hydrogel,and verified that adding non-degradable material PNIPAAm can postpone the degradation of HA more effectively than degradable material MC.PNIPAAm prepared with 5 kGy dose radiation,MBAAm/NIPAAm(M/M)=0.015,monomer concentration=3% produced XLHA-PNIPAAm with slowest enzymatic biodegradability.DSC results showed that temperature-sensitivity of the XLHA-PNIPAAm was more stable than that of XLHA-MC.Two composite hydrogels were qualified in cytotoxicity and hemolysis tests and the biocompatibility of XLHA-PNIPAAm hydrogel showed better than XLHA-MC hydrogel.展开更多
A multi-stimuli-responsive hydrogel,P(VI-co-MAAC-NE),was successfully constructed by covalently integrating the aggregation-induced emission(AIE)moiety(Z)-N-(4-(1-cyano-2-(4-(diethylamino)phenyl)vinyl)-phenyl)methacry...A multi-stimuli-responsive hydrogel,P(VI-co-MAAC-NE),was successfully constructed by covalently integrating the aggregation-induced emission(AIE)moiety(Z)-N-(4-(1-cyano-2-(4-(diethylamino)phenyl)vinyl)-phenyl)methacrylamide(NE)into a dynamic hydrogen-bonding network composed of 1-vinylimidazole(VI)and methacrylic acid(MAAC)groups.The dense hydrogen-bonding network not only provides enhanced mechanical robustness,but also significantly enhances the AIE effect of NE by restricting its molecular motion.Under various external stimuli,the hydrogen bonds within the hydrogel network undergo reversible dissociation and reformation,thus enabling synergistic modulation of the hydrogel’s mechanical properties and luminescence behavior.Specifically,organic solvents disrupt the hydrogen-bonding network and the aggregation of the AIE moiety NE,resulting in macroscopic swelling and fluorescence quenching of the hydrogel.In strongly acidic conditions,protonation of NE molecules suppresses the intramolecular charge transfer(ICT)process,yielding a blue-shifted emission band accompanied by intense blue fluorescence;in highly alkaline environments,deprotonation of carboxyl groups induces hydrogel swelling and disperses NE aggregates,leading to pronounced fluorescence quenching.Moreover,the system exhibits thermally activated shape-memory behavior:heating above the glass transition temperature(T_(g):ca.62℃)softens the hydrogel to allow programmable reshaping,and subsequent hydrogen bond reformation at ambient conditions locks in the resultant geometries without sacrificing the hydrogel’s fluorescence performance.By capitalizing on these multi-stimuli-responsive characteristics and shape-memory behavior,the potential of hydrogel P(VI-co-MAAC-NE)for advanced information encryption and anti-counterfeiting applications is demonstrated.This work not only provides a versatile material platform for sensing and information storage,but also offers new insights into the design of intelligent soft materials integrating AIE features with dynamically regulated supramolecular network structures.展开更多
Conducting hydrogels have garnered significant interest in the field of wearable electronics.However,simultaneously achieving high transparency,high conductivity,strong adhesion,and self-healing ability within a short...Conducting hydrogels have garnered significant interest in the field of wearable electronics.However,simultaneously achieving high transparency,high conductivity,strong adhesion,and self-healing ability within a short time remains a major challenge.In this study,a multifunctional mussel-inspired hydrogel was synthesized in only 5 min,with polydopamine(PDA)-polypyrrole(Ppy)-polyaniline(PANi)and poly(vinyl alcohol)(PVA)nanoparticles incorporated into the polyacrylamide(PAM)network.The resulting hydrogel exhibited high transparency(about 90% light transmission in the range of 400-800 nm),high conductivity((95.4±0.4)×10^(-4)S/cm),tensile strength(32.60±1.03 k Pa),strain at break(904.46%±11.50%),and adhesive strength(30-60 k Pa).It also demonstrated rapid self-healing properties(about 48% strength recovery within 1h at 50℃)and water-dependent shape memory behavior.As a wearable strain sensor,the hydrogel successfully detected finger flexion,wrist movements,facial expression changes,and breathing with high sensitivity and stability.The calculated gauge factor(GF)was 7.44±0.31,which is higher than that of many previously reported hydrogels.Compared with previous oyster-inspired or Ppy-based hydrogels,our system showed a much shorter synthesis time,higher transparency,and enhanced multifunctionality.These findings highlight the potential of the proposed hydrogel for next-generation flexible electronics,e-skin,and biomedical monitoring devices.展开更多
We proposed a strategy using high-concentration tannic acid(TA) solutions to form robust and dense supramolecular networks in hydrogels,driven by the high osmotic pressure of the TA solution.The resulting hydrogels ar...We proposed a strategy using high-concentration tannic acid(TA) solutions to form robust and dense supramolecular networks in hydrogels,driven by the high osmotic pressure of the TA solution.The resulting hydrogels are both transparent and tough,with highly compacted networks.The hydrogels exhibit an ultimate tensile strength of approximately 4.55 MPa and a toughness of 160 MJ/m^(3).Additionally,the hydrogels adhere to a wide range of substrates,including metals,ceramics,glass,and even Teflon,with an adhesion strength of up to 42 kPa on Teflon plates.Given the biocompatibility and biodegradability of both PVA and TA,along with the hydrogels' toughness,transparency,and adhesiveness,we anticipated broad applications in the biomedical field,such as in articular cartilage restoration,electronic skin,and wound dressings.Additionally,these hydrogels hold significant potential for applications in wearable technology and optoelectronic devices.展开更多
Hydrogels are widely employed in various cutting-edge fields due to their excellent flexibility and tunability.However,hydrogels undergo significant swelling when immersed in seawater or other ionic solutions,leading ...Hydrogels are widely employed in various cutting-edge fields due to their excellent flexibility and tunability.However,hydrogels undergo significant swelling when immersed in seawater or other ionic solutions,leading to a severe decline in their performance.Herein,we develop a composite hydrogel(PAH)with anti-swelling capability in different solution environments,constructed through hydrogen bonding interactions between rigid aramid nanofibers(ANF)and flexible poly(vinyl alcohol)(PVA).The dense three-dimensional skeleton within PAH not only dissipates energy to enhance its strength and toughness but also effectively inhibits water molecule penetration.Even after immersion in different ionic solutions,PAH maintains its structural integrity(equilibrium swelling ratio of only 0.1%),while retaining excellent mechanical properties.This work provides a simple and effective strategy for improving the anti-swelling ability of hydrogels in different solutions,offering insights for broadening the application scope of hydrogels.展开更多
The currently reported conductive hydrogels are mainly used to detect the mechanical signals of human movement,whereas the application of detecting weak electrophysiological signals in epidermal electrodes is still li...The currently reported conductive hydrogels are mainly used to detect the mechanical signals of human movement,whereas the application of detecting weak electrophysiological signals in epidermal electrodes is still limited by a low signal-to-noise ratio and motion artifacts.In this study,a one-pot method was used to prepare a hydrogel conductor with excellent flexibility,self-adhesiveness,and compliance by introducing chitosan quaternary ammonium salt(HAAC)and 2-acrylamide-2-methylpropanesulfonic acid(AMPS)into the polyacrylamide(PAAm)hydrogel network.By adjusting the AMPS and HAAC contents,the hydrogel showed skin-like mechanical properties and surface adhesion,successfully eliminating the gap with the skin surface.The self-adhesive hydrogel showed a lower impedance(approximately 190 kΩ)than commercial Ag/AgCl electrodes.Notably,the hydrogel electrodes exhibited a significantly higher signal-to-noise ratio(SNR)than the commercial electrodes at the same level of muscle contraction.The hydrogel electrodes could accurately detect dynamic weak EMG signals and successfully drive the prosthetic hand to grasp without errors.Importantly,the combination of hydrogel strain sensors and epidermal electrodes can quantify the mode,frequency,and intensity of human movement,which has broad application prospects in data acquisition for daily exercise,fitness,and rehabilitation.展开更多
MXene is a promising conductive nanofiller for hydrogels due to its excellent electricity conductivity and water dispersibility.However,MXene is prone to oxidize in the presence of air and water,resulting in a signifi...MXene is a promising conductive nanofiller for hydrogels due to its excellent electricity conductivity and water dispersibility.However,MXene is prone to oxidize in the presence of air and water,resulting in a significant loss of conductivity.Polydopamine(PDA)has been coated on MXene to enhance its antioxidation stability via the physical barrier and chemical reducing ability of PDA,which unavoidably causes severe aggregation and a significant decrease in conductivity due to the crosslinking and insulation of PDA.Herein,we propose a facile strategy to construct a highly conductive,stable,and self-healing MXene-based polyvinyl alcohol(PVA)hydrogel by a controlled assembly of PDA and cellulose nanocrystal(CNC).PDA is first formed by oxidation self-polymerization in PVA solution without the presence of CNC and MXene,which can effectively reduce the content of aggregation-inducing groups and avoid the formation of an insulating PDA layer on the surface of MXene.The addition of CNCs results in the easy dispersion of a high content of MXene via hydrogen bonding and electrostatic interactions.The PVA-PDA hydrogel with MXene and CNC as conductive and reinforcing nanofillers(PP-CM)is cross-linked by dynamic borax covalent bonds and shows a conductivity of 7.14 S m^(-1).The introduction of PDA effectively protects MXene and results in only a 14%decrease in conductivity after 7 days,significantly improving antioxidant stability.This hydrogel also possesses rapid self-healing capabilities,achieving 90.5%self-healing efficiency within 10 min.This versatile approach opens new avenues for the preparation and application of MXene-based conductive hydrogels.展开更多
Lignin,the most abundant natural aromatic polymer globally,has garnered considerable interest due to its rich and diverse active functional groups and its antioxidant,antimicrobial,and adhesive properties.Recent resea...Lignin,the most abundant natural aromatic polymer globally,has garnered considerable interest due to its rich and diverse active functional groups and its antioxidant,antimicrobial,and adhesive properties.Recent research has significantly improved the performance of lignin-based hydrogels,suggesting their substantial potential in fields such as biomedicine,environmental science,and agriculture.This paper reviews the process of lignin extraction,systematically introduces synthesis strategies for preparing lignin-based hydrogels,and discusses the current state of research on these hydrogels in biomedical and environmental protection fields.It concludes by identifying the existing challenges in lignin hydrogel research and envisioning future prospects and development trends.展开更多
The development of solar-driven interfacial evaporation technology is pivotal for addressing global water scarcity.However,it is hindered by the difficulty in synergizing high photothermal conversion with low water ev...The development of solar-driven interfacial evaporation technology is pivotal for addressing global water scarcity.However,it is hindered by the difficulty in synergizing high photothermal conversion with low water evaporation enthalpy into a single material.Herein,we propose an iron-aldehyde-cooperative dynamic covalent anchoring strategy,successfully constructing a covalently locked,hydroxymethyl-functionalized PEDOT-PVA integrated dual-network hydrogel(MEPH).This strategy employs Fe3+to achieve the one-step in situ oxidative polymerization of hydroxymethyl EDOT while concurrently forming a physical hybrid network with PVA,which is subsequently reinforced by covalent cross-linking using glutaraldehyde.This design endows the MEPH with exceptional broadband light absorption(>99%),efficient water transport,and regulated water state within the hydrogel matrix,leading to a reduced evaporation enthalpy of 732 J·g^(−1).The resulting evaporator achieves an ultrahigh evaporation rate of 4.95 kg·m^(−2)·h^(−1)under 1-sun illumination,corresponding to an energy conversion efficiency exceeding 95%,while maintaining stable,salt-resistant operation in high-salinity environments.Outdoor experiments validate its outstanding practicality for seawater and wastewater purification,with the produced freshwater significantly promoting plant growth,highlighting its great potential in sustainable agricultural water cycles.This iron-aldehyde-cooperative dynamic covalent anchoring strategy provides an innovative design paradigm for a new generation of high-performance and robust solar evaporators.展开更多
基金the National Natural Science Foundation of China (No. 20276065).
文摘Temperature-sensitive hydrogel—poly(N-isopropyl acrylamide) (PNIPA) was prepared and applied to protein refolding. PNIPA gel disks and gel particles were synthesized by the solution polymerization and inverse suspension polymerization respectively. The swelling kinetics of the gels was also studied. With these prepared PNIPA gels, the model protein lysozyme was renatured. Within 24h, PNIPA gel disks improved the yield of lysozyme activity by 49.3% from 3375.2U·mg^-1 to 5038.8U·mg^-1. With the addition of faster response PNIPA gel beads, the total lysozyme activity recovery was about 68.98% in 3h, as compared with 42.03% by simple batch dilution. The novel refolding system with PNIPA enables efficient refolding especially at high protein concentrations. Discussion about the mechanism revealed that when PNIPA gels were added into the refolding buffer, the hydrophobic interactions between denatured proteins and polymer gels could prevent the aggregation of refolding intermediates, thus enhanced the protein renaturation.
基金Research Fund for the Doctoral Programof Higher Education of China(No.20050058006)
文摘In this study,the hydrogels composites with coatings based on a temperature-sensitive linear copolymer of N-tert-butylacrylamide(NTBA)and acrylamide(AAm)on cotton fabrics have been developed.The cotton fabrics were coated using aqueous solution of the linear copolymer,1,2,3,4-butanetertracarboxylic acid(BTCA)as a cross-linker and sodium hypophosphite(SHP)as a catalyst,followed by drying and curing.The effects of cross-linking reaction conditions in coating process on water-impermeable ability of coated cotton fabrics were investigated in detail.The results indicate that the coated fabrics have temperature sensitivity.The coatings of poly(NTBA-co-AAm)hydrogels were bonded on the surface of the cotton fabrics,as verified by SEM and optical microscopy,which gave the water-impermeable ability to the hydrogels composites.Moreover,the hydrogels formed in the coating process also identified that - COOH of BTCA reacted with -NH2 in the linear polymer and formed three-dimensional network hydrogels.FTIR and XPS were used to characterize the cross-linking reaction of - COOH of BTCA and - OH of cellulose.
文摘The swelling behavior of a temperature-sensitive poly-N-isopropylacrylamide(PNIPAM) hydrogel circular cylinder is studied subjected to combined extension-torsion and varied temperature. In this regard, a semi-analytical solution is proposed for general combined loading. A finite element(FE) analysis is conducted, subjecting a hydrogel cylinder to the combined extension-torsion and the varied temperature to evaluate the validity and accuracy of the solution. A user-defined UHYPER subroutine is developed and verified under free and constrained swelling conditions. The FE results illustrate excellent agreement with the semi-analytical solution. Due to the complexity of the problem, some compositions and applied loading factors are analyzed. It is revealed that for larger cross-linked density and larger ending temperature, the cylinder yields higher stresses and smaller radial swelling deformation. Besides, the radial and hoop stresses increase by applying larger twist and axial stretch. The hoop stresses intersect at approximately R/Rout = 0.58, where the hoop stress vanishes. Besides, the axial force has direct and inverse relationships with the axial stretch and the twist, respectively. However, the resultant torsional moment behavior is complex, and the position of the maximum point varies significantly by altering the axial stretch and the twist.
文摘A kind of novel copolymer hydrogel of poly（N, N-dimethylaminoethyl methacrylate-co-N-isopropylacrylamide） （poly[DMAEMA/NIPAAm]） was synthesized by the initiation of K2S2O8, N, N＇-methylene-bis（acrylamide） （Bis） was used as the crosslinker. The effects of monomer content, pH and temperature on swelling ratio of the hydrogel were investigated; the thermo-sensitivity in deionized water and in physiological saline was determined. It showed that the swelling ratio of the hydrogel could be changed by changing the temperature or pH alternately. Both swelling ratio and LCST （Lower Critical Solution Temperature） of the hydrogel decreased with the increase of NIPAAm in the co-polymer content.
基金supported by the National Natural Science Foundation of China(No.51508233)the Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment
文摘Nanoscale zero-valent iron(n ZVI) particles supported on a porous, semi-interpenetrating(semi-IPN), temperature-sensitive composite hydrogel(PNIPAm-PHEMA). n ZVI@PNIPAmPHEMA, was successfully synthesized and characterized by FT-IR, SEM, EDS, XRD and the weighing method. The loading of nZVI was 0.1548 ± 0.0015 g/g and the particle size was30–100 nm. NZVI was uniformly dispersed on the pore walls inside the PNIPAm-PHEMA.Because of the well-dispersed n ZVI, the highly porous structure, and the synergistic effect of PNIPAm-PHEMA, nZVI@PNIPAm-PHEMA showed excellent reductive activity and wide p H applicability. 95% of 4-NP in 100 m L of 400 mg/L 4-NP solution with initial p H 3.0–9.0 could be completely reduced into 4-AP by about 0.0548 g of fresh supported n ZVI at 18–25 °C under stirring(110 r/min) within 45 min reaction time. A greater than 99% 4-NP degradation ratio was obtained when the initial p H was 5.0–9.0. The reduction of 4-NP by nZVI@PNIPAm-PHEMA was in agreement with the pseudo-first-order kinetics model with Kobsvalues of 0.0885–0.101 min-1.NZVI@PNIPAm-PHEMA was able to be recycled, and about 85% degradation ratio of 4-NP was obtained after its sixth reuse cycle. According to the temperature sensitivity of PNIPAmPHEMA, n ZVI@PNIPAm-PHEMA exhibited very good storage stability, and about 88.9%degradation ratio of 4-NP was obtained after its storage for 30 days. The hybrid reducer was highly efficient for the reduction of 2-NP, 3-NP, 2-chloro-4-nitrophenol and 2-chloro-4-nitrophenol. Our results suggest that PNIPAm-PHEMA could be a good potential carrier, with n ZVI@PNIPAm-PHEMA having potential value in the application of reductive degradation of nitrophenol pollutants.
基金National Natural Science Foundation of China (81972886 and 82172736)Shanghai Health and Family Planning Commission Fund (202240235)+1 种基金Natural Science Foundation of Shanghai (21ZR1451400)Shanghai Jiading District Health and Family Planning Commission Fund (2021-KY-10)。
文摘Atherosclerosis remains a major cause of morbidity and mortality worldwide.Intraplaque neovascularization critically promotes atherosclerotic progression and instability.Vascular endothelial growth factor A(VEGFA)stimulates aberrant microvessel growth in plaques by inducing endothelial cell proliferation and migration.Pigment epithelium-derived factor(PEDF)potently inhibits VEGFA-dependent neovascularization.This study introduces a thermosensitive hydrogel(PFSgel)developed from poloxamer 407(F127)and sodium alginate(SA)to deliver PEDF locally to atherosclerotic lesions.The PFSgel demonstrated a suitable liquid-solid transition at body temperature(37°C),then forming a stable 3D network structure after SA gelling with the Ca2+in the physiological environment which contributed to the character of controlled release.Rheological analysis confirmed its phase transition temperature of 28.7°C and notable self-healing properties,making it ideal for dynamic vascular environments.In vitro experiments showed that PFSgel could suppress VEGFA-induced endothelial cells’proliferation and migration through modulation of CD31 and MMP-2/MMP-9 signaling.Notably,in vivo degradation test validated the controlled release pattern of PFSgel.In Apoedeficient atherosclerotic mice,ultrasound-guided PFSgel injection onto the abdominal aorta enabled gradual in situ release of encapsulated PEDF.This effectively reduced plaque burden,neovascularization,and luminal stenosis,even with exogenous VEGFA administration.Histological analyses confirmed reduced lipid deposition,plaque area,and neovascularization within plaques.Overall,this novel in situforming PEDF delivery platform enables targeted suppression of pathological neovascularization via CD31 and MMP-2/MMP-9 pathways,representing a promising approach to stabilize high-risk plaques by intervening against VEGFA-dependent neovascularization.
基金financially supported by the National Natural Science Foundation of China(No.52173301)International Science and Technology Cooperation Project of Sichuan Province(No.2022YFH0019)Innovative Research Team of Southwest Petroleum University(No.2017CXTD01)。
文摘Flexible hydrogels have shown promise as strain sensors in medical monitoring,human motion detection and intelligent robotics.For a hydrogel strain sensor,certain challenges need to be urgently addressed for practical applications,such as the damage caused by external effects,leading to equipment failure,and the inability to perceive ambient temperature,resulting in single functionality.Herein,a stretchable,self-healing and dual temperature-strain sensitive hydrogel,with a physically-crosslinked network,is designed by constructing multiple dynamic reversible bonds.Graphene oxide(GO)and iron ions(Fe^(3+))act as dynamic bridges in the cross-linked network and are mediated by the covalent and hydrogen bonding,rendering excellent stretchability to the hydrogel.The reversible features of coordination interactions and hydrogen interactions endow excellent recoverability and self-healing properties.Moreover,the incorporated N-isopropyl acrylamide(NIPAM)provides excellent temperature responsiveness to the hydrogel,facilitating the detection of external temperature changes.Meanwhile,the hydrogels exhibited strain-sensitivity,with a wide working range of 1%-300%,fast response and electrical stability,which can be used as flexible sensors to monitor body motions,e.g.,speaking and the bending of finger,wrist,elbow and knee.Overall,the hydrogel possesses dual sensory capabilities,combining external temperature and strain,for potential applications in wearable multifunctional sensing devices.
基金funded by the Beijing Municipal Natural Science Foundation,China(7202147 and 7172072,China)
文摘Post-traumatic stress disorder(PTSD)is a psychiatric disease that seriously affects brain function.Currently,selective serotonin reuptake inhibitors(SSRIs)are used to treat PTSD clinically but have decreased efficiency and increased side effects.In this study,nasal cannabidiol inclusion complex temperature-sensitive hydrogels(CBD TSGs)were prepared and evaluated to treat PTSD.Mice model of PTSD was established with conditional fear box.CBD TSGs could significantly improve the spontaneous behavior,exploratory spirit and alleviate tension in open field box,relieve anxiety and tension in elevated plus maze,and reduce the freezing time.Hematoxylin and eosin and c-FOS immunohistochemistry slides showed that the main injured brain areas in PTSD were the prefrontal cortex,amygdala,and hippocampus CA1.CBD TSGs could reduce the level of tumor necrosis factor-a caused by PTSD.Western blot analysis showed that CBD TSGs increased the expression of the 5-HT1 A receptor.Intranasal administration of CBD TSGs was more efficient and had more obvious brain targeting effects than oral administration,as evidenced by the pharmacokinetics and brain tissue distribution of CBD TSGs.Overall,nasal CBD TSGs are safe and effective and have controlled release.There are a novel promising option for the clinical treatment of PTSD.
文摘Semi-interpenetrating （semi-IPNs） hydrogels containing biocompatible silk sericin （SS） and poly（N-isopropylacrylamide）（PNIPAM） were prepared as novel cellular matrices. Their maximum swelling degree and basic characteristics for biomedical applications such as mouse ？broblasts （L929） cell proliferation and desorption were investigated. The results showed that the incorporation of high hydrophilic SS into PNIPAM hydrogel increased the maximum swelling degree of the semi-IPNs hydrogels, and the adhesion and growth of the L929 on semi-IPNs hydrogels were at least comparable to, or even better than, that on conventional PNIPAM hydrogel. In addition, L929 cells were found to detach from the hydrogels surface naturally by controlling environmental temperature. These results suggest great potential of semi-IPNs hydrogels in tissue engineering.
基金financially supported by the National Natural Science Foundation of China(Nos.52273009 and 21674037).
文摘Insulin is an essential and versatile protein taking part in the control of blood glucose levels and protein anabolism.However,under prolonged storage or high temperature stress,insulin tends to unfold and aggregate into toxic amyloid fibrils,leading to loss of physiological function.Inspired by natural chaperones,a series of temperature-sensitive polycaprolactone-based micelles were designed to prevent insulin from deactivation.The micelles were fabricated through the self-assembly of amphiphilic copolymers of methoxy poly(ethylene glycol)-poly(4-diethylformamide caprolactone-co-caprolactone)(mPEG_(17)-P(DECL-co-CL)),which had a regular spherical morphology with particle sizes of about 100 nm.In addition,the lower critical solution temperature(LCST)of the micelles could be tuned to 9 and 29℃by changing the ratio of DECL to CL.Benefiting from the temperature-sensitivity of DECL segment,the binding ability of micelles to insulin could be modulated by changing the temperature.Above LCST,micelles effectively inhibited insulin aggregation and protected it from thermal inactivation due to the strong binding ability between the hydrophobic segment DECL and insulin.Below LCST,DECL segment returned to hydrophilic and bound weakly with insulin,leading to the release of insulin and assisting in its recovery of secondary structure.Thus,these temperature-sensitive micelles provided an effective strategy for insulin protection.
基金Supported by National Natural Science Foundation of China(52404010).
文摘A temperature-sensitive mud cake remover(G315)was developed using ethyl lactate as the primary component.Based on this,a temperature-sensitive acidic completion fluid(CF-G315)was formulated.Core evaluation tests,mud cake dissolution tests and corrosion tests were conducted to analyze the mud cake removal performance of G315,the removal efficiency of CF-G315,and its ability to modify the near-wellbore reservoirs,corrosion to casing and hydrolysis performance.Results indicate that ethyl lactate in G315 exhibits weak acidity at room temperature and decomposes into lactic acid under high temperatures.The lactic acid reacts with the calcium carbonate in the mud cake,generating bubbles that dislodge the mud cake and form soluble salts that are subsequently removed by fluid flow,thereby ensuring effective mud cake clearance.CF-G315 removes mud cake efficiently and enhances near-wellbore reservoir permeability.It demonstrates low corrosivity and environmental compatibility,contributing to equipment safety,simplified operational procedures and reduced operational risks.CF-G315 is promising for application in scenarios such as horizontal wells,open-hole completions and gravel pack completions.
基金The Nattional Key Scientific Program-Nanoscience and Nanotechnologygrant number:2009CB930000
文摘To get a sort of new scaffold material for soft tissue reconstruction,we have prepared XLHA-PNIPAAm and XLHA-MC injectable hydrogels through blending crosslinked HA(XLHA) and two temperature-sensitive materials differed in degradation poly(N-isopropylacrylamide)(PNIPAAm) and methylcellulose(MC),respectively.We tested the injectablility,enzymatic biodegradability,temperature-sensitivity,structure cytotoxicity and hemolysis of the two injectable hydrogels.Our research has successfully obtained the preparation condition of XLHA-PNIPAAm injectable hydrogel,and verified that adding non-degradable material PNIPAAm can postpone the degradation of HA more effectively than degradable material MC.PNIPAAm prepared with 5 kGy dose radiation,MBAAm/NIPAAm(M/M)=0.015,monomer concentration=3% produced XLHA-PNIPAAm with slowest enzymatic biodegradability.DSC results showed that temperature-sensitivity of the XLHA-PNIPAAm was more stable than that of XLHA-MC.Two composite hydrogels were qualified in cytotoxicity and hemolysis tests and the biocompatibility of XLHA-PNIPAAm hydrogel showed better than XLHA-MC hydrogel.
文摘A multi-stimuli-responsive hydrogel,P(VI-co-MAAC-NE),was successfully constructed by covalently integrating the aggregation-induced emission(AIE)moiety(Z)-N-(4-(1-cyano-2-(4-(diethylamino)phenyl)vinyl)-phenyl)methacrylamide(NE)into a dynamic hydrogen-bonding network composed of 1-vinylimidazole(VI)and methacrylic acid(MAAC)groups.The dense hydrogen-bonding network not only provides enhanced mechanical robustness,but also significantly enhances the AIE effect of NE by restricting its molecular motion.Under various external stimuli,the hydrogen bonds within the hydrogel network undergo reversible dissociation and reformation,thus enabling synergistic modulation of the hydrogel’s mechanical properties and luminescence behavior.Specifically,organic solvents disrupt the hydrogen-bonding network and the aggregation of the AIE moiety NE,resulting in macroscopic swelling and fluorescence quenching of the hydrogel.In strongly acidic conditions,protonation of NE molecules suppresses the intramolecular charge transfer(ICT)process,yielding a blue-shifted emission band accompanied by intense blue fluorescence;in highly alkaline environments,deprotonation of carboxyl groups induces hydrogel swelling and disperses NE aggregates,leading to pronounced fluorescence quenching.Moreover,the system exhibits thermally activated shape-memory behavior:heating above the glass transition temperature(T_(g):ca.62℃)softens the hydrogel to allow programmable reshaping,and subsequent hydrogen bond reformation at ambient conditions locks in the resultant geometries without sacrificing the hydrogel’s fluorescence performance.By capitalizing on these multi-stimuli-responsive characteristics and shape-memory behavior,the potential of hydrogel P(VI-co-MAAC-NE)for advanced information encryption and anti-counterfeiting applications is demonstrated.This work not only provides a versatile material platform for sensing and information storage,but also offers new insights into the design of intelligent soft materials integrating AIE features with dynamically regulated supramolecular network structures.
文摘Conducting hydrogels have garnered significant interest in the field of wearable electronics.However,simultaneously achieving high transparency,high conductivity,strong adhesion,and self-healing ability within a short time remains a major challenge.In this study,a multifunctional mussel-inspired hydrogel was synthesized in only 5 min,with polydopamine(PDA)-polypyrrole(Ppy)-polyaniline(PANi)and poly(vinyl alcohol)(PVA)nanoparticles incorporated into the polyacrylamide(PAM)network.The resulting hydrogel exhibited high transparency(about 90% light transmission in the range of 400-800 nm),high conductivity((95.4±0.4)×10^(-4)S/cm),tensile strength(32.60±1.03 k Pa),strain at break(904.46%±11.50%),and adhesive strength(30-60 k Pa).It also demonstrated rapid self-healing properties(about 48% strength recovery within 1h at 50℃)and water-dependent shape memory behavior.As a wearable strain sensor,the hydrogel successfully detected finger flexion,wrist movements,facial expression changes,and breathing with high sensitivity and stability.The calculated gauge factor(GF)was 7.44±0.31,which is higher than that of many previously reported hydrogels.Compared with previous oyster-inspired or Ppy-based hydrogels,our system showed a much shorter synthesis time,higher transparency,and enhanced multifunctionality.These findings highlight the potential of the proposed hydrogel for next-generation flexible electronics,e-skin,and biomedical monitoring devices.
基金Funded by the Guangdong Major Project of Basic and Applied Basic Research(No.2021B0301030001)the National Key Research and Development Program of China(No. 2021YFB3802300)the National Natural Science Foundation of China(Nos. 52403153 and 52203169)。
文摘We proposed a strategy using high-concentration tannic acid(TA) solutions to form robust and dense supramolecular networks in hydrogels,driven by the high osmotic pressure of the TA solution.The resulting hydrogels are both transparent and tough,with highly compacted networks.The hydrogels exhibit an ultimate tensile strength of approximately 4.55 MPa and a toughness of 160 MJ/m^(3).Additionally,the hydrogels adhere to a wide range of substrates,including metals,ceramics,glass,and even Teflon,with an adhesion strength of up to 42 kPa on Teflon plates.Given the biocompatibility and biodegradability of both PVA and TA,along with the hydrogels' toughness,transparency,and adhesiveness,we anticipated broad applications in the biomedical field,such as in articular cartilage restoration,electronic skin,and wound dressings.Additionally,these hydrogels hold significant potential for applications in wearable technology and optoelectronic devices.
基金supported by the National Natural Science Foundation of China(No.52573131)the National Key Research and Development Program of China(No.2020YFA0710303)。
文摘Hydrogels are widely employed in various cutting-edge fields due to their excellent flexibility and tunability.However,hydrogels undergo significant swelling when immersed in seawater or other ionic solutions,leading to a severe decline in their performance.Herein,we develop a composite hydrogel(PAH)with anti-swelling capability in different solution environments,constructed through hydrogen bonding interactions between rigid aramid nanofibers(ANF)and flexible poly(vinyl alcohol)(PVA).The dense three-dimensional skeleton within PAH not only dissipates energy to enhance its strength and toughness but also effectively inhibits water molecule penetration.Even after immersion in different ionic solutions,PAH maintains its structural integrity(equilibrium swelling ratio of only 0.1%),while retaining excellent mechanical properties.This work provides a simple and effective strategy for improving the anti-swelling ability of hydrogels in different solutions,offering insights for broadening the application scope of hydrogels.
基金financially supported by the Science and Technology Plan Project of the Jilin Province(No.YDZJ202401546ZYTS).
文摘The currently reported conductive hydrogels are mainly used to detect the mechanical signals of human movement,whereas the application of detecting weak electrophysiological signals in epidermal electrodes is still limited by a low signal-to-noise ratio and motion artifacts.In this study,a one-pot method was used to prepare a hydrogel conductor with excellent flexibility,self-adhesiveness,and compliance by introducing chitosan quaternary ammonium salt(HAAC)and 2-acrylamide-2-methylpropanesulfonic acid(AMPS)into the polyacrylamide(PAAm)hydrogel network.By adjusting the AMPS and HAAC contents,the hydrogel showed skin-like mechanical properties and surface adhesion,successfully eliminating the gap with the skin surface.The self-adhesive hydrogel showed a lower impedance(approximately 190 kΩ)than commercial Ag/AgCl electrodes.Notably,the hydrogel electrodes exhibited a significantly higher signal-to-noise ratio(SNR)than the commercial electrodes at the same level of muscle contraction.The hydrogel electrodes could accurately detect dynamic weak EMG signals and successfully drive the prosthetic hand to grasp without errors.Importantly,the combination of hydrogel strain sensors and epidermal electrodes can quantify the mode,frequency,and intensity of human movement,which has broad application prospects in data acquisition for daily exercise,fitness,and rehabilitation.
基金support from Youth Promotion of Guangdong Natural Science Foundation(2024A1515030005)Guangdong Province Ordinary Universities Characteristic Innovation Project(2024KTSCX096)+4 种基金Guangdong Province University Key Field Special Program(2023ZDZX3002)Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education)Naikai University,Guangdong Provincial Key Laboratory of Optical Information Materials and Technology(No.2023B1212060065)Programs of Science and Technology Department of Yunnan Province(202301AT070217)MOE International Laboratory for Optical Information Technologies,the 111 Project,Science and Technology Bureau of Huzhou(2022GG24)ScienceK Ltd.
文摘MXene is a promising conductive nanofiller for hydrogels due to its excellent electricity conductivity and water dispersibility.However,MXene is prone to oxidize in the presence of air and water,resulting in a significant loss of conductivity.Polydopamine(PDA)has been coated on MXene to enhance its antioxidation stability via the physical barrier and chemical reducing ability of PDA,which unavoidably causes severe aggregation and a significant decrease in conductivity due to the crosslinking and insulation of PDA.Herein,we propose a facile strategy to construct a highly conductive,stable,and self-healing MXene-based polyvinyl alcohol(PVA)hydrogel by a controlled assembly of PDA and cellulose nanocrystal(CNC).PDA is first formed by oxidation self-polymerization in PVA solution without the presence of CNC and MXene,which can effectively reduce the content of aggregation-inducing groups and avoid the formation of an insulating PDA layer on the surface of MXene.The addition of CNCs results in the easy dispersion of a high content of MXene via hydrogen bonding and electrostatic interactions.The PVA-PDA hydrogel with MXene and CNC as conductive and reinforcing nanofillers(PP-CM)is cross-linked by dynamic borax covalent bonds and shows a conductivity of 7.14 S m^(-1).The introduction of PDA effectively protects MXene and results in only a 14%decrease in conductivity after 7 days,significantly improving antioxidant stability.This hydrogel also possesses rapid self-healing capabilities,achieving 90.5%self-healing efficiency within 10 min.This versatile approach opens new avenues for the preparation and application of MXene-based conductive hydrogels.
基金supported by the National Natural Science Foundation of China(21706052,22278114)Natural Science Foundation of Henan Province(242300421575).
文摘Lignin,the most abundant natural aromatic polymer globally,has garnered considerable interest due to its rich and diverse active functional groups and its antioxidant,antimicrobial,and adhesive properties.Recent research has significantly improved the performance of lignin-based hydrogels,suggesting their substantial potential in fields such as biomedicine,environmental science,and agriculture.This paper reviews the process of lignin extraction,systematically introduces synthesis strategies for preparing lignin-based hydrogels,and discusses the current state of research on these hydrogels in biomedical and environmental protection fields.It concludes by identifying the existing challenges in lignin hydrogel research and envisioning future prospects and development trends.
基金financially supported by the Natural Science Foundation of Jiangxi Province(No.20232ACB204002)the Jiangxi Provincial Key Laboratory of Flexible Electronics(No.20242BCC32010).
文摘The development of solar-driven interfacial evaporation technology is pivotal for addressing global water scarcity.However,it is hindered by the difficulty in synergizing high photothermal conversion with low water evaporation enthalpy into a single material.Herein,we propose an iron-aldehyde-cooperative dynamic covalent anchoring strategy,successfully constructing a covalently locked,hydroxymethyl-functionalized PEDOT-PVA integrated dual-network hydrogel(MEPH).This strategy employs Fe3+to achieve the one-step in situ oxidative polymerization of hydroxymethyl EDOT while concurrently forming a physical hybrid network with PVA,which is subsequently reinforced by covalent cross-linking using glutaraldehyde.This design endows the MEPH with exceptional broadband light absorption(>99%),efficient water transport,and regulated water state within the hydrogel matrix,leading to a reduced evaporation enthalpy of 732 J·g^(−1).The resulting evaporator achieves an ultrahigh evaporation rate of 4.95 kg·m^(−2)·h^(−1)under 1-sun illumination,corresponding to an energy conversion efficiency exceeding 95%,while maintaining stable,salt-resistant operation in high-salinity environments.Outdoor experiments validate its outstanding practicality for seawater and wastewater purification,with the produced freshwater significantly promoting plant growth,highlighting its great potential in sustainable agricultural water cycles.This iron-aldehyde-cooperative dynamic covalent anchoring strategy provides an innovative design paradigm for a new generation of high-performance and robust solar evaporators.
