Gamma radiation has been shown particularly useful for the functionalization of surfaces with stimuli-responsive polymers. This method involves the formation of active sites (free radicals) onto the polymeric backbone...Gamma radiation has been shown particularly useful for the functionalization of surfaces with stimuli-responsive polymers. This method involves the formation of active sites (free radicals) onto the polymeric backbone as a result of the exposition to high-energy radiation, in which a proper microenvironment for the reaction among monomer and/or polymer and the active sites takes place, thus leading to propagation which forms side chain grafts. The modification of polymers using high-energy irradiation may be performed by the following methods: direct or simultaneous, pre-irradiation oxidative and pre-irradiation. The most frequent ones correspond to the pre-irradiation oxidative method and the direct one. Radiation-grafting has many advantages over conventional methods considering that it does not require catalyst nor additives to initiate the reaction, and in general, no changes on the mechanical properties with respect to the pristine polymeric matrix are observed. This chapter focused on the synthesis of smart polymers and coatings obtained by the use of gamma radiation. In addition, diverse applications of these materials in the biomedical field are also reported.展开更多
Smart polymers have enormous potential in various applications.In particular,smart polymeric drug delivery systems have been explored as“intelligent”delivery systems able to release,at the appropriate time and site ...Smart polymers have enormous potential in various applications.In particular,smart polymeric drug delivery systems have been explored as“intelligent”delivery systems able to release,at the appropriate time and site of action,entrapped drugs in response to specific physiological triggers.These polymers exhibit a non-linear response to a small stimulus leading to a macroscopic alteration in their structure/properties.The responses vary widely from swelling/contraction to disintegration.Synthesis of new polymers and crosslinkers with greater biocompatibility and better biodegradability would increase and enhance current applications.The most fascinating features of the smart polymers arise from their versatility and tunable sensitivity.The most significant weakness of all these external stimuli-sensitive polymers is slow response time.The versatility of polymer sources and their combinatorial synthesis make it possible to tune polymer sensitivity to a given stimulus within a narrow range.Development of smart polymer systems may lead to more accurate and programmable drug delivery.In this review,we discuss various mechanisms by which polymer systems are assembled in situ to form implanted devices for sustained release of therapeutic macromolecules,and we highlight various applications in the field of advanced drug delivery.展开更多
Owing to the outstanding photophysical properties,organic luminescent materials featuring aggregation-induced emission(AIE)characteristics have attracted wide attention in various fields.Numerous researches focused on...Owing to the outstanding photophysical properties,organic luminescent materials featuring aggregation-induced emission(AIE)characteristics have attracted wide attention in various fields.Numerous researches focused on low-mass AIE luminogens,and relatively less attention has been paid on AIE polymers and the related applications,in spite of the fact that AIE polymers exhibit excellent advantages of processability,multifunctional integration and synergistic effects.In this review,we briefly summarize and discuss the superiorities of AIE polymers in preparation,properties and bio-applications,and the considerable progress in these aspects are introduced as well.Finally,the structure-property relationship,challenges and opportunities are also discussed.Hopefully,this review will be a trigger for smart AIE polymer research and further broaden their applications.展开更多
Aggregation-induced emission(AIE)luminogens are attractive dyes to probe poly-mer properties that depend on changes in chain mobility and free volume.When embedded in polymers the restriction of intramolecular motion(...Aggregation-induced emission(AIE)luminogens are attractive dyes to probe poly-mer properties that depend on changes in chain mobility and free volume.When embedded in polymers the restriction of intramolecular motion(RIM)can lead to their photoluminescence quantum yield(PLQY)strong enhancement if local microviscosity increases(lowering of chain mobility and free volume).Nonethe-less,measuring PLQY during stimuli,i.e.heat or mechanical stress,is technically challenging;thus,emission intensity is commonly used instead,assuming its direct correlation with the PLQY.Here,by usingfluorescence lifetime as an absolutefluorescence parameter,it is demonstrated that this assumption can be invalid in many commonly encountered conditions.To this aim,different poly-mers are loaded with tetraphenylenethylene(TPE)and characterized during the application of thermal and mechanical stress and physical aging.Under these con-ditions,polymer matrix transparency variation is observed,possibly due to local changes in refractive index and to the formation of microfractures.By combin-ing different characterization techniques,it is proved that scattering can affect the apparent emission intensity,while lifetime measurements can be used to ascertain whether the observed phenomenon is due to modifications of the photophysi-cal properties of AIE dyes(RIM effect)or to alterations in the matrix optical properties.展开更多
Polymers are being used extensively in drug delivery due to their surface and bulk properties. They are being used in drug formulations and in drug delivery devices. These drug delivery devices may be in the form of i...Polymers are being used extensively in drug delivery due to their surface and bulk properties. They are being used in drug formulations and in drug delivery devices. These drug delivery devices may be in the form of implants for controlled drug delivery. Polymers used in colloidal drug carrier systems, consisting of small particles, show great advantage in drug delivery systems because of optimized drug loading and releasing property. Polymeric nano particulate systems are available in wide variety and have established chemistry. Non toxic, biodegradable and biocompatible polymers are available. Some nano particulate polymeric systems possess ability to cross blood brain barrier. They offer protection against chemical degradation. Smart polymers are responsive to atmospheric stimulus like change in temperature;pressure, pH etc. thus are extremely beneficial for targeted drug delivery. Some polymeric systems conjugated with antibodies/specific biomarkers help in detecting molecular targets specifically in cancers. Surface coating with thiolated PEG, Silica-PEG improves water solubility and photo stability. Surface modification of drug carriers e.g. attachment with PEG or dextran to the lipid bilayer increases their blood circulation time. Polymer drug conjugates such as Zoladex, Lupron Depot, On Caspar PEG intron are used in treatment of prostate cancer and lymphoblastic leukemia. Polymeric Drug Delivery systems are being utilized for controlled drug delivery assuring patient compliance.展开更多
Inter-salt shale oil reservoirs located between two salt layers are always accompanied by high temperature and high salinity. However, the present commonly used water-soluble polymers in fracturing fluids su er from p...Inter-salt shale oil reservoirs located between two salt layers are always accompanied by high temperature and high salinity. However, the present commonly used water-soluble polymers in fracturing fluids su er from poor tolerance to high temperature and high salinity. Thermoviscosifying polymers(TVP) whose aqueous solution shows viscosity increase upon increasing temperature and salt concentration have received considerable attention recently, which is promising for utilization in fracturing fluids to overcome these problems. In this work, both the salt-induced viscosifying property and mechanism of a TVP solution were investigated and the performance of TVP used as fracturing fluid based on the conditions of the Jianghan inter-salt shale oil reservoir in China was evaluated. It is found that the salt-induced viscosifying property of the TVP solution decreases with temperature and shear rate, but increases with polymer concentration. The number of intermolecular hydrophobic domains increases with the salt concentration contributing to the strengthening of a 3D network structure, which results in an increase in viscosity. In addition, the TVP fracturing fluid formulated with saturated brine exhibits excellent temperature and shear resistance, sand-suspending performance, and gel-breaking performance. Its viscosity remains above50 m Pa s after being sheared for 1 h even at a high temperature of 140 °C and the sand-suspending stability can be maintained for more than 1 week at 100 °C. Furthermore, the fracturing fluid can be easily broken down within 12h using 0.2 wt%–0.3 wt% potassium persulfate without residue.展开更多
By using redispersible polymer powder（RPP） and carbon fiber（CF） to adjust the flexibility and electrical properties of the smart aggregate, a new kind of smart aggregate with Z type structure was proposed. The stu...By using redispersible polymer powder（RPP） and carbon fiber（CF） to adjust the flexibility and electrical properties of the smart aggregate, a new kind of smart aggregate with Z type structure was proposed. The study shows that Z type aggregate is more sensitive to the feedback of external force than the prism aggregate in the same loading environment, and it indicates that Z type aggregate is more suitable for the research and application of concrete health monitoring. Although the incorporation of RPP would cause the compressive strength of the aggregates and the elastic modulus of hardened cement mortar to reduce slightly within the dosage of RPP by 2.25% because of the polymer film formed in the internal system, this would improve the deformability of the aggregates. In the early loading stage（in the first 60 seconds）, the intelligent concrete specimens implanted with Z type smart aggregate do not show higher sensitivity as expected, although the resistance change rate changes a little bit more, the overall of it is still in balance. Adding RPP could improve the flexibility of smart aggregates exactly, and it plays an active role in prolonging the life of the smart aggregates. By implanting Z type aggregates the damage and failure of the concrete structure could be predicted accurately in this study. The results of this paper will help to promote further research and application of intelligent concrete.展开更多
Cryopreservation is a fundamental technology in biomedical research,regenerative medicine,and tissue engineering,enabling the long-term storage of cells,tissues,and organs.However,its effectiveness is limited by chall...Cryopreservation is a fundamental technology in biomedical research,regenerative medicine,and tissue engineering,enabling the long-term storage of cells,tissues,and organs.However,its effectiveness is limited by challenges such as intracellular ice formation,cryoprotectant toxicity,and reduced post-thaw viability.This review explores the crucial role of encapsulation in enhancing cryopreservation efficiency,with a focus on recent advances in materials science,bioengineering,and cryobiology.Emerging technologies,such as nanotechnology and stimuli-responsive polymers,are transforming encapsulation strategies.Innovations such as microfluidic systems offer precise control over cooling rates and cryoprotectant distribution,thereby mitigating conventional limitations.The review also addresses current obstacles related to scaling up encapsulation processes and ensuring the long-term biocompatibility and stability of preserved specimens.By synthesizing recent findings,this work provides a comprehensive resource for researchers and clinicians seeking to enhance biopreservation techniques and their applications in contemporary medicine and biotechnology.Finally,the review identifies critical knowledge gaps that must be addressed to improve the efficacy of cryopreservation strategies and advance their clinical translation.展开更多
Silicone rubber films were modified by the consecutive grafting of 2-(diethylamino)ethyl methacrylate (DEAEMA) and N-vinylcaprolactam (NVCL) using direct method on two steps with gamma-rays. The effect of absorbed dos...Silicone rubber films were modified by the consecutive grafting of 2-(diethylamino)ethyl methacrylate (DEAEMA) and N-vinylcaprolactam (NVCL) using direct method on two steps with gamma-rays. The effect of absorbed dose and monomer concentration on grafting degree was determined. The grafted samples were verified by FTIR-ATR spectroscopy and swelling;thermal properties were analyzed by DSC and TGA. The stimuli-responsive behavior was studied by swelling and/or DSC. Thermo- and pH-sensitive films of (PP-g-DEAEMA)-g-NVCL presented a pH critical at 3.2 and LCST around 63.5℃.展开更多
In nature,animals adapt themselves to different states in response to environmental changes for the purposes of alarming danger,courtship,protection,and so forth,which are realized by altering in-body molecules or mic...In nature,animals adapt themselves to different states in response to environmental changes for the purposes of alarming danger,courtship,protection,and so forth,which are realized by altering in-body molecules or microstructures.For example,chameleons will change skin colors(Figure 1A)to attract the attention of mates or warn potential enemies,and the color variation is closely related to the molecules released by pigment cells.Inspired by these smart behaviors,scientists are endeavoring to explore and design smart materials for advanced applications,which are demanded to achieve an intelligent,sustainable,and comfortable human life in the future.展开更多
Thermosensitive polymers show an entropy-driven transition from a well-solvated to a poorly solvated polymer chain, resulting in a more compact globular conformation. The transition at the lower critical solution temp...Thermosensitive polymers show an entropy-driven transition from a well-solvated to a poorly solvated polymer chain, resulting in a more compact globular conformation. The transition at the lower critical solution temperature（LCST） is often sharp, which allows for a wide range of smart material applications.At the LCST, oligo（ethylene glycol）-substituted polyisocyanides（PICs） form soft hydrogels, composed of polymer bundles similar to biological gels, such as actin, fibrin and intermediate filaments. Here, we show that the LCST of PICs strongly depends linearly on the length of the ethylene glycol（EG） tails; every EG group increases the LCSTand thus the gelation temperature by nearly 30 ℃. Using a copolymerisation approach, we demonstrate that we can precisely tailor the gelation temperature between 10 ℃ and 60 ℃and, consequently, tune the mechanical properties of the PIC gels.展开更多
The advancement of fiber materials over the centuries has played a crucial role in the progress of human civilization.Smart polymer fibers(SPFs)are a revolutionary family of materials with sensory,feedback,and respons...The advancement of fiber materials over the centuries has played a crucial role in the progress of human civilization.Smart polymer fibers(SPFs)are a revolutionary family of materials with sensory,feedback,and responsive attributes to chemical and physical stimuli,and are characterized by diverse microscopic structures.Multidimensional fiber microstructures have been fabricated by sophisticated preparation technologies,such as electrospinning,wet spinning,and microfluidic spinning,resulting in SPFs with responsiveness to various stimuli,such as thermal,pH,light,electricity,moisture,magnetic field,and multiple stimuli-responsive properties.In the past decade,cross-disciplinary developments in the refinement,intellectualization,and functionalization of SPFs and notable progress in the fibers'microstructure and stimuli-responsive properties have enabled wide applications in biomedicine,smart textiles,sensors,and water treatment.Herein,to comprehensively facilitate SPFs development in multidisciplinary and multifunctional domains,we elaborate on the correlation among material classification,microstructures formed by common preparation processes,stimuli-responsive properties,and their comprehensive applications.Finally,we aim to inspire scientists with diverse research backgrounds to apply multidisciplinary knowledge to promote the development and industrialization of SPFs.展开更多
Precise recognition and specific interactions between biomolecules are key prerequisites for ensuring the performance of all actives within living organisms.The convergence of biomolecular recognition systems into syn...Precise recognition and specific interactions between biomolecules are key prerequisites for ensuring the performance of all actives within living organisms.The convergence of biomolecular recognition systems into synthetic materials could endow the materials with high specificity and biological sensitivity;this,in turn,enables precise drug release,monitoring or detection of important biomolecules,and cell manipulation through targeted capture or release of specific biomolecules.Meanwhile,from the perspective of materials science,the application of conventional polymers in practical biological systems poses several challenges,such as low responsiveness and sensitivity,inadequate targetability,insufficient anti-interference capacities,and unsatisfactory biocompatibility.These problems could be partly attributed to the polymers'weak discrimination abilities toward target biomolecules in the presence of interfering substances with high abundance.In particular,the proposition of“precision medicine”project raises higher demands for the design of biomaterials in terms of their precision and targetability.Therefore,there is an urgent demand for the development of new-generation biomaterials with precise recognition and sensitive responsiveness comparable to biomacro-molecules.This promotes a new research direction of biomolecule-responsive polymers and their diverse applications.This review focuses on the origin and construction of biomolecule-responsive polymers,as well as their attractive applications in drug delivery systems,bio-detection,bio-sensing,separation,and enrichment,as well as regulating cell adhesion.展开更多
Chiral separation that is closely related to daily life is a meaningful research. Polysaccharide-(e.g., cellulose, amylose derivatives) based chiral packing materials afford powerful chiral stationary phases(CSPs) tow...Chiral separation that is closely related to daily life is a meaningful research. Polysaccharide-(e.g., cellulose, amylose derivatives) based chiral packing materials afford powerful chiral stationary phases(CSPs) toward a broad range of racemic compounds. However, considering the explosive growth of specific chiral drugs, the separation efficiencies of these CSPs need further improvement, which calls for new approaches and strategies. Smart polymers can change their physical or chemical properties dynamically and reversibly according to the external stimuli(e.g., thermo-, pH, solvent, ion, light, critical parameters for chromatographic separation) exerted on them, subsequently resulting in tunable changes in the macroscopic properties of materials. In addition to their excellent controllability, the introduction of chiral characteristics into the backbones or side-chains of smart polymers provides a promising route to realize reversibly conformational transition in response to the chiral analytes. This dramatic transition may significantly improve the performance of materials in chiral separation through modulating the enantioselective interactions between materials and analytes. With the help of chirality-responsive polymers, intelligent and switchable CSPs could be developed and applied in column-liquid chromatography. In these systems, the elution order or enantioselectivity of chiral drugs can be precisely modulated, which will help to solve many challenging problems that involve complicated enantiomers. In this paper we introduce some typical examples of smart polymers that serve as the basis for a discussion of emerging developments of CPSs, and then briefly outline the recent CSPs based on natural and certain synthetic polymers.展开更多
Shape memory elastomers,a class of smart polymers,can remember their initial shapes under external stimuli and have potential applications in many fields,including medical devices,artificial muscles,actuators,and soft...Shape memory elastomers,a class of smart polymers,can remember their initial shapes under external stimuli and have potential applications in many fields,including medical devices,artificial muscles,actuators,and soft robots.Therefore,this review aims to explore research progress on the molecular structures,stimuli-responsive mechanisms,and emerging applications of shape memory elastomers and their composites in recent years.First,the molecular structures,shape memory effects,and working mechanisms of shape memory elastomers are thoroughly discussed and explained based on different external stimuli,including heat,light,electricity,magnetic fields,and solvents.Subsequently,emerging applications of shape memory elastomers,such as artificial muscles,actuators,soft robots,smart electronics,and aerospace,are presented.Finally,future challenges and insights into shape memory elastomers are discussed.Shape memory elastomers have received extensive attention and show great application potential in many emerging fields.展开更多
Comprehensive Summary A disulfide-based poly(ether-b-amide)copolymer with rapid self-healing capability under moderate conditions was synthesized from 4,4’-dithiodibutyric acid(DTDBA),isophorondiamine(IPDA)and poly(t...Comprehensive Summary A disulfide-based poly(ether-b-amide)copolymer with rapid self-healing capability under moderate conditions was synthesized from 4,4’-dithiodibutyric acid(DTDBA),isophorondiamine(IPDA)and poly(tetramethylene oxide)(PTMO)based on a two-step method.The incorporation of IPDA with asymmetric structure and substantial steric hindrance not only effectively decreased the number of regular H-bonds,but also inhibited the crystallization of polyamide segments,imparting the synthesized poly(ether-b-amide)copolymer with an amorphous structural feature.Based on the coordination of segmental diffusion and recombination of disulfide bonds and hydrogen bonds,the scratches and damaged mechanical properties of PEBADS-I611 could be completely self-healed after healing at 40°C for only 11 min and 3 h,respectively.展开更多
基金H.I.Melendez-Ortiz is grateful to the program Cátedras-CONACyT(Mexico)This chapter was supported by DGAPA-UNAM Grant IN200714+1 种基金CONACYT-CNPq Project 174378(Mexico)CNPq project number 490200/2011-7(Brazil).
文摘Gamma radiation has been shown particularly useful for the functionalization of surfaces with stimuli-responsive polymers. This method involves the formation of active sites (free radicals) onto the polymeric backbone as a result of the exposition to high-energy radiation, in which a proper microenvironment for the reaction among monomer and/or polymer and the active sites takes place, thus leading to propagation which forms side chain grafts. The modification of polymers using high-energy irradiation may be performed by the following methods: direct or simultaneous, pre-irradiation oxidative and pre-irradiation. The most frequent ones correspond to the pre-irradiation oxidative method and the direct one. Radiation-grafting has many advantages over conventional methods considering that it does not require catalyst nor additives to initiate the reaction, and in general, no changes on the mechanical properties with respect to the pristine polymeric matrix are observed. This chapter focused on the synthesis of smart polymers and coatings obtained by the use of gamma radiation. In addition, diverse applications of these materials in the biomedical field are also reported.
文摘Smart polymers have enormous potential in various applications.In particular,smart polymeric drug delivery systems have been explored as“intelligent”delivery systems able to release,at the appropriate time and site of action,entrapped drugs in response to specific physiological triggers.These polymers exhibit a non-linear response to a small stimulus leading to a macroscopic alteration in their structure/properties.The responses vary widely from swelling/contraction to disintegration.Synthesis of new polymers and crosslinkers with greater biocompatibility and better biodegradability would increase and enhance current applications.The most fascinating features of the smart polymers arise from their versatility and tunable sensitivity.The most significant weakness of all these external stimuli-sensitive polymers is slow response time.The versatility of polymer sources and their combinatorial synthesis make it possible to tune polymer sensitivity to a given stimulus within a narrow range.Development of smart polymer systems may lead to more accurate and programmable drug delivery.In this review,we discuss various mechanisms by which polymer systems are assembled in situ to form implanted devices for sustained release of therapeutic macromolecules,and we highlight various applications in the field of advanced drug delivery.
基金Natural Science Foundation of Guangdong Province,Grant/Award Number:2019B030301003National Natural Science Foundation of China,Grant/Award Number:21788102Innovation and Technology Commission of Hong Kong,Grant/Award Number:ITC-CNERC14S01。
文摘Owing to the outstanding photophysical properties,organic luminescent materials featuring aggregation-induced emission(AIE)characteristics have attracted wide attention in various fields.Numerous researches focused on low-mass AIE luminogens,and relatively less attention has been paid on AIE polymers and the related applications,in spite of the fact that AIE polymers exhibit excellent advantages of processability,multifunctional integration and synergistic effects.In this review,we briefly summarize and discuss the superiorities of AIE polymers in preparation,properties and bio-applications,and the considerable progress in these aspects are introduced as well.Finally,the structure-property relationship,challenges and opportunities are also discussed.Hopefully,this review will be a trigger for smart AIE polymer research and further broaden their applications.
基金Ministero dell’Universitàe della Ricerca,Grant/Award Number:20179BJNA2。
文摘Aggregation-induced emission(AIE)luminogens are attractive dyes to probe poly-mer properties that depend on changes in chain mobility and free volume.When embedded in polymers the restriction of intramolecular motion(RIM)can lead to their photoluminescence quantum yield(PLQY)strong enhancement if local microviscosity increases(lowering of chain mobility and free volume).Nonethe-less,measuring PLQY during stimuli,i.e.heat or mechanical stress,is technically challenging;thus,emission intensity is commonly used instead,assuming its direct correlation with the PLQY.Here,by usingfluorescence lifetime as an absolutefluorescence parameter,it is demonstrated that this assumption can be invalid in many commonly encountered conditions.To this aim,different poly-mers are loaded with tetraphenylenethylene(TPE)and characterized during the application of thermal and mechanical stress and physical aging.Under these con-ditions,polymer matrix transparency variation is observed,possibly due to local changes in refractive index and to the formation of microfractures.By combin-ing different characterization techniques,it is proved that scattering can affect the apparent emission intensity,while lifetime measurements can be used to ascertain whether the observed phenomenon is due to modifications of the photophysi-cal properties of AIE dyes(RIM effect)or to alterations in the matrix optical properties.
文摘Polymers are being used extensively in drug delivery due to their surface and bulk properties. They are being used in drug formulations and in drug delivery devices. These drug delivery devices may be in the form of implants for controlled drug delivery. Polymers used in colloidal drug carrier systems, consisting of small particles, show great advantage in drug delivery systems because of optimized drug loading and releasing property. Polymeric nano particulate systems are available in wide variety and have established chemistry. Non toxic, biodegradable and biocompatible polymers are available. Some nano particulate polymeric systems possess ability to cross blood brain barrier. They offer protection against chemical degradation. Smart polymers are responsive to atmospheric stimulus like change in temperature;pressure, pH etc. thus are extremely beneficial for targeted drug delivery. Some polymeric systems conjugated with antibodies/specific biomarkers help in detecting molecular targets specifically in cancers. Surface coating with thiolated PEG, Silica-PEG improves water solubility and photo stability. Surface modification of drug carriers e.g. attachment with PEG or dextran to the lipid bilayer increases their blood circulation time. Polymer drug conjugates such as Zoladex, Lupron Depot, On Caspar PEG intron are used in treatment of prostate cancer and lymphoblastic leukemia. Polymeric Drug Delivery systems are being utilized for controlled drug delivery assuring patient compliance.
基金financial support from State Energy Center for Shale Oil Research and Development(Grant No.G5800-17-ZS-KFNY008)
文摘Inter-salt shale oil reservoirs located between two salt layers are always accompanied by high temperature and high salinity. However, the present commonly used water-soluble polymers in fracturing fluids su er from poor tolerance to high temperature and high salinity. Thermoviscosifying polymers(TVP) whose aqueous solution shows viscosity increase upon increasing temperature and salt concentration have received considerable attention recently, which is promising for utilization in fracturing fluids to overcome these problems. In this work, both the salt-induced viscosifying property and mechanism of a TVP solution were investigated and the performance of TVP used as fracturing fluid based on the conditions of the Jianghan inter-salt shale oil reservoir in China was evaluated. It is found that the salt-induced viscosifying property of the TVP solution decreases with temperature and shear rate, but increases with polymer concentration. The number of intermolecular hydrophobic domains increases with the salt concentration contributing to the strengthening of a 3D network structure, which results in an increase in viscosity. In addition, the TVP fracturing fluid formulated with saturated brine exhibits excellent temperature and shear resistance, sand-suspending performance, and gel-breaking performance. Its viscosity remains above50 m Pa s after being sheared for 1 h even at a high temperature of 140 °C and the sand-suspending stability can be maintained for more than 1 week at 100 °C. Furthermore, the fracturing fluid can be easily broken down within 12h using 0.2 wt%–0.3 wt% potassium persulfate without residue.
基金Funded by the Natural Science Foundation of Fujian Province(No.2016J01241)the National Natural Science Foundation of China(No.51608212)the Science&Technology Pillar Program of Fujian Provincial Education Department(No.JA14024)
文摘By using redispersible polymer powder（RPP） and carbon fiber（CF） to adjust the flexibility and electrical properties of the smart aggregate, a new kind of smart aggregate with Z type structure was proposed. The study shows that Z type aggregate is more sensitive to the feedback of external force than the prism aggregate in the same loading environment, and it indicates that Z type aggregate is more suitable for the research and application of concrete health monitoring. Although the incorporation of RPP would cause the compressive strength of the aggregates and the elastic modulus of hardened cement mortar to reduce slightly within the dosage of RPP by 2.25% because of the polymer film formed in the internal system, this would improve the deformability of the aggregates. In the early loading stage（in the first 60 seconds）, the intelligent concrete specimens implanted with Z type smart aggregate do not show higher sensitivity as expected, although the resistance change rate changes a little bit more, the overall of it is still in balance. Adding RPP could improve the flexibility of smart aggregates exactly, and it plays an active role in prolonging the life of the smart aggregates. By implanting Z type aggregates the damage and failure of the concrete structure could be predicted accurately in this study. The results of this paper will help to promote further research and application of intelligent concrete.
基金supported by the National Natural Science Foundation of China(82172114)the"Challenge and Response"project for key and common technology research of Hefei(GJ2022SH08).
文摘Cryopreservation is a fundamental technology in biomedical research,regenerative medicine,and tissue engineering,enabling the long-term storage of cells,tissues,and organs.However,its effectiveness is limited by challenges such as intracellular ice formation,cryoprotectant toxicity,and reduced post-thaw viability.This review explores the crucial role of encapsulation in enhancing cryopreservation efficiency,with a focus on recent advances in materials science,bioengineering,and cryobiology.Emerging technologies,such as nanotechnology and stimuli-responsive polymers,are transforming encapsulation strategies.Innovations such as microfluidic systems offer precise control over cooling rates and cryoprotectant distribution,thereby mitigating conventional limitations.The review also addresses current obstacles related to scaling up encapsulation processes and ensuring the long-term biocompatibility and stability of preserved specimens.By synthesizing recent findings,this work provides a comprehensive resource for researchers and clinicians seeking to enhance biopreservation techniques and their applications in contemporary medicine and biotechnology.Finally,the review identifies critical knowledge gaps that must be addressed to improve the efficacy of cryopreservation strategies and advance their clinical translation.
文摘Silicone rubber films were modified by the consecutive grafting of 2-(diethylamino)ethyl methacrylate (DEAEMA) and N-vinylcaprolactam (NVCL) using direct method on two steps with gamma-rays. The effect of absorbed dose and monomer concentration on grafting degree was determined. The grafted samples were verified by FTIR-ATR spectroscopy and swelling;thermal properties were analyzed by DSC and TGA. The stimuli-responsive behavior was studied by swelling and/or DSC. Thermo- and pH-sensitive films of (PP-g-DEAEMA)-g-NVCL presented a pH critical at 3.2 and LCST around 63.5℃.
基金supported by the Science and Technology Project of State Grid Corpora-tion of China(5700-202399630A-3-2-ZN)the National Natural Science Foundation of China(52173241)the Youth Top-notch Talents Program of Chongqing(cstc2024ycjh-bgzxm0132 and CQYC20220511198).
文摘In nature,animals adapt themselves to different states in response to environmental changes for the purposes of alarming danger,courtship,protection,and so forth,which are realized by altering in-body molecules or microstructures.For example,chameleons will change skin colors(Figure 1A)to attract the attention of mates or warn potential enemies,and the color variation is closely related to the molecules released by pigment cells.Inspired by these smart behaviors,scientists are endeavoring to explore and design smart materials for advanced applications,which are demanded to achieve an intelligent,sustainable,and comfortable human life in the future.
基金the Netherlands Organisation for Scientific Research (NWO)for providing and supporting beam time at the DutchBelgium beamline(DUBBLE) for SAXS experiments(No. BM26-02773)financial support from NWO (VENI grant No. 680-47-437)+2 种基金the Euopean Union's 2020 ResearchInnovation Programme under Grant Agreement No. 642687project Biogel
文摘Thermosensitive polymers show an entropy-driven transition from a well-solvated to a poorly solvated polymer chain, resulting in a more compact globular conformation. The transition at the lower critical solution temperature（LCST） is often sharp, which allows for a wide range of smart material applications.At the LCST, oligo（ethylene glycol）-substituted polyisocyanides（PICs） form soft hydrogels, composed of polymer bundles similar to biological gels, such as actin, fibrin and intermediate filaments. Here, we show that the LCST of PICs strongly depends linearly on the length of the ethylene glycol（EG） tails; every EG group increases the LCSTand thus the gelation temperature by nearly 30 ℃. Using a copolymerisation approach, we demonstrate that we can precisely tailor the gelation temperature between 10 ℃ and 60 ℃and, consequently, tune the mechanical properties of the PIC gels.
基金funded by the National Natural Science Foundation of China(Grant No.92271112).
文摘The advancement of fiber materials over the centuries has played a crucial role in the progress of human civilization.Smart polymer fibers(SPFs)are a revolutionary family of materials with sensory,feedback,and responsive attributes to chemical and physical stimuli,and are characterized by diverse microscopic structures.Multidimensional fiber microstructures have been fabricated by sophisticated preparation technologies,such as electrospinning,wet spinning,and microfluidic spinning,resulting in SPFs with responsiveness to various stimuli,such as thermal,pH,light,electricity,moisture,magnetic field,and multiple stimuli-responsive properties.In the past decade,cross-disciplinary developments in the refinement,intellectualization,and functionalization of SPFs and notable progress in the fibers'microstructure and stimuli-responsive properties have enabled wide applications in biomedicine,smart textiles,sensors,and water treatment.Herein,to comprehensively facilitate SPFs development in multidisciplinary and multifunctional domains,we elaborate on the correlation among material classification,microstructures formed by common preparation processes,stimuli-responsive properties,and their comprehensive applications.Finally,we aim to inspire scientists with diverse research backgrounds to apply multidisciplinary knowledge to promote the development and industrialization of SPFs.
基金National Key Research and Development Program of China,Grant/Award Number:2022YFC3400800National Natural Science Foundation of China,Grant/Award Numbers:22004120,22174138,22104013+2 种基金DICP Innovation Funding,Grant/Award Numbers:I202243,I202229Dalian Outstanding Young Scientific Talent,Grant/Award Number:2020RJ01Natural Science Foundation of Jiangxi Province,Grant/Award Numbers:20212BAB213002,20232BAB213049。
文摘Precise recognition and specific interactions between biomolecules are key prerequisites for ensuring the performance of all actives within living organisms.The convergence of biomolecular recognition systems into synthetic materials could endow the materials with high specificity and biological sensitivity;this,in turn,enables precise drug release,monitoring or detection of important biomolecules,and cell manipulation through targeted capture or release of specific biomolecules.Meanwhile,from the perspective of materials science,the application of conventional polymers in practical biological systems poses several challenges,such as low responsiveness and sensitivity,inadequate targetability,insufficient anti-interference capacities,and unsatisfactory biocompatibility.These problems could be partly attributed to the polymers'weak discrimination abilities toward target biomolecules in the presence of interfering substances with high abundance.In particular,the proposition of“precision medicine”project raises higher demands for the design of biomaterials in terms of their precision and targetability.Therefore,there is an urgent demand for the development of new-generation biomaterials with precise recognition and sensitive responsiveness comparable to biomacro-molecules.This promotes a new research direction of biomolecule-responsive polymers and their diverse applications.This review focuses on the origin and construction of biomolecule-responsive polymers,as well as their attractive applications in drug delivery systems,bio-detection,bio-sensing,separation,and enrichment,as well as regulating cell adhesion.
基金supported by the National Natural Science Foundation of China(21104061,21275114,91127027,51173142)the China National Funds for Distinguished Young Scientists(51325302)+2 种基金the Major State Basic Research Development Program of China(2013CB933002)the Program of Introducing Talents of Discipline to Universities(B13035)Hubei Provincial Department of Education for financial assistance through the Chutian Scholar Program
文摘Chiral separation that is closely related to daily life is a meaningful research. Polysaccharide-(e.g., cellulose, amylose derivatives) based chiral packing materials afford powerful chiral stationary phases(CSPs) toward a broad range of racemic compounds. However, considering the explosive growth of specific chiral drugs, the separation efficiencies of these CSPs need further improvement, which calls for new approaches and strategies. Smart polymers can change their physical or chemical properties dynamically and reversibly according to the external stimuli(e.g., thermo-, pH, solvent, ion, light, critical parameters for chromatographic separation) exerted on them, subsequently resulting in tunable changes in the macroscopic properties of materials. In addition to their excellent controllability, the introduction of chiral characteristics into the backbones or side-chains of smart polymers provides a promising route to realize reversibly conformational transition in response to the chiral analytes. This dramatic transition may significantly improve the performance of materials in chiral separation through modulating the enantioselective interactions between materials and analytes. With the help of chirality-responsive polymers, intelligent and switchable CSPs could be developed and applied in column-liquid chromatography. In these systems, the elution order or enantioselectivity of chiral drugs can be precisely modulated, which will help to solve many challenging problems that involve complicated enantiomers. In this paper we introduce some typical examples of smart polymers that serve as the basis for a discussion of emerging developments of CPSs, and then briefly outline the recent CSPs based on natural and certain synthetic polymers.
基金supported by the National Natural Science Foundation of China(Grant:52033011,52273104)Guangdong Basic and Applied Basic Research Foundation(Grant:2022A1515011972,2023A1515010694).
文摘Shape memory elastomers,a class of smart polymers,can remember their initial shapes under external stimuli and have potential applications in many fields,including medical devices,artificial muscles,actuators,and soft robots.Therefore,this review aims to explore research progress on the molecular structures,stimuli-responsive mechanisms,and emerging applications of shape memory elastomers and their composites in recent years.First,the molecular structures,shape memory effects,and working mechanisms of shape memory elastomers are thoroughly discussed and explained based on different external stimuli,including heat,light,electricity,magnetic fields,and solvents.Subsequently,emerging applications of shape memory elastomers,such as artificial muscles,actuators,soft robots,smart electronics,and aerospace,are presented.Finally,future challenges and insights into shape memory elastomers are discussed.Shape memory elastomers have received extensive attention and show great application potential in many emerging fields.
基金financially supported by the National Key Program of China(No.2022-1400600).
文摘Comprehensive Summary A disulfide-based poly(ether-b-amide)copolymer with rapid self-healing capability under moderate conditions was synthesized from 4,4’-dithiodibutyric acid(DTDBA),isophorondiamine(IPDA)and poly(tetramethylene oxide)(PTMO)based on a two-step method.The incorporation of IPDA with asymmetric structure and substantial steric hindrance not only effectively decreased the number of regular H-bonds,but also inhibited the crystallization of polyamide segments,imparting the synthesized poly(ether-b-amide)copolymer with an amorphous structural feature.Based on the coordination of segmental diffusion and recombination of disulfide bonds and hydrogen bonds,the scratches and damaged mechanical properties of PEBADS-I611 could be completely self-healed after healing at 40°C for only 11 min and 3 h,respectively.
