Poly(arylene sulfide sulfone)/graphene nanoplate(PASS/GNP) composites with segregated structure based on continuous polymer fiber skeletons were fabricated by coating a thin conductive layer on the PASS fibers and the...Poly(arylene sulfide sulfone)/graphene nanoplate(PASS/GNP) composites with segregated structure based on continuous polymer fiber skeletons were fabricated by coating a thin conductive layer on the PASS fibers and then performing compression molding. The formation of a unique segregated conductive network endowed the PASS/GNP composites with high electrical conductivity and excellent electromagnetic interference(EMI) shielding effectiveness(SE), reaching 17.8 S/m and 30.1 d B, respectively, when the content of the GNPs in the conductive layer was 20 wt%. The PASS/GNP composites also exhibited outstanding mechanical properties, which was attributed to the continuous PASS fiber skeletons that could withstand large loads and the strong interfacial interaction between the conductive layers and the PASS fibers that could provide good stress transfer. This approach is suitable for most soluble polymers.展开更多
Poly(decamethylene terephthalamide/decamethylene isophthalamide)-block-polyvinyl alcoho)(PA10 T/10 IPEG) copolymer/graphene oxide(GO) composites were prepared via in-situ melt polymerization and two different nano-fil...Poly(decamethylene terephthalamide/decamethylene isophthalamide)-block-polyvinyl alcoho)(PA10 T/10 IPEG) copolymer/graphene oxide(GO) composites were prepared via in-situ melt polymerization and two different nano-filler addition approaches were compared. The relationship between the micro-structure and performance of the elastomer composites prepared by one-step and two-step methods was explored. The results show that the two-step method significantly promoted the dispersion of the GO in a polymer matrix, and facilitated the grafting of more hard molecular chains. Thus, the elastic modulus and tensile strength of the nanocomposite have been significantly improved by the presence of GO. This was because of the strong interaction between the functional groups on the surface of the GO and the hard molecular chains. This would be also be favorable to load transfer across the interface. Additionally, the elongation at the break of composites increased by 10% with the addition of a small amount of GO(0.2% wt). This is because hard domains tend to be enriched on the surface of GO in composites and act as a lubricating layer at the interface between the GO and matrix, leading to increased deformation ability. This work provides an effective strategy to prepare elastomer composites with high strength and toughness.展开更多
Bacterial infections are a major cause of chronic infections.Thus,antibacterial material is an urgent need in clinics.Antibacterial nanofibers,with expansive surface area,enable efficient incorporation of antibacteria...Bacterial infections are a major cause of chronic infections.Thus,antibacterial material is an urgent need in clinics.Antibacterial nanofibers,with expansive surface area,enable efficient incorporation of antibacterial agents.Meanwhile,structure similar to the extracellular matrix can accelerate cell growth.Electrospinning,the most widely used technique to fabricate nanofiber,is often used in many biomedical applications including drug delivery,regenerative medicine,wound healing and so on.Thus,this review provides an overview of all recently published studies on the development of electrospun antibacterial nanofibers in wound dressings and tissue me-dicinal fields.This reviewer begins with a brief introduction of electrospinning process and then discusses electrospun fibers by incorporating various types of antimicrobial agents used as in wound dressings and tissue.Finally,we finish with conclusions and further perspectives on electrospun antibacterial nanofibers as 2D biomedicine materials.展开更多
Pre-polymerized vinyl trimethoxy silane(PVTMS)@MWCNT nano-aerogel system was constructed via radical polymerization,sol-gel transition and supercritical CO_(2)drying.The fabricated organic-inorganic hybrid PVTMS@MWCNT...Pre-polymerized vinyl trimethoxy silane(PVTMS)@MWCNT nano-aerogel system was constructed via radical polymerization,sol-gel transition and supercritical CO_(2)drying.The fabricated organic-inorganic hybrid PVTMS@MWCNT aerogel structure shows nano-pore size(30-40 nm),high specific surface area(559 m^(2)g^(−1)),high void fraction(91.7%)and enhanced mechanical property:(1)the nano-pore size is beneficial for efficiently blocking thermal conduction and thermal convection via Knudsen effect(beneficial for infrared(IR)stealth);(2)the heterogeneous interface was beneficial for IR reflection(beneficial for IR stealth)and MWCNT polarization loss(beneficial for electromagnetic wave(EMW)attenuation);(3)the high void fraction was beneficial for enhancing thermal insulation(beneficial for IR stealth)and EMW impedance match(beneficial for EMW attenuation).Guided by the above theoretical design strategy,PVTMS@MWCNT nano-aerogel shows superior EMW absorption property(cover all Ku-band)and thermal IR stealth property(ΔT reached 60.7℃).Followed by a facial combination of the above nano-aerogel with graphene film of high electrical conductivity,an extremely high electromagnetic interference shielding material(66.5 dB,2.06 mm thickness)with superior absorption performance of an average absorption-to-reflection(A/R)coefficient ratio of 25.4 and a low reflection bandwidth of 4.1 GHz(A/R ratio more than 10)was experimentally obtained in this work.展开更多
In this work,Epoxidized natural rubber/sawdust short fiber(ENR-50/SD)composites at different fiber content(5,10,15 and 20 phr)and size(fine size at 60–100μm and coarse size at 10–20 mm)were prepared using two-roll ...In this work,Epoxidized natural rubber/sawdust short fiber(ENR-50/SD)composites at different fiber content(5,10,15 and 20 phr)and size(fine size at 60–100μm and coarse size at 10–20 mm)were prepared using two-roll mill and electrical-hydraulic hot press machine respectively.Curing characteristics,water uptake,tensile,morphological,physical,and thermal properties of the composites were investigated.Results indicated that the scorch time and cure time became shorter whereas torque improved as SD content increase.Though the decline of tensile strength and elongation at break values,modulus,hardness and crosslinking density have shown enhancements with the increasing of SD content.The water uptake percentage of all samples has shown an increasing as SD content increase.However,the low SD content,particularly fine size have presented lower water uptake.The temperature of weight%loss(5 and 50 wt%loss)of 5 phr SD(low content)have recorded higher temperature compared to 20 phr SD(high content)in the rubber composites,which indicated higher thermal stability.The fine size of SD has recorded better overall properties than SD coarse size at same loading in the rubber composites.展开更多
The rapid advancement of flexible electronics creates an urgent demand for high-performance printed electronic materials.MXene-based inks have been widely studied and used for screen-printing electronics,while they us...The rapid advancement of flexible electronics creates an urgent demand for high-performance printed electronic materials.MXene-based inks have been widely studied and used for screen-printing electronics,while they usually suffer from poor screen-printability and inadequate mechanical properties of the printed coatings.Therefore,we incorporate 2,2,6,6-tetramethylpiperidinooxy oxidized cellulose nanofibers into MXene ink to regulate its rheology and enhance printability on both porous A4 paper and compact polyethylene terephthalate substrates.The introduction of cellulose enables precise control over the rheology and microstructure of the resultant MXene coatings.Critically,the strong interfacial hydrogen bonding and physical entanglement between cellulose and MXene contribute to the substantial enhancements of the mechanical properties and structural stability of the resultant composite coatings,where a remarkable 9.04-fold increase of hardness and a 1.74-fold increase of Young’s modulus are achieved.The interfacial binding strength between the coating and substrate is also well enhanced with the anchoring of cellulose.This work thereby presents a promising strategy for the design and fabrication of flexible screen-printed electronics.展开更多
基金the Natural Science Foundation of China (Grant No. 21274094, 21304060 and 51573103)the Jiangsu Provincial Key Research and Development Program (Grant No. BE2019008) for providing financial support。
文摘Poly(arylene sulfide sulfone)/graphene nanoplate(PASS/GNP) composites with segregated structure based on continuous polymer fiber skeletons were fabricated by coating a thin conductive layer on the PASS fibers and then performing compression molding. The formation of a unique segregated conductive network endowed the PASS/GNP composites with high electrical conductivity and excellent electromagnetic interference(EMI) shielding effectiveness(SE), reaching 17.8 S/m and 30.1 d B, respectively, when the content of the GNPs in the conductive layer was 20 wt%. The PASS/GNP composites also exhibited outstanding mechanical properties, which was attributed to the continuous PASS fiber skeletons that could withstand large loads and the strong interfacial interaction between the conductive layers and the PASS fibers that could provide good stress transfer. This approach is suitable for most soluble polymers.
基金the financial support from the Jiangsu Provincial Key Research and Development Program (Grant No. BE2019008)the Natural Science Foundation of China (Grant No. 51573103, 21274094 and 21304060)。
文摘Poly(decamethylene terephthalamide/decamethylene isophthalamide)-block-polyvinyl alcoho)(PA10 T/10 IPEG) copolymer/graphene oxide(GO) composites were prepared via in-situ melt polymerization and two different nano-filler addition approaches were compared. The relationship between the micro-structure and performance of the elastomer composites prepared by one-step and two-step methods was explored. The results show that the two-step method significantly promoted the dispersion of the GO in a polymer matrix, and facilitated the grafting of more hard molecular chains. Thus, the elastic modulus and tensile strength of the nanocomposite have been significantly improved by the presence of GO. This was because of the strong interaction between the functional groups on the surface of the GO and the hard molecular chains. This would be also be favorable to load transfer across the interface. Additionally, the elongation at the break of composites increased by 10% with the addition of a small amount of GO(0.2% wt). This is because hard domains tend to be enriched on the surface of GO in composites and act as a lubricating layer at the interface between the GO and matrix, leading to increased deformation ability. This work provides an effective strategy to prepare elastomer composites with high strength and toughness.
基金supported by the National Natural Science Foundation of China(Project No.51573103,No.21274094)2019 Foundation Research fostering project 21 and postdoctoral fund(2019SCU12007)from SiChuan University
文摘Bacterial infections are a major cause of chronic infections.Thus,antibacterial material is an urgent need in clinics.Antibacterial nanofibers,with expansive surface area,enable efficient incorporation of antibacterial agents.Meanwhile,structure similar to the extracellular matrix can accelerate cell growth.Electrospinning,the most widely used technique to fabricate nanofiber,is often used in many biomedical applications including drug delivery,regenerative medicine,wound healing and so on.Thus,this review provides an overview of all recently published studies on the development of electrospun antibacterial nanofibers in wound dressings and tissue me-dicinal fields.This reviewer begins with a brief introduction of electrospinning process and then discusses electrospun fibers by incorporating various types of antimicrobial agents used as in wound dressings and tissue.Finally,we finish with conclusions and further perspectives on electrospun antibacterial nanofibers as 2D biomedicine materials.
基金the National Natural Science Foundation(No.52073187)NSAF Foundation(No.U2230202)for their financial support of this project+3 种基金National Natural Science Foundation(No.51721091)Programme of Introducing Talents of Discipline to Universities(No.B13040)State Key Laboratory of Polymer Materials Engineering(No.sklpme2022-2-03)support of China Scholarship Council
文摘Pre-polymerized vinyl trimethoxy silane(PVTMS)@MWCNT nano-aerogel system was constructed via radical polymerization,sol-gel transition and supercritical CO_(2)drying.The fabricated organic-inorganic hybrid PVTMS@MWCNT aerogel structure shows nano-pore size(30-40 nm),high specific surface area(559 m^(2)g^(−1)),high void fraction(91.7%)and enhanced mechanical property:(1)the nano-pore size is beneficial for efficiently blocking thermal conduction and thermal convection via Knudsen effect(beneficial for infrared(IR)stealth);(2)the heterogeneous interface was beneficial for IR reflection(beneficial for IR stealth)and MWCNT polarization loss(beneficial for electromagnetic wave(EMW)attenuation);(3)the high void fraction was beneficial for enhancing thermal insulation(beneficial for IR stealth)and EMW impedance match(beneficial for EMW attenuation).Guided by the above theoretical design strategy,PVTMS@MWCNT nano-aerogel shows superior EMW absorption property(cover all Ku-band)and thermal IR stealth property(ΔT reached 60.7℃).Followed by a facial combination of the above nano-aerogel with graphene film of high electrical conductivity,an extremely high electromagnetic interference shielding material(66.5 dB,2.06 mm thickness)with superior absorption performance of an average absorption-to-reflection(A/R)coefficient ratio of 25.4 and a low reflection bandwidth of 4.1 GHz(A/R ratio more than 10)was experimentally obtained in this work.
文摘In this work,Epoxidized natural rubber/sawdust short fiber(ENR-50/SD)composites at different fiber content(5,10,15 and 20 phr)and size(fine size at 60–100μm and coarse size at 10–20 mm)were prepared using two-roll mill and electrical-hydraulic hot press machine respectively.Curing characteristics,water uptake,tensile,morphological,physical,and thermal properties of the composites were investigated.Results indicated that the scorch time and cure time became shorter whereas torque improved as SD content increase.Though the decline of tensile strength and elongation at break values,modulus,hardness and crosslinking density have shown enhancements with the increasing of SD content.The water uptake percentage of all samples has shown an increasing as SD content increase.However,the low SD content,particularly fine size have presented lower water uptake.The temperature of weight%loss(5 and 50 wt%loss)of 5 phr SD(low content)have recorded higher temperature compared to 20 phr SD(high content)in the rubber composites,which indicated higher thermal stability.The fine size of SD has recorded better overall properties than SD coarse size at same loading in the rubber composites.
基金supported by the Tianfu Yongxing Laboratory Organized Research Project Funding(Grant No.2023KJGG12)the State Key Laboratory of Polymer Materials Engineering(Grant No.sklpme2022-3-20)+1 种基金the Joint Project for Talent Innovation Sharing Alliance of Quanzhou(Grant No.2022C001L)the Opening Project of Guangxi Key Laboratory of Calcium Carbonate Resources Comprehensive Utilization(Grant No.HZXYKFKT202306).
文摘The rapid advancement of flexible electronics creates an urgent demand for high-performance printed electronic materials.MXene-based inks have been widely studied and used for screen-printing electronics,while they usually suffer from poor screen-printability and inadequate mechanical properties of the printed coatings.Therefore,we incorporate 2,2,6,6-tetramethylpiperidinooxy oxidized cellulose nanofibers into MXene ink to regulate its rheology and enhance printability on both porous A4 paper and compact polyethylene terephthalate substrates.The introduction of cellulose enables precise control over the rheology and microstructure of the resultant MXene coatings.Critically,the strong interfacial hydrogen bonding and physical entanglement between cellulose and MXene contribute to the substantial enhancements of the mechanical properties and structural stability of the resultant composite coatings,where a remarkable 9.04-fold increase of hardness and a 1.74-fold increase of Young’s modulus are achieved.The interfacial binding strength between the coating and substrate is also well enhanced with the anchoring of cellulose.This work thereby presents a promising strategy for the design and fabrication of flexible screen-printed electronics.
