Chitosan as an antibacterial agent and heparin as an anti-adhesive agent were alternatively deposited onto aminolyzed poly(ethylene terephthalate)(PET) to construct anti-adhesive and antibacterial multilayer films.The...Chitosan as an antibacterial agent and heparin as an anti-adhesive agent were alternatively deposited onto aminolyzed poly(ethylene terephthalate)(PET) to construct anti-adhesive and antibacterial multilayer films.The contact angle and UV data verified the progressive build-up of the multilayer film by alternate deposition of the polyelectrolytes.PRT experiment and in vitro antibacterial assay indicated that the multilayer-modified PET films had much better hemocompatibility and much stronger antibacterial performance than(unmodified) PET.Such an easy processing and shape-independent method to prepare an anti-adhesive and(antibacterial) surface may have a good potential for surface modification of cardiovascular devices.展开更多
Carbon nanotubes(CNTs)incorporated polymeric composites have been extensively investigated for microwave absorption at target frequencies to meet the requirement of radar cross-section reduction.In this work,a strateg...Carbon nanotubes(CNTs)incorporated polymeric composites have been extensively investigated for microwave absorption at target frequencies to meet the requirement of radar cross-section reduction.In this work,a strategy of efficient utilization of CNT in producing CNT incorporated aramid papers is demonstrated.The layer-by-layer self-assembly technique is used to coat the surfaces of meta-aramid fibers and fibrils with CNT,providing novel raw materials available for the large-scale papermaking.The hierarchical construction of CNT networks resolves the dilemma of increasing CNT content and avoiding the agglomeration of CNT,which is a frequent challenge for CNT incorporated polymeric composites.The composite paper,which contains abundant heterogeneous interfaces and long-range conductive networks,is capable of reaching a high permittivity and dielectric loss tangent at a low CNT loading,its complex permittivity is,so far,adjustable in the range of(1.20−j0.05)to(25.17−j18.89)at 10 GHz.Some papers with optimal matching thicknesses achieve a high-efficiency microwave absorption with a reflection loss lower than−10 dB in the entire X-band.展开更多
Using layer-by-layer self-assembly technique,we have successfully constructed nanostructured composite films of conjugated polymer (sulfonic acid ring substituted polyaniline, SPAn)/ semiconductor nanoparticles(Q-CdS)...Using layer-by-layer self-assembly technique,we have successfully constructed nanostructured composite films of conjugated polymer (sulfonic acid ring substituted polyaniline, SPAn)/ semiconductor nanoparticles(Q-CdS).The processes synthesis have been studied by UV-Vis, contact angle measurement, XPS and AFM techniques.The results indicated that the self-assembly processes were dependent on the pH of the solution of each component and the doping time.It has been found that the roughness of the assembled nano-composite films increases as the layer number increases.The main reason can be attributed to the generation of adsorption defects from partially adsorbed film surface in film fabrication processes.展开更多
Biodegradable multilayer films of alternating poly- L -lysine(PLL) and deoxyribonucleic acid(DNA) layers were fabricated onto quartz substrates by the layer-by-layer(LbL) self-assembly method. UV-Visible spectra showe...Biodegradable multilayer films of alternating poly- L -lysine(PLL) and deoxyribonucleic acid(DNA) layers were fabricated onto quartz substrates by the layer-by-layer(LbL) self-assembly method. UV-Visible spectra showed that PLL and DNA can successfully be adsorbed and form multilayer films via LbL. Degradation experiments were carried out with enzymes. AFM was utilized to measure the changes of thickness of multilayer films. The gradual decrease of thickness of multilayer films with the increase of degradation time was observed. In our experiments, about 85% of films was degraded in 35 h. Our study provided a novel gene delivery system using LbL method,which may be applied to gene therapy.展开更多
文摘Chitosan as an antibacterial agent and heparin as an anti-adhesive agent were alternatively deposited onto aminolyzed poly(ethylene terephthalate)(PET) to construct anti-adhesive and antibacterial multilayer films.The contact angle and UV data verified the progressive build-up of the multilayer film by alternate deposition of the polyelectrolytes.PRT experiment and in vitro antibacterial assay indicated that the multilayer-modified PET films had much better hemocompatibility and much stronger antibacterial performance than(unmodified) PET.Such an easy processing and shape-independent method to prepare an anti-adhesive and(antibacterial) surface may have a good potential for surface modification of cardiovascular devices.
基金the National Natural Science Foundation of China(No.U21A2093).
文摘Carbon nanotubes(CNTs)incorporated polymeric composites have been extensively investigated for microwave absorption at target frequencies to meet the requirement of radar cross-section reduction.In this work,a strategy of efficient utilization of CNT in producing CNT incorporated aramid papers is demonstrated.The layer-by-layer self-assembly technique is used to coat the surfaces of meta-aramid fibers and fibrils with CNT,providing novel raw materials available for the large-scale papermaking.The hierarchical construction of CNT networks resolves the dilemma of increasing CNT content and avoiding the agglomeration of CNT,which is a frequent challenge for CNT incorporated polymeric composites.The composite paper,which contains abundant heterogeneous interfaces and long-range conductive networks,is capable of reaching a high permittivity and dielectric loss tangent at a low CNT loading,its complex permittivity is,so far,adjustable in the range of(1.20−j0.05)to(25.17−j18.89)at 10 GHz.Some papers with optimal matching thicknesses achieve a high-efficiency microwave absorption with a reflection loss lower than−10 dB in the entire X-band.
文摘Using layer-by-layer self-assembly technique,we have successfully constructed nanostructured composite films of conjugated polymer (sulfonic acid ring substituted polyaniline, SPAn)/ semiconductor nanoparticles(Q-CdS).The processes synthesis have been studied by UV-Vis, contact angle measurement, XPS and AFM techniques.The results indicated that the self-assembly processes were dependent on the pH of the solution of each component and the doping time.It has been found that the roughness of the assembled nano-composite films increases as the layer number increases.The main reason can be attributed to the generation of adsorption defects from partially adsorbed film surface in film fabrication processes.
文摘Biodegradable multilayer films of alternating poly- L -lysine(PLL) and deoxyribonucleic acid(DNA) layers were fabricated onto quartz substrates by the layer-by-layer(LbL) self-assembly method. UV-Visible spectra showed that PLL and DNA can successfully be adsorbed and form multilayer films via LbL. Degradation experiments were carried out with enzymes. AFM was utilized to measure the changes of thickness of multilayer films. The gradual decrease of thickness of multilayer films with the increase of degradation time was observed. In our experiments, about 85% of films was degraded in 35 h. Our study provided a novel gene delivery system using LbL method,which may be applied to gene therapy.
