再生纤维素/聚乙烯醇/壳聚糖/二氧化钛抗菌复合膜的制备及性能

以微晶纤维素(MCC)和聚乙烯醇(PVA)为原料,1-丁基-3-甲基咪唑氯盐([Bmim]Cl)为溶剂,通过MCC溶解再生与PVA共混制备再生纤维素(RGC)/PVA基膜,并利用壳聚糖(CS)和纳米二氧化钛(TiO₂)共混液包覆方法制备RGC/PVA/CS/TiO₂抗菌复合膜。通过FT-IR、XRD和SEM对复合膜的形貌和结构进行表征,并对复合膜的热学、力学、光学、阻隔和抑菌等性能进行测试分析。研究结果表明：壳聚糖和二氧化钛成功复合于纤维素基膜,RGC/PVA/CS/TiO₂复合膜的热分解主要由CS-TiO₂包覆层和RGC/PVA基膜的分解构成。与再生纤维素(RGC)膜相比,当TiO₂质量分数为0.2%时,RGC/PVA/CS/TiO₂复合膜的拉伸强度提升了39.28%,断裂伸长率提升了51.66%,透光率保持在88.72%,氧气透过率下降了47.77%,且对大肠杆菌、金黄色葡萄球菌和枯草杆菌具有良好的抑制作用。     

鱼鳞明胶/壳聚糖/薰衣草精油抗菌复合膜制备及性能

以鱼鳞明胶(SG)和壳聚糖(CS)为原料,薰衣草精油(LEO)为抗菌剂,通过共混法制备抗菌复合膜,通过FTIR、XRD、SEM和热重分析对复合膜的形貌和结构进行表征及对力学、光学、阻隔、抑菌等性能测试分析。结果表明,LEO与SG/CS基膜较好复合,与SG/CS基膜相比,当LEO添加量为1%时,复合膜具有良好的力学强度(26.36 MPa),断裂伸长率提升了12.96%；透明度有所下降,透光率为70.50%；耐水性能和水蒸气阻隔性能显著增强,含水率、水溶性和水蒸汽透过率分别下降了22.48%、30.49%和26.03%；DPPH自由基清除率提高了247.88%,抗氧化性显著提高；同时对大肠杆菌和金黄色葡萄球菌具有良好的抑菌作用。     

聚乙烯醇/淀粉/凤仙透骨草提取物复合膜制备及性能

以聚乙烯醇(Polyvinyl alcohol,PVA)、淀粉(Starch,ST)为原料,凤仙透骨草提取物(Impatiens balsamina extract,IBE)为抗菌剂,通过共混法制备抗菌复合膜,通过FTIR、XRD、SEM和热重分析对复合膜的形貌和结构进行表征及对力学、光学、阻隔、抑菌等性能测试分析。结果表明,IBE与PVA/ST基膜复合良好,制备的PVA/ST/IBE抗菌复合膜对大肠杆菌、白色葡萄球菌和枯草杆菌具有良好的抑菌作用,抑菌性能随着IBE含量的增加而逐渐提高；同时具有良好的力学强度,IBE添加量为12.5 mL的复合膜拉伸强度达到22.97±0.68 MPa,断裂伸长率相比PVA/ST基膜提升了79.22%；透明度有所下降,透光率下降了11.90%；氧气阻隔性能良好,氧气透过系数为1.771±0.196×10_-12 ^cm₃^.cm/(cm₂^.s.Pa),在环保包装、食品保鲜等领域具有广阔的应用前景。     

纳米纤维素/壳聚糖/明胶复合膜的制备及其性能研究

以明胶（Gel）、壳聚糖（CS）、纳米纤维素（NCC）为原料,采用溶液共混法制备了不同NCC和CS质量比的纳米纤维素/壳聚糖/明胶复合膜。采用紫外-可见分光光度计、扫描电镜（SEM）、红外光谱仪（FT-IR）、X射线衍射仪（XRD）、热分析仪（TGA）和质构仪对所制备复合膜的透光性能、显微结构、化学结构、晶体结构、热学性能和力学性能进行了分析。结果表明：纳米纤维素、壳聚糖、明胶之间形成相互作用较强的网络结构。复合膜表面光滑,分散均匀,具有良好的相容性。随着纳米纤维素含量的增加,复合膜透光率呈下降的趋势。与壳聚糖膜相比,复合膜的热稳定性显著提高。当纳米纤维素与壳聚糖质量比为7：1时,复合膜拉伸强度最高可达到33 MPa,断裂伸长率可达到14.9%,吸水率最大值可达到341%。     

交联壳聚糖/蒙脱土复合膜的制备及性能研究

以壳聚糖（CS）为基质材料，蒙脱土（MMT）为填料，采用戊二醛（GA）交联改性并结合溶液插层法制备了交联壳聚糖/蒙脱土（CS/GA/MMT）复合膜。通过扫描电子显微镜、X射线衍射仪、红外光谱仪及热重分析仪对复合膜的结构进行了表征，考察了MMT用量对复合膜的吸水性能、水蒸气阻隔性能和力学性能的影响。结果表明，交联改性CS可提高CS膜的耐水性，CS/GA膜的吸水率较CS膜降低了9.6 %；MMT可提高复合膜的耐水性、水蒸气阻隔性能、力学性能和热稳定性；当MMT的用量为CS质量的5 %时，复合膜的各项性能较好，吸水率、水蒸气透过率和断裂伸长率较CS膜分别降低了37.3 %、36.7 %和41.9 %，且拉伸强度提高了160.5 %。     

纳米纤维素晶须-壳聚糖/聚乙烯醇复合膜性能与细胞相容性

以椰壳纤维为原料,制备了纳米纤维素晶须,用硅烷偶联剂对纳米纤维素晶须进行改性,将改性后纳米纤维素晶须与壳聚糖、聚乙烯醇共混,采用溶液浇铸法制备了改性纳米纤维素晶须-壳聚糖/聚乙烯醇复合膜。采用FTIR、DSC、TG、XRD和SEM对改性纳米纤维素晶须-壳聚糖/聚乙烯醇复合膜的结构、热性能、结晶行为和形貌进行表征与分析,对复合膜的力学性能和水接触角进行测试,将成纤维细胞L929接种到复合膜上,对其进行细胞相容性实验。结果表明,添加改性纤维素晶须,能够使壳聚糖/聚乙烯醇复合膜的热性能、结晶行为和力学性能提高,成纤维细胞在复合膜上具有较好的黏附和生长,制备的纳米纤维素晶须-壳聚糖/聚乙烯醇复合膜具有良好的综合性能和细胞相容性。     

PVA/活性炭微胶囊复合膜的制备与性能研究

以壳聚糖为壁材、活性炭为芯材,采用乳化-固化法制备了壳聚糖包覆的活性炭微胶囊,并将其与聚乙烯醇(PVA)复合,得到PVA/活性炭微胶囊复合膜。利用光学显微镜、扫描电镜、红外光谱等手段确定了制备微胶囊的最佳工艺参数,并考察了微胶囊用量对PVA复合膜性能的影响。结果表明:当壳聚糖用量为1.5%,乳化剂用量为1.5%,油/水相比为5:1,交联剂用量为1.0 ml,芯壁比为1:2时,可制备出成球效果较好的壳聚糖包覆的活性炭微胶囊;活性炭经壳聚糖包覆后可提高其与PVA的相容性,少量微胶囊的添加即可有效改善PVA复合膜的力学、阻隔等性能。     

壳聚糖-多巴胺/蒙脱土复合膜的制备和抗水性能研究

采用京尼平（genipin）作为交联剂制备得到壳聚糖-多巴胺/蒙脱土复合膜。结果表明,京尼平交联的多巴胺添加到壳聚糖/蒙脱土中制备得到的壳聚糖-多巴胺/蒙脱土复合膜的抗水性能显著增强。同时,对不同pH值（2、4.5、9和11）水溶液的抗水性能也明显增强。复合膜的强度性能随多巴胺用量增加而增大。XRD结果表明,京尼平的加入使壳聚糖和蒙脱土分子重新排列。抗水性能的增强与京尼平交联后形成的聚多巴胺密切相关。这对开发壳聚糖生物基膜材料提供了有价值的理论基础和实践意义。     

一种壳聚糖/纳米纤维素复合膜的制备及性能研究

采用流延法制备了壳聚糖/纳米纤维素复合膜。探究了纳米纤维素和壳聚糖不同质量比时复合膜的各项性能:表征了膜的形貌,测定了复合膜的机械性能、热收缩性、吸水性、降解性、热稳定性。结果表明:复合膜中壳聚糖和纳米纤维素混合均匀,纳米纤维素和壳聚糖质量比为10%的复合膜吸水及降解性好,CNC质量比为50%时,膜拉伸强度最大,比单纯壳聚糖膜提升了154%。     

Ag NPs改性鱼鳞明胶-琼脂复合膜的制备及性能表征

利用鱼鳞明胶作为还原剂和稳定剂制备银纳米颗粒（silver nanoparticles, Ag NPs），研究Ag NPs添加量（0.04wt%-0.2wt%）对鱼鳞明胶-琼脂复合膜的理化性能和抗菌性能的影响。通过透射电子显微镜和X射线粉末衍射对合成的Ag NPs进行表征，结果表明制得Ag NPs为球形形貌，平均粒径为9.3 ?1.8 nm。随着Ag NPs添加量的增加，鱼鳞明胶-琼脂复合膜的色泽变黄渐深，透明度下降，对紫外和可见光的吸收增强，同时，复合膜的断裂延展性、水蒸气阻隔性能和耐水性能显著增强，而厚度和抗拉强度却无明显变化。FTIR和热重分析结果表明，Ag NPs与膜基质间存在化学相互作用，并在一定程度上改善了复合膜的热稳定性。抑菌环实验结果显示，复合膜可以在0.04wt%-0.2wt%较低的银浓度下实现良好的抗菌效果。研究结果将为鱼鳞明胶可降解抗菌包装材料的开发提供新思路。     

Improvement of the thermal transport performance of a poly(vinylidene fluoride) composite film including silver nanowire

The miniaturization trend of electronic devices requires that components have a high heat dissipation in industrial applications and in daily life. In this context, a highly thermally conductive film was fabricated with silver nanowire (AgNW) and poly(vinylidene fluoride) (PVDF) with a bar‐coating method. The thermal transport performance and mechanism of the AgNW/PVDF composite film were investigated. The through‐plane and in‐plane thermal conductivity of the AgNW/PVDF composite film reached 0.31 and 1.61 W m^?1 K^?1, respectively; these values far exceeded those of the pristine PVDF film. The experiment illustrated that the thermally conductive pathways formed successfully in the PVDF substrate with the addition of AgNW, and the heat tended to transfer along the thermally conductive pathway rather than along the PVDF substrate. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43554.     

醋酸纤维素/壳聚糖复合膜制备与性能优化

为拓展醋酸纤维素(CA)在可降解包装材料中的应用,采用溶液共混法制备了醋酸纤维素(CA)和壳聚糖(CS)复合膜,研究了CS含量对CA/CS二元复合膜性能的影响。通过观察并分析复合膜的形貌、断面结构、化学键发现,CS能够充分结合膜内外的孔隙结构,两者之间强烈的相互作用增强了复合膜的各项性能。性能测试结果表明,当CS含量为10%时,复合膜的力学性能达到最大,断裂伸长率及抗拉强度分别增加12.37%和38.62 MPa,降解损失率提高了50.14%。同时,抑制了大肠杆菌及金黄色葡萄球菌的生长,抗菌率最高能够达到73.9%和54.6%。因此,CS在提高CA膜的力学性能和降解性能的同时,还赋予了复合膜优异的抗菌性。     

改性纤维素和壳聚糖共混膜的制备及性能研究

将水溶性的纤维素衍生物——羟乙基纤维素与壳聚糖乙酸水溶液用溶液浇铸法制得羟乙基纤维素/壳聚糖(HEC/CS)共混膜。确定了该共混膜的最佳制备条件,并测试了其力学性能和生物降解性能。结果表明:HEC/CS共混膜具有好的抗菌性。     

Graphene/silver nanowire sandwich structures for transparent conductive films

We report a simple graphene/silver nanowire (AgNW)/graphene sandwich structure that can be used to prepare highly transparent conductive films; the electrical conductivity of this structure is superior to those of pure AgNW or graphene/AgNW films. Upon increasing the graphene content, the ratio of the direct current (DC) conductivity to the optical conductivity of the three-layer graphene/AgNW/graphene film increased from 4.7 to 44, primarily as a result of connecting and clipping effects. At low contents of AgNW, the graphene played a role of connecting the AgNWs, thereby increasing the DC conductivity by nearly seven orders of magnitude relative to that of pure AgNW films; when the AgNW content was high, the DC conductivity was also enhanced, by 23.8-fold. Observing the second-order zone-boundary phonons, the enhancement in conductivity resulted mainly from tighter contact between the AgNWs, arising from restacking of the top and bottom graphene sheets.     

Large-size graphene microsheets as a protective layer for transparent conductive silver nanowire film heaters

A new strategy is reported for the fabrication of silver nanowire (AgNW) film heaters using reduced small/or large-size graphene oxide (rSGO or rLGO) sheets as an over-coating protective layer. The results show that ultrathin rLGO microsheets provide the best combination of protective effect and electrical properties on AgNW networks and thus could enable the design of high-performance transparent film heaters. As a consequence, good optical transparency and electrical conductivity, good oxidation resistance and thermal stability, and good heating performances are achieved with as-made rLGO/AgNW film heaters. Specifically, the rLGO/AgNW hybrid film annealed at 700 °C shows a low sheet resistance of 27 Ω sq⁻¹ and a good optical transparency of 80%. Furthermore, it exhibits good heating characteristics and defrosting performance at low voltages. The results presented here may pave the way for a new promising application of rLGO/AgNW hybrid film in transparent film heaters and other electrical devices.     

High performance of carbon nanotubes/silver nanowires-PET hybrid flexible transparent conductive films via facile pressing-transfer technique

To obtain low sheet resistance, high optical transmittance, small open spaces in conductive networks, and enhanced adhesion of flexible transparent conductive films, a carbon nanotube (CNT)/silver nanowire (AgNW)-PET hybrid film was fabricated by mechanical pressing-transfer process at room temperature. The morphology and structure were characterized by scanning electron microscope (SEM) and atomic force microscope (AFM), the optical transmittance and sheet resistance were tested by ultraviolet-visible spectroscopy (UV-vis) spectrophotometer and four-point probe technique, and the adhesion was also measured by 3M sticky tape. The results indicate that in this hybrid nanostructure, AgNWs form the main conductive networks and CNTs as assistant conductive networks are filled in the open spaces of AgNWs networks. The sheet resistance of the hybrid films can reach approximately 20.9 to 53.9 Ω/□ with the optical transmittance of approximately 84% to 91%. The second mechanical pressing step can greatly reduce the surface roughness of the hybrid film and enhance the adhesion force between CNTs, AgNWs, and PET substrate. This process is hopeful for large-scale production of high-end flexible transparent conductive films.     

Electrical behavior and positive temperature coefficient effect of graphene/polyvinylidene fluoride composites containing silver nanowires

Polyvinylidene fluoride (PVDF) composites filled with in situ thermally reduced graphene oxide (TRG) and silver nanowire (AgNW) were prepared using solution mixing followed by coagulation and thermal hot pressing. Binary TRG/PVDF nanocomposites exhibited small percolation threshold of 0.12 vol % and low electrical conductivity of approximately 10^-7 S/cm. Hybridization of TRGs with AgNWs led to a significant improvement in electrical conductivity due to their synergistic effect in conductivity. The bulk conductivity of hybrids was higher than a combined total conductivity of TRG/PVDF and AgNW/PVDF composites at the same filler loading. Furthermore, the resistivity of hybrid composites increased with increasing temperature, giving rise to a positive temperature coefficient (PTC) effect at the melting temperature of PVDF. The 0.04 vol % TRG/1 vol % AgNW/PVDF hybrid exhibited pronounced PTC behavior, rendering this composite an attractive material for making current limiting devices and temperature sensors.     

Direct electrospinning of Ag/polyvinylpyrrolidone nanocables

Core-sheath silver nanowire/polyvinylpyrrolidone (AgNW/PVP) nanocables have been fabricated via an efficient single-spinneret electrospinning method. The core-sheath structure is revealed by combining several characterization methods. A possible formation mechanism of the AgNW/PVP nanocable involving a strong stretching during the electrospinning process is proposed. Further, electrical measurements were performed on AgNW/PVP nanocables as well as bare AgNWs, which indicated the nanocables became insulating due to the isolation of highly conductive AgNWs by insulating PVP sheath. Therefore, the described fabrication method holds potential for the fabrication of low-cost metal/polymer composite materials for nanoelectronic applications in general.