Fabrication of Au/SiO2 Nanocomposite Films by Self-Assembly Multilayer Method

Gold colloid was prepared by chemical reduction of hydrogen tetrachloroaurate, polyelectrolyte/gold nanoparticle/silica nanoparticie composite films were fabricated via an electrostatic self-assembly multilayer method, and composite films of gold nanoparticle dispersed in silica matrix were formed by heat-treating the polyelectrolyte/gold nanoparticle/silica nanoparticle composite films to eliminate the polyelectrolyte. The obtained composite films were investigated with UV-vis, TEM, AFM and XRD. The results show that the self-assembly multilayer method is a promising process to produce composite films of gold nanoparticle-dispersed in organic and/or inorganic matrixes.     

Effect of γ-ray irradiation on the microstructure and self-heating property of carbon fiber/polyethylene composite films

High-density polyethylene composite films filled with various contents of carbon fiber (CF) were manufactured by melt mixing. The electrical and self-heating properties of the composite films were investigated. The composite films containing 10 wt% CF were exposed to γ-ray irradiation. The structural, morphological, and self-heating properties of the irradiated composite films were examined. The results indicated that the surface temperature (T_s) of the composite films was strongly dependent on the applied voltage and filler content. The T_s of the irradiated composite films was higher than that of the non-irradiated films, which contributed to the lower thermal expansion and the higher degree of crystallization of the irradiated composite films. In addition, the mechanical properties of the irradiated composite films were significantly improved. Using a rechargeable battery as the applied voltage source to evaluate the self-heating property of the irradiated composite films, a heating temperature of 54.2 °C was achieved, which lasted for 6 h.     

Wood cell wall mimicking for composite films of spruce nanofibrillated cellulose with spruce galactoglucomannan and arabinoglucuronoxylan

Two hemicelluloses (HCs), galactoglucomannan (GGM) and arabinoglucuronoxylan (AGX), and nanofibrillated cellulose (NFC) were isolated from spruce wood and used for the preparation of composite films containing high amounts of cellulose, i.e. 85 and 80 wt% of NFC, respectively. The films were prepared in two ways: (i) by the pre-sorption of HCs on NFC and (ii) by the mixing of components in the usual way. Pre-sorption was applied in an attempt to mimic the carbohydrate biosynthesis pattern during wood cell wall development, where HCs were deposited on the cellulose fibrils prior to lignification taking place. It was assumed that pre-sorption would result in a better film-forming as well as stronger and denser composite films. The mechanical, thermal, structural, moisture sorption and oxygen barrier characteristics of such composite films were tested in order to examine whether the performance of composite films prepared by pre-sorption was better, when compared to the performance of composite films prepared by mixing. The performance of composite films was also tested with respect to the HCs used. All the films showed quite similar barrier and mechanical properties. In general, stiff, strong and quite ductile films were produced. The moisture sorption of the films was comparably low. The oxygen barrier properties of the films were in the range of commercially used poly ethylene vinyl alcohol films. However, the pre-sorption procedure for the preparation of composite films resulted in no additional improvement in the performance of the films compared to the corresponding composite films that had been prepared using the mixing process. Almost certainly, the applied mixing process led to an optimal mixing of components for the film performance achieved. The GGM contributed to a somewhat better film performance than the AGX did. Indications were observed for stronger interactions between the GGM and NFC than that for the AGX and NFC.     

铜基碳纳米管复合薄膜电沉积制备工艺

为获得碳纳米管分布均匀且导电性良好的铜基碳纳米管复合材料,用超声辅助搅拌复合电沉积方法制备了Cu/MWCNT复合薄膜.采用扫描电子显微镜(SEM)、四探针电阻率仪等研究了电沉积过程中复合电镀液中碳纳米管浓度、电镀液p H值、脉冲电流密度等各项电沉积工艺参数以及不同退火温度对复合薄膜的组织形貌和电阻率的影响规律.结果表明:改变镀液中碳纳米管含量和电镀液的p H值可以改变镀层中碳纳米管的含量及分布,MWCNTs质量浓度升高到2 g/L时,复合薄膜中MWCNTs的质量分数达2.17%;改变电流密度可以细化镀层组织并改善碳纳米管在镀层中的分布,从而提高镀膜的致密度并降低镀层的电阻率;合适的热处理温度可以改善薄膜结晶度和致密度,并提高导电性.镀液中MWCNTs质量浓度为2 g/L,电镀液p H为2,电流密度为20 A/dm2,电镀时温度在25℃且加入超声辅助搅拌时,所得到的复合镀膜经400℃退火后电阻率最低.     

具有多层结构的聚合物复合薄膜的介电和磁性能

采用旋涂法制备了 Fe3 O4/聚偏氟乙烯(PVDF)复合薄膜(A)、多壁碳纳米管(MWCNT)/PVDF复合薄膜(B)以及纯PVDF薄膜(P)。利用热压法制备具有3层结构的AAA、ABA及APA 复合薄膜。为了探究层状结构对复合薄膜介电和磁性能的影响,制备了单层膜A作为对比(厚度与AAA复合薄膜相同)。分别研究了薄膜的介电和磁性能。结果表明：由于界面效应,同等厚度的AAA复合薄膜较A膜而言具有较高的介电常数;以B和P薄膜替代AAA结构中间层薄膜后,其中ABA复合薄膜的介电常数高于AAA及APA复合薄膜,同时保持较低的介电损耗。对于磁性能,层状结构对复合薄膜的饱和磁化强度及矫顽力均无明显的影响,而ABA复合薄膜的饱和磁化强度高于AAA及APA复合薄膜,且ABA和APA复合薄膜的矫顽力增加。层状结构设计不仅能够调节复合材料的介电性能和磁性能,而且有利于不同纳米填料的分散,为制备多功能聚合物复合材料提供了一定的借鉴作用。     

Size-controlled Ag nanoparticle modified WO3 composite films for adjustment of electrochromic properties

Size-controllable Ag nanoparticle ultrathin films, which were fabricated by vacuum deposition method from high purity Ag wire onto cleaned indium tin oxide conducting glass, have different color fabricated by variation of preparation conditions. The UV/Vis spectra showed that optical absorption peak of these Ag nanoparticle films can be tuned in a range from 457 nm to >650 nm. Scanning electron microscopy images showed that with increasing film thickness Ag particle size was larger. Ag/WO₃ composite films were prepared by cathodic electrodeposition of WO₃ onto the surface of Ag nanoparticle films. Spectroelectrochemistry and electrochromic properties of the resulting composite films were characterized. It was found that the electrochemical and electrochromatic properties of the composite films were adjustable with change the size of Ag nanoparticles in the composite films. Compared with a single component system of WO₃, a substantial enhancement in the electroactive and electrochromic performance for the Ag embedded WO₃ composite system was clearly observed.     

纳米银/壳聚糖复合膜的制备及性能

目的将纳米银(AgNPs)加入到壳聚糖(CS)中制备AgNPs复合膜,探究AgNPs的含量(质量分数为0.5%,1%,2%)对复合膜的结构与性能的影响。方法采用柑橘皮提取液还原合成AgNPs粒子,与CS通过共混流延法制备复合膜,测定复合膜的红外光谱、微观形貌、溶胀率、溶解度、拉伸性能和抑菌效果等。结果采用柑橘皮提取液还原合成的AgNPs在CS基材中具有较好的分散性。当AgNPs的质量分数为1%及以上时,复合膜的结晶度降低,溶胀率和溶解度显著增加,拉伸强度和断裂伸长率均显著降低。复合膜对大肠杆菌和金黄色葡萄球菌的生长抑制效果均随AgNPs含量的增加而显著增强。结论AgNPs在CS基材中分散良好,并大大增强了复合膜的抗菌活性。     

TiO2--Ta2O5 composite thin films deposited by radio frequency ion-beam sputtering

TiO2--Ta2O5 composite films were prepared by a radio frequency ion-beam sputtering deposition process, and the refractive indices and extinction coefficients of the composite films were found to be between those of the TiO2 and Ta2O5 films. The structure of the as-deposited films was amorphous, and the surface roughness was approximately 0.1 nm. The residual stress of the composite films was less than that of pure TiO2 film. The structure of the composite films after annealing was amorphous, with low surface roughness and slightly increased residual stress. The film containing 6.3% TiO2 displayed better properties than either the pure TiO2 or the pure Ta2O5 film.     

MOF/聚合物复合膜基底的研究进展

目的对国内外MOF/聚合物复合膜的基底种类进行综述,并总结聚合物基底的表面改性或修饰方法的研究进展,从而在一定程度上丰富MOF/聚合物复合膜的种类。方法总结和分析MOF/聚合物复合膜的基底,即选择聚酯、聚酰胺、聚乙烯醇、聚苯乙烯和聚砜等聚合物材料作为基底的最新研究成果;对聚合物基底的表面改性或修饰方法及主要机理进行阐述;展望MOF/聚合物复合膜的应用前景。结果MOF/聚合物复合膜的基底种类以及基底表面的改性或修饰方法虽呈现多样化趋势,但MOF/聚合物复合膜制备的简便性、普遍性还有待进一步提高。结论总结了现有MOF/聚合物复合膜的基底种类,并分析了其表面改性或修饰方法,为进一步开发MOF/聚合物复合膜的应用潜能打下了良好基础。     

硅基氧化物薄膜的结构及光吸收特性的研究

采用射频磁控共溅射方法制备了纳米Ge颗粒尺寸的Ge-SiO2薄膜、非晶Si-SiO2薄膜和非晶AlSiO复合薄膜，分析了样品的结构，研究发现3类样品均存在较强的吸收，对于Ge-SiO2薄膜观察到光吸收边随Ge颗粒尺寸变小而蓝移的现象，这主要是由于Ge颗粒的量子限域效应所引起的。而对于非晶样品也出现了光吸收边蓝移和能隙展宽的现象，这可能是由于样品中的杂质或缺陷等受到限域作用的结果。     

POSS对壳聚糖膜的阻湿与拉伸性能的影响

目的研究以四甲基铵基笼形聚倍半硅氧烷(Octa TMA POSS)为填料,制备壳聚糖基复合膜,对壳聚糖薄膜的水蒸气阻隔性能和力学性能进行改善。方法采用溶液共混流延法制备复合膜,测定其水蒸气透过系数、表面接触角、溶胀度、溶解度、吸附等温曲线、拉伸性能、成膜液流变性能、微观形貌和X射线衍射等。结果笼形聚倍半硅氧烷的加入可提高复合膜对水分子的阻隔性,尤其是质量分数为3%时,其水蒸气透过系数下降了15.9%。同时,壳聚糖薄膜的力学性能也得到改善,在质量分数低于5%时,壳聚糖薄膜的抗拉强度、弹性模量可同时得到提高。结论四甲基铵基笼形聚倍半硅氧烷的加入可改善壳聚糖薄膜的阻湿性能和力学性能,可大大提升其在食品包装领域的应用潜力。     

Effect of enzymatic degradation of chitosan in polyhydroxybutyrate/chitosan/calcium phosphate composites on in vitro osteoblast response

Polyhydroxybutyrate/chitosan/calcium phosphate composites are interesting biomaterials for utilization in regenerative medicine and they may by applied in reconstruction of deeper subchondral defects. Insufficient informations were found in recent papers about the influence of lysozyme degradation of chitosan in calcium phosphate/chitosan based composites on in vitro cytotoxicity and proliferation activity of osteoblasts. The effect of enzymatic chitosan degradation on osteoblasts proliferation was studied on composite films in which the porosity of origin 3D scaffolds was eliminated and the surface texture was modified. The significantly enhanced proliferation activity with faster population growth of osteoblasts were found on enzymatically degraded biopolymer composite films with α-tricalcium phosphate and nanohydroxyapatite. No cytotoxicity of composite films prepared from lysozyme degraded scaffolds containing a large fraction of low molecular weight chitosans (LMWC), was revealed after 10 days of cultivation. Contrary to above in the higher cytotoxicity origin untreated nanohydroxyapatite films and porous composite scaffolds. The results showed that the synergistic effect of surface distribution, morphology of nanohydroxyapatite particles, microtopography and the presence of LMWC due to chitosan degradation in composite films were responsible for compensation of the cytotoxicity of nanohydroxyapatite composite films or porous composite scaffolds.     

A facile synthesis of α-Ni(OH)2-CNT composite films for supercapacitor application

The α-Ni(OH)₂-CNT composite films have been successfully synthesized by a simple chemical method and their supercapacitive properties were investigated by variation of CNT. The structural, compositional, morphological, wettability and electrochemical properties of the composite films were studied by using various characterization techniques. X-ray diffraction analysis revealed that the synthesized composite films are polycrystalline in nature. FT-Raman spectroscopy result showed the characteristic Raman band of CNT and α-Ni(OH)₂ which confirmed the formation of α-Ni(OH)₂-CNT composite. SEM micrographs showed porous microstructure of the synthesized films and hydrophilic nature of the films was confirmed from wettability studies. Furthermore, the effect of the variation of CNT on the electrochemical properties of the synthesized composite films was discussed. The electrochemical performance of the composite films was studied by using cyclic voltammetry (CV) and Galvanostatic charge–discharge (GCD) techniques. The α-Ni(OH)₂-CNT composite showed highest specific capacitance of 544 F g^?1 with high retention capability of 85% after 1500th cycle and excellent cycling stability.     

分心木碳点/聚乙烯醇复合膜的制备及其在草莓保鲜的应用

目的 制备不同浓度碳点的未掺杂分心木碳点（1-CDs）/聚乙烯醇复合膜和氮掺杂分心木碳点（2-CDs）/聚乙烯醇复合膜,以延长草莓的货架期。方法 采用流延法制备复合膜,探讨不同浓度CDs对复合膜的光致发光行为、疏水性、力学性能、紫外吸收性能和阻隔性能的影响,并比较不同薄膜对草莓的保鲜效果。结果 碳点和聚乙烯醇分子内或分子间发生了较强的相互作用,碳点的加入增强了复合膜的疏水性和紫外吸收性能,2-CDs/PVA-6复合膜在60s时的接触角为65.3°,断裂伸长率和拉伸强度分别为(220.6±6.3)%、(107.55±4.9)MPa,2-CDs/PVA-6复合膜在波长300 nm时的紫外可见光透过率接近0,该复合膜对草莓的保鲜效果最好。结论 作为包装材料,2-CDs/PVA-6复合膜表现出潜在的应用价值,能够延长草莓的货架期。     

茶多酚对壳聚糖/聚乙烯醇复合膜性能的影响

目的以茶多酚为改性剂对壳聚糖/聚乙烯醇复合膜进行共混改性,制备一种综合性能良好的绿色包装材料。方法采用溶液共混法制备不同茶多酚质量分数的壳聚糖/聚乙烯醇复合膜,并对其进行红外光谱分析,以及力学性能、水溶性、气体阻隔性、抗氧化性能的测试。结果茶多酚与壳聚糖/聚乙烯醇基质间发生了分子间相互作用,当茶多酚的质量分数为2%时复合膜的综合性能最好,拉伸强度提高了4.99%,且可保持较高的断裂伸长率,水溶性、水蒸气透过率和氧气透过率分别降低了82.43%,51.40%和72.77%,抗氧化能力增强了58.54%。结论添加适量的茶多酚能够提高壳聚糖/聚乙烯醇复合膜的力学性能和耐水性,并改善其气体阻隔性和抗氧化性能。     

Biodegradable amylose films reinforced by graphene oxide and polyvinyl alcohol

Graphene oxide/amylose (GO/amylose) composite films with different amounts of graphene oxide (GO), glycerol and polyvinyl alcohol (PVA) were prepared by a solution casting method. The structure, morphologies, and properties of the films were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermal gravimetric analysis, UV–vis spectroscopy and tensile tests. The results indicated good dispersion of the GO nanosheets in the GO/amylose composite films and consequently a significant improvement in their mechanical properties. The addition of GO increased the tensile strength of the GO/amylose films, significantly. When glycerol was used as a plasticizer, the elongation at break of the films increased. When PVA was also added to the composite films, the films were mechanically strong and flexible. The incorporation of GO also decreased the moisture absorbability and UV transmittance of the films. The stability of the GO/amylose films in acidic and alkaline solutions was also studied and the films had excellent stability in both acidic and alkaline aqueous mediums.     

纳米纤维素/壳聚糖复合膜的制备和性能

目的获得力学性能和阻隔性能优异的食品包装用壳聚糖膜。方法通过超声法由糠醛渣纤维素制备纳米纤维素(NCC),将其与壳聚糖(CS)共混流延制备纳米纤维素/壳聚糖复合膜(NCC-CS)。结果复合膜中NCC质量分数为5%时,NCC-CS的拉伸强度比纯CS膜提高了30%,NCC-CS的透湿量比纯CS膜降低了24%。SEM分析结果表明NCC-CS复合膜微观结构致密。FT-IR和XRD的分析结果表明CS与NCC间存在着较强的相互作用。结论 NCC的加入对CS膜的力学性能和阻隔性能的提高有促进作用。     

SiO2含量与粒径对PLA/SiO2复合膜性能的影响

目的 为了提高聚乳酸材料的力学性能和气体阻隔性,选择二氧化硅为共混材料,通过改变二氧化硅的粒径和含量,研究SiO2对SiO2/PLA复合膜性能的影响.方法 用流延法制备二氧化硅/聚乳酸(SiO2/PLA)复合膜.采用力学性能测试、结晶性测试、热稳定测试和透氧、透水蒸汽测试等分析手段对制备的复合膜进行力学性和阻隔性的表征.结果 在PLA材料中添加适量的SiO2对复合膜的拉伸强度和弹性模量会有增强作用,并且粒径越小,增强效果越明显;粒径为50 nm,质量分数为2％时复合膜表现出更佳的力学性能.同时,随着SiO2含量的增加,氧气透过系数呈先降低后升高的趋势,在SiO2质量分数为2％时透过系数最小,复合膜的氧气阻隔性最好;不同粒径不同含量的SiO2透湿性测试结果表明,SiO2粒径为50 nm,质量分数为2％时复合膜的阻隔性效果最好.结论 二氧化硅的加入能够提升聚乳酸的弹性模量和阻隔性,并且二氧化硅的粒径和不同添加量对复合膜的性能有很大影响.     

花青素-明胶/聚乙烯醇-淀粉复合膜制备与表征

目的 制备花青素明胶/聚乙烯醇淀粉双层复合膜,以期提高花青素单层膜的综合性能.方法 采用流延法分别制备紫薯、紫甘蓝、黑米、黑枸杞、玫瑰、玫瑰茄等6种花青素明胶/聚乙烯醇淀粉双层复合膜,并对比研究膜层的微观组织结构、含水率、力学性能及光学性能.结果 从红外光谱图中可以看出,双层复合膜分子结构没有出现新的特征峰,双层膜结合方式为物理结合,没有新的结构生成,且除紫甘蓝明胶/聚乙烯醇淀粉双层复合膜外,其余复合膜均存在明显的分层界线,2层结合处膜层结构均匀致密,结合良好.不同双层膜的含水率差异显著,而双层复合膜比花青素单层膜的含水率明显降低,不同双层膜的拉伸强度和断裂伸长率差异不显著,与单层花青素明胶复合膜相比,双层复合膜的拉伸强度和断裂伸长率大幅增加,其中紫薯双层膜的拉伸强度增加了75％,断裂伸长率增加了22.9％;所有双层复合膜的透光率相差不大,均在80％以上;与花青素明胶单层膜相比,双层膜的雾度增加了20％左右.结论 制备的双层膜改善了单层膜的力学性能,提高了花青素明胶单层膜的综合性能.     

Composite films prepared by immersion deposition of manganese oxide in carbon nanotubes grown on graphite for supercapacitors

Manganese oxide/carbon nanotube (CNT) composite films on graphite were prepared by growing CNTs on the substrate using chemical vapor deposition (CVD), followed by immersion in an aqueous solution of potassium permanganate. The CVD growth created favorable conditions for deposition of the oxide on the electrode, and an aligned porous structure of the composite films, which originated from the CNT growth, could be managed. Electrochemical behaviors of the CNT and the composite films for supercapacitors were studied in 1 M Na₂SO₄ solution. While the oxide deposition in the CNT films was identified as contributing to capacitance enhancement, it was also found that a mild heat treatment could improve performance of the composite films.