富含苹果皮根皮素壳聚糖-聚乙烯醇抗氧化保鲜膜的研制

壳聚糖-PVA复合膜在食品包装领域具有可降解、抑菌、成膜性好的应用优势,但存在阻隔性能差、机械强度低、抑菌性低、热稳定性差等缺点.基于对壳聚糖-PVA复合膜性能上进行改进,将天然抗氧化成分根皮素加入其中,通过溶液复合法制备不同浓度(质量分数0%、1%、2%和3%) 富含苹果皮提取物根皮素的壳聚糖-PVA复合膜,测定其机械性质与水蒸气透过率,并对其结构进行表征.根皮素的加入增加了壳聚糖-PVA复合膜的热稳定性、拉伸强度和水蒸气透过率,降低了其断裂伸长率.用扫描电子显微镜(SEM)进一步研究了薄膜的表面和截面.此外,红外光谱(FT-IR)测试显示,在薄膜基体中形成了氢键.X-射线衍射(XRD)分析表明,根皮素的添加对壳聚糖-PVA膜的无定形性没有影响.与对照相比,富含根皮素的壳聚糖-PVA膜的抗氧化活性(ABTS和DPPH自由基清除能力和还原能力)和抗菌能力均有所提高.上述结果表明,根皮素是一种优良的添加剂,有助于壳聚糖-PVA膜的性能提高,在食品包装薄膜开发方面具有潜在应有价值.     

Preparation of narrow band gap V2O5/TiO2 composite films by micro-arc oxidation

V₂O₅/TiO₂ composite films were prepared on pure titanium substrates via micro-arc oxidation (MAO) in electrolytes consisting of NaVO₃. Their morphology and elements were characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis. Phase composition and valence states of species in the films were characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Ultraviolet-visible diffuse reflectance spectra (UV-Vis DRS) were also employed to evaluate the photophysical property of the films. The V₂O₅/TiO₂ composite films show a sheet-like morphology. Not only V₂O₅ phase appears in the films when the NaVO₃ concentration of the electrolyte is higher than 6.10 g/L and is loaded at the surface of anatase, but also V⁴⁺ is incorporated into the crystal lattice of anatase. In comparison with pure TiO₂ films the V₂O₅/TiO₂ composite films exhibit significantly narrow band gap energy. The film prepared in an electrolyte consisting of NaVO₃ with a concentration of 8.54 g/L exhibits the narrowest band gap energy, which is approximately 1.89 eV. The V₂O₅/TiO₂ composite films also have the significantly enhanced visible light photocatalytic activity. The film prepared in an electrolyte consisting of NaVO₃ with a concentration of 8.54 g/L exhibits the best photocatalytic activity and about 93% of rhodamine is degraded after 14 h visible light radiation.     

碳量子点修饰的二氧化钛纳米片阵列薄膜的构筑及光电化学性能*

为了提高纳米二氧化钛(TiO_2)的光电化学性能,首先采用水热法,以稀盐酸、钛酸丁酯和氟钛酸铵作为原料,在掺杂氟的氧化锡(FTO)导电玻璃上制备了(001)面主导的TiO_2纳米片阵列薄膜。通过电化学腐蚀法制得均一、稳定、高活性碳量子点(carbon quantum dots,CQDs),再通过电泳法将CQDs修饰到TiO_2纳米片阵列薄膜表面,形成CQDs/TiO_2纳米片阵列复合材料。利用扫描电镜(scanning electron microscope,SEM)、 X射线衍射(X-ray diffraction,XRD)、拉曼光谱、X射线光电子能谱(X-ray photoelectron spectroscopy,XPS)和紫外可见光谱(UV-vis)对复合材料的形貌、晶型、表面元素成分和光吸收能力进行表征,通过电化学工作站测试复合材料的光电化学性能。结果表明:CQDs/TiO_2复合材料为锐钛矿晶型,形貌规整均匀;CQDs修饰后TiO_2纳米片的最大吸收波长由388 nm增加到576 nm,光化学能转化率高达2.38%,光电流是TiO_2纳米片的8倍,交流阻抗减小,具有非常优异的光电化学性能。     

水热法制备TiO2-ZnO纳米棒分级结构及其光电性能研究

为了增加光电极光生电子传输通道并提高其光敏剂的负载能力,采用两步水热法制备了一种新颖的TiO_2-ZnO纳米棒分级结构。采用水热法在FTO导电玻璃基底上生长TiO_2纳米棒有序阵列膜,通过浸泡提拉在TiO_2纳米棒上包覆一层ZnO溶胶,经烧结形成ZnO种子层;再次采用水热法于TiO_2纳米棒上生长ZnO纳米棒,形成TiO_2-ZnO纳米棒分级结构,通过旋涂辅助连续离子反应分别在TiO_2纳米棒阵列和TiO_2-ZnO纳米棒分级结构中沉积光敏剂CdS纳米晶,形成CdS/TiO_2纳米棒复合膜和CdS/TiO_2-ZnO纳米分级结构复合膜。利用SEM,TEM,XRD、紫外-可见吸收光谱、瞬态光电流图谱等表征和测试手段,对样品的形貌、结构、光吸收和光电性能进行了表征和测试。结果表明,与单纯的TiO_2纳米棒阵列相比,TiO_2-ZnO分级结构可以沉积更多的CdS光敏剂,CdS/TiO_2-ZnO纳米分级结构复合膜的光吸收性能和瞬态光电流均明显优于CdS/TiO_2纳米复合薄膜。凭借优异的光电性能,TiO_2-ZnO分级结构在太阳电池光阳极材料中具有很好的应用前景。     

CdS修饰低密度TiO2纳米棒阵列复合膜的制备及光电性能

为了提高CdS光敏层在TiO₂一维纳米棒阵列中的填充率,在TiO₂种子层的基础上,采用水热法于FTO导电玻璃表面生长了棒长较短、棒间距较大的低密度TiO₂一维纳米棒阵列膜,通过化学浴沉积在TiO₂纳米棒表面包覆CdS种子层,以此为基底采用水热法于TiO₂一维纳米阵列中生长CdS光敏层。采用SEM,XRD及紫外-可见吸收光谱对不同CdS水热生长时间的TiO₂/CdS复合膜结构进行了表征,并对其光电性能进行了研究。结果表明,低密度TiO₂纳米棒阵列有利于CdS生长液在阵列中渗入形成完全包覆的CdS种子层,CdS光敏层通过水热过程在整个TiO₂纳米棒表面均匀生长,逐渐形成CdS对TiO₂纳米棒阵列的完全填充和包覆,并在阵列顶端形成由CdS纳米短棒组成的花状修饰层;CdS的修饰将TiO₂一维纳米阵列膜的光吸收拓展至可见光区,水热生长7 h所得到的TiO₂/CdS复合膜具有最高光电流。所制备的CdS修饰低密度TiO₂纳米棒复合膜在太阳电池器件中具有很好的应用前景。     

Blend films of chitosan/starch

Chitosan-starch blend films were prepared, and their structure and properties were studied by FT-IR, X-ray diffraction, SEM and measurement of tensile strength. IR spectra and SEM analysis showed that the two polysaccharides were compatible, when the starch was less than 30% by weight. From X-ray diffraction patterns of blend fllms, it was observed that crystallization of starch was inhibited, and recrystallization of chitosan was also affected by starch. Crystal form I, one of the main two crystal forms of chitosan, drastically increased in 30% starch content films. These results indicated that the interactions between chitosan and starch molecules exist in the blend films. The tensile strength of the film were improved when chitosan and starch were blended by weight ratios of 8∶2 and 7∶3, in which the highest tensile strength (781 kg/cm²) was achieved.     

淀粉链支比对淀粉/琼脂复合膜微结构及性能的影响

 采用流延法制得不同配比的淀粉/琼脂复合膜，研究了不同链支比的淀粉对淀粉/琼脂复合膜微结构及性能的影响。对制得的复合膜进行扫描电镜（SEM）观察、傅里叶红外光谱（FTIR）测试、X-射线衍射（XRD）测试、机械性能测试以及亲疏水性能测试，对不同配比淀粉/琼脂复合膜的微结构及性能进行了对比。研究结果表明，琼脂含量一定时，Waxy/琼脂复合膜的断裂伸长率小于另外两种；随着琼脂含量的增加，各复合膜的拉伸强度增加，且G50/琼脂复合膜的水接触角显著增加，而琼脂较弱的亲水性降低了复合膜表面的亲水性。     

聚氨酯/聚乙烯醇共混物若干结构与性能的关系

作者运用 SEM,动态粘弹,DSC,WAXS,应力-应变,密度测试和吸湿、透湿实验等方法,对PU/PVA 共混物的形态结构,动态力学性能,热性能,结晶性,拉伸力学性能和吸湿、透湿性等进行了系统的研究,并探讨了湿法凝固薄膜的微孔透湿性。     

Mg-2.4Nd-0.5Sr-0.3Zr生物镁合金表面耐蚀抑菌层的制备与表征

以AgNO_3溶液为介质,采用水热法在Mg-2.4Nd-0.5Sr-0.3Zr生物镁合金表面制备具有抗菌性能的耐蚀膜层,通过XRD、SEM、EDS等技术,对不同水热温度及时间条件下所制膜层的形貌及物相结构进行表征,结合电化学测试及抑菌试验,考察了水热条件对膜层耐蚀性和抗菌性能的影响。结果表明,Mg-2.4Nd-0.5Sr-0.3Zr合金表面膜层主要由层片状Mg(OH)_2和颗粒状Ag/Mg(OH)_2聚集混合组成,随着水热温度的升高及反应时间的延长,膜层厚度逐渐增加。电化学测试结果显示,膜层能有效改善合金的耐蚀性,且随着表面膜层厚度的增加,对应合金样品的耐蚀性增强。此外,经过水热处理制得的合金样品在金色葡萄球菌培养24h后,产生了明显的抑菌圈,表现出了良好的抗菌效果。     

TiO2/SiO2/GQDs双层增透膜的制备及其在太阳能板中的应用

采用溶胶-凝胶法制备了SiO₂ 和TiO₂ 纳米溶胶,采用水热法制备了石墨烯量子点（graphene quantum dots,GQDs）。为进一步提高光伏太阳能板的透光率,设计了一种TiO₂/SiO₂/GQDs双层增透膜结构。探究了薄膜的结构、自清洁性能和增透性能,并进一步讨论了GQDs在增透性中的作用。结果表明,SiO₂-TiO₂/TiO₂-GQDs结构的双层薄膜厚度为120 nm时,太阳能板上的光透过率由未涂敷的85%增加至95%。接触角实验和室外耐环境性能实验测试表明,复合膜层接触角为10°,并具有良好的亲水性和耐环境性能。此外,户外实验结果表明,涂覆该薄膜的太阳能电板发电效率提高6%。由此说明双层增透膜可有效地提高太阳能电池板的光能利用率和使用寿命,可高效地利用太阳能。     

碳纳米管/纳米TiO2-聚苯胺复合膜电极的电化学制备及表征

在含有0.2 mol/L苯胺的0.5 mol/L　H₂SO₄溶液中， 采用循环伏安法(CV)， 以扫描速度50 mV/s, 扫描电位-0.1~0.9 V，在碳纳米管/纳米TiO₂(CNT/nanoTiO₂)膜电极上实现了苯胺的电化学聚合， 用电化学阻抗谱（EIS）和CV法对制备的碳纳米管/纳米TiO₂聚苯胺(CNT/nanoTiO₂ PAn)复合膜电极的电化学性质进行了表征， 从扫描电镜对膜层的微观形貌观察发现， 这种在纳米基体上聚合得到的聚苯胺膜层呈疏松、 多孔的纳米纤维网状结构， 同时具有良好的导电性， 不同于在普通金属基体上聚合得到的颗粒状聚苯胺膜.     

Interfacial interaction between polyurethane/poly (methacrylateco-styrene) coating and the regenerated cellulose film

Water-resistant films were prepared by coating the surface of regenerated cellulose films with castor oil-based polyurethane (PU)/ poly-(methacrylate-co-styrene) [P (MA-St)]. The effects of the ratio of PU to P (MA-St) copolymer on tensile strength (dry and wet states), vapor permeability, size stability, and water resistivity of the coated films were studied. The interfacial interaction between cellulose and the PU/P (MA-St) coating was analyzed using infrared (IR), ultraviolet (UV), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential thermal analysis (DTA), and electron probe microanalysis (EPMA). The results indicated that the mechanical properties and water resistivity of the coated films significantly enhanced, and the biodegradability was displayed, when the ratio of PU to P (MA-St) was 8∶2 by weight. The chemical bonds and hydrogen bonds between the cellulose, PU, and the copolymer exist in the coated films. It is regarded that PU/P (MA-St) semi-interpenetrating polymer networks (IPNs) were formed, and a shared network of PU with both the cellulose and the coating in the coated film occurred simultaneously resulting in a strong bonding between the coating layer and the film. Supported by the State Economy and Trade Commission of China Gong Ping: born in 1963, Ph. D candidate     

Preparation of graphene and TiO2 layer by layer composite with highly photocatalytic efficiency

A process for fabricating graphene and TiO₂ layer by layer composite was introduced to improve the photocatalytic activity by controlling the layers, thickness and the mass ratio between graphene and TiO₂. The graphene oxide (GO) was synthesized from natural graphite powder by the modified Hummers method. Large-area uniform GO and TiO₂ thin films were made by a spin-coating process in turn. After exposure of the TiO₂/GO multilayer film to UV light irradiation which allows the reduction of GO to graphene, a novel photocatalytic structure as graphene and TiO₂ layer by layer composite was synthesized. The cross-sectional SEM image showed that a clear layer by layer microstructure with a single layer thickness of graphene or TiO₂ was in the range of about 50 nm. The total thickness of the film was around 5 μm which was varied according to the layer number of spin coating process. Raman spectra revealed that significant structural changes occurred through UV light irradiation. Photodegradation for methylene blue (MB) exhibited that the layer by layer composite is of higher photocatalytic activity than the pure TiO₂ layer.     

Interfacial interaction between polyurethane/poly (methacrylateco-styrene) coating and the regenerated cellulose film

Water-resistant films were prepared by coating the surface of regenerated cellulose films with castor oil-based polyurethane (PU)/ poly-(methacrylate-co-styrene) [P (MA-St)]. The effects of the ratio of PU to P (MA-St) copolymer on tensile strength (dry and wet states), vapor permeability, size stability, and water resistivity of the coated films were studied. The interfacial interaction between cellulose and the PU/P (MA-St) coating was analyzed using infrared (IR), ultraviolet (UV), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential thermal analysis (DTA), and electron probe microanalysis (EPMA). The results indicated that the mechanical properties and water resistivity of the coated films significantly enhanced, and the biodegradability was displayed, when the ratio of PU to P (MA-St) was 8∶2 by weight. The chemical bonds and hydrogen bonds between the cellulose, PU, and the copolymer exist in the coated films. It is regarded that PU/P (MA-St) semi-interpenetrating polymer networks (IPNs) were formed, and a shared network of PU with both the cellulose and the coating in the coated film occurred simultaneously resulting in a strong bonding between the coating layer and the film. Supported by the State Economy and Trade Commission of China Gong Ping: born in 1963, Ph. D candidate     

Preparation and magnetic properties of CoFe2O4/TiO2 composite films

Using （Ti（OC4H9）4） and metal chlorates as starting materials, CoFe2O4/TiO2 composite films were prepared by sol-gel method. The effects of heat treatment temperature and pH of the precursor on microstructure and magnetic properties were studied. The phase structure of the samples was examined by X-ray diffraction. The microstructure was examined by scanning electron microscope, atomic force microscope and polarized microscope. The magnetic property was measured by vibrating sample magnetometer. The results show that the crystals of different phases grow up independently. CoFe2O4 is uniformly embedded into the TiO2 matrix in the prepared composite films, and the growth of composite films is dependent on the heat treatment temperatures and PH of the precursor. The average size of CoFe2O4 crystal is 19 nm in Nanocomposite film prepared when the heat treatment temperature is 800℃ and the pH of the precursor is between 2 and 3. The magnetism of the composite films is enhanced as the heat treatment temperature increases.     

Magnetic Cotton Fabric Coated with Poly( vinyl alcohol )( PVA )/Magnetic Attapulgite( MAT ) Composite Solution

Magnetic fiber or fabric incorporating magnetic particles was widely used in the field of magnetic health-care.The cotton fabric was modified with poly(vinyl alcohol)(PVA)/magnetic attapulgite(MAT)composite solution by coating,which was the PVA solution blended with MAT.The mechanical and magnetic properties were characterized by scanning electronic microscopy(SEM),vibrating sample magnetometer(VSM)and tensile strength test.The results of SEM show that MAT can scatter uniformly in the PVA film and the PVA/MAT polymer film has good combination with cotton fabric.The results of other tests show that the addition of PVA/MAT polymer film not only brings uniform magnetism to cotton fabric,but also increases the mechanical strength of the material.Besides,the proportion of PVA/MAT and dipping time are studied in order to determine the best parameters for further study on magnetic cotton fabric.     

成膜条件对TiO_2显微结构与光媒特性的影响

用有机金属化学气相沉淀(MOCVD)与溶胶 凝胶(sol gel)法制备二氧化钛薄膜·通过XRD,FE SEM,AFM以及光照TiO2薄膜来降解橙色Ⅱ溶液的方法,研究了TiO2膜的晶体结构、微观表面特性与形貌以及薄膜的光媒特性·比较了不同的TiO2薄膜形成条件对晶格特性与光媒活度的影响·结果表明,成膜温度对薄膜的微观结构及晶体学特性有很大影响;用MOCVD方法得到的TiO2膜,其光媒活度明显高于用sol gel法得到的TiO2膜·     

Photocatalytic Oxidation of NOx with Porous TiO2 Nanometer Thin Film

A new kind of porous nano-TiO2 composite films was prepared on the glass substrate with the water glass as hinders and the sodium fluorosilicate as solidifying reagent. The morphologies of the films were studied by scanning electron microscope(SEM). The UV-Vis spectrophotometer was also used to investigate the absorption of the films. The gasphase photocatalytic oxidation of nitrogen oxides on the composite film was carried out in TiO2 UV system, and some important factors affecting the photocatalytic oxidation were also studied such as the catalyst concentration, vapor pressure and the presence of oxygen. The results showed the conversion of NOx reached 97.5% after 2 h UV-irradiation. The final product of photo-oxidation was detected to be HNO3 hy FT-IR. The way of photocatalytic oxidation of NOx was possibly useful in the practical application.     

TiO2多孔性薄膜的制备及其环境净化性能研究

采用溶胶-凝胶工艺，以聚乙二醇（PEG）为造孔剂，不锈钢丝网为金属基底，制备了TiO₂多孔性薄膜。通过IR，SEM，BET，Raman光谱等测试方法对TiO₂多孔性薄膜进行了表征。实验结果表明,通过控制制备条件得到的TiO₂薄膜具有锐钛矿晶型和多孔性结构。TiO₂多孔性薄膜的光催化性能与煅烧温度和镀膜次数密切相关。450℃热处理、镀膜4次的TiO₂多孔性薄膜具有较高的活性和稳定性，其对气相甲醛的降解率比普通TiO₂薄膜高28.8%，在TiO₂多孔性薄膜连续使用4次后，甲醛的降解率仍维持在80%以上。     

CaCO<Subscript>3</Subscript> film synthesis from ladle furnace slag: morphological change,new material properties,and Ca extraction efficiency

A rapidly air-cooled ladle furnace slag (RA-LFS), which is a type of steelmaking slag discharged from a steel mill, was used to synthesize CaCO₃ film. The CaCO₃ film with 35 cm2 of surface area was synthesized under atmospheric conditions, and the surface morphology of the CaCO₃ films was changed by using additives (CaCl₂ and ethylene glycol). Especially, the addition of CaCl₂ changed the surface morphology of CaCO₃ film with pore and induced new material properties, such as water adsorption. The (012) face of CaCO₃ film (calcite) was rapidly decreased by the addition of CaCl₂. The major components of RA-LFS were calcium (type of CaO, 53.9wt%) and aluminum (type of Al₂O₃, 37.9wt%), and the major crystal phases of RA-LFS were C₃S, C₁₂A₇, and C₃A. The calcium extraction efficiency of RA-LFS was significantly increased after the CaCO₃ film synthesis. The material properties (hardness and elastic modulus) and the thermal characteristics of the CaCO₃ films were analyzed by nano-indentation and thermogravimetry-differential thermal analysis. The synthesized CaCO₃ films from RA-LFS and Ca(OH)₂ (reagent) showed similarities in terms of their material properties and the decomposition temperature.