染料敏化太阳能电池的内部阻抗分析

为了进一步研究染料敏化太阳能电池的性能与内部阻抗的关系，应用电化学阻抗谱来研究电池内部电子转移过程的阻抗特性．结合适当的等效电路和理论模型对电池的阻抗谱图进行分析，结果表明，电池的内部阻抗主要来自至少3个方面：高频区域为铂和电解质界面的阻抗；中频区域为电子在二氧化钛薄膜中的传输和复合阻抗；低频区域为电解质内部的扩散阻抗．其中电子在二氧化钛薄膜中的传输和复合阻抗是影响染料敏化太阳能电池内部阻抗的主要方面，电解质的扩散对电池内部阻抗的影响较小．     

Biodegradable starch/poly (vinyl alcohol) film reinforced with titanium dioxide nanoparticles

Biodegradable starch/poly (vinyl alcohol)/nano-titanium dioxide (ST/PVA/nano-TiO₂) nanocomposite films were prepared via a solution casting method. Their biodegradability, mechanical properties, and thermal properties were also studied in this paper. A general full factorial experimental approach was used to determine effective parameters on the mechanical properties of the prepared films. ST/PVA/TiO₂ nanocomposites were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results of mechanical analysis show that ST/PVA films with higher contents of PVA have much better mechanical properties. In thermal analysis, it is found that the addition of TiO₂ nanoparticles improves the thermal stability of the films. SEM micrographs, taken from the fracture surface of samples, illustrate that the addition of PVA makes the film softer and more flexible. The results of soil burial biodegradation indicate that the biodegradability of ST/PVA/TiO₂ films strongly depends on the starch proportion in the film matrix. The degradation rate is increased by the addition of starch in the films.     

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.     

壳聚糖/玉米淀粉基质复合膜的制备与性能分析

以壳聚糖和玉米淀粉为主要基质,分别加入甘油、聚乙烯醇、明胶和气相二氧化硅,采用溶液共混后流延方法制备食品包装膜。分析了壳聚糖和玉米淀粉的最佳质量比以及添加剂的用量对包装膜力学性能和吸水率的影响。结果表明：当壳聚糖和玉米淀粉质量比为100：214,甘油含量为玉米淀粉质量的20%时,壳聚糖/玉米淀粉膜的综合性能较好;聚乙烯醇含量为玉米淀粉质量的60%、明胶固含量为玉米淀粉质量的10%、气态二氧化硅固含量为玉米淀粉质量的4%时,所得膜在各自系列膜中的性能较佳。     

PREPARATION AND CHARACTERIZATION OF MODIFIED STARCH-BASED BIODEGRADABLE MATERIALS REINFORCED WITH PULP FIBER

INTRODUCTIONThe developments of environmentally friendly polymeric are classified into two categories: the degradable synthetic polymers (PCL [1- 2], PLA and PVA [3], etc.) and the renewable natural polymers (chitin, pectin, cellulose [4-7] and starch [8], etc.) Among these, starch has been considered for many years as a polymer with a high potential for packaging application because of low cost, renewability and biodegradability. It usually has two major components and appears as a mi…     

PREPARATION AND CHARACTERIZATION OF MODIFIED STARCH-BASED BIODEGRADABLE MATERIALS EINFORCED WITH PULP FIBER

Native com starch and hydroxypropyl starch (HPS)based plastic films were prepared using the short pulp fiber as reinforcement and the glycerol as the plasticizer. The results of tensile test showed that the tensile strength and the elongation at break increased with the pulp contents. With the glycerol contents,the elongation at break increased considerably, but the tensile strength decreased. The water uptake of the films decreased with the pulp contents and hydroxypropylation, but increased with the glycerol contents. So it is concluded that the films was reinforced by pulp fiber and hydroxypropylation.     

光/生物降解塑料薄膜制备及其性能研究

以玉米淀粉、低密度聚乙烯和线型低密度聚乙烯为主要原料,制得光/生物降解塑料薄膜,所得降解薄膜中淀粉质量分数约为30%,厚度约为20 μm.研究结果表明:吹膜料的流变性能接近聚乙烯,为剪切变稀的假塑性流体,可用通用塑料加工设备加工;该薄膜的力学性能接近纯聚乙烯薄膜,并具有较好的光降解性能;薄膜经紫外光照射或曝露在户外均可发生明显降解,其降解产物中含有羰基和不饱和碳-碳双键的聚合物.     

电沉积NiHCF薄膜的离子选择性研究

采用电沉积方法在铂、铝基体上制备出具有电化学控制离子交换（ESIX）性能的电活性NiHCF（Nickel Hexacyanoferrate）薄膜，在1mol／L（NaNO3＋CsNO3）和1mol／L（KNO3＋CsNO3）混合溶液中分别测定了不同Cs^＋浓度下薄膜的伏安特性曲线和电化学交流阻抗谱，并根据CV曲线和EIS曲线的变化特征分析了薄膜对Cs^＋／K^＋和Cs^＋／Na^＋离子的选择性。结果表明，交流阻抗技术与循环伏安法相结合可较好地用来表征混合溶液中离子膜的选择性。     

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。     

二氧化锡超微粒子气敏薄膜的复数阻抗谱研究

用直流气体放电活化反应蒸发法制备了二氧化锡超微粒子薄膜，测量了薄膜的阻抗谱，验证了超微粒子薄膜的内部模拟等效电路。研究了温度、还原性气体以及热处理对阻抗谱的影响，并用氧吸附理论和晶界热垒理论定性地解释了这些现象。     

硅烷水解时间对Q235钢表面VTES膜层耐蚀性的影响

利用硅烷溶液水解的方法,在Q235钢表面制备了乙烯基三乙氧基硅烷(VTES)膜,利用电化学阻抗谱(EIS)和动电位极化法研究了用不同水解时间的硅烷溶液制备的乙烯基三乙氧基硅烷膜在3.5%NaCl水溶液中的耐蚀性能.结果表明,用水解8天的硅烷溶液在Q235钢表面制备的乙烯基三乙氧基硅烷膜层,腐蚀过程中阳极和阴极反应受到抑制,耐蚀性能最佳;与原始Q235钢比较,腐蚀电流密度减小近3个数量级,极化电阻Rp提高近2个数量级,低频阻抗值提高至少3个数量级.     

聚吡咯/聚砜复合膜的电化学制备及其电化学性能

采用电化学聚合法制备了聚吡咯（PPY）／聚砜（PSF）复合膜，分别用扫描电子显微镜（SEM）和红外光谱（FT—IR）表征了复合膜的表面形态和化学组分，并用循环伏安法和电化学交流阻抗法对其电化学性能进行了研究．结果表明，复合膜呈双层不对称孔结构，其内层（与工作电极接触的一面）是由黑色聚吡咯组成的带少量微孔的致密导电层，而外层（与溶液接触的一面）则是由白色聚砜组成的具有许多微孔的绝缘层；相同条件下所制的复合膜电化学重复性好，在酸性溶液中具有较好的电化学稳定性和电化学活性．     

电化学聚合单壁碳纳米管／聚苯胺复合物的电容特性研究

采用原位电化学聚合含有饱和单壁碳纳米管（SWNT）的苯胺（ANI）溶液来制备单壁碳纳米管／聚苯胺（SWNT／PANI）复合膜,对复合膜的表面形貌与结构性质采用扫描电子显微镜进行观察,并用循环伏安法,充放电测试,和交流阻抗测试等手段对复合膜的电化学电容特性进行详细探讨．实验结果表明,纯PANI和SWNT／PANI复合物的比电容量分别为156．5F／g,186．4F／g．由复平面阻抗谱图的最高频率点可以求出纯PANI和SWNT／PANI复合膜的内阻分别为15．8,6．7Ω．     

Effect of Starch Dodecenylsuccinylation on the Adhesion and Film Properties of Dodecenylsuccinylated Starch for Polyester Warp Sizing

A series of dodecenylsuccinylated starches（ DSSs） with different degree of substitution（ DS） were prepared via the esterification of dodencenylsuccinic anhydride with hydrolyzed cornstarch in aqueous dispersion for investigating the influences of starch dodecenylsuccinylation upon the performances such as apparent viscosity and surface tension of starch paste, film behaviors,and adhesion to fibers for warp sizing. It was found that the dodecenylsuccinylation was able to reduce the surface tension of cooked starch paste and enhance the adhesion of starch to polyester fibers. It was also capable of depressing the brittleness of native starch and improving the mechanical behaviours such as breaking elongation and work-to-break of starch film. Initial increase in DS level of dodecenylsuccinylation enhanced these positive effects,while excessively increasing the level resulted in marked reduction in tensile strength of starch film and significant decrement in reaction efficiency. X-ray diffraction patterns of starch films showed the dodecenylsuccinates derivatized onto the backbones of starch depressed the degree of crystallinity of starch film. Based on the paste behaviors, adhesion, and film properties, the dodecenylsuccinylation level is recommended in a range of 0. 015-0. 025 for sizing polyester warps.     

淀粉—聚乙烯薄膜的研究

探讨了几种淀粉和LDPE共混体系的性能,结果表明,淀粉经过变性,降低了数均分子量和链之间的缠绕程度,提高了在高聚物共混体系中的分散性;加入增容剂,又进一步改善了淀粉表面的性质,缩小了共混体系组份间的性质差异;共混后,可得到相态稳定、分散均匀、界面粘结力强的共混膜料。对不同配方试片的力学性能、流变学性质以及形态进行了比较,研制出了较为理想的可降解的农用覆盖膜和包装材料用膜。     

十二烷基硫醇对铜的缓蚀作用

利用自组装方法在铜表面制备十二烷基硫醇单层膜,采用失重法、电化学极化曲线法和交流阻抗法,研究在不同成膜时间条件下得到的自组装膜在0.51 mol/L的NaCl溶液中对铜的缓蚀作用.实验结果表明:十二烷基硫醇膜对铜具有较好的缓蚀作用,经自组装处理后铜电极在NaCl溶液中电荷传递的电阻增大,腐蚀电流密度下降.该膜对腐蚀反应的阴极过程具有更强的阻碍作用,在吸附时间为30 min时,可产生较好的缓蚀效果.     

用于高频磁阻抗效应的软磁薄膜研究

讨论了用于高频磁阻抗效应传感技术的ＮｅＦｅ软磁薄膜制备和薄膜单轴各向异性产生方法及机理．用射频磁控溅射法在几十ｋＡ／ｍ磁场定向下制备出具有一定单轴各向异性的Ｎｉ８１Ｆｅ１９软磁薄膜,并对所测得的薄膜各种磁化曲线进行了分析     

溶剂对导电聚吡咯防腐蚀性能的影响

采用循环伏安法分别在含吡咯+NaClO4的乙腈中和水中,在不锈钢表面制备了聚吡咯(PPy)膜.用扫描电子显微镜观察了PPy膜的表面形貌,用四探针法测量了PPy膜的电导率,用动电位极化曲线和电化学阻抗谱研究了在1mol/L H2SO4中PPy膜对不锈钢的防腐蚀性能.结果表明,在两种溶剂中制备的PPy膜都由球状粒子组成,但在水中制备的PPy膜结节较多.在乙腈中制备的PPy的电导率和对不锈钢的防护性能都显著高于在水中制备的PPy.由于乙腈的给电子性较水的小,与吡咯聚合中间体的作用小,链反应较难终止,使得PPy聚合链共轭度长,膜的缺陷少,电导率大,防腐性能好.     

阳极氧化铝电解着色研究

应用XPS和离子探针显微分析法,检测了在含有Cu~(2 ),Sn~(2 )或Ni~(2 )电解液中,电解着色的铝氧化膜孔隙中沉积物的组成,考察了着色过程的电极行为以及膜阻抗的变化.结果表明,在电解着色过程中,AC负半周发生金属的沉积和H~ 的还原,正半周发生氧化膜的活化和部分沉积金属的氧化,孔隙中的沉积物是金属及其氧化物的水溶胶,它导致膜的交流阻抗增大.由此,文中提出了电极交流阻抗等效电路,并求得各参数值.实验结果可较好地说明氧化膜阻扰与色调的关系,以及不同着色膜性能的差别.     

MFS结构铁电薄膜C-V特性的研究及界面电位降的计算

利用准分子激光原位淀积方法制备了BIT／PZT／BIT,PZT／BIT和BIT层状铁结构电薄膜,借助HP4192A低频率阻抗分析仪对样品的C—V特性进行了测试,用半导体理论讨论了金属—铁电薄膜—半导体（MFS）结构的电容电压（C—V）特性,由C-V曲线理论算出界面电位降Vi,结果表明,界面电位降与测量电容、薄膜电容及耗尽层电容有关．在三种结构中,BIT／PZT／BIT结构的界面电压降为最小,其界面效应优于单层和双层结构的界面效应．