N,N-二甲基乙酰胺/氯化锂体系下醋酸纤维素/聚醚砜共混膜的制备与表征

为提高纯聚醚砜(PES)膜的亲水性和抗污染能力,以N,N-二甲基乙酰胺/氯化锂(DMAc/LiCl)体系为溶剂,以聚乙烯吡咯烷酮(PVP K30)为添加剂,采用相转化法制备醋酸纤维素(CA)/聚醚砜(PES)共混膜.探讨和分析了成膜过程中的各种因素对膜纯水通量和BSA(牛血清蛋白)截留性能的影响.确定CA/PES共混膜的最佳铸膜条件为:聚醚砜质量分数18%,PVP K30的质量分数4%,醋酸纤维素质量分数3%,预蒸发时间为20s.对共混膜进行了SEM形貌结构、热稳定性、接触角测试、BSA抗污染性能和共混相容性分析表征.结果表明,DMAc/LiCl体系下制备的CA/PES共混膜亲水性和BSA抗污染性能高于纯PES膜,CA/PES共混体系为部分相容体系,CA/PES共混膜的高温热稳定性稍有下降.     

醋酸纤维素类渗透功能膜的研究进展

随着膜法水处理技术的迅猛发展,对渗透功能膜制备及应用技术的要求日益提高。与常规渗透膜制备所采用的主流膜材料聚酰胺相比,醋酸纤维素(CA)及其衍生物由于兼具无可比拟的资源优势和独特的耐氧化性等优势而备受关注。围绕醋酸纤维素类渗透膜在纳滤、反渗透和正渗透等领域的应用,简要介绍了该类膜材料的制备方法和改性方法,回顾了其在海水淡化、油水分离、重金属脱除、手性分离等领域的应用进展,并在分析醋酸纤维素类渗透膜产品在应用领域的技术和性能优势的基础上,指出了醋酸纤维素类渗透膜进一步发展需要重点关注的研究方向。     

金属微粒/醋酸纤维素共混膜的形态与渗透性研究

本文运用扫描镜对不对称醋酸纤维素膜、含有金属微粒的(W,Nb,Zn,Cr,Fe,Mo,Cu 等)不对称醋酸纤维素共混膜的形态进行了描述,用自动吸附测定仪测定了膜的表面积孔体积、平均孔半径、平衡时单位膜重量吸附氮气的体积等,并探讨了膜的形态及吸附性能与渗透性之间的联系。     

用BET法测定反渗透与超过滤膜的皮层孔分布

BET法是一种用气体低温吸附测定固体孔径结构的方法。本文详细叙述了BET 法的原理,数据处理和实验方法,测定了两种反渗透膜(二、三混合醋酸纤维素非对称膜,FT-30复合膜)和三种超滤膜(聚矾膜、三醋酸纤维素膜和聚矾酰胺膜)的最可几孔径。结果表明:用ST-03型表面孔径测定仪BET法测定分离膜皮层孔径的范围为γ<300(?)。     

再生纤维素超滤膜的研制及其耐污染性研究

以纤维素浆板和二醋酸纤维素为原料 ,通过直接制膜和醋酸纤维素成膜后水解两种方法制备再生纤维素超滤膜 ,并以酱油、药酒和牛奶等为料液 ,对膜进行了耐污染实验 .与聚砜和聚丙烯腈膜比较 ,再生纤维素膜具有良好的耐污染特性 .     

“爱普生”杯“印象江南”浙江高校摄影大奖赛

浙江省高等摄影教育专业委员会与爱普生(上海)信息产品有限公司联合举办的“爱普生”杯“印象江南”摄影大奖赛,从2005年6月21日开始征稿,10月30日截稿,11月进行评选,12月初展出,之后在该省高校进行巡回展示,届时爱普生公司与省专委会将同时举办摄影讲座。这次影赛面向浙江全省高校大学生征集摄影作品,设一等奖2名,二等奖5名,三等奖10名,佳作奖43名。作品题材不限,表现手法不限。参赛方法:请将作品交浙江省各高校摄影教师处。“爱普生”杯“印象江南”浙江高校摄影大奖赛     

钛醋酸纤维素合成及膜性能研究

研究了各种反应条件对钛纤维素合成的影响。进行了钛醋酸纤维素合成,得到了不同含钛量的钛醋酸纤维素。X—射线衍射显示,钛醋酸纤维素为无定形固体。热重分析表明,钛醋酸纤维素的热稳定性比醋酸纤维素有所提高。用甘油—正丙醇为添加剂,丙酮为溶剂,制得了在20kg/cm~2压力下,脱盐率达96—97%,水通量达1.0—1.8ml/cm~2·h 的钛醋酸纤维素反渗透膜。与醋酸纤维素膜相比较,钛醋酸纤维素膜可在较高温度下使用,具有一定的耐热性。     

铝合金微弧电泳复合膜层的工艺制备

采用微弧氧化的方法先在铝合金表面制备一层致密多孔的陶瓷层,然后再通过电泳处理在铝合金表面制备出微弧电泳复合膜层.采用扫描电镜对复合膜层的表面形貌和截面线进行扫描分析,通过电化学分析和划格法测结合力试验对微弧电泳膜层性能进行了检测分析,并进一步探讨了不同的微弧氧化参数对后续电泳成膜的影响.结果表明,微弧电泳复合膜层的耐碱性及与基体间结合力均优于传统电泳膜层,且微弧氧化膜层的厚度影响后续电泳能否成膜,氧化层的致密性影响后续电泳膜层的光洁度.     

镀锌板表面有机硅烷-磷化复合膜与阴极电泳漆膜配套性研究

本文介绍了一种可以满足阴极电泳涂装要求的有机硅烷化的磷化处理液,对有机硅烷化的磷化转化膜进行电化学、耐碱性、溶出率、硫酸铜点滴测试,结果显示当有机硅烷和磷化成分配比为8：2时,其耐蚀性最好。通过分析入槽前干膜和湿膜的电化学等性能,发现无论是湿膜或干膜在一定条件下均能得到均一致密的膜层。讨论不同电泳电压、电泳时间对膜厚以及膜外观的影响,当电泳电压为150V、电泳时间为120s时,可形成性能优异的电泳漆膜。     

日中即将联合提出铝阳极氧化复合膜国际标准提案

铝合金阳极氧化电泳涂装复合膜已经被我国建筑业市场所认可，电泳涂装已经由单一的光这透明的电泳漆发展到目前的消光电泳漆和有色电泳漆。目前国内外复合膜的相关标准有日本工业标准JIS H 8620-1992“铝及铝合金阳极氧化涂装复合膜”、中国国家标准GB 5237.3（2005）“铝合金建筑型材第三部分：电泳涂漆型材”和美国建筑制造业标准AAMA612-02（2002）“建筑铝阳极氧化膜与透明有机膜复合膜的性能要求和试验方法规范”，但还没有铝阳极氧化复合膜的国际标准。     

壳聚糖-硫酸软骨素共混膜性质的研究

以溶液共沸法制成不同共混比例的壳聚糖－硫酸软骨素共混膜,通过观察共混膜的表面形态结构、结晶度、红外吸收及透光率,发现壳聚糖和硫酸软骨素两种分子具有较好的相容性,分子间具有较强的相互作用,所形成的共混膜表面结构均匀单一。通过研究共混膜的各种性质发现硫酸软骨素的混入可以改善膜的力学特性,提高膜的透光性及渗透性,降低膜的吸水性及对蛋白的吸附性。以共混膜为载体培养兔角膜内皮细胞,发现硫酸软骨素的引入可明显提高膜和细胞的相容性,兔角膜内皮细胞可在膜上长期生长,结果提示此共混膜可作为细胞培养的良好载体,用于器官损伤修复及细胞移植。     

Electrospun cellulose acetate membrane for size separating and antibacterial screening of crude polysaccharides

This study aims to produce electrospun cellulose acetate (CA) membrane as the alternative supporting medium for a separation of crude polysaccharides by electrophoresis and a screening of their antibacterial activity. Among the tested conditions of fabrication, electrospun CA membrane at 57% porosity showed the best separation of each polysaccharide from the standard mixture and the crude extract of Aloe vera via electrophoresis. As compared with the commercial CA membrane, the produced electrospun CA membrane demonstrated more separated spots of polysaccharides. The antibacterial activity of the electrophoretic polysaccharide was also determined against Escherichia coli and Staphylococcus aureus as the inhibition zone after the bacterial culture agar was overlaid on the membrane and incubated for 24 h. The results of this study suggested the potential application of electrospun CA membrane combining with electrophoresis as a simple method for separating crude polysaccharides and screening for their antibacterial activity.Inspec keywords: electrospinning, polymers, antibacterial activity, microorganisms, electrophoresis, biomedical materials, porosityOther keywords: electrospun cellulose acetate membrane, size separating, antibacterial screening, crude polysaccharides, alternative supporting medium, electrophoresis, antibacterial activity, electrospun CA membrane, standard mixture, Aloe vera, electrophoretic polysaccharide, Escherichia coli, Staphylococcus aureus, bacterial culture agar     

Fumarate copolymers-based membranes overlooking future transdermal delivery devices: synthesis and properties

Novel copolymers of vinyl acetate and dialkylfumarates, poly(VA-co-DRF) with R = isopropyl (DIPF) or octan-2-yl (DOF), were synthesized by radical copolymerization under microwave conditions. The products were characterized by ¹H NMR and FTIR spectroscopies, size exclusion chromatography and differential scanning calorimetry. Based on these copolymers three membranes supported on polyvinyl alcohol were prepared and their morphology, swelling and mechanical properties were studied. The swelling kinetic was analyzed and interpreted in light of the Fick transport model, showing that the water transport occurs through a non-Fickian diffusion mechanism. The results show that the membrane prepared of poly(VA-co-DOF) exhibited excellent properties as potential platform for transdermal delivery system: they exhibited good tensile strength, moderated swelling and form thin and transparent films.     

使用单片机驱动微型针式打印头的一种新型设计方法

本文介绍了微型针式打印头EPSON M-192与单片机AT89C51的硬件接口的一种新型设计方法，同时给出了在此硬件设计基础上直接利用单片机驱动EPSON M-192的软件设计方法并重点阐述了如何装配打印字符点阵的软件算法。     

Indium-doped ZnO thin films deposited by the sol–gel technique

Conducting and transparent indium-doped ZnO thin films were deposited on sodocalcic glass substrates by the sol–gel technique. Zinc acetate and indium chloride were used as precursor materials. The electrical resistivity, structure, morphology and optical transmittance of the films were analyzed as a function of the film thickness and the post-deposition annealing treatments in vacuum, oxygen or argon. The obtained films exhibited a (002) preferential growth in all the cases. Surface morphology studies showed that an increase in the films' thickness causes an increase in the grain size. Films with 0.18 μm thickness, prepared under optimal deposition conditions followed by an annealing treatment in vacuum showed electrical resistivity of 1.3 × 10^− 2 Ωcm and optical transmittance higher than 85%. These results make ZnO:In thin films an attractive material for transparent electrodes in thin film solar cells.     

染料的纳滤分离性能和机理

考察了醋酸纤维素纳滤膜对染料溶液的分离性能,纳滤膜对染料溶液有很好的分离效果,其分离过程中筛分起主导作用;试验不同孔径的醋酸纤维素纳滤膜对萘系衍生物．以及不同材料的纳滤膜对相同分子量有机物的截留效果,其分离性能是由有机物性质和范德华引力共同作用的;分析磺化聚醚砜膜对有机物的截留和染料与膜材料界面力数据,结果表明纳滤膜分离性能是由膜、溶液和溶质三者共同决定的．     

Regulating the quorum sensing signalling circuit to control bacterial virulence: in silico analysis

Pathogenic bacteria employ a communication mechanism, known as quorum sensing (QS), to obtain information about their cell density and to synchronise their behaviour. Most bacteria species use QS signalling circuits to optimise the secretion of virulence factors that damage their host. Recently, QS has been recognised as a target for antimicrobial drugs that can control bacterial infections. Here the QS process is modelled as a state transition graph with transitions depending on the diffusion and local concentration of the QS molecules (autoinducers). Based on this model a simulation tool has been developed to simulate the QS process in both open and confined spaces. Using this simulation tool a number of numerical experiments has been carried out with various strategies of QS circuit regulation. The results of these experiments showed that regulation of the QS signalling circuit can lead to significantly reduced bacterial virulence.     

壳聚糖-透明质酸共混膜性质的研究

以溶液共混法制成不同比例的壳聚糖一透明质酸共混膜,通过观察各种共混膜的表面形态结构、结晶度、透光率等,发现在以较低比例混入透明质酸所形成的共混膜中两种高分子的相容性较好,分子间存在较强的相互作用力,形成的共混膜表面结构均匀单一。通过对共混膜理化性质的研究,发现透明质酸的混入可以有效的改变壳聚糖膜的力学特性、吸水性、吸附性以及对小分子物质的渗透性。以共混膜和壳聚糖膜为载体培养兔角膜细胞,结果发现较低比例的透明质酸可以显著提高壳聚糖膜与角膜细胞的相容性,能够有效的支持细胞在膜上生长,结果提示以一定共混比例制成的壳聚糖一透明质酸共混膜可以作为细胞体外培养的良好载体,可用于器官损伤修复以及细胞移植。     

边缘结构材料对透明件疲劳寿命的影响及优化

本文通过对某飞机侧风挡有机层合玻璃透明件进行增压载荷下低周疲劳试验,发现其边缘连接孔周围出现变形甚至破裂的现象。基于ABAQUS软件中隐式计算的方法对该侧风挡进行了增压载荷加载的仿真分析。建立了解析刚体模拟透明件和机身骨架之间的螺栓连接结构。计算结果中透明件的应力分布与疲劳试验中透明件边缘的破坏规律一致。选择涤纶钢作为透明件边缘的加强材料,对新结构的透明件进行了相同的低周疲劳试验。试验结果未发现其边缘孔位置出现变形及破坏,同时仿真结果显示层合透明件的最高应力水平下降了50.5%。通过仿真分析发现随着边缘粘接材料弹性模量的增加,透明件的最大等效应力降低,但变化率减小。本文结论对透明件边缘粘接材料的选择及结构的优化具有一定的指导意义。     

In Vitro Release Study of Verapamil Hydrochloride Through Sodium Alginate Interpenetrating Monolithic Membranes

Polymeric sodium alginate interpenetrating network membranes containing verapamil hydrochloride were fabricated for transdermal application. The membranes were evaluated for their physical properties, weight and thickness uniformity, water vapor transmission, as well as drug content uniformity. All the thin patches were transparent, smooth, and flexible. The drug-loaded membranes were analyzed by X-ray diffraction to understand the drug polymorphism inside the membrane. The transdermal patches were permeable to water vapor, indicating the permeability characteristics of the polymers. The in vitro drug release was performed in distilled water using a Keshary-Chien diffusion cell. The release data were analyzed to understand the mechanism of drug release.