纤维素辐照改性及其应用

辐照技术利用电离辐射诱发物理化学反应(例如交联、聚合、接枝、降解等)对材料进行加工或改性,与常规加工方法相比,具有节能、无环境污染等特点。将辐照技术应用于纤维素改性过程近年已成为非动力核技术应用领域研究的热点之一。本工作对目前纤维素的辐照技术及其基本反应机理进行了概述,其中包括纤维素膜材料、纤维素水凝胶、纤维素微晶/纳米材料,并对纤维素辐照改性过程的辐照环境,包括溶剂、敏化剂、温度、辐照剂量、环境氛围、结晶度等进行了总结。     

紫外光辐照VBIMBr接枝PI渗透汽化膜的制备及性能

以功能化离子液体溴化-1-丁基-3-乙烯基咪唑(VBIMBr)为改性剂,使用紫外光辐照法对PI膜进行改性,制备VBIMBr接枝改性PI渗透汽化膜,并对辐照时间、辐照距离和单体浓度等制备参数进行了优化.在辐照时间30 min,辐照距离30 cm,单体浓度15wt％的优化条件下,所制得的接枝改性膜对90wt％异丙醇-水体系的渗透通量为48.18 g/(m2?h),分离因子为1536.01.与PI膜相比,接枝改性膜的渗透通量降低了10.6％,分离因子提升了797.7％.     

辐照水性聚氨酯的复合改性研究与应用进展

综述了辐照水性聚氨酯(WPU)最常用的多元改性方法,重点介绍了γ射线(Co-60)辐照WPU和紫外光(UV)固化WPU的改性方法。改性后的辐照WPU的耐候性和机械性能要远优于WPU,辐照WPU经改性后可应用于印花粘合剂、地板涂料、木器漆涂料和汽车漆膜等领域。最后展望了辐照WPU的发展前景。     

醋酸纤维素超滤膜γ射线辐照改性

本文探讨醋酸纤维素超滤膜Ｃｏ＾６０γ射线辐照改性的可能性，分析了γ射线辐照改性机理，研究了吸收剂量，膜形态，铸膜液的组成对改性的影响。结果表明，γ射线辐照是醋酸纤维素超滤膜改性的一个有效方法。     

聚砜超滤膜表面辐照改性研究

实验以聚砜为膜材料,聚乙二醇（PEG）为添加剂,采用浸入沉淀相转化法制备聚砜平板超滤膜,然后对实验制备的聚砜膜进行紫外辐照改性,考察了辐照对聚砜膜结构和性能的影响,研究了膜辐照前后断裂强度的变化,通过表面接触角测定仪、红外分析仪（FTIR）、扫描电镜（SEM）、改性膜的水通量和截留性能等方法来表征膜辐照前后的结构和性能变化,聚砜超滤膜经紫外辐照改性取得了良好的效果。     

电离辐照技术在PTFE改性产品开发中的应用

综合介绍了电离辐照技术在PTFE改性产品开发中的应用情况,并简要介绍该技术在PTFE改性中应用的最新进展。     

聚砜超滤膜表面辐照改性研究

以聚砜为膜材料,聚乙二醇(PEG)为添加剂,采用浸入沉淀相转化法制备聚砜平板超滤膜,然后对实验制备的聚砜膜进行紫外辐照改性,考察了辐照对聚砜膜结构和性能的影响,研究了膜辐照前后断裂强度的变化,通过表面接触角测定仪、红外分析仪(FTIR)、扫描电镜(SEM)、改性膜的纯水通量和截留性能等方法来表征膜辐照前后的结构和性能变化.研究表明:聚砜膜断裂强度经辐照后变小,但降低幅度不大;在乙醇溶液中紫外辐照后,开始纯水通量提高而截留率降低,但降低幅度不大,时间增加到一定时通量又降低,截留率变化也不大;表面接触角随辐照时间的增长而减小,表明改性后膜表面的亲水性得到明显改善;通过FTIR分析证实在聚砜膜表面产生了新的官能团;SEM实验证实反应只发生在聚砜膜的表面而非膜内部.聚砜超滤膜经紫外辐照改性取得了良好的效果.     

聚砜超滤膜表面辐照改性研究

以聚砜为膜材料,聚乙二醇（PEG）为添加剂,采用浸入沉淀相转化法制备聚砜平板超滤膜,然后对实验制备的聚砜膜进行紫外辐照改性,考察了辐照对聚砜膜结构和性能的影响,研究了膜辐照前后断裂强度的变化,通过表面接触角测定仪、红外分析仪（FTIR）、扫描电镜（SEM）、改性膜的纯水通量和截留性能等方法来表征膜辐照前后的结构和性能变化。研究表明,聚砜膜断裂强度经辐照后强度变小,但是降低幅度不大;在乙醇溶液中紫外辐照后,开始纯水通量提高而截留率降低,但降低幅度不大,时间增加到一定时通量又降低,截留率变化也不大;表面接触角随辐照时间的增长而减小,表明改性后膜表面的亲水性得到明显改善;通过FTIR分析证实在聚砜膜表面产生了新的官能团;SEM实验证实反应只发生在聚砜膜的表面而非膜内部。聚砜超滤膜经紫外辐照改性取得了良好的效果。     

PBO纤维增强有机硅压敏胶的制备及性能研究

采用60Coγ-射线辐照的方法,对硝酸酸化预处理后的PBO纤维进行表面原位改性.结果表明预处理后纤维表面被硝酸刻蚀,生成羧基,化学活性增强,且呈单根分散,尺寸减小,纤维在辐照溶液中的分散性大幅提高.辐照原位改性后纤维表面生成纳米含硅涂层,其与有机硅压敏胶的界面结合力得到了提高.采用辐照处理后的高耐温性PBO纤维改性有机...     

助剂对聚氯乙烯辐照改性的影响

本文研究了代表性的增塑剂邻苯二甲酸二丁酯(DBP)、稳定剂硬脂酸铅及多官能团单体三羟甲基丙烷三丙烯酸酯(TMPTA)和季戊四醇四丙烯酸酯(PETA)对聚氯乙烯(PVC)γ辐照改性的影响,测试了不同配方的 PVC 于不同剂量辐照时的凝胶含量、力学性能、热失重性能。结果表明,DBP 和硬脂酸铅对 PVC 的辐照交联是有益的。多官能团单体 TMPTA 和 PETA 对 PVC 的辐射交联有很大的促进作用。加入多官能团单体的 PVC 经辐照后,其拉伸强度、耐热性能和增塑剂束缚性能大大改善。     

凹凸棒石复合分离膜的研究进展

凹凸棒石（ATP）是一种廉价易得的天然粘土矿物，具有比表面积大、阳离子交换容量高、表面官能团丰富等特点，通过不同的方法改性，可以与各种基膜结合形成复合膜。综述了ATP复合分离膜的不同制备方法，比较了其优缺点；总结了ATP添加量对复合膜拉伸强度、杨氏模量、断裂伸长率等力学性能的影响，进而介绍了ATP复合分离膜在CO2分离、重金属分离、染料分离、油水分离等方面的应用，并分析了其分离机理。最后展望了ATP复合分离膜的面临挑战和研究方向。     

Past and Future Strategies to Inhibit Membrane Localization of the KRAS Oncogene

KRAS is one of the most studied oncogenes. It is well known that KRAS undergoes post-translational modifications at its C-terminal end. These modifications are essential for its membrane location and activity. Despite significant efforts made in the past three decades to target the mechanisms involved in its membrane localization, no therapies have been approved and taken into the clinic. However, many studies have recently reintroduced interest in the development of KRAS inhibitors, either by directly targeting KRAS or indirectly through the inhibition of critical steps involved in post-translational KRAS modifications. In this review, we summarize the approaches that have been applied over the years to inhibit the membrane localization of KRAS in cancer and propose a new anti-KRAS strategy that could be used in clinic.     

离子交换膜改性的研究现状及发展趋势

离子交换膜已广泛应用于化工、废水治理等工业领域。但是,目前所使用的离子交换膜选择透过性低、机械强度差、抗污染能力弱,对离子交换膜进行改性可以改善这些性能。综述了离子交换膜的改性方法,包括组成改性（表面改性和掺杂改性）和结构改性（中空纤维结构改性和增加膜基质孔隙率改性）。通过对这些方法进行分析对比得出：表面改性和掺杂改性,以聚合物为添加剂,技术简单、易操作,并且能够提高膜的综合性能,是膜改性的重要发展方向;中空纤维结构改性,由于膜的使用条件严格、清洗困难,目前得不到广泛应用,但是中空纤维结构改性使膜的结构从根本上发生了改变,这是膜改性的一个重要途径;增加膜的孔隙率只适合多孔膜的改性,这种方法研究较少。     

高分子反渗透膜材料改性研究进展

介绍了反渗透膜的高分子材料及其衍生物材料的种类,叙述了改性方法及研究进展,提出了今后的研究方向.     

Modifications and applications of hyperbranched aliphatic polyesters based on dimethylolpropionic acid

Over the past 16 years, hyperbranched polyesters (HBPEs) based on dimethylolpropionic acid have received much attention due to their unique structural characters, their excellent physical and chemical properties as well as their potential applications in coatings, additives, drug delivery, composites, membrane science and supermolecular chemistry. HBPEs have recently become one of the types of commercialized hyperbranched polymers, and their modifications and applications are focuses of research. This paper reviews the developments in the modifications and applications of HBPEs. Copyright © 2010 Society of Chemical Industry     

Current Approaches in Improving Hemocompatibility of Polymeric Membranes for Biomedical Application

Suitable membranes for blood‐contacting medical applications need to be resistant in confrontation with blood proteins and cells, while possessing high blood compatibility and permeability at the same time. Herein, an overview of the recent advances and strategies that have been used to enhance the hemocompatibility of polymeric membranes is provided. The review focuses on two modification strategies: (i) physical modifications and (ii) chemical modifications. It also highlights the current progress in the design of hemocompatible‐functionalized membranes for biomedical applications. Subsequently, the commonly applied biocompatibility tests are also discussed and finally the future perspectives of the application of polymeric membranes in the biomedical field are presented.

     

Hydrophobizing polyether sulfone membrane by sol-gel for water desalination using air gap membrane distillation

ABSTRACT

The hydrophobic polyether sulfone membranes were prepared by the sol-gel method to be applied in an air gap membrane distillation setup for desalination. The surface modifications were carried out using Trimethylsilyl chloride (TMSCl) and Methyltrimethoxysilane (MTMS) solutions. The membranes were characterized using Attenuated Total Reflection Infrared (ATR-IR) spectroscopy, Scanning Electron Microscopy (SEM), and Optical Contact Angle (OCA) methods. The effects of membrane preparation as well as operating conditions such as temperature difference, salt concentration, feed rotation speed, and cold-side temperature on membrane performance were investigated using central composite design method. It was found that feed temperature has the largest effect among the parameters on the permeation flux. The flow rate and salt rejection of the membrane in the optimum conditions were 4.47 Kg m^?2 h^?1 and 99.37%, respectively.     

Microstructure coarsening in Ba0.5Sr0.5Co0.8Fe0.2O3-δ during reactive air brazing

Reactive air brazing of the ceramic oxygen transport membrane material BSCF causes microstructural modifications. The trend towards minimizing of membrane thicknesses requires a physical understanding of these modifications since they may influence both oxygen permeation and mechanical properties. To this purpose, wetting samples with variations in the Ag-xCuO braze alloy (1 < x < 25 at.-%) and the brazing time (0 < t < 120 min) were characterized by quantitative image analysis. We found that the pore size in reactive air brazed BSCF increases with increased brazing time as well as CuO-content in the braze. A local porosity minimum is always observed at the end of the reaction zone close to the unaffected bulk BSCF. Additionally, a zone with unidirectionally elongated grains at the end of which silver residues were found is observed. The observed coarsening effects are explained by liquid melt film penetration along the grain boundaries which increases the grain boundary mobility. Phase field simulations qualitatively confirmed the experimentally observed elongated grain structure.     

小型水产加工企业废水处理工艺改造

某水产加工公司原废水处理系统已不能满足环保要求,根据水产加工行业废水的特点,在原有传统处理工艺的基础上进行了工艺改造,增加了絮凝反应池和MBR池,改造了好氧池,大大改善了出水水质,使排放废水达到《污水综合排放标准》(GB 8978—1996)一级排放标准要求。     

高亲水膜-聚乙烯醇复合膜的研究进展

PVA复合膜是将亲水性的PVA皮层材料负载于支撑体上形成的。本文对PVA复合膜在不同领域（RO、UF、MF）中的应用研究进展以及改性PVA复合膜的研究情况进行了综述,并对将来的研究方向提出了展望。