N-异丙基丙烯酰胺凝胶在NaCl水溶液中溶胀行为的预测研究

In this paper, a model is presented to correlate and predict the swelling behavior of hydrogels in aqueous solutions of electrolytes. The model is a combination of VERS-model, “phantom network“ theory and “free-volume“ contribution. The VERS-model is used to calculate Gibbs excess energy; “phantom network“ theory to describe the elastic properties of polymer network, and “free-volume“ contribution to account for additional difference in the size of the species. To test the model, a series of N-isopropylacrylamide based hydrogels are synthesized by free radical polymerization in oxygen-free, deionized water at 25~C under nitrogen atmosphere. Then, the degree of swelling of all investigated gels as well as the partition of the solute between the gel phase and the surrounding coexisting liquid phase are measured in aqueous solution of sodium chloride. The model test demonstrates that the swelling behavior correlated and predicted by the model agrees with the experimental data within the experimental uncertainty. The phase transition appeared in the experiment, and the influences of the total mass fraction of polymerizable materials ξgel as well as the mole fraction of the crosslinking agent YCR on the swelling behavior of IPAAm-gels can also be predicted correctly. All these show the potential of such model for correlation and prediction of the swelling behavior of hydrogels in aqueous solutions of electrolytes.     

染料刚果红的光催化降解过程研究

在考察光催化降解优化条件的基础上,侧重研究了刚果红的光催化脱色与矿化之间的关系,结果表明刚果红的光催化降解首先是生色基团破坏而脱色,并伴随酸化最后才被矿化,即矿化发生在脱色之后,两者并非同时进行.     

芳烃污染空气光催化净化材料研究进展与展望

芳烃化合物是一类难降解的有毒挥发性有机物,排放到大气对生态环境有极大的危害。光催化技术作为一种高级氧化技术是未来环境净化技术的发展方向之一。然而,经典的TiO2材料对芳烃的光催化氧化,不仅活性低而且极易失活,这在很大程度上制约了光催化技术在空气净化领域的实际应用。在综述国内外研究进展的基础上,简要总结了最近几年我们在芳烃污染空气的光催化净化材料开发和性能研究方面的一些进展。研究结果显示,有众多宽带隙半导体材料对芳烃表现出比TiO2更加优异的光催化活性和活性稳定性;有些材料甚至在可见光诱导下可表现出非常高的光催化活性。此外,在反应气氛中添加少量氢气可以大幅度提高贵金属修饰TiO2对苯的光催化降解效率。这些进展充分显示出光催化技术在工业三苯废气处理和空气净化等方面的广阔应用前景。     

化学武器及其模拟剂的光催化消除研究进展

光催化不仅在环境污染治理等方面有着潜在而广泛的应用背景,并且在军事防化领域还有重要的实际应用价值.笔者评述了目前光催化在军事防化领域的研究概况,并对存在的问题和未来的发展动向进行简要分析.     

不同有机化合物在TiO2负载活性炭纤维上的

以环氧树脂为炭质前驱体将TiO₂粉体粘附于ACF表面，然后在N2气氛460 ℃焙烧，树脂热解、逸失使剩余残炭成为二者之间的连接体，获得TiO₂/ACF复合产品。ACF负载TiO₂后，其比表面积降低，但仍很好地维持了ACF的孔隙结构。由SEM可知，纳米级单体TiO₂颗粒以微小团簇结构分布于ACF表面。以对氨基苯酚、亚甲基兰和β-环状糊精三种不同分子尺寸的有机化合物为探针，通过TiO₂/ACF对它们的光催化降解研究发现，化合物自身分子尺寸对其降解程度有重要影响。具有适宜分子尺寸亚甲基兰的去除程度最高，TiO₂/ACF的降解速率高于悬浮态P25，在重复利用过程中未见降低。通过对比三种有机分子在有、无紫外光照下的去除程度，可确认有机分子是被降解而非吸附于TiO₂/ACF上。     

固体超强酸高效光催化剂的中试生产工艺研究

简述了固体超强酸光催化剂的制备原理，并对其生产工艺进行了设计，据此建立了一条中试装置并进行了试运行，结果表明该工艺是完全可行的，产品质量和产量稳定，运行正常，可以推广放大用于实际企业生产。     

Prediction of Swelling Behavior of AT-Isopropylacrylamide Hydrogels in Aqueous Solution of Sodium Chloride

In this paper, a model is presented to correlate and predict the swelling behavior of hydrogels in aqueous solutions of electrolytes. The model is a combination of VERS-model, "phantom network" theory and "free-volume" contribution. The VERS-model is used to calculate Gibbs excess energy; "phantom network" theory to describe the elastic properties of polymer network, and "free-volume" contribution to account for additional difference in the size of the species. To test the model, a series of N-isopropylacrylamide based hydrogels are synthesized by free radical polymerization in oxygen-free, deionized water at 25℃ under nitrogen atmosphere. Then, the degree of swelling of all investigated gels as well as the partition of the solute between the gel phase and the surrounding coexisting liquid phase are measured in aqueous solution of sodium chloride. The model test demonstrates that the swelling behavior correlated and predicted by the model agrees with the experimental data within the experimental uncert     

四丁基锡在Pt/HY分子筛表面的接枝反应及其催化性能的研究

研究了真空条件下四丁基锡(SnBu4)在Pt/HY分子筛超笼表面的接枝反应,并用元素分析、ICP、GC-MS、XRD、FTIR、TG、BET、UV-Vis等方法对产物的组成、结构和性质进行了表征。研究结果表明,SnBu4与Pt/HY分子筛表面羟基可以定量、有选择性地进行化学反应,将确定数目的SnBu3碎片接枝在分子筛的超笼中。经SnBu4改性后的Pt/HY分子筛的骨架结构没有被破坏,接枝反应发生在分子筛表面,BET比表面积和孔体积变小,表面性质发生变化。将改性后的Pt/HY分子筛应用于糠醛气相氢化反应,糠醇的选择性明显增加。     

二甲氨基异丙氧基铜(Ⅱ)在MCM-41表面的化学接枝

首次研究了高真空条件下二甲氨基异丙氧基铜(∏)与MCM-41分子筛的接枝反应,并用元素分析、ICP、XRD、FTIR、TGA、N2吸附和UV-Vis等方法对产物的组成、结构和性质进行表征,初步研究结果表明,两者在室温下可以发生化学反应,导致其完整地接枝在分子筛表面.     

含铁Y沸石的表面金属有机化学制备及其催化性能研究

采用表面金属有机化学法制备的Fe/Y沸石催化剂(记作Fe/Y-G)与液相浸渍法制得的Fe/Y沸石样品(记作Fe/Y-Ⅰ)相比对CO氧化表现出更为优异的催化性能,在623 K下反应时Fe/Y-G样品的催化活性是Fe/Y-Ⅰ催化剂的3倍,催化剂结构表征结果表明,CO催化氧化活性与Y沸石表面铁的微观结构密切的联系,以Fe-O-Al结构形式存在于Y沸石表面的孤立铁可能是CO催化氧化的活性中心.