粗碲粉加压氧化浸出工艺研究

针对上游工序发生改变，研究了采用加压氧化浸出工艺处理粗碲粉。采用单因素试验考察了液固比、游离碱度、反应压力、反应温度、反应时间对浸出效果的影响，确定最佳工艺条件为：液固比10，游离碱浓度40g/L，反应压力0.8MPa，反应温度75℃，氧化时间2h。试验结果表明碲的浸出率可达95.45％，金银富集在20倍以上。     

Development of silver nanoparticles‐loaded calcium alginate beads embedded in gelatin scaffolds for use as wound dressings

Silver nanoparticles (AgNPs)‐loaded calcium alginate beads embedded in gelatin scaffolds were developed to sustain and maintain the release of silver (Ag⁺) ions over an extended time period. The UV irradiation technique was used to reduce Ag⁺ ions in alginate solution to AgNPs. The average sizes of AgNPs ranged between ca 20 and ca 22 nm. The AgNPs‐loaded calcium alginate beads were prepared by electrospraying of a sodium alginate solution containing AgNPs into calcium chloride (CaCl₂) solution. The AgNPs‐loaded calcium alginate beads were then embedded into gelatin scaffolds. The release characteristics of Ag⁺ ions from both the AgNPs‐loaded calcium alginate beads and the AgNPs‐loaded calcium alginate beads embedded in gelatin scaffolds were determined in either deionized water or phosphate buffer solution at 37 °C for 7 days. Moreover, the AgNPs‐loaded calcium alginate beads embedded in gelatin scaffolds were tested for their antibacterial activity and cytotoxicity. © 2014 Society of Chemical Industry     

银掺杂介孔二氧化钛的制备及可见光催化性能

以表面活性剂十六烷基三甲基溴化铵(CTAB)为模板、钛酸四丁酯为钛源、硝酸银为掺杂离子前驱体,通过液晶模板辅助溶胶-凝胶法制备银掺杂介孔二氧化钛(Ag/MT),借助于X射线衍射、N2吸附-脱附、差热分析仪、X射线光电子能谱、紫外可见分光光度计、透射电子显微镜等对样品的结构进行了表征,以亚甲基蓝(MB)为目标降解物,探讨了合成产物的可见光催化性能。结果表明:银掺杂降低了介孔二氧化钛(MT)粒径和光生电子-空穴复合率,提高了比表面积和Ti 3+和羟基浓度,使得Ag/MT的光催化活性高于纯MT和P25,银掺杂减小TiO2带隙能,使其具有很高的可见光催化活性。最佳光催化条件为Ag/MT和MB的浓度分别为0.6g/L和1mg/L。     

乙烯-乙酸乙烯酯共聚物Levapren 800硫化胶溶度参数的测定及应用

采用溶胀实验及计算机HSPiP软件对牌号为Levapren 800的乙烯-乙酸乙烯酯硫化胶的溶度参数进行了研究。结果表明,单一溶剂与混合溶剂都可用于Levapren 800硫化胶溶度参数的测定,用溶胀法测得其一维溶度参数(δt)为18.90~19.25(J/cm3)1/2。通过HSPiP软件测得Levapren 800硫化胶的δt为19.97(J/cm3)1/2;三维溶度参数的色散力、极性力和氢键力溶度参数分别为18.20,5.50,6.10(J/cm3)1/2。利用三维溶度参数可以预测Levapren 800硫化胶在标准实验油中的溶胀行为;相对能量差对预测聚合物在溶剂中的溶胀性能方面具有一定的应用价值。     

乙烯-乙酸乙烯酯共聚物/氢化丁腈橡胶共混物的相态结构和低温性能研究

采用熔融共混法制备乙烯-乙酸乙烯酯共聚物(EVM)/氢化丁腈橡胶(HNBR)共混物,研究其硫化特性、相态结构、动态力学性能、物理性能和低温拉伸性能。结果表明:当EVM/HNBR共混比为70/30时,EVM形成连续相,HNBR形成分散相;随着HNBR用量的增大,HNBR相态由分散相向连续相转变。HNBR的加入可以提高EVM的耐低温性能,当EVM/HNBR共混比为30/70时,共混物-40℃下的低温拉断伸长率可达300%左右。差示扫描量热分析表明,随着HNBR用量的增大,共混物玻璃化温度降低。     

Investigation of synergistic effect of nano sized Ag/TiO2 particles on antibacterial,physical and mechanical properties of UV-curable clear coatings by experimental design

The synergistic effect of nano titanium dioxide (10 and 30 nm) and nano silver (10 nm) as antibacterial agents were investigated on UV curable clear coating. Antibacterial and physical–mechanical properties of coating were optimized using experimental design in response surface method. Twenty different samples of nano Ag and nano TiO₂ were prepared in this method. Antibacterial properties on Gram-negative bacteria (Escherichia coli) were investigated. The results revealed that using equal amounts of two sizes of nano TiO₂ promote the antibacterial activity of nano Ag. So, the coating shows strong activity against E. coli. Physical–mechanical properties such as surface hardness, abrasion resistance, scratch resistance and gloss of the coating were evaluated. The results depicted appropriate physical–mechanical properties. Also, scanning electron microscope (SEM), atomic force microscope (AFM) and Fourier transform infrared (FT-IR) spectroscopy were used to study the effect of nano particles on coating properties.     

叔碳酸乙烯酯改性VAE乳液的研究

在VAE乳液生产工艺中引入改性单体叔碳酸乙烯酯,通过调整改性单体的加入量、选择合适的乳化剂和保护胶体的品种和用量,生产出符合DBJ/T01-63-2002《外墙外保温用聚合物砂浆质量检验标准》并适合喷雾干燥生产可再分散乳胶粉的三元共聚乳液。     

磺化硅胶催化合成乙酸正辛酯的研究

磺化硅胶是一种以化学键键合而成,性能稳定的固体酸催化剂。文章以冰醋酸和正辛醇为原料,磺化硅胶为催化剂,合成了乙酸正辛酯,并获得了最佳合成条件:n(乙酸)∶n(正辛醇)=1∶1.2,回流时间为50 min,催化剂用量为反应物总质量的0.8%,乙酸正辛酯的酯化率可达97.5%,催化剂重复使用5次后的酯化率仍达91.1%。磺化硅胶对乙酸正辛酯的合成具有良好的催化活性。     

一种钼酸盐钝化液配制与其对镀锌钢材钝化效果的初步探索

通过对钼酸盐钝化实验的研究,了解了钼酸盐对镀锌层进行钝化的工艺,探讨了钝化液组成及工艺条件对钝化成膜及膜层耐蚀性的影响。用醋酸铅溶液对钝化膜进行点滴试验,并对其结果进行了分析,得出了一些有参考价值的结论。