Lubrication of poly(vinyl alcohol) chain orientation by carbon nano‐chips in composite tapes

The extraordinary structural properties of graphene and carbon nanotube materials motivate the development of practical methods for their use in fabricating continuous, strong, and tough composite fibers. Poly(vinyl alcohol) (PVA)/carbon nano‐chip fiber (CNCF) composite tapes with 0.5 wt % loading show that Young's modulus, tensile strength, and toughness are increased by 585%, 653%, and 20%, respectively as compared to the control (PVA) tapes. Nano‐chips exfoliated from the CNCF during processing, lubricate polymer chain alignment, and orientation during drawing, where composite tapes could be drawn to higher draw ratios compared with the control tapes. As a result, the Herman's orientation factor (f) increased from 0.5 (control tape) to 0.8 (composite tape). Theoretical analysis shows ～ 16 vol % of the composite tapes consists of fully oriented PVA chains, which contributes to its exceptional mechanical performance. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis and anticorrosion properties of poly(2,3‐dimethylaniline) doped with phosphoric acid

Poly(2,3‐dimethylaniline) (P(2,3‐DMA)) was synthesized chemically by using phosphoric acid (H₃PO₄) as protonic acid. The optimum ratio for n(H₃PO₄)/n(2,3‐DMA)/n(APS) was 2.5/1/2, and the optimum temperature was 30°C. The spectra of ultraviolet‐visible and infrared demonstrate that the structure of P(2,3‐DMA) was similar with polyaniline (PANI) except for the 2,3‐ortho‐substitute methyl. The result of X‐ray diffraction and solubility analysis indicate that owing to the 2,3‐ortho‐substitute benzene ring, the P(2,3‐DMA) has poorly partial crystallinity and better solubility. In addition, the anticorrosion property of P(2,3‐DMA) was better than PANI. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Evaporation of Pure Droplets in the Convective Regime Under High Mass Flux

An analytical expression analogous to the D² law was introduced, based on a mass transfer consideration, to describe the evaporation of pure droplets in the convective regime based on the Ranz-Marshall-type correlation for the Sh number. Comparison was made to single droplet drying experiments of pure water. It was found that the effect of mass transfer coefficient depression is significant under the high mass flux condition from the droplet. An expression was obtained to approximate the total time required for complete evaporation of a pure droplet. This expression can be used as a quick computation tool for more fundamental studies on droplet evaporation under controlled ambient conditions.     

MIBR-纳滤组合工艺在生活污水回用中的应用研究

将膜固定化微生物反应器(MIBR)与纳滤系统相匹配,构建MIBR-纳滤组合工艺,研究MIBR-纳滤系统对生活污水的处理效果。结果表明,最佳的HRT为8 h,MIBR-纳滤系统对污水中的COD、NH3-N的去除率都达到99%以上,对浊度和色度的去除更显示了其优越性,膜对整个系统起到了稳定和强化的作用。     

氨苄西林质谱解析及其离子化方式研究

通过对于氨苄西林正离子模式质谱谱图的解析,探讨了氨苄西林的离子化方式和裂解规律。研究表明：氨苄西林存在3种质子化方式,不同的质子化方式所形成分子离子具有不同的裂解方式;质子化的质子具有明显的活性,是质谱进一步裂解的主要原因;离子化方式对于质谱峰的丰度会产生重要影响。本研究为氨苄西林质谱分析和构效关系研究提供了重要的实验基础与理论依据。     

浅析互动式教学在化工生产技术教学中的应用

随着高职教育的发展,互动教学模式在高职专业课程教学中的应用越来越广泛。本文根据目前高职学生学习化工生产技术课程的现状和互动教学模式的特征,阐述了互动教学模式在高职化工生产技术教学中的应用。     

二甲基二烯丙基氯化铵-丙烯酰胺共聚物的合成及其絮凝效果研究

选择二甲基二烯丙基氯化铵、丙烯酰胺为共聚单体,过硫酸铵为引发剂,乙二胺四乙酸二钠为助剂,通过逐渐滴加单体与引发剂的方法进行聚合反应,合成了絮凝剂二甲基二烯丙基氯化铵-丙烯酰胺共聚物(PDA)。探索了合成的最佳工艺条件,对合成的目标产物进行了红外光谱表征,确保合成产物结构的正确性;对共聚物进行了粘度、絮凝效果测试,结果表明,PDA共聚物絮凝剂在膨润土分散液中具有良好的絮凝效果,可快速沉淀,沉降高度0.5 cm需要时间不超过30 s,放置24 h沉降高度可达3.8 cm。     

硫酸蒸煮法去除废糖蜜中氯离子的实验研究

利用废糖蜜作还原剂,还原浸出低品位软锰矿,是一种经济环保的还原方法,但废糖蜜中含有一定的氯离子,在实际生产过程中会对电解阳极板产生严重的腐蚀破坏作用。实验通过硫酸蒸煮法去除废糖蜜和再生废水中的氯离子,考察了反应温度、反应时间和硫酸浓度等因素的影响。实验结果表明,在硫酸质量分数为40%~45%、反应时间为2 h、反应温度为80 ℃的条件下处理废糖蜜还原软锰矿,相对浸出率可达91.51%,符合要求。     

浮法玻璃析晶缺陷的原因分析

通过对生产中出现大量的析晶缺陷的分析,找到其产生的原因,以减少或消除这种缺陷对浮法玻璃质量的影响。     

RAFT聚合制备温敏性含糖共聚物

采用酶促法合成了含糖单体6-O-乙烯基己二酸-D-吡喃型葡萄糖酯(OVAG),使用可逆加成链断裂转移自由基聚合法(RAFT聚合)将N-异丙基丙烯酰胺(NIPAAm)和OVAG共聚,制备分散度(PDI)低且具有温度敏感性的含糖高聚物Poly(NIPAAm-co-OVAG)。用1HNMR,傅里叶变换红外光谱(FTIR),凝胶渗透色谱(GPC)对聚合物进行了表征。通过透射电子显微镜(TEM)发现自组装形成的聚合物胶束结构规整且粒径均匀。通过紫外-可见光谱对聚合物温敏性检查表明,共聚物的低临界溶解温度(LCST)可以通过共聚单体的比例进行调控。当NIPAAm与OVAG的摩尔比为14∶1时,共聚物的LCST值为36℃,在人体温度下可以形成纳米胶束,在药物载体方面拥有广阔前景。