提高乙二醇紫外线透过率技术进展

介绍了影响乙二醇紫外线透过率的因素，分析了乙二醇产品中的微量羰基化合物杂质是影响其紫外线透过率的主要因素；认为在乙二醇纯化过程中使用吸附、膜分离和添加有关试剂等物理、化学方法可以提高其紫外线透过率。     

光纤束透过率的测试研究

介绍了光纤束透过率,它表征光纤透光性能,反映光纤材料、光纤和集束加工的能力。传统光学系统透过率测试装置不能完全适用于光纤束的测试。通过理论分析和测试技术的研究,研制的光纤束透过率测试装置能连续反映250～1 100 nm透过率值,测量精确度:≤2%,并能进一步了解到光纤及光纤束的一些特征。     

橡胶的透过性与配合技术

对气体和液体的透过性，由来就是橡胶材料或橡胶制品的重要的物理性能之一，轮胎等抗气体透过或胶管等抗液体透过的低透过性橡胶制品，早就在各领域进行了研究并实际应用。近年来，人们利用聚合物的透过性功能研究了隐形眼镜和各种分离膜等制品，但也不可忽视，因透过和扩散致使各种橡胶制品产生许多不良现象，如增塑剂，硫化剂，促进剂和石蜡等各种配合剂的喷霜或污染，迁移等，以及因氧气，水份等透过而引起制品老化等，另外，近年来由于环保问题的全球化，人们对高屏蔽性即低透过性材料的要求在日益增强。     

建筑外墙涂料水蒸气透过性能测试方法比较

涂料的透湿性直接影响了外墙保温系统保温效果的发挥,其良好的透湿性对于现代建筑节能意义重大.但当前市场中外墙涂料的透湿性能参差不齐,对此国家和建筑行业制定了详细的测试方法供涂料生产企业和使用方进行性能验证.通过对比GB/T 17146-1997《建筑材料水蒸气透过性能试验方法》和JG/T309-2011《外墙涂料水蒸气透过率的测定及分级》关于试验方法的异同,并以市售乳胶漆为例详细介绍了JG/T 309中关于水蒸气透过率的测试方法,证明了减重法涂料水蒸气透过率测试具有一定的合理性和操作性.     

辊涂镀膜工艺对光伏减反射玻璃透过率性能的影响

介绍了辊涂镀减反射膜的构造及工艺原理,并研究辊涂工艺参数对镀膜玻璃透过率的影响因素,分析了可见光透过率和有效透过率的区别。     

离子交换膜选择透过机理的研究进展

综述了近年来国内外离子交换膜选择透过机理的研究进展,指出了研究离子选择透过性的目的,详细介绍了唐南平衡理论,双电层理论和空穴传递双电层理论及各理论优势和存在的问题,探讨了膜微观结构与离子在膜相中传输机制。并讨论了电流密度、膜溶液边界条件以及离子自身性质对膜选择透过性的影响。并且提出选择透过机理的未来研究方向是结合试验进一步优化离子传输机制模型,并采用仿真工具模拟传输过程,提高模型的普适性。这有助于分析离子在膜中传递机理,并为膜制造和应用工艺提供理论指导。     

乳酸透过聚合物包装膜透过系数的测定

本文根据乳品公司要求,测量聚合物包装膜阻挡水溶液中乳酸透过的性能,提出了具有可行性的试验设计思路.并详细描述实验装置和具体操作方法,浓度分析方法和数据处理方法.     

木粉对缓释化肥包膜透过能力的调控

采用48μm和150μm木粉为填料制备了聚苯乙烯/木粉复合膜,考察了木粉含量、复合膜厚、木粉粒径对复合膜透过性能的影响。结果表明,木粉可以很有效地调控聚苯乙烯膜对尿素的透过能力,复合膜对尿素的透过速度明显大于纯聚苯乙烯膜的透过速度;随着木粉含量的增加,复合膜对尿素的透过速度增加。光学显微镜观察发现,木粉中纤维状结构明显,复合膜在水中浸泡后其中木粉吸水溶胀,成为复合膜中尿素透过快速通道。     

光伏压延玻璃花型角对透过率的影响

根据光伏压延玻璃的实际使用情况研究了压花面朝下时花型角对光学性能的影响,利用菲涅尔公式以及几何光学定律计算了不同花型角的光伏压延玻璃在光线垂直入射和斜入射情况下的透过率,并和无花型时的平面玻璃的透过率进行了对比,结果表明:垂直入射时只有花型角在120°~140°时能起到增加透过率的作用;斜入射时由于光线在花型左侧面发生全发射,综合来看压花玻璃的透过率不如平面玻璃的透过率。     

阳离子交换膜对氯离子透过率的研究

在电渗析过程中，离子交换膜隔绝反离子并使同离子通过，但实际使用过程中并非完全隔离，在电渗析过程中仍有部分反离子透过膜，限制了离子交换膜的应用效果，尤其是在氯离子环境中阳离子交换膜在实际使用过程中会有氯离子透过阳膜到达产物与阳极，产生的氯气污染环境、加剧膜的氧化，降低了膜的透过性，形成了恶性循环，为探究电渗析过程中离子交换膜对氯离子的截留效果，本文开展了阳离子交换膜对氯离子透过率的相关研究，研究表明，阳离子交换膜的种类对阳离子交换膜对氯离子的透过率有重要影响；电流密度和原料初始浓度的增加会导致阳离子交换膜对氯离子的透过率增加，实际生产中为减少产物中氯离子的含量，同时保证较高的生产效率，需要综合考量各方面的影响因素以确定最佳的工艺条件。     

Hydrophobicity and Water Vapor Permeability of Ethylene-plasma-coated Whey,Chitosan and Starch Films

Abstract

Water vapor transmission rate was measured on uncoated and ethyfeae-plasma-coated whey (65-93.5% whey protein), on chitosan and starch films and on aluminum-coated chitosan. Surface hydrophobicity was assessed by contact angle measurements, and X-ray photoelectron spectroscopy was used to characterize the coatings. The water vapor transmission rate through the uncoated polymer films was highest for starch and lowest for chitosan. Whey showed intermediate water permeability, with the sample containing 65% whey-protein having the lowest water vapor transmission rate. An improvement in water vapor barrier properties was observed only for the aluminum-coated sample and not for any of the polyethylene-coated samples. It is observed that the penetrating water caused the substrate to swell and the polyethylene coating layer to crack. According to profilometry, the thickness of the polyethylene coating layer was 0.1-1 μm after 15 min exposure time. The coating was hydrophobic and contained almost exclusively carbons typical of linear or crosslinked hydrocarbons. It is suggested that the observed decrease in hydrophobicity with time during the contact angle measurements is due to the reorientation at the surface of carbonyls present in small amounts in the coating.     

聚乳酸水蒸气阻隔性的改性

聚乳酸(PLA)用于产品包装时不仅要满足所必需的力学性能、化学稳定性、透明性、印刷性以及热封性等,还要满足产品对阻隔性的要求.采用共混、添加助剂的方法以提高PLA对水蒸气的阻隔作用.结果显示:乙烯-乙烯醇共聚物(EVOH)、有机蒙脱土(OMMT)的加入可以降低PLA的水蒸气透过率(WVTR),且随着其含量的增加,WVTR值逐渐减小,当EVOH质量含量达到50％时,WVTR值减小了61％,OMMT含量达到9％时,WVTR值减小了58％;在OMMT/PLA共混物中加入聚癸二酸丙三醇酯(PGS)后,WVTR值增加.     

Investigating the structural effect of electrospun nano-fibrous polymeric films on water vapor transmission

Electrospun polymers have many applications in the industry.However, the structure of these polymers has been less widely considered by researchers.In this work, the structural effect of electrospun and casted films of polyacrylonitrile(PAN) and polyvinylidene fluoride(PVDF) polymers on water vapor transmission were investigated.Sorption of water vapor was measured at 35, 60 and 80 ℃ and different relative humidities.The diffusion coefficients were calculated based on mass changes of the polymer sample.The water vapor transmission rate(WVTR) was also measured at 35 ℃ and 90% relative humidity.The results indicated that electrospun nano-fibrous polymers(ESNPs) absorb much higher water vapor compared to non-porous casted polymers.The interaction of water molecules with mentioned polymers was investigated based on Flory-Huggins theory.The Flory-Huggins interaction parameter of electrospun films was less than casted films, suggesting much better interaction of water molecules with electrospun films.It was also found that electrospun films have anomalous kinetic behavior and do not obey the Fickian diffusion model.Finally, it was revealed that ESNPs show less resistance to water vapor transmission and they are good candidates for the applications of water vapor separation using membranes.     

Some Remarks on the Classification of Water Vapor Sorption Isotherms and Blahovec and Yanniotis Isotherm Equation

Mathematical analysis was performed on equations describing water vapor sorption isotherms. It was shown that an identity exists between the Blahovec and Yanniotis (BY), D'Arcy and Watt (DW), and generalized D'Arcy and Watt (GDW) models. The original BY model has been modified to account for temperature dependence of the model parameters. This modification enables the application of this model to describe sorption data obtained at different temperatures. A new method for classification of sorption isotherms has been proposed that is much simpler than the classification established by Blahovec and Yanniotis.     

密封材料的透水性研究

本文探讨了橡胶密封材料的结构对透水性的影响,介绍了透水性的测试方法以及几种材料的水蒸汽透过系数。     

化学气相传输法制备无水溴化铒

报导了制备无水纯ErBr3的化学气相传输法。Er2O3为原料，无水溴化铝为溴化剂和传输介质。Er2O3与过量的溴化铝反应，生成ErBr3(s)。ErBr3(s)在高温与溴化铝反应生成气态配合物，该配合物在低温分解。利用453—753K的温度梯度场，实现ErBr3的化学气相传输，获无水纯ErBr3产物。     

水蒸气蒸馏实验内容的绿色化改进

有机化学实验是有机化学教学中不可缺少的重要环节。文章从蒸馏内容方面对传统的大学有机化学实验中水蒸气蒸馏进行了改进。与传统水蒸气蒸馏实验相比,避免了有毒有害物质的使用,减少了环境污染,节能环保,操作简便,并具有较强的趣味性和实用价值。这样既可树立学生的环保意识,又能实施化学实验绿色化。     

壳牌煤气化工艺技术中水汽管道的设计特点分析

水汽系统是壳牌粉煤气化技术的核心之一。介绍了壳牌煤气化技术中水汽系统的工艺流程,并结合实际工程经验,探讨了以气化炉、合成气冷却器、中压蒸汽汽包、中压循环水泵为核心的水汽系统的设备布置;提出了水汽系统进水主管、进水支管、回水主管、回水支管、汽包进出口管道、循环水泵进出口管道等主要管道的设计要点,并对水汽系统管道的支吊架设置特点进行了分析与研究。     

Binary Adsorption of n‐Butane or Toluene and Water Vapor

To clean the air in cars of noxious gases by adsorption, predominantly activated carbon is used. The height of the activated carbon layer is especially small in cabin air filtration. As test substances for adsorptive filters in cabin air filtration, toluene and n‐butane are prescribed in several engineering standards, e.g., ISO TS 11155‐2. In the study presented, the differences in binary adsorption between toluene or n‐butane and water vapor are investigated with emphasis on adsorption equilibrium and kinetics at temperatures between 15 °C and 33 °C, and relative humidity varying between 0 % and 90 %. The range of input concentrations is from 2 ppm_V up to 80 ppm_V.     

碳酸丙烯酯—水二元系溶液蒸汽分压的推算

从Ｖａｎ Ｌａａｒ方程出发，推算碳酸丙烯酯－水二元系溶液中碳酸丙烯酯和水的活度系数，然后再利用非理想溶液的Ｒａｏｕｌｔ定律，分别算出碳酸丙烯酯和水的蒸汽分压。