阳离子羟乙基纤维素溶液黏度性能的研究

以羟乙基纤维素（HEC）为原料,2-氯-4,6-二（N,N-二甲基-N-苄基1,3-丙二胺）1,3,5-均三嗪为改性剂,制备出不同取代度阳离子羟乙基纤维素。同时探讨了取代度及其浓度、阳离子及其浓度、转子转速、温度、pH值对阳离子羟乙基纤维素（CHEC）的黏性行为的影响。结果表明,阳离子羟乙基纤维素溶液黏度随着CHEC浓度增大、温度的升高、pH值的增加而减小。同一CHEC质量浓度下,取代度越高,转子的转速降低,黏度增大。CHEC在K₂SO₄溶液中的黏度总低于MgSO₄溶液中黏度;随着阳离子浓度的增加,CHEC溶液的黏度降低。     

复合镀层电刷镀工艺的研究

在电刷镀溶液中加入一定数量的一种或几种不同溶性固体非金属颗粒,通过电刷镀工艺沉积而获得硬度较高,耐磨,耐蚀,自润滑的复合镀层。在天龙４＃－４快速镍刷镀液及天龙６＃－６非晶态镍磷合金镀液的基础上,就其镀液组成,添加剂等条件进行了试验,选择,并对加入的固体颗粒的分散数量,颗粒径的大小进行了试验,确定了工艺参数,形成了完善可行工艺。     

改性羟乙基纤维素水溶液流变性能的研究进展

综述了经疏水化改性和阳离子化改性的羟乙基纤维素水溶液的流变学性能及其影响因素,如改性羟乙基纤维素的相对分子质量、溶液浓度、温度、侧链的种类、侧链链长、物质的量分数及其分布等;评述了表面活性剂与改性羟乙基纤维素形成复合体系溶液的流变性能。分析了由于改性羟乙基纤维素分子结构的改变而使其溶液体系增黏的机理。     

快速型镍系列电刷镀溶液及工艺研究

快速镍电刷镀液是一种应用面广、用量大的镀液，但在应用中也发现一些不足。为此通过试验研究，开发了快速型镍系列电刷镀液，形成二十余种刷镀液，镀层性能各有不同，适用于多种用途。本文系统研究快速型镍系列电刷镀液组份及工艺条件。在此基础上测试了镀液特性、技术参数、镀层性能，并进行了实际应用，证明该镀液沉积速度快，镀厚能力强，镀层硬度高且范围广，具有良好耐磨性能，镀层致密有光，具有一定的韧性，与基体结合强度高     

可溶阳极快速镍溶液电刷镀工艺的优化

随着电刷镀技术的深入发展和广泛应用，对镀液的质量和性能要求越来越高，本文主要对可溶阳极快速镍溶液的电刷镀溶液的配方及工艺进行优化，确定了最佳工艺，提高刷镀的可靠性和成功率。     

电刷镀技术基本知识系列讲座（四）电刷镀溶液

沉积金属溶液是电刷镀技术中主要的溶液体系，是电刷镀溶液的核心技术所在，从本讲开始对主要的电刷镀沉积金属溶液进行介绍。     

羟乙基纤维素精制的工业化实验

介绍了羟乙基纤维素的结构、性质及制备方法。通过实验选择以75%的丙酮溶液为洗液,采用旋转式压力洗涤过滤机洗涤,能有效去除羟乙基纤维素中的杂质,获得高纯度羟乙基纤维素产品,达到工业化提纯羟乙基纤维素的目的。     

电刷镀技术基本知识系列讲座（四）电刷镀溶液

电刷镀技术中采用专用的电刷镀溶液完成电刷镀作业的镀前处理、沉积镀层、镀后处理等工序，是与槽镀等溶液有极大不同的一个独立而完整的体系，是电刷镀技术的一个重要的组成部分。     

电刷镀技术基本知识系列讲座（四）——电刷镀溶液

沉积金属溶液是电刷镀溶液体系中数量最多、用途最广的溶液品种，一般又称之为“镀液”，以示与表面准备及其它用途溶液的区别。沉积金属溶液的质量是决定镀层性能的最基本的因素，而电刷镀工艺中的设备、工辅具、表面准备及刷镀工艺等则都是为了最大限度地达到沉积金属溶液应该达到的性能而展开的，因此必须对沉积金属溶液的基本性能有所了解。     

新型ABS化学镀镍工艺的初步研究

探索了采用丙烯酸和其酯类的共聚物钠盐溶液对ABS塑料表面化学镀镍前处理的可行性，并测试了Ni-P镀层的成分、形态、生长情况以及导电性。结果表明．在pH4．5和在pH5．5下，施镀时间为30min时，磷的质量分数分别达到7．256％和3．394％，此时分别出现非晶和微晶，同时在pH5．5下施镀，在前5min内以颗粒数目增多为主．在此后的时间段内以颗粒粒径增大为主，在施镀20min时颗粒粒径尺寸达到1μm，电阻为0．7Ω。     

Synthesis of carbon nanotubes on pulse plated Ni nanocrystalline substrate in ethanol flames

A novel process for synthesizing carbon nanotubes (CNTs) in ethanol flames is described. The CNTs grow on a nanocrystalline Ni layer which was electro-deposited on a Ni substrate using periodic reverse (PR) pulse plating. The grain size of the plating and CNT morphology were revealed using XRD, SEM, TEM and Raman spectroscopy. It was found that the quality of the plating and the corresponding CNTs were related to two plating parameters: output pulse frequency (f) and duty cycle (r). The growth mechanism of CNTs in this process is discussed.     

1-(2-三甲基硅氧乙基)-5-巯基四氮唑的合成研究

以乙醇胺为起始原料,经三甲基氯硅烷保护制得2-(三甲基硅氧基)乙胺,再经与二硫化碳反应,再与溴乙烷缩合得到N-(2-三甲基硅氧乙基)二硫代氨基甲酸乙酯、然后再与叠氮化钠成环反应合成了1-(2-三甲基硅氧乙基)-5-巯基四氮唑.用三甲基氯硅烷作为乙醇胺的羟基保护试剂,保护和脱保护具有反应条件温和、收率高等 优点,反应总收...     

Dispersion of Boron Nitride Powders in Aqueous Suspensions with Cellulose

The dispersion of nitride and carbide ceramic particles in water is difficult, due to the absence of hydroxyl groups on their surface. Boron nitride (BN) is not an exception and despite its numerous applications, no effective dispersant has been identified so far. We demonstrate here the dispersion properties of two cellulose derivatives for hexagonal BN powders, hydroxyl ethyl cellulose and methyl cellulose. The effect of particle size and cellulose concentration was investigated. The adsorption of cellulose onto the surface of the BN particles was confirmed by isotherm adsorption. Zeta potential measurements show a charge screening effect of the cellulose The suspensions obtained were highly loaded and stable versus pH, and thus could lead to homogeneous codispersion of BN particles and sintering additives.     

Chemical‐vapor‐sensitive materials based on a multiwalled carbon nanotube/hydroxyl propyl methylcellulose/cellulose composite

A type of chemical vapor‐sensing material made from multiwalled carbon nanotubes/hydroxyl propyl methyl cellulose/cellulose composite films were prepared in the room‐temperature ionic liquid 1‐butyl‐3‐methylimidazolium chloride ([BMIm]Cl). A typical negative vapor coefficient was observed when the film was placed in polar organic solvents, such as methanol and ethanol. The sensitivity of the film to vapors increased significantly with increasing temperature. Interestingly, the resistance of the films increased almost linearly with decreasing vacuum, and the changes in resistance with the vacuum show good repeatability. The surface morphology, thermostability, and stress–strain properties of the composite films were analyzed with scanning electron microscopy, thermogravimetric analysis, and an electrical universal testing machine, respectively. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41639.     

Electroless Plating of Carbon Nanotubes with Copper

A simple chemical method was employed to coat carbon nanotubes with a layer of copper. Due to the hydrophobic nature, large surface curvature, small diameter and large aspect ratio, it is difficult to gain continuous electroless plating layer on the surface of carbon nanotubes. In this paper, a series methods (oxidization, sensiti-zation and activation) are used to add active sites before electroless plating, and the adjustment of the traditional composition of copper electroless plating bath and operating condition can decelerate electroless plating rate. The samples before and after coating were analyzed using transmission electron microscopy and energy-dispersive X-ray spectroscopy. The results showed that the surface of carbon nanotubes was successfully coated with continuous layer of copper, which lays a good foundation for applying carbon nanotubes in composites.     

碳纳米管的化学镀铜

A simple chemical method was employed to coat carbon nanotubes with a layer of copper. Due to the hydrophobic nature, large surface curvature, small diameter and large aspect ratio, it is difficult to gain continuous electroless plating layer on the surface of carbon nanotubes. In this paper, a series methods (oxidization, sensitization and activation) are used to add active sites before electroless plating, and the adjustment of the traditional composition of copper electroless plating bath and operating condition can decelerate electroless plating rate. The samples before and after coating were analyzed using transmission electron microscopy and energy-dispersive X-ray spectroscopy. The results showed that the surface of carbon nanotubes was successfully coated with continuous layer of copper, which lays a good foundation for applying carbon nanotubes in composites.     

核电变压器套管腐蚀分析及防护措施研究

分析了某核电站主变压器套管发生腐蚀的原因:套管从刷镀厂到生产现场期间未进行镀银面的防护,导致套管长期与空气接触而腐蚀。腐蚀后的套管经现场刷镀后发生二次锈蚀,原因是套管未进行镀镍处理就直接镀银。提出了相应的防腐措施:在套管制造和装配阶段涂抹凡士林或包裹防护袋;在连接试验阶段对接线板加装一层防护板;在现场安装阶段涂抹凡士林、包裹防护袋,并加装防护钢板以及钢制套管防护罩,防止套管腐蚀及磕碰。     

复合刷镀Ni-SiC的工艺研究

复合刷镀是一种新的刷镀工艺方法,Ｎｉ－ＳｉＣ复合刷镀层的硬度及耐磨性能良好,具有很好的经济、使用价值。介绍了复合刷镀设备,研究、分析了复合刷镀Ｎｉ－ＳｉＣ镀液配方、工作电压、溶液温度、镀笔运动速度等工艺条件对镀层中ＳｉＣ含量和沉积速度的影响,提出了复合刷镀Ｎｉ－ＳｉＣ的工艺条件。     

聚乙烯亚胺对Si3N4纳米微粒复合刷镀的影响

研究了聚乙烯亚胺对刷镀(Ni-P)-Si3N4纳米微粒复合镀液中Si3N4纳米微粒的分散性、刷镀层性能及结构的影响,并确定了聚乙烯亚胺在复合刷镀液中的最佳含量。结果表明,聚乙烯亚胺能有效阻止复合刷镀液中颗粒的絮凝、团聚,其用量对复合刷镀层中Si3N4含量、刷镀层硬度及耐磨性能有显著的影响。当其质量浓度为0.8 g/L时,获得了微粒均匀分散,稳定悬浮的复合刷镀液,复合刷镀层微观表面结构致密,微粒分布均匀,磨损量最小,显微硬度最大。     

Gold supported on carbon nanotubes for the selective oxidation of glycerol

Gold nanoparticles were supported on multi-walled carbon nanotubes (MWCNTs) by different methods and tested in the selective oxidation of glycerol under basic conditions, with the main purpose of evaluating the effect of the preparation technique on the activity and selectivity. The catalytic performances largely depended on the gold crystallite size. The sol immobilization method was the most suitable technique to prepare gold supported on carbon nanotubes. The use of MWCNTs as support for Au nanoparticles resulted in the oxidation of the secondary hydroxyl group, and therefore, a remarkable high dihydroxyacetone selectivity of about 60% is obtained independently of the preparation method used. A possible explanation based on the peculiar characteristics of the support is proposed. It was also concluded that dihydroxyacetone in the final mixture can be stabilized by lowering the pH to about 3.