化学镀银织物的制备及性能研究

通过化学镀的方法将银颗粒镀到轧光涤纶织物表面,以制备化学镀银织物,并对镀银织物的性能进行了分析。通过对镀银织物的表观形貌、导电性能、红外隐身性能等测试分析,筛选出最佳镀液浓度。结果表明,镀层织物的方块电阻和红外发射率会随着镀液中硝酸银的浓度增加而降低,当镀液中硝酸银的浓度为14.0 g/L时,施镀后的涤纶织物具有光泽且光滑的表面,其方块电阻值可达90.29 mΩ·cm~(-2),红外发射率为0.37,并具有一定的电磁屏蔽性能。     

氟硼酸体系二价锡合金镀液抗氧化剂的筛选

为了防止镀液中Sn2+的氧化,需在基础镀液中加入抗氧化剂。采用自然氧化法做分析试验:(1)测定苯酚、间苯二酚和对苯二酚3种不同抗氧化剂对镀液稳定性的影响;(2)测定添加不同质量浓度的对苯二酚对镀液的稳定性及镀层成分的影响。分析结果表明,在Pb-Sn-Cu三元合金电镀中采用质量浓度5g/L的对苯二酚作为抗氧化剂,镀液的稳定性适中,镀层质量良好。     

玻璃纤维化学镀Ni-W-P工艺研究

研究硫酸镍浓度、钨酸钠浓度、次亚磷酸钠浓度、柠檬酸钠浓度及镀液温度和反应时间对玻璃纤维化学镀Ni-W-P工艺的增重率(镀层沉积速率的表征指标)的影响,然后结合单因素试验结果,并通过正交试验,确定了玻璃纤维化学镀Ni-W-P工艺的最优镀液配方和工艺参数。     

胎圈钢丝化镀锡青铜工艺研究

研究胎圈钢丝化镀锡青铜的镀液配方 ,分析了 ρ(Cu2 +) ρ(Sn2 +)之比和硫酸浓度对镀液的影响 :ρ(Cu2 +) ρ(Sn2 +)之比应控制在 13以上 ,硫酸浓度可在一定范围波动 ,对镀层含锡量影响不明显。加入研制的添加剂可增加镀液稳定性。为提高镀层与橡胶的粘结力 ,应加强钢丝表面前处理和镀后处理。     

气保焊丝镀铜质量对其防锈性能的影响

分析气体保护焊丝的锈蚀原因及化学镀铜质量对焊丝防锈能力的影响。认为焊丝镀铜层厚度、镀层结合力、镀层稳定性是影响其防锈能力的重要因素。提高镀层厚度可以显著提高焊丝的防锈能力。镀铜层结合力及其稳定性明显影响焊丝的防锈性能,而影响镀铜层结合力及其稳定性的最主要因素是焊丝的镀前表面质量和镀液的性能。使用分子筛型镀液添加剂对提高镀层厚度、镀层结合力及其稳定性都非常有利。     

Zn-Fe-La三元合金耐蚀性研究

研究电沉积Zn-Fe-La三元合金镀层的耐腐蚀性能,通过对镀层在pH为7,质量分数为5%的NaCl溶液中Tafel曲线的测量、SEM和能谱分析,考察FeSO4、ZnCl2、LaCl3质量浓度对合金镀层耐腐蚀性能的影响。结果表明:当镀液中FeSO4质量浓度为40 g/L、ZnCl2质量浓度为25 g/L、LaCl3质量浓度为12 g/L时,所制备的三元合金镀层的耐蚀性能最优;稀土盐的加入增大了电沉积的阴极极化,有利于Fe的沉积,对Zn的沉积有一定的阻化作用,可改善镀层表面形貌,降低孔隙率,使结晶细化,表面更加平整,有效提高了镀层的耐腐蚀性。     

化学置换镀锡青铜工艺研究

胎圈钢丝的化学置换镀锡青铜已列入“十五”金属制品科技发展建议。介绍置换镀锡青铜的原理及镀层成分控制措施 ,在镀液中降低Sn2 + 含量、增加镀液的酸度有利于镀液的稳定 ,加入添加剂也可提高镀液的稳定性。对提高镀层的结合强度 ,镀层的防变色处理方法及该工艺技术规范也作了说明     

分子筛型添加剂对气保焊丝化学镀铜质量的影响

对气保焊丝的镀铜层质量存在的问题以及分子筛型添加剂的作用进行深入分析,指出焊丝镀铜层质量主要表现在镀铜层厚度、镀层结合力及其稳定性,影响焊丝化学镀铜层结合力及其稳定性的主要因素是焊丝的镀前表面质量和镀液的性能。使用分子筛型镀液添加剂不仅能提高镀层厚度还能提高镀层结合力及其稳定性,因而明显改善焊丝的整体防锈性能。     

化学镀银涤纶织物的制备及其性能

利用化学镀方法制备镀银电磁屏蔽涤纶织物.分别采用场发射电镜( FE-SEM)、电子能谱(EDS)和X射线衍射(XRD)表征镀层的表面形貌、成分和结晶情况;考察了织物的厚度、增重率、耐摩擦色牢度、表面电阻、抗静电性、拉伸断裂强力、断裂伸长率、刚柔性、悬垂性以及透气性.结果表明:镀层为高纯度立方面心结构的单质银;化学镀银后...     

提高钢丝镀铜层耐蚀性的探讨

阐述钢丝镀前处理、镀铜工艺参数、镀后处理等对镀层耐蚀性的影响 ,着重介绍镀铜工艺参数包括镀铜方式、镀液成分、镀液温度、镀液中杂质对镀层耐蚀性的影响 ,指出要提高铜层的耐蚀性 ,镀液中硫酸铜和硫酸的质量浓度应分别达到 80～ 10 0 g/L和 10 0～ 12 0g/L ,并适当使用添加剂。提出了提高钢丝镀铜层耐蚀性的措施     

Production of electromagnetic shielding fabrics by optimization of electroless silver plating conditions for PET fabrics

This study aimed to investigate the optimal electroless silver plating conditions on poly (ethylene terephthalate) (PET) to develop electromagnetic shielding fabrics by comparison with two different activation agents (silver nitrate mixture and palladium chloride mixture). The add-on yield and thickness of plated fabrics were improved when the electroless silver plating was performed after the activation by silver nitrate mixtures compared to the activation by palladium chloride mixtures. The stability of plated surfaces after the activation by silver nitrate mixtures was proved after laundering by surface morphology and electromagnetic wave shielding effectiveness. The electroless silver plating condition was optimized to temperature of 15 °C, plating time of 30 min, dextrose concentration of 45 g/L, and silver nitrate concentrations as a plating material of 50 g/L. The electromagnetic wave shielding effectiveness and electrical conductivity of plated fabrics were maintained even after repeated laundering cycles. Electron probe microanalysis was concluded that the silver was attached on plated PET surfaces, and about 17.8% of silver was observed by inductive coupled plasma spectrometer.     

接枝改性对淀粉与PVA混溶性的影响

以过硫酸钾-硫代硫酸钠引发淀粉与甲基丙烯酸接枝,其产物经红外光谱分析证明为接枝产物.以接枝共聚物作为增容剂,考察了PVA醇解度、接枝淀粉加入量以及接枝率对淀粉与PVA溶液共混体系的影响.同时考察了接枝淀粉与PVA-1799两种浆液溶液共混体系的稳定性.结果表明:接枝淀粉的加入可提高共混浆液的稳定性;随着PVA醇解度增加或淀粉接枝率、接枝产物添加量的增加,浆液的稳定性提高.     

化学镀银织物电磁屏蔽效能及透湿透气性能研究

为研究化学镀银对织物性能的影响,采用葡萄糖作还原剂对涤纶织物进行镀银,借助扫描电镜、网络分析仪、织物透湿仪、织物透气量仪等,对镀银织物的表面镀层形貌、织物的电磁屏蔽效能,以及织物的透湿、透气性能进行测试分析。结果表明:随着增重率的变大,织物的屏蔽效能增加,当增重率达到37%时,电磁屏蔽效能增加不明显,故应根据需要合理选择面料的镀层厚度;研究还发现镀层厚度对织物的透湿、透气性有影响。     

涤纶织物纳米TiO2颗粒化学复合镀银

采用化学镀技术,实现了不同分散剂分散纳米TiO2颗粒涤纶织物表面化学复合镀银,借助SEM、XRD和TG对镀层表面形貌、结构和织物热性能进行研究,测试织物的电磁波屏蔽、导电、耐磨、透气和光催化性能.结果表明:用PVP&T80作分散剂时,纳米TiO2的引入对镀层结构没有影响,但晶粒尺寸增大;随着纳米TiO2质量浓度的增加,...     

气保焊丝锈蚀原因分析及提高防锈能力的措施

通过对气体保护焊丝锈蚀原因的分析,认为影响镀铜层厚度、结合力及其稳定性的主要原因是焊丝的镀前表面质量和镀液的性能;确保镀铜前后钢丝表面清洁,控制镀铜层厚度在2.0~5.0μm,采用分子筛型镀液添加剂可以提高焊丝的防锈能力。     

塑料模具的化学复合镀工艺研究

选用45钢作为模具基体材料作试样进行Ni-P/SiC/PTFE化学复合镀，对镀液的pH值、温度和搅拌速度等工艺参数进行了分析，并给出了提高化学复合镀稳定性的工艺措施。该工艺可显著降低镀层的摩擦系数，大大提高其耐磨性和自润滑性，从而可提高模具的使用寿命，防止工件粘膜，改善制品表面质量。     

Identification of volatile/semivolatile products derived from chemical remediation of cis-1,3-dichloropropene by thiosulfate

The prevalent use of soil fumigants has resulted in air pollution in some agricultural regions. Our previous research showed that application of thiosulfate fertilizers at the soil surface may offer an effective and economical approach to reduce the emission of halogenated fumigants via a chemical remediation process. In this fumigant emission-reduction strategy, volatile 1,3-dichloropropene (1,3-D) reacts with thiosulfate to generate a nonvolatile Bunte salt (thiosulfate derivative of 1,3-D). However, the decomposition of the Bunte salt may be associated with the production of perceptible odors. This study investigated the stability of this reaction product in different environmental media. Hydrolysis experiments demonstrated that the thiosulfate derivative was relatively stable in neutral and moderately acidic aqueous solutions. In contrast, the thiosulfate derivative was readily converted to a dialkyl disulfide via a base hydrolysis process in pH 10 buffer solution. In a strongly acidic solution, a mercaptan and a dialkyl disulfide compound were detected as two primary hydrolysis products. In soil, this initial reaction product underwent a series of biotic conversions to generate several volatile or semivolatile organic sulfur compounds. The formation and distribution of four volatile/semivolatile products in the air and soil were detected in different soils treated with the thiosulfate derivative of 1,3-D. This study indicated that odors occurring in soil treated with halogenated fumigants and thiosulfate fertilizers might arise from the generation and release of these and other volatile/semivolatile organic sulfur products. The environmental fate and effects of such volatile/semivolatile sulfur compounds should be considered in the application of sulfur-containing fertilizers in fumigated fields.