电位滴定法测定标准物质DIANP的纯度

为了定值标准物质DIANP,建立了测定DIANP纯度的电位滴定法.该滴定法的条件是:DMSO作溶剂,NaOH溶液作反应试剂,使DIANP中的N-3和AgN03中的Ag+反应,生成AgN3沉淀.由EQP曲线算得标准物质DIANP纯度为99.85％,相对标准偏差为0.13％,与液相色谱法比较,结果无显著差异,该方法的扩展不...     

铜矿尾砂及低品位铜矿的电化学浸出

研究了采用电化学浸出法对铜矿尾砂及低品位铜矿的综合利用。研究结果表明：选取铜矿尾砂与乙炔黑的质量比约为20：1．电解液为0．789mol／L的Na2SO4溶液,溶液的pH取7,电解电流固定在160mA的条件下,以浓度为65‰68％的浓HN03溶解铜矿尾砂所得到的铜为基准,该电解法提铜的提取率高达96．2％．电化学浸出法,可以有效地从铜矿尾砂及低品位铜矿中回收铜。     

工业氢氧化镁制备高纯度氟化镁工艺探究

实验采用工业级高纯Mg(OH)2为原料,通过酸溶、除杂、氟化步骤成功制备了纯度在99％以上的高纯度MgF2.其中,HN03溶解能够对Mg(OH)2原料进行难溶除杂,随后通过草酸-双氧水法除去大部分金属离子杂质,最后与分析纯NH4F制备高纯度MgF2.实验结果表明,在25℃氟镁比为2∶1的条件下,制备得到的MgF2纯度最...     

二氧化硅溶胶的制备及性能影响研究

以正硅酸乙酯、水、乙醇和酸性催化剂为原料,制备了SiO2溶胶。研究了催化剂的种类、反应温度、反应时间、添加剂等因素对SiO2溶胶性能的影响。实验结果表明：在[H^＋]相同的条件下,酸催化剂对溶胶粘度的影响为：HF〉HCI〉HN03〉H2S04〉HAC,对凝胶时间的影响为：HAC〉H2S04〉HC1〉HN03〉HF,几种溶胶固含量的大小为：H2S04〉HN03〉HCl〉HAC,制备二氧化硅膜用硅溶胶较适合采用盐酸或硝酸作为催化剂;随着反应温度的升高,溶胶的粘度、固含量和粒径均逐步增大,凝胶时间则缩短;随着反应时间的延长,溶胶的粘度、固含量以及粒径逐步增大,凝胶时间则变短;向在溶胶中加入DMF后,溶胶粘度、固含量变小,凝胶时间延长,SiO2粒子的粒径增大。     

铝型材表面无铬钝化液

本专利是关于处理铝型材表面的环保型表面无铬钝化液。它是将一定量的下述组分即：分子量30—200万的树脂，硅胶粉，ZnS或Na2s、磷酸二氢钠（NaH2P04）、HF、HN03按照顺序分别加入一定量水中，搅拌到全部溶解后即为成品。本发明以树脂为主要成分，不含任何金属，对环境无任何污染，对人体无伤害。由于采用树脂及其它助剂反应后在Al表面形成保护膜，达到防腐和增强附着力的功能。     

碳化钨化学腐蚀液组成的研究

碳化钨硬质合金特殊的耐磨性和化学稳定性使得对其的加工条件很苛刻，采用HN03与HF混酸做腐蚀剂，在适宜的腐蚀工艺条件下，能够控制腐蚀速度和材料表面光洁度，可以实现对碳化钨硬质合金的精细加工。     

HN—型高固色率活性染料的低盐染色法

HN－型高固色率活性染料红HN－2B，金黄HN－R，深蓝HN－2G，其吸色率在95％以上，固色率在85％左右。以几种不同的染色,用HN－型高固色率活性染料对棉纱及棉布进行了染色，染色结果表明，在中温下，该活性染料可以采用低盐染色。当盐的加入量减少为30g/L (是标准加入量的1／2），其最适宜的染色条件:浴比1：20，染色深度3％，40℃上梁，60℃固色，氯化钾20g/L和柠檬酸三钠为10g/L，碱磷酸三钠的加入量为4＋10g/L时，其K／S值下降百分数：红HN－2B为10．16；金黄HN－4为5．57，深蓝HN－2G为8．57。     

金属刻蚀剂

金属铁刻蚀剂H:0/HCIH:0/HN03HAC/践0。热HZO/NaOHH?O/C r03HCI/H:02HN03/HAC/丙酮HF/HNO3热HCI/HNO。热HCI/HNO3热HCI/HNO3热HCI/HNO3比丰l:11:11:110:l(重童)5:1(重量)铅锰铂锋扼把铂休代金属刻蚀剂~~     

1，3-丙二醇发酵液过滤除菌过程中的膜污染与再生

从膜的污染与再生角度出发,初步讨论了温度和压力对膜污染和再生的影响。通过试验表明,提高温度有利于减缓膜污染的速度,最适温度为60℃;提高膜表面流速同时减小膜压力,有利于减缓膜污染。而采用1％NaOH和0．05％EDTA混合溶液清洗膜30min后,再以0．5％HN03溶液清洗5min,膜通量可迅速恢复。     

河道淤砂提钪浸出试验研究

对从河道淤砂中提取钪的新工艺进行了研究。试验考察了盐酸、硝酸、硫酸以及盐酸加助溶剂浸出钪时各因素的影响和浸出效果,以及氯化焙烧浸出、碱熔合浸出的浸出效果。试验结果表明,在三种酸的浸出试验中HN03浸出率为59．20％,略高于盐酸,但盐酸加助熔剂浸出率高达80．94％。而氯化焙烧浸出、碱熔合一水解浸出的浸出率分别高达82,79％和99．79％。     

从含银实验废液中回收银并制备硝酸银

采用高温还原法回收实验废液中的银(回收率达98%以上,回收银纯度达99.90%),然后溶于硝酸,制备实验用试剂—硝酸银。硝酸银的回收率为97.5%。     

不同介质中锌还原氯化银的研究

本文研究了在不同介质中锌还原氯化银制取金属银的影响。结果表明金属锌还原氯化银的最佳硫酸浓度为0.05～0.5mol/L,在此浓度范围内具有较快的反应速度,银的产率达99％。在氯化钠溶液中锌能较好地还原氯化银,在硝酸钠溶液中锌不能还原氯化银。提出了应该在百分之一的氯化钠溶液中用锌还原氯化银制取金属银的结论。     

Green Formation of Spherical and Dendritic Silver Nanostructures under Microwave Irradiation without Reducing Agent

The rapid and green formation of spherical and dendritic silver nanostructures based on microwave irradiation time was investigated. Silver nanoparticles were successfully fabricated by reduction of Ag(+) in a water medium and using polyvinylpyrrolidone (PVP) as the stabilizing agent and without the use of any other reducing agent, and were compared with those synthesized by conventional heating method. UV-vis absorption spectrometry, transmission electron microscopy (TEM), atomic absorption spectroscopy (AAS) and photon correlation spectroscopy (PCS) measurements, indicated that increasing the irradiation time enhanced the concentration of silver nanoparticles and slightly increased the particle size. There was a lack of large silver nanoparticles at a high concentration, but interestingly, the formation and growth of silver dendrite nanostructures appeared. Compared to conventional heating methods, the silver nanoparticle suspension produced by irradiated microwaves was more stable over a six-month period in aqueous solution without any signs of precipitation.     

Effects of Silver on Barium Titanate as a Function of Stoichiometry

This work examines the effects of Ag on stoichiometric and nonstoichiometric BaTiO₃ in terms of the unit cell dimensions, the polycrystalline microstructure, and the dielectric properties. Stoichiometric BaTiO₃ and compositions with 0.5 mol% TiO₂ excess and 0.5 mol% BaO excess were prepared via solid-state synthesis with varying amounts of Ag up to 0.3 mol%. Experimental results indicate that stoichiometry plays a significant role in the solubility of Ag and its effects on the physical properties. Overall, the solubility of Ag was negligible in stoichiometric BaTiO₃. However, compositions with excess TiO₂ stabilized the solubility of Ag as evidenced from changes in the unit cell dimensions and dielectric properties. Based on these data, it is proposed that Ag occupies the A-site in the perovskite structure with an upper limit of Ag solubility of 0.06 mol% Ag in BaTiO₃ with 0.5 mol% excess TiO₂. Dielectric measurements showed that Ag concentrations approaching 0.3 mol% gave rise to an increase in the space charge effect, especially at temperatures above T _C. In both nonstoichiometric compositions, the presence of a liquid Ag phase during thermal processing was found to affect microstructural development and sintering.     

从卤化银废液中回收银并制备硝酸银标准溶液

利用铁与浓盐酸反应产生的H2与AgCl、AgI废液反应，可得到粗制银粉；将粗制银粉与硝酸反应转化成硝酸银后，加入紫铜，制得99．99％以上的纯银粉；再用纯银粉制备硝酸银标准溶液，从而实现了卤化银废液的有效回收。     

载银活性炭的载银量分析

采用灼烧法预处理，银量法滴定来测定载银活性炭的载银量，获得稳定而准确的分析结果。结果表明，制备载银活性炭时所加入的银并未全部吸附在活性炭上；吸附性能高的活性炭能制得高载银量的载银活性炭。     

不同Br~-浓度下铂电极上镀银层的氧化动力学

本文采用循环伏安法研究了镀银铂电极在溴化钾溶液中的成核过程及氧化动力学,结果表明:AgBr的形成包括三个步骤,首先在银表面某些吸附Br~-的特殊位置上以平面方式成核,然后经过二个三维的成核步骤。在较低浓度的KBr溶液中,AgBr的形成由溶液中的Br~-迁移控制。在较高浓度的溶液中,由于生成的AgBr膜是高度松散的,速度控制步骤转化为在膜孔内Br~-的迁移。随着AgBr的生成以及AgBr的溶解沉积作用,膜孔被堵塞,同时反应速度转化为由AgBr膜中的Ag~+迁移控制。电镜结果也支持了以上结论。     

无机抗菌磷酸盐玻璃及其性能的研究

采用高温熔融法,在磷酸盐玻璃的配合料中引入抗菌剂硝酸银,一次烧制而成制得抗菌玻璃材料,对磷酸盐玻璃的抗菌性能和缓释性能进行分析.结果表明:制备抗菌磷酸盐玻璃时,合适的银质量分数为1.5%～2.0%,处理温度在1200～1350℃,即获得良好的抗菌效果和缓释性.     

紫外光固化聚氨酯基导电银浆的制备及其性能研究

以超细球银与片状银粉复配作为导电相,二官能度的端乙烯基聚氨酯丙烯酸酯预聚物作为粘结相,制备出高电导率、高附着力和高柔韧性的紫外光固化聚氨酯基导电银浆。研究了超细球银与片状银粉的相对用量对银浆电导率、附着力和耐弯折性能的影响,并通过扫描电镜对银浆中银粉的分散状态进行了分析。结果表明:采用适量的超细球银与片状银粉复配,可以有效提高银浆的电导率和力学性能。当超细球银用量为6.6%(wt),片状银粉用量为65%(wt)时,银浆的电导率高达1.33×106S/m;与聚对苯二甲酸乙二醇酯基材具有良好的附着力,百格测试级别为5B;耐弯折性能优良,10次弯折测试后,电导率仍能达到3.38×105S/m。     

Ethene/Ethane (C2H4/C2H6) Separation through an Inorganic–Organic Hybrid Membrane Containing Silver(I) Ions as Olefin Carriers, Using Poly(N-vinylpyrrolidone) as a Mediation Agent

Novel inorganic–organic membranes that contained Ag⁺ ions as olefin carriers were prepared using sol–gel and dip-coating processes. The permeance of the membranes for nitrogen, helium, ethane (C₂H₆), and ethene (C₂H₄) were evaluated using the single-gas permeation method at temperatures of 298, 373, and 423 K. The results showed that the selectivity of the membranes to C₂H₄ against C₂H₆ increased as the measurement temperature increased, because the decomplexation rate of C₂H₄ molecules from Ag⁺ sites is enhanced by increases in the temperature. Fourier transform infrared spectrophotometry of the hybrid membranes and the performance of the membranes at 373 and 423 K indicated that poly( N -vinylpyrrolidone) (PVP) had a role in increasing the flexibility of the inorganic network and also served as a mediation agent to fix Ag⁺ ions in the polymer segments, because of the coordination interaction between the Ag⁺ ions and the PVP.