On the relationship between corrosion inhibiting effect and molecular structure

In order to relate the corrosion inhibition effect of organic compounds for steel in acid media to their molecular characteristics, SCF calculations have been performed for thiourea and nine derivatives, for two further sulphur-containing organic compounds and for urea and two derivatives. The structure of all compounds has been optimised, ionisation potential, dipole moments and the electron density distribution has been computed. It is seen that the dominant molecular parameter for the inhibition effect is the ionisation potential and that there is a clear relation between the increase in corrosion inhibition and the decrease of the ionisation potential.     

Determination of the metastable zone and induction time of thiourea for cooling crystallization

The solubility,metastable zone width(MSZW),and induction time of thiourea for cooling crystallization were experimentally determined in the temperature range of 283-323 K. The solubility data could be well described by the Apelblat equation model as lnx=-99.55+1071.66/T+16.27 lnT. The determinations of the effects of various stirring and cooling rates indicated that the MSZW increased with increasing and decreasing cooling and stirring rates,respectively.Furthermore,the induction times at various temperatures and supersaturation ratios were also measured.The results indicated that homogeneous nucleation could occur at high supersaturation,whereas heterogeneous nucleation was more likely to occur at low supersaturation.Based on the classical nucleation theory and induction period data,the calculated solid-liquid interfacial tensions of thiourea in deionized water at 302.46 and 312.58 K were 2.86 and 2.94 mJ·m~(-2),respectively.     

硫脲在0.5mol/L硫酸溶液中对A3钢缓蚀作用的电化学研究

为研究硫脲在硫酸溶液中对A3钢的缓蚀作用,并为实际生产中选用硫脲作为缓蚀剂的可行性评价提供参考,采用稳态极化曲线和电化学阻抗谱图(EIS)方法分别研究了A3钢在0.5mol/L硫酸溶液和0.5mol/L硫酸溶液+0.3g/L硫脲混合介质中的腐蚀行为.对硫脲在0.5mol/L硫酸溶液中对A3钢的缓蚀作用给出了评价,证明了硫脲在防止腐蚀的过程中对阴阳两极极化过程均有显著作用,并得出其为一种混合抑制型缓蚀剂的结论.     

硫脲／二氰二胺／环氧树脂潜伏固化体系

通过测定固化过程的凝胶化时间及红外光谱图,考察了硫脲及其衍生物对二氰二胺/环氧树脂体系的固化促进作用;讨论了硫脲及其衍生物/二氰二胺/环氧树脂体系的组成配比对固化特性、室温贮存性能和固化后粘合剪切强度的影响。     

树脂矿浆法从提金尾浆中回收银的研究

研究了用３５３Ｅ树脂从树脂矿浆法提金的某银金矿氰化尾浆中进一步回收银的工艺。４段逆流矿浆吸附，树脂银容量为１２ｍｇ／ｇ，银吸附率达９８．５％，载银树脂先用氰化钠溶液解吸铜、铁，水洗后硫脲硫酸溶液解吸银、再电沉积回收，银的解吸率及电积率均在９８％左右。     

从载金树脂解吸液中电积金,银的研究与工业应用

本文阐述了在隔膜电解槽中，用电积法直接从载金树脂硫脲硫酸解吸液中回收金、银的技术。系统研究了离子交换膜、电极材料、电解液金浓度、电流密度、槽电压等因素对电积过程的影响；初步探讨了电积过程中金浓度的变化规律。通过了小型、台架、半工业和工业试验。在所选电解条件下，金的电积率＞９９％，银电积率９８％，合质金含金９２％－９５％，白银含银９７％。该项技术已应用于工业生产中。     

Polymer Supported Synthesis of Multi-substituted Pyrimidine-4-one Derivatives via Pbf-activated Thiourea

Efficient polymer supported synthesis of multi-substituted pyrimidine-4-one derivatives was described.Target products were produced from fluorenylmethoxycarbonyl(Fmoc) protected β-amino acid loaded on hydroxymethyl resin through deprotection, N-alkylation, guanidine formation, and cleavage of 2,2,4,6,7-pentamethyl dihydrobenzofuran-sulfonyl(Pbf) by trifluoracetic acid(TFA) followed with cyclization. The procedure has the advantages of easy operation, mild reaction conditions, and forming multiple substituents.     

The effect of organic additives in electrodeposition of Co from an amide-type ionic liquid

The effect of organic additives, coumarin and thiourea (TU), on the electrodeposition of cobalt (Co) was investigated in an amide-type ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide (BMPTFSA), containing Co(TFSA)₂ as a Co source. In case of addition of coumarin, the deposition potential of Co shifted to the positive side while there was no change in the coordination environment of Co²⁺. However, the surface morphology was changed by addition of coumarin, suggesting the specific adsorption of coumarin on the surface of electrode. On the other hand, the deposition potential of Co shifted to the more positive side by addition of TU, probably due to the change in the coordination environment of Co²⁺ from [Co(TFSA)₃]⁻ to [Co(TU)₄]²⁺. The diffusion coefficient of [Co(TU)₄]²⁺ was determined as 7.2 × 10⁻⁸ cm² s⁻¹ at 27 °C by chronoamperometric method. The surface morphology of electrodeposit obtained from the electrolyte with TU was flat and less granular as compared to that without TU.     

超声波处理对纤维素碱脲体系溶解性能的影响

采用碱／尿素／水体系、碱／尿素／硫脲／水体系分别制备纤维素溶液,在溶解的不同阶段用超声波进行处理,并利用光学显微镜、偏光显微镜和X射线衍射对溶解效果进行表征。研究结果表明：溶解之前对纤维素原料的超声波处理主要是对纤维形态结构和超分子结构的破坏,略微增大溶解度;溶解过程中对纤维素溶液超声波处理则可以强化润胀,促进分散,显著增大纤维素的溶解度;在碱／尿素／水体系中超声波对溶解的促进作用强于在碱／尿素／硫脲,水体系中。