论文部分内容阅读
用失重法研究硫脲对低碳钢表面在盐酸溶液中的吸附特性及缓蚀作用。应用吸附理论和Frumkin等温式及Flory Huggins等温式处理实验数据 ,发现低浓度的硫脲自 2mol·L-1盐酸中在低碳钢表面上产生的吸附过程是一个取代吸附过程 ,而且是一个熵增过程。尤其应该注意侧向作用力和被吸附的硫脲分子所代替的水分子数 ,其表面覆盖度随温度和浓度的增大而增大 ,并认为这种吸附是产生缓蚀作用的重要原因。实验结果还表明 :在 3 0℃时 ,吸附过程中侧向作用力影响较大 ,并遵循Frumkin等温式 ,其吸附分子垂直地吸附在金属表面 ;在 3 5℃— 5 0℃时 ,吸附分子在金属表面水平吸附 ,其侧向作用力可忽略 ,遵循Flory Huggins等温式。根据这些结果计算出吸附自由能、吸附焓、吸附熵 ,说明表面覆盖度中温度的影响起因于吸附熵的变化
Adsorption Characteristics and Inhibition of Thiourea on the Surface of Low Carbon Steel in Hydrochloric Acid Solution by Weight Loss Method. Adsorption theory and Frumkin isotherm and Flory Huggins isothermal processing experimental data found that low concentrations of thiourea from 2mol·L-1 hydrochloric acid on the surface of low-carbon steel adsorption process is a substitution of adsorption process, and is an entropy Increase the process. In particular, attention should be paid to the lateral forces and the number of water molecules replaced by the adsorbed thiourea molecules. The surface coverage increases with temperature and concentration, and this adsorption is considered to be an important cause of corrosion inhibition. The experimental results also show that the lateral force has a great effect on the adsorption process at 30 ℃, and follows the Frumkin isothermal equation. The adsorption molecule adsorbs vertically on the metal surface. At 35 ℃ -50 ℃, the adsorption molecule Horizontal adsorption on the metal surface, the lateral force negligible, follow the Flory Huggins isothermal equation. Based on these results, the free energy of adsorption, enthalpy of adsorption, and entropy of adsorption were calculated, which indicated that the influence of temperature on surface coverage was caused by the change of adsorption entropy