The effect of sodium carboxymethyl cellulose (Na-CMC) on the corrosion behavior of mild steel in 1.0 mol·L-1 HCl solution has been investigated by using weight loss (WL) measurement, potentiodynamic polarization,...The effect of sodium carboxymethyl cellulose (Na-CMC) on the corrosion behavior of mild steel in 1.0 mol·L-1 HCl solution has been investigated by using weight loss (WL) measurement, potentiodynamic polarization, linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS) methods. These results showed that the inhibition efficiency of Na-CMC increased with increasing the inhibitor concentration. Potentiodynamic polarization studies revealed that the Na-CMC was a mixed type inhibitor in 1.0 mol·L-1 HCl. The adsorption of the inhibitor on mild steel surface has been found to obey the Langmuir isotherm. The effect of temperature on the corrosion behavior of mild steel in 1.0 mol·L-1 HCl with addition of 0.04% of Na-CMC has been studied in the temperature range of 298-328 K. The associated apparent activation energy (E*a ) of corrosion reaction has been determined. Scanning electron microscopy (SEM) has been applied to investigate the surface morphology of mild steel in the absence and presence of the inhibitor molecules.展开更多
Sodium carbonate and carboxymethyl cellulose powders are compressed into two-component tablets with three mass ratios,97%:3%,95%:5% and 93%:7%.The dissolution tests for two-component tablets and reference pure sodium ...Sodium carbonate and carboxymethyl cellulose powders are compressed into two-component tablets with three mass ratios,97%:3%,95%:5% and 93%:7%.The dissolution tests for two-component tablets and reference pure sodium carbonate tablets are carried out at various temperatures.The dissolution process of each tablet is measured by electrical conductivity tracking method and the concentration of dissolved sodium carbonate is quanti fied with calibrated conductivity-concentration converting equation of sodium carbonate.The quanti fied dissolution data is fitted with both surface reaction model and diffusion layer model and the results clearly show that surface reaction model is suggested as the appropriate dissolution model for all measured tablets.Therefore,it is determined that carboxymethyl cellulose is a stable element to remain the dissolution mechanism of tablet unchanged.The dissolution rate constant quanti fied with surface reaction model presents that carboxymethyl cellulose-sodium carbonate two-component tablets obtain signi ficant higher dissolution rate constant than pure sodium carbonate tablet and higher proportion of carboxymethyl cellulose leads to apparent higher dissolution rate constant.The results prove for the usage of carboxymethyl cellulose in most practical applications at a relative low-level,the effect of carboxymethyl cellulose is effective and positive for two-component tablet to enhance the dissolution process and improve dissolution rate constant and this effect is speculated coming from its dynamic physical transforming process in water including dilation and conglutination.展开更多
Waterborne nanoscale carbon black dispersion （NCBD） was widely used in inkjet printing, spun.dyeing fibers and coloration fabrics. In this paper, NCBD was prepared using sodium carboxymethyl cellulose （CMC） as dis...Waterborne nanoscale carbon black dispersion （NCBD） was widely used in inkjet printing, spun.dyeing fibers and coloration fabrics. In this paper, NCBD was prepared using sodium carboxymethyl cellulose （CMC） as dispersant. Effects of CMC viscosity, ultrasonic time and oxidation with hydrogen peroxide on carbon black （CB） particle size were discussed. The results showed that CB particle size decreased by mechanical agitation while it Increased by ultrasonic with the increase of CMC viscosity. Uitrasonk is a more effective method to disperse CB particles than that of mechanical agitation. CB particle size lbviously decreased with itcreasing ultrasonic time and arrived at about 160 nm for 60min.In addition,oxidation with 2 mol/L of H2O2 and 0.2wt% of CMC300 reduced CB particle size to 160nm at 90℃ for 2.5h.展开更多
采用Anton Paar MCR 302流变仪,研究了羧甲基纤维素钠在甘油质量分数分别为0%,20%,40%,60%和80%的甘油-水混合溶剂中的流变特性。发现甘油-水混合CMC溶液为无屈服力非牛顿流体,具有剪切稀化特性;随甘油质量分数的增加,CMC溶液黏度增大...采用Anton Paar MCR 302流变仪,研究了羧甲基纤维素钠在甘油质量分数分别为0%,20%,40%,60%和80%的甘油-水混合溶剂中的流变特性。发现甘油-水混合CMC溶液为无屈服力非牛顿流体,具有剪切稀化特性;随甘油质量分数的增加,CMC溶液黏度增大、剪切稀化特性逐渐明显、结构恢复变慢;溶液从黏弹性流体逐渐向黏弹性固体转变,内部结构增强,刚性增大。经高温处理后,CMC混合溶液的黏度均会显著增加,且增加值随甘油量增加而增大。亲水性多糖类聚合物的分子主链带有羟基,具有形成氢键的能力。甘油带3个醇羟基,与水形成氢键比水与水之间的氢键更强,可促进体系中羟基间氢键形成,增加氢键数量以及氢键作用力,增大了聚合物分子链缠绕、分子链段缠结。展开更多
基金TUBITAK(104T417) for partially supporting the work by providing us withthe necessary equipment
文摘The effect of sodium carboxymethyl cellulose (Na-CMC) on the corrosion behavior of mild steel in 1.0 mol·L-1 HCl solution has been investigated by using weight loss (WL) measurement, potentiodynamic polarization, linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS) methods. These results showed that the inhibition efficiency of Na-CMC increased with increasing the inhibitor concentration. Potentiodynamic polarization studies revealed that the Na-CMC was a mixed type inhibitor in 1.0 mol·L-1 HCl. The adsorption of the inhibitor on mild steel surface has been found to obey the Langmuir isotherm. The effect of temperature on the corrosion behavior of mild steel in 1.0 mol·L-1 HCl with addition of 0.04% of Na-CMC has been studied in the temperature range of 298-328 K. The associated apparent activation energy (E*a ) of corrosion reaction has been determined. Scanning electron microscopy (SEM) has been applied to investigate the surface morphology of mild steel in the absence and presence of the inhibitor molecules.
基金the Institute of Particle and Science Engineering,University of Leeds and Procter & Gamble Newcastle Innovation Centre(UK) for partially funding the project
文摘Sodium carbonate and carboxymethyl cellulose powders are compressed into two-component tablets with three mass ratios,97%:3%,95%:5% and 93%:7%.The dissolution tests for two-component tablets and reference pure sodium carbonate tablets are carried out at various temperatures.The dissolution process of each tablet is measured by electrical conductivity tracking method and the concentration of dissolved sodium carbonate is quanti fied with calibrated conductivity-concentration converting equation of sodium carbonate.The quanti fied dissolution data is fitted with both surface reaction model and diffusion layer model and the results clearly show that surface reaction model is suggested as the appropriate dissolution model for all measured tablets.Therefore,it is determined that carboxymethyl cellulose is a stable element to remain the dissolution mechanism of tablet unchanged.The dissolution rate constant quanti fied with surface reaction model presents that carboxymethyl cellulose-sodium carbonate two-component tablets obtain signi ficant higher dissolution rate constant than pure sodium carbonate tablet and higher proportion of carboxymethyl cellulose leads to apparent higher dissolution rate constant.The results prove for the usage of carboxymethyl cellulose in most practical applications at a relative low-level,the effect of carboxymethyl cellulose is effective and positive for two-component tablet to enhance the dissolution process and improve dissolution rate constant and this effect is speculated coming from its dynamic physical transforming process in water including dilation and conglutination.
基金Supported by National Natural Science Foundation of China( No.50173012) and863Hi-tech Research and Development Program ofChina (2002AA327120)
文摘Waterborne nanoscale carbon black dispersion （NCBD） was widely used in inkjet printing, spun.dyeing fibers and coloration fabrics. In this paper, NCBD was prepared using sodium carboxymethyl cellulose （CMC） as dispersant. Effects of CMC viscosity, ultrasonic time and oxidation with hydrogen peroxide on carbon black （CB） particle size were discussed. The results showed that CB particle size decreased by mechanical agitation while it Increased by ultrasonic with the increase of CMC viscosity. Uitrasonk is a more effective method to disperse CB particles than that of mechanical agitation. CB particle size lbviously decreased with itcreasing ultrasonic time and arrived at about 160 nm for 60min.In addition,oxidation with 2 mol/L of H2O2 and 0.2wt% of CMC300 reduced CB particle size to 160nm at 90℃ for 2.5h.
文摘采用Anton Paar MCR 302流变仪,研究了羧甲基纤维素钠在甘油质量分数分别为0%,20%,40%,60%和80%的甘油-水混合溶剂中的流变特性。发现甘油-水混合CMC溶液为无屈服力非牛顿流体,具有剪切稀化特性;随甘油质量分数的增加,CMC溶液黏度增大、剪切稀化特性逐渐明显、结构恢复变慢;溶液从黏弹性流体逐渐向黏弹性固体转变,内部结构增强,刚性增大。经高温处理后,CMC混合溶液的黏度均会显著增加,且增加值随甘油量增加而增大。亲水性多糖类聚合物的分子主链带有羟基,具有形成氢键的能力。甘油带3个醇羟基,与水形成氢键比水与水之间的氢键更强,可促进体系中羟基间氢键形成,增加氢键数量以及氢键作用力,增大了聚合物分子链缠绕、分子链段缠结。
