Evaluation of Steric Repulsive Force in the Aqueous Dispersion System of Dimethomorph Powder with Lignosulfonates via X-ray Photoelectron Spectroscopy

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• 作者：Zhili Li ; Yuxia Pang ; Yuanyuan Ge ; Xueqing Qiu
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：December 22, 2011
• 年：2011
• 卷：115
• 期：50
• 页码：24865-24870
• 全文大小：865K
• 年卷期：v.115,no.50(December 22, 2011)
• ISSN：1932-7455

文摘

X-ray photoelectron spectroscopy (XPS) was adopted to evaluate steric repulsive force in the aqueous dispersion system of dimethomorph powder with lignosulfonate (LS). The calculation of adsorption layer thickness (ALT) of LS on dimethomorph based on the relative intensity of the N 1s peak from XPS was presented. The ALT was correlated with the volume-based average particle size (VAPS) of dimethomorph suspensions that indicated the dispersion efficiency of LS. As expected, VAPS decreased linearly with growing ALT; namely, the dispersion efficiency of LS increased with growing ALT except Kinsperse. Zeta potential experiments demonstrated that the dominant electrostatic repulsive forces controlled the particle dispersing mechanism when Kinsperse was used as dispersant. The positive-going relationship of dispersion efficiency of LS with ALT confirmed that it would be feasible to use ALT to evaluate steric repulsive forces in the dispersion system of dimethomorph with LS, and that would lead to a potential utilization in other dispersion systems.