非離子界面活性劑吸附對黏土懸浮液流變與表面性質之影響

本研究使用三種非離子型界面活性劑，目的在於探究（1）非離子界劑吸附於黏土表面的機制與（2）非離子界劑濃度、結構和鏈長度對黏土－水懸浮液流變行為之影響。結果顯示非離子型界面活性劑C_9PE_(10)、C_9PE_(20)和PEG60與bentonite吸附劑間的親和力強。高電荷NaSAz表面佔據水合金屬陽離子多因而減少提供非離子界劑吸附之位置。C_9PE_(10)的EO鏈約為C_9PE_(20)的一半長，縮短吸附於bentonite表面彼此間之距離，因此強化了垂直於bentonite表面之碳氫鏈疏水作用，導致更多C_9PE_(10)吸附於低電荷fisher bentonite表面。XRD繞射圖顯示三種非離子界劑皆可進入層間並擴展bentonite層間距。非離子界劑添加有效的降低低電荷fisher bentonit漿料的黏度使由非牛頓流體轉變為牛頓流體。混凝實驗證實吸附非離子界劑C_9PE_(10)或C_9PE_(20)的fisher bentonite，以面對面（FF）方式相互連結，降低黏土在水相環境的剝離作用，形成黏土粒徑大、顆粒數少之情形。

關鍵字

非離子界面活性劑；吸附；黏土；流變行為

並列摘要

The objectives of this study were (1) to understand the sorption mechanism of non-ionic surfactants on bentonites and (2) to determine the effect of non-ionic surfactant sorption on the dispersion characteristics of clay-water suspensions. Three non-ionic surfactants were used in this study. Results indicated that the hydrophobic interaction between CH2-CH2-O groups and siloxane surface is the major driving force for non-ionic surfactants adsorption on bentonite. High-charge NaSAz with a large portion of the siloxane surface covered by negatively-charged sites indicate diminishing non-ionic surfactant adsorption capacity. The expansion of the d001 spacing of bentonite after surfactant adsorption indicates that non-ionic surfactants can effectively reduce the viscosity of low-charge bentonite suspensions. The viscosity reduction is presumably due to the micro-flocculation (face to face) between bentonite particles caused by the hydrophobic interaction between hydrocarbon chains of non-surfactants. This finding is also supported by the rheological test results that the de-lamination of low-charge bentonite in water is reduced due to C9PE10 or C9PE20 adsorption.

並列關鍵字

non-ionic surfactant ； adsorption ； clay ； rheological behavior

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