Stabilization of metalic and non-metallic suspensions using Nanocrystalline Cellulose (CNC)

在这项建议中，纤维素纳米晶(CNCS)被用来作为各种悬浮液的稳定剂，包括二氧化硅、铁和锆悬浮液。初步实验和观察表明，这些化合物在稳定胶体悬浮液方面可能非常有效。这将取决于要稳定的悬浮液/分散体的类型、其浓度、颗粒大小和分布以及表面特征。本项目中使用的纤维素纳米晶(CNC)可以通过强酸水解法从纤维素纤维中提取出来。水解条件影响纤维素纳米晶的大小和表面性质。使用硫酸进行水解会导致表面带有阴离子硫基团的纳米颗粒，从而导致静电稳定的纳米颗粒水悬浮液。这些悬浮液的稳定性还取决于离子强度、pH、尺寸和浓度。这些悬浮液的形态变化已被很好地理解，并已成功地与流变性以及pH、表面电荷和离子强度相关联。将详细研究它们与金属和非金属悬浮液/分散体的相互作用，即(1)悬浮液的稳定和(2)稳定的机理(下划线物理)。

In this proposal, Cellulose Nanocrystals (CNCs) are proposed to be used as stabilizing agents for various suspensions including silica, iron and zirconium. Preliminary experiments and observations have shown that these could be extremely effective in stabilizing colloidal suspensions. This will depend on the type of suspension/dispersion to be stabilised, its concentration, particle size and distribution as well surface characteristics. Cellulose nanocrystals (CNC) which will be used in this project can be extracted from cellulose fibers using strong acid hydrolysis. The hydrolysis conditions affect the size and surface properties of cellulose nanocrystals. Using sulfuric acid for the hydrolysis results in CNC particles with anionic sulfur groups on the surface, leading to electrostatically stabilized CNC aqueous suspensions. The stability of these suspensions also depends on the ionic strength, pH, size and concentration. The morphological changes of these suspensions are well understood and they have been correlated successfully with rheological properties as well as pH, surface charge and ionic strength. Their interactions with metallic and non-metallic suspensions/dispersions will be studied in detail i.e. (i)stabilization of the suspensions and (ii) mechanisms (underlined physics) for stabilization.