| 초록 |
The nanotube structure of halloysite has led to increased interest in its applications as nanoreactors or nanotemplates, catalysts, and capillaries. Since many cases of the applications make use of the lumen of the halloysite, it is important to control the effective lumen size or diameter. The simplest method to do this is to control the pH of the system, because the functional groups of the external or internal surface of the halloysite can readily be affected by changing the pH, thus gives different aggregation/dispersion properties which can increase or decrease the effective lumen volume or diameter. We used two different system, untreated halloysite and carboxylate-modified halloysite. They showed different pH dependence; untreated halloysite showed good dispersibility only at basic condition, but carboxylate-modified halloysite dispersed well at both acidic and basic conditions. |
