Formation and Mechanical Characterization of Aminoplast Core/Shell Microcapsules
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- 作者：Melanie Pretzl ; Martin Neubauer ; Melanie Tekaat ; Carmen Kunert ; Christian Kuttner ; G茅raldine Leon ; Damien Berthier ; Philipp Erni ; Lahoussine Ouali ; Andreas Fery
- 刊名：ACS Applied Materials & Interfaces
- 出版年：2012
- 出版时间：June 27, 2012
- 年：2012
- 卷：4
- 期：6
- 页码：2940-2948
- 全文大小：531K
- 年卷期：v.4,no.6(June 27, 2012)
- ISSN：1944-8252
文摘
This work aims at establishing a link between process conditions and resulting micromechanical properties for aminoplast core/shell microcapsules. The investigated capsules were produced by the in situ polymerization of melamine formaldehyde resins, which represents a widely used and industrially relevant approach in the field of microencapsulation. Within our study, we present a quantitative morphological analysis of the capsules鈥?size and shell thickness. The diameter of the investigated capsules ranged from 10 to 50 渭m and the shell thickness was found in a range between 50 and 200 nm. As key parameter for the control of the shell thickness, we identified the amount of amino resin per total surface area of the dispersed phase. Mechanical properties were investigated using small deformations on the order of the shell thickness by atomic force microscopy with a colloidal probe setup. The obtained capsule stiffness increased with an increasing shell thickness from 2 to 30 N/m and thus showed the same trend on the process parameters as the shell thickness. A simple analytical model was adopted to explain the relation between capsules鈥?geometry and mechanics and to estimate the elastic modulus of the shell about 1.7 GPa. Thus, this work provides strategies for a rational design of microcapsule mechanics.