Microencapsulation of a Crop Protection Compound by Initiated Chemical Vapor Deposition

• Published in: Macromolecular rapid communications. 2012-08, Vol.33 (16), p.1375-1380
• Main Authors: Bose, Ranjita K., Heming, Alex M., Lau, Kenneth K. S.
• Format: Article
• Language: English
• Subjects: Applied sciences; coatings; controlled release; Exact sciences and technology; Gases - chemistry; Hydrophobic and Hydrophilic Interactions; initiated chemical vapor deposition; microencapsulation; Organic polymers; Physicochemistry of polymers; Polymerization; Polymers - chemical synthesis; Polymers - chemistry; Preparation, kinetics, thermodynamics, mechanism and catalysts; pulsed iCVD; Volatilization
• ISSN: 1022-1336; 1521-3927
• DOI: 10.1002/marc.201200214

In this work, initiated chemical vapor deposition (iCVD) has been employed as a one‐step liquid‐free process combining polymerization and coating for the encapsulation of 3D non‐planar substrates. Coatings have been applied using iCVD specifically to encapsulate microparticles of a highly water‐soluble crop protection compound (CPC) for controlled release. Release behavior has been compared among different coatings synthesized using different iCVD processing conditions, including varying degrees of polymer hydrophobicity, continuous and pulsed deposition, and crosslinking. iCVD has been found to provide tunable synthesis of hydrophobic, crosslinked polymers with control over mass diffusivity, and coating thickness for enhancing barrier properties. Initiated chemical vapor deposition (iCVD) is a viable liquid‐free process for the tandem synthesis and conformal coating of polymers onto microparticles of a crop protection compound. By varying iCVD conditions, the barrier properties of the coatings can be controlled via tuning hydrophobicity, crosslinking, film thickness, and mass diffusivity.