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Microcapsules for Enhanced Cargo Retention and Diversity
Author(s) -
Zieringer Maximilian A.,
Carroll Nick J.,
Abbaspourrad Alireza,
Koehler Stephan A.,
Weitz David A.
Publication year - 2015
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201403175
Subject(s) - materials science , inert , chemical engineering , emulsion , porosity , polymer , fabrication , nanotechnology , toluene , solvent , composite material , chemistry , organic chemistry , medicine , alternative medicine , pathology , engineering
Prevention of undesired leakage of encapsulated materials prior to triggered release presents a technological challenge for the practical application of microcapsule technologies in agriculture, drug delivery, and cosmetics. A microfluidic approach is reported to fabricate perfluoropolyether (PFPE)‐based microcapsules with a high core‐shell ratio that show enhanced retention of encapsulated actives. For the PFPE capsules, less than 2% leakage of encapsulated model compounds, including Allura Red and CaCl 2 , over a four week trial period is observed. In addition, PFPE capsules allow cargo diversity by the fabrication of capsules with either a water‐in‐oil emulsion or an organic solvent as core. Capsules with a toluene‐based core begin a sustained release of hydrophobic model encapsulants immediately upon immersion in an organic continuous phase. The major contribution on the release kinetics stems from the toluene in the core. Furthermore, degradable silica particles are incorporated to confer porosity and functionality to the otherwise chemically inert PFPE‐based polymer shell. These results demonstrate the capability of PFPE capsules with large core–shell ratios to retain diverse sets of cargo for extended periods and make them valuable for controlled release applications that require a low residual footprint of the shell material.