Hybrid poly(allylamine hydrochloride)-graphene oxide microcapsules: preparation, characterization and application in textiles with controlled release behavior

Permeable microcapsules are suitable forming blocks for functional materials based on controlled release. This study reports the design of a stimuli-responsive fabric coated with a type of hybrid microcapsules prepared via a layer-by-layer (LBL) approach. The resulted fabric can be used as a healthy care material. The functional microcapsules comprise polyelectrolytes poly(allylamine hydrochloride) (PAH) and graphene oxide (GO). The self-assembly of these oppositely charged surrounding components generated a hollow space to load functional molecules such as dyes, labels and drugs via a responsive trigger. The polyelectrolyte PAH ensured a robust structure and pH sensibility. GO sheets provided near-infrared (NIR) laser-induced release through photothermal effects. These hybrid microcapsules (PAH/GO)(n)PAH can then be used to load Atractylodes, a traditional Chinese herb, and then adhere to cotton fabrics to develop functional textiles. The encapsulated Atractylodes can then be released from the (PAH/GO)(n)PAH-coated cotton fabric. During the subsequent period of the entire process, the release rate was significantly accelerated by NIR irradiation. After washing 20-30 times, microcapsules were coated on cotton fibers. Using this technique, functional textiles for controlled release by external stimulation coupled with other synergetic effects could be obtained. Note that (PAH/GO)(n)PAH microcapsules can provide sustained drug release in simulated sweat and control the release rate through NIR irradiation, which shows its potential as an external skin drug delivery system.