Direct preparation of gelatin microcapsules on paper surface using simple coacervation technique

A simple coacervation technique was used to coat a functional paper with gelatin microcapsules containing geraniol to prepare functional papers with sustained fragrance release. This method eliminated the need for microcapsule preparation and coating with a binder. A gelatin solution containing geraniol and Tween 20 was coacervated using sodium carbonate (Na₂CO₃) solution; the final Na₂CO₃ concentration in the solution was 5 wt %. Filter papers impregnated with the coacervation mixture were immersed in 0–20 wt % Na₂CO₃ solutions. Gelatin microcapsules were formed on the paper surface when 15 or 20 wt % Na₂CO₃ solutions were used. The maximum amount of geraniol was fixed on paper prepared under these conditions, and the percentage of residual geraniol in the paper (RES) was about 70% after 72 h; this value was much higher than that for a blank sheet. The formation of gelatin microcapsules was important for the fixation and sustained release of geraniol. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013