Influence of the matrix and polymerization methods on the synthesis of BC/PANi nanocomposites: an IGC study

Inverse gas chromatography (IGC) is a technique for evaluating surface properties. The current work emphasizes the use of IGC to evaluate the surface physicochemical changes during different bacterial cellulose (BC) processing methods as well as upon polyaniline (PANi) incorporation. The processing methods (oven-drying, freeze-drying, and regeneration) caused changes in the BC surface group distribution, where upon freeze-drying and regeneration, a more acidic behavior is obtained, compared to oven-drying (K_b/K_a decreased up to 24%). Through freeze-drying, the structural pore preservation increases (54%) the BC porosity, whereas through regeneration, the porosity decreases (23%), compared to BC oven-drying. Regarding the nanocomposites, with PANi incorporation, the overall properties evaluated by IGC were significantly changed. The \(\gamma_{\text{s}}^{\text{total}}\) increases up to 150%, indicating a more reactive surface in the nanocomposites. Also, is observed a sevenfold increase in the K_b/K_a and a less porous surface (up to 85%). Hence, the current work highlights the use of IGC as a viable technique to evaluate the physicochemical changes upon different BC modifications.