Inverse gas chromatography (IGC) for studying the cellulosic materials surface characteristics: a mini review

Cellulose is one of the most abundant and sustainable biopolymers on earth. Various types of cellulosic materials such as natural fibres, regenerated cellulose fibres, cellulose derivatives and nanocellulose have increasingly been utilised in developing fibre-reinforced polymeric composites. Analysis of surface physicochemical properties of cellulose-based fillers is essential to maximise fibre-matrix interfacial adhesion to obtain excellent mechanical performance. Among different techniques which can be used to investigate the surface science of cellulose-based materials, inverse gas chromatography (IGC) has been proven as a successful technique for characterising the surface activity, evaluating the efficiency of surface modification methods, and predicting the behaviour of final products. IGC is a versatile approach to evaluate surface energy, acidic-basic characteristics, and surface heterogeneity. These key parameters are used in (i) evaluating the efficiency of different surface treatments for adding new functional groups, (ii) determining the compatibility of cellulosic materials with various polymer matrices to ensure optimal fibre-matrix interaction, and (iii) predicting the performance of cellulose-reinforced composites in actual applications. This article provides a concise review on recent progress in using IGC method for surface analysis of different forms of cellulosic materials in the context of fibre-reinforced composites. For future perspective, the IGC technique can be extensively applied in studying cellulosic materials with high application potential in a variety of fields. This review paper will shed light on understanding the surface characteristics of cellulose-based composites and pave the way for their real-world applications.