The cationization increases the efficiency in the microfibrillation obtaining a nonaggregated and stable CNF suspension [126]. The cationic CNF could be potentially useful in high volume applications, such as strengthening agents for nanocomposites or paper. In this last context, as cellulosic fibers are inherently negatively charged, cationic CNF can replace the commonly usedcationic polyelectrolytes as efficient strength additives [136]. Quaternization has been applied to cationize the surface of the cellulose with quaternary ammoniumcations (NH4 1) [175]. This reaction can be performed using (23-epoxypropyl) trimethylammonium chloride in the presence of water, isopropanol, and sodium hydroxide (Fig. 5.7D). Other methods to produce quaternized CNF used (2-chloroethyl) trimethylammonium chloride