Hydrophobisation of lignocellulosic materials part I: physical modification

Abstract This review is the first part of a comprehensive hydrophobisation lignocellulosic materials. The purpose this has been to compare physical methods We have compared molecular adsorption with plasma etching and grafting. Adsorption are facile rely upon simple mixing or coating substrate hydrophobing agent. However, none surfactant-based reviewed here reach contact angles above 90°, making them unsuitable for applications where high degree required. Nevertheless, surfactant based well suited compatibilising material hydrophobic matrix/polymer in cases only slight decrease hydrophilicity On other hand, wax- lignin-based coatings can provide hydrophobicity substrates. Plasma requires more complex set-up but relatively cheap. By physically surface without deposition coating, rendered hydrophobic, reaching 120°. A major drawback method need set-up, some researchers co-deposit fluorine-based layers, which negative environmental impact. An alternative grafting, single molecules grafted on, initiated by radicals formed plasma. also vast majority species be on. Examples include fatty acids, silanes alkanes. Contact 110° achieved method, both fluorine non-toxic may used Graphical abstract