Markedly improved hydrophobicity of cellulose film via a simple one-step aminosilane-assisted ball milling

Abstract Most cellulose products lack water resistance due to the existence of abundant hydroxyl groups. In this work, microfibrillated cellulose (MFC) was modified via 3-aminopropyltriethoxysilane (APTES)-assisted ball milling. Under the synergism between high-energy mechanical force field and APTES-modification, the fibrillation and hydrophobization of MFC were achieved simultaneously. Free-standing translucent cellulose films made of modified MFC were fabricated. The original crystal form of cellulose is maintained. The hydrophobicity of cellulose film markedly increases and the water contact angle goes up to 133.2 ± 3.4 °, which might be ascribed to the combined effects of APTES-modification and rough film surface. In addition, the thermostability and mechanical properties of cellulose film are also improved via mechanochemical modification. This work provides a novel one-step fibrillation-hydrophobization method for cellulose.