Recent Progress in Cellulose Hydrophobization by Gaseous Plasma Treatments

Area of Science:

• Materials Science
• Polymer Science
• Surface Chemistry

Background:

• Cellulose is abundant and suitable for biobased plastics.
• Hydrophilicity and hygroscopicity limit cellulose fiber application in composites.
• Plasma treatment offers a solution for cellulose hydrophobization.

Purpose of the Study:

• To review and critically evaluate plasma methods for cellulose hydrophobization.
• To identify challenges and future research directions in plasma modification of cellulose.

Main Methods:

• Review of scientific literature on plasma treatment of cellulose.
• Analysis of plasmas sustained in fluorine-containing gases (e.g., tetrafluoromethane).
• Analysis of plasmas sustained in silicon-containing gases (e.g., hexamethyldisiloxane), often requiring oxygen pre-treatment.

Main Results:

• Fluorine-containing plasmas enable direct hydrophobic coating deposition.
• Silicon-containing plasmas require pre-treatment (e.g., oxygen plasma) for optimal adhesion.
• Discrepancies in results are attributed to gas-phase/surface kinetics, sample heating, water desorption, etching/deposition competition, plasma radiation, and dusty plasma formation.

Conclusions:

• Plasma technology is key to overcoming cellulose hydrophilicity for advanced composites.
• Understanding plasma-surface interactions is crucial for reproducible and effective cellulose modification.
• Further research should address identified scientific and technological challenges for broader application.