Infiltration of Proteins in Cholesteric Cellulose Structures

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Science

Background:

• Cellulose nanocrystals (CNCs) self-assemble into chiral nematic (cn) structures, mimicking natural cholesteric organizations known for dissipative fracture mechanisms.
• Strong supramolecular interactions between CNCs and macromolecules typically lead to aggregation in liquid media, hindering composite formation.
• Existing methods struggle to incorporate strongly interacting secondary components into CNC-based materials.

Purpose of the Study:

• To develop a novel infiltration method for preparing nanocomposite materials using chiral nematic CNCs (cn-CNCs) with strongly interacting secondary components.
• To investigate the feasibility of incorporating diverse macromolecules, including proteins and polymers, into cn-CNC structures.
• To evaluate the impact of infiltration on the optical and mechanical properties of the resulting hybrid materials.

Main Methods:

• Preparation of cn-CNC films and subsequent infiltration with various loadings of silk proteins, bovine serum albumin, and poly(ethylene glycol) polymers.
• Evaluation of infiltration extent and impact using UV-vis spectroscopy to analyze optical reflection properties.
• Observation of fracture dissipation mechanisms through electron microscopy.

Main Results:

• The infiltration method successfully introduced secondary components into cn-CNC films, creating hybrid materials.
• Optical reflection properties were altered by the infiltration process, indicating successful integration.
• Electron microscopy revealed insights into the fracture dissipation mechanisms of the infiltrated cn-CNC composites.
• Poly(ethylene glycol) polymers of varying molecular weights were used to establish infiltration limits.

Conclusions:

• The developed infiltration technique enables the formation of nanocomposites with cn-CNCs and otherwise incompatible secondary phases.
• This approach overcomes limitations of conventional mixing methods for creating advanced CNC-based materials.
• The method holds potential for introducing virtually any secondary phase into cn-CNC structures for diverse applications.