Bioinspired assembly of surface-roughened nanoplatelets

Area of Science:

• Materials Science
• Nanotechnology
• Biomimetics

Background:

• Nacre, the iridescent inner layer of mollusk shells, exhibits exceptional mechanical properties due to its brick-and-mortar nanostructure.
• Mimicking natural structures is a key strategy for developing advanced materials with superior performance.

Purpose of the Study:

• To develop a novel electrophoretic deposition (EPD) technique for creating ordered multilayers of surface-roughened inorganic nanoplatelets.
• To fabricate bio-inspired nanocomposite films with enhanced mechanical properties by mimicking nacre's structure.
• To investigate the role of surface modification and polyelectrolyte use in improving film integrity and performance.

Main Methods:

• Surface modification of gibbsite nanoplatelets with sol-gel silica to increase roughness.
• Electrophoretic deposition (EPD) to assemble silica-coated nanoplatelets into ordered multilayers.
• Use of polyethyleneimine to improve film adhesion and prevent cracking during drying.
• Infiltration of nanoplatelet multilayers with photocurable monomer and subsequent photopolymerization to form polymer nanocomposites.

Main Results:

• Successfully fabricated ordered multilayers of surface-roughened inorganic nanoplatelets using EPD.
• Developed self-standing nanocomposite films with high transparency.
• Achieved a three-fold increase in tensile strength and a ten-fold increase in toughness compared to pure polymer.
• Experimental tensile strength results align with predictions from a shear lag model.

Conclusions:

• The novel EPD technology enables the creation of nacre-mimicking nanostructures with significantly enhanced mechanical properties.
• Surface roughening and strategic use of polyelectrolytes are crucial for fabricating robust, high-performance nanocomposite films.
• This biomimetic approach offers a promising pathway for designing advanced structural materials.