Functional polymeric hybrid nanotubular materials derived from natural cellulose substances

Abstract

Template synthesis is regarded as an effective pathway to replicate the unique structures and morphologies of natural substances with guest substrates to introduce designed functions into artificial materials, but it is generally limited to inorganic materials syntheses due to the severe calcination treatment to remove the template during the fabrication process. Here, a series of polymeric hybrid nanotubular materials were fabricated employing natural cellulosic substances as templates via versatile alternative layer-by-layer deposition strategies and successive removal of cellulose component by a solution dissolving process under mild conditions. Thin layers of various polyelectrolytes and polysaccharide such as heparin were deposited onto titania thin film pre-coated cellulose nanofibers of natural cellulose substance (e.g. commercial filter paper) through electrostatic interaction and covalent links, respectively. The cellulose substance template was dissolved away by low-temperature sodium hydroxide/urea solution treatment, resulting in corresponding polymeric hybrid nanotubular materials. In spite of the employed raw polymers and deposition strategies, all the obtained nanotubular products successfully memorized the original structures and morphologies of the natural cellulose template. Importantly, since a mild chemical dissolution process was employed instead of calcination to selectively remove the template cellulose substrate, the final polymeric hybrid products were left undamaged, and furthermore, brought their unique instinct properties such as significant anticoagulative properties originated from heparin. Our present research broadens the availability of raw materials for synthesizing bio-inspired products, and provides such products with advanced bio-organic functions.