Surface modification of cellulose via photo-induced click reaction.

To pursue highly functional ecologically friendly materials, functionalized cellulose has gained increasing number of research interests within the last decades. Compared with other cellulose modification approaches, surface modification of cellulose via photo-induced click reaction is a particular attractive cellulose modification strategy as it integrates the advantages of photochemistry, click reaction and surface modification. High efficiency, quantitative conversion and spatial temporal control are achieved. The physical and chemical properties of various cellulose surfaces are also effectively regulated by using this strategy, which significantly expands their applications. In this mini-review, we summarized the recent progress in cellulose surface modification via photo-induced click reactions. The principles and the merits of photo-induced thiol-X and cycloaddition reactions were compared and highlighted. Photo-induced thiol-ene reaction, thiol-yne reaction, tetrazole-ene cycloaddition, Diels-Alder cycloaddition, and azide-alkyne cycloaddition applied in modification of various cellulose surfaces were introduced in order. At last, the challenges and outlook of photo-induced click reaction in cellulose surface modification were discussed. We hope this review will provide insights into photo-induced click chemistry, cellulose surface modification and novel sustainable materials.