Schematic illustration for metal-free thiol-yne and hydroxyl-yne reactions to modify synthetic polymer and polysaccharide. (a) Modification of synthetic polymers derived from reversible addition-fragmentation chain-transfer (RAFT) polymerization. General synthetic route for the terminal modification with activated alkynes, as an illustration, affording PDMA-TPE. (b) Typical PL spectra of PDMA-TPE in water-THF mixtures with different water contents and (c) change of PL maximum of PDMA-TPE with water content of the aqueous mixture (insets: photographs of PDMA-TPE dispersion samples under UV illumination). (d) Synthetic route employed for the modification of hydroxypropyl cellulose (HPC) via the hydroxyl-yne reaction.