title: Xyloglucan-Functional Latex Particles via RAFT-Mediated Emulsion Polymerization for the Biomimetic Modification of Cellulose.
abstract: Herein, we report a novel class of latex particles composed of a hemicellulose, xyloglucan (XG), and poly(methyl methacrylate) (PMMA), specially designed to enable a biomimetic modification of cellulose. The formation of the latex particles was achieved utilizing reversible addition-fragmentation chain transfer (RAFT) mediated surfactant-free emulsion polymerization employing XG as a hydrophilic macromolecular RAFT agent (macroRAFT). In an initial step, XG was functionalized at the reducing chain end to bear a dithioester. This XG macroRAFT was subsequently utilized in water and chain extended with methyl methacrylate (MMA) as hydrophobic monomer, inspired by a polymerization-induced self-assembly (PISA) process. This yielded latex nanoparticles with a hydrophobic PMMA core stabilized by the hydrophilic XG chains at the corona. The molar mass of PMMA targeted was varied, resulting in a series of stable latex particles with hydrophobic PMMA content between 22 and 68 wt % of the total solids content (5-10%). The XG-PMMA nanoparticles were subsequently adsorbed to a neutral cellulose substrate (filter paper), and the modified surfaces were analyzed by FT-IR and SEM analyses. The adsorption of the latex particles was also investigated by quartz crystal microbalance with dissipation monitoring (QCM-D), where the nanoparticles were adsorbed to negatively charged model cellulose surfaces. The surfaces were analyzed by atomic force microscopy (AFM) and contact angle (CA) measurements. QCM-D experiments showed that more mass was adsorbed to the surfaces with increasing molar mass of the PMMA present. AFM of the surfaces after adsorption showed discrete particles, which were no longer present after annealing (160 °C, 1 h) and the roughness (Rq) of the surfaces had also decreased by at least half. Interestingly, after annealing, the surfaces did not all become more hydrophobic, as monitored by CA measurements, indicating that the surface roughness was an important factor to consider when evaluating the surface properties following particle adsorption. This novel class of latex nanoparticles provides an excellent platform for cellulose modification via physical adsorption. The utilization of XG as the anchoring molecule to cellulose provides a versatile methodology, as it does not rely on electrostatic interactions for the physical adsorption, enabling a wide range of cellulose substrates to be modified, including neutral sources such as cotton and bacterial nanocellulose, leading to new and advanced materials.
authors.affiliation: KTH Royal Institute of Technology , School of Chemical Science and Engineering, Department of Fibre and Polymer Technology, Teknikringen 56, SE-100 44 Stockholm, Sweden.
authors.forename: Fiona L
authors.initials: FL
authors.lastname: Hatton
authors.affiliation: CelluTech AB, Teknikringen 38, SE-114 28 Stockholm, Sweden.
authors.forename: Marcus
authors.initials: M
authors.lastname: Ruda
authors.affiliation: Université de Lyon , Univ Lyon 1, CPE Lyon, CNRS, UMR 5265, C2P2 (Chemistry, Catalysis, Polymers and Processes), Team LCPP, Bat 308F, 43 Bd du 11 Novembre 1918, 69616 Villeurbanne, France.
authors.forename: Muriel
authors.initials: M
authors.lastname: Lansalot
authors.affiliation: Université de Lyon , Univ Lyon 1, CPE Lyon, CNRS, UMR 5265, C2P2 (Chemistry, Catalysis, Polymers and Processes), Team LCPP, Bat 308F, 43 Bd du 11 Novembre 1918, 69616 Villeurbanne, France.
authors.forename: Franck
authors.initials: F
authors.lastname: D'Agosto
authors.affiliation: KTH Royal Institute of Technology , School of Chemical Science and Engineering, Department of Fibre and Polymer Technology, Teknikringen 56, SE-100 44 Stockholm, Sweden.
authors.forename: Eva
authors.initials: E
authors.lastname: Malmström
authors.affiliation: KTH Royal Institute of Technology , School of Chemical Science and Engineering, Department of Fibre and Polymer Technology, Teknikringen 56, SE-100 44 Stockholm, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Carlmark
mesh_terms: D000327:Adsorption; D001672:Biocompatible Materials / Q000737:chemistry*; D032701:Biomimetics; D002482:Cellulose / Q000737:chemistry*; D005936:Glucans / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D018625:Microscopy, Atomic Force; D008863:Microspheres; D053758:Nanoparticles / Q000737:chemistry; D058105:Polymerization; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D014990:Xylans / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D005936:Glucans; D011134:Polysaccharides; D014990:Xylans; C029353:xyloglucan; C007916:hemicellulose; D002482:Cellulose; D019904:Polymethyl Methacrylate