Multifunctional scalable coated paper sheets for UV shielding and sublimation printing applications.

Agricultural residues are produced annually; recycling these wastes in various ways is considered economically valuable. In this context, biopolymer-reinforced composite materials were developed to create alternative, eco-friendly, and sustainable resources for different applications. With advancements in innovative chemical techniques, cellulose nanofibers with silica have been simultaneously obtained. Rice residues were transformed into silica-based cellulose nanofibers (SCN(NP)) through hydrolysis using ammonium persulfate (APS) under microwave radiation at 70 °C, 1.25 M APS, an irradiation time of 20 min, and a liquor ratio of 1:75. Additionally, rice residue was converted into silica nanostructure SiO(2NP) via hydrochloric acid hydrolysis followed by calcination at 600 °C. The principal characterizations of the extracted SCN(NP) and SiO(2NP) were evaluated using FTIR, XRD, BET surface area analysis, SEM, TEM, EDX and ζ-potential measurements. To produce cellulose/silica hybrid composites on a paper matrix, co-processing of the isolated SiO(2NP) and/or SCN(NP), which contained silica, was considered. Different concentrations of [SiO(2NP) (0.25-3%w/v)/SCN(NP) (0.5%w/v)] nanocomposites were used to modify the fabricated paper sheets, with cationic polyacrylamide (CPAM) serving as a binder. Fabricated paper sheets treated with various concentrations of (CPAM/SiO(2NP)/SCN(NP)) nanocomposite solutions were prepared. The impact of SiO(2NP) and/or SCN(NP) on the modified paper's surface structure, strength, barrier, and UV shielding characteristics was examined. To evaluate color properties, the fabricated paper sheets treated with different concentrations of CPAM/SiO(2NP)/SCN(NP), were silk-screen printed using disperse dye. Under different conditions (temperatures of 170-210 °C and time of 30-60 s.), the printed paper sheets were tested as heat transfer paper in sublimation transfer printing of polyester fabrics. Polyester samples printed using sheets treated with CPAM/0.5% SCN(NP) and CPAM/3% SiO(2NP) showed enhanced color depth. All polyester samples printed with modified sheets demonstrated outstanding fastness properties. Additionally, some treated paper sheets showed remarkable transfer stability during a second printing run.