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The elaboration of a low-cost and effective approach to synthesize hybrid composite materials based on the conventional thermoplastics and natural biopolymers is a sustainable alternative to the production of "traditional" plastics. Cellulose is one of the most abundant biopolymers. Its fibrils possess outstanding mechanical characteristics and, hence, attract considerable interest of researchers during recent decades. However, modification of the hydrophobic polymer matrix by cellulose fibrils is significantly complicated by the hydrophilic nature of the latter. In this study, we propose an effective and low-cost approach to the synthesis of polystyrene at the cellulose microfibrils composite material via the emulsion polymerization method. The obtained fibrous composite was comprehensively analyzed with FTIR spectroscopy, SEM, TGA, and DSC, and was further employed to produce sponge hybrid materials. We investigated the influence of the cellulose/polystyrene ratio on the density, porosity, pore volume, and water uptake of the obtained sponge materials. The sample containing 70 wt.% of cellulose demonstrated the best water absorption properties while preserving its shape, even after 24 h of floating on water. The produced sponge materials might be employed as sorption materials for the purification and desalination of waters of various origins, filtration, and collection of undesirable elements under specific industrial or natural conditions. [ABSTRACT FROM AUTHOR]

The current environmental problems require the use of low-energy, environmentally friendly methods and nature-like technologies for the creation of materials. In this work, we aim to study the possibility of the direct biotransformation of fibrillar cellulose by fungi through obtaining a cellulose/mycelium-based biocomposite. The cellulose micro- and nanofibrils were used as the main carbon sources in the solid-phase cultivation of basidiomycete Trametes hirsuta. The cellulose fibrils in this process act as a template for growing mycelium with the formation of well-developed net structure. The biotransformation dynamics of cellulose fibrils were studied with the help of scanning electron microscopy. The appearance of nitrogen in the structure of formed fibers was revealed by elemental analysis and FTIR-spectroscopy. The fibers diameters were estimated based on micrograph analysis and the laser diffraction method. It was shown that the diameter of cellulose fibrils can be tuned by fungi through obtaining cellulose-based mycelium fibers with a narrower diameter-size distribution as compared to the pristine cellulose fibrils. The morphology of the resulting mycelium differed when the micro or nanofibrils were used as a substrate. [ABSTRACT FROM AUTHOR]

Emulsion interfacial polymerization is a versatile approach for the encapsulation of organic phase-change materials to improve their stability and prevent their elution and leakage. Herein, we report the successful octadecane encapsulation by the preparation of Pickering emulsions stabilized with carboxylated cellulose nanofibrils (CNF) at various ionic strengths of the dispersive medium. The stable capsule shells were obtained through the formation of amide bonds in the reaction with polymeric isocyanate dissolved in the oil phase. The addition of 5–200 mM NaCl resulted in different adsorption behaviors of carboxylated CNF, which led to an increase in capsule shell thickness (up to 530 nm), improved octadecane encapsulation efficiency (up to 78 %) and thermal stability, as well as reduced elution in organic medium with increasing ionic strength. The study presents a new strategy for the encapsulation of phase-change materials by surfactant-free emulsion interfacial polymerization into containers with defined and adjustable properties. [Display omitted] • Octadecane was loaded in a Pickering emulsion stabilized with carboxylated NFC. • Addition of NaCl led to adsorption of NFC clusters instead of the separate fibrils. • Shell was crosslinked by amide bonding in reaction of carboxyls with polyisocyanate. • The salt addition led to thicker capsule shell and improved thermal stability. • The capsules prepared with salt addition better prevented octadecane elution. [ABSTRACT FROM AUTHOR]

• Cellulose microfibers were modified with Fe 3 O 4 nanoparticles in a tunable way. • Adsorption of lauric acid onto Fe 3 O 4 -modified fibers leads to shape-stable PCM. • Magnetic PCM composites can store thermal energy under alternating magnetic field. • Magnetite nanoparticles improves light-to-thermal conversion of PCM composites. Fe 3 O 4 -modified cellulose microfibers containing 7, 16, and 31 wt% of magnetite were prepared via co-precipitation of Fe2+ and Fe3+ salts. The magnetic phase-change composites were synthesized by adsorption of lauric acid onto the modified fibers with the highest saturation magnetization (23 emu/g) and magnetic-to-thermal conversion. The resulted composites demonstrated the saturation magnetization of 11.2 emu/g and latent heat storage capacity of 90 J/g corresponding to the loading efficiency of lauric acid of 49–51 wt%. The IR-imaging revealed the efficient accumulation of latent heat in the phase-change composite under the simulated sunlight and high frequency alternating magnetic field along with the excellent shape stability of the composites during the melting of lauric acid. [ABSTRACT FROM AUTHOR]

• MFC was modified with Ag nanoparticles with a mass content of 13% • Adsorption of SA onto AgMFC fibers results in shape stable PCM composites. • Ag nanoparticles do not affect the phase transitions of SA on the fiber surface. • SA/AgMFC composites have improved heating and cooling rate comparing to SA/MFC ones. • The improved heat transfer in SA/AgMFC composites reduces their thermal stability. Composite phase change material was prepared via adsorption of stearic acid onto cellulose microfibrils modified with Ag nanoparticles. The latent heat storage capacity, cycling performance, thermal stability, and heating/cooling rate of the composites were studied with differential scanning calorimetry, thermogravimetric analysis, and thermal imaging and compared to those of the composite prepared by adsorption of stearic acid onto pure microfibrillar cellulose. The modification of cellulose with Ag nanoparticles improves the heating and cooling rate of the composites and promotes latent heat release during the solidification of stearic acid on the fiber surface. [ABSTRACT FROM AUTHOR]