Shuji Fujisawa

Pickering emulsion, which is an emulsion stabilized by solid particles, offers a wide range of potential applications because it generally provides a more stable system than surfactant-stabilized emulsion. Among various solid stabilizers, nanocellulose may open up new opportunities for future Pickering emulsions owing to its unique nanosizes, amphiphilicity, and other favorable properties (e.g. chemical stability, biodegradability, biocompatibility, and renewability). In this review, the prepara

Surface grafting of crystalline and ultrafine cellulose nanofibrils with poly(ethylene glycol) (PEG) chains via ionic bonds was achieved by a simple ion-exchange treatment. The PEG-grafted cellulose nanofibrils exhibited nanodispersibility in organic solvents such as chloroform, toluene, and tetrahydrofuran. Then, the PEG-grafted cellulose nanofibril/chloroform dispersion and poly(L-lactide) (PLLA)/chloroform solution were mixed, and the PEG-grafted cellulose nanofibril/PLLA composite films with

Polystyrene (PS) composites reinforced with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanofibrils (TOCNs) with various weight ratios were fabricated by casting and vacuum-drying mixtures of PS/N,N-dimethylformamide (DMF) solution and TOCN/DMF dispersion. TOCNs of 3 to 4 nm width were dispersed homogeneously at the individual nanofibril level in the PS matrix, such that the TOCN/PS nanocomposite films exhibited high optical transparencies and their tensile strengths, elastic

Cellulose nanofibril (CNF) is a promising nanofiller for polymer nanocomposite materials, and a critical challenge in designing these materials is organization of the nanostructure using a facile process. Here, we report a facile aqueous preparation process for nanostructured polystyrene (PS)/CNF composites via the formation of a CNF-stabilized Pickering emulsion. PS nanoparticles, with a narrow size distribution, were synthesized by free radical polymerization in water using CNF as a stabilizer

Abstract Cellulose nanofiber (CNF) is a crystalline fiber composed of a bundle of cellulose molecular chains and is expected to be used as a new biomass-derived nanomaterial. The CNF has a unique morphology: a few to tens of nanometer width and a submicrometer to micrometer length. Its application to various materials, in particular its utilization as a polymer reinforcing material, has been anticipated due to its excellent mechanical properties. However, CNFs and plastics are generally hard to

Chitin nanofiber (ChNF) has received significant research attention owing to its potential for use in a variety of applications, such as medicine and cosmetics. Here, we synthesize a novel ChNF material, ChNF-coated polymer microparticles, using a Pickering emulsion-templated approach. Two varieties of ChNF with different crystal structures, lengths, and surface charges were used to form the microparticle shells. When ChNFs with a shorter length and greater surface charge were used, the micropar

Nanocellulose was prepared from wood pulp via a one-pot oxidation reaction using only a highly concentrated solution of sodium hypochlorite pentahydrate (NaClO·5H2O) and subsequent mechanical treatment. The concentration of NaClO in the solution was 22%, and the oxidation reaction times were 0.5, 2, and 6 h. The carboxy group content in the pulp increased with reaction time and reached 0.87 mmol/g after oxidation for 6 h. The oxidized pulp fibers were successfully refined down to nanocellulose b

Here, we develop a robust approach to forming an ∼8 nm thick cellulose nanofiber (CNF) shell on polymer microparticles through an emulsion-templated assembly. The median diameter of the CNF-shelled microparticles was 3.0 μm. The microparticles showed good dispersibility in water with a ζ-potential of -46.7 ± 0.5 mV and had good mechanical resistance. The surface CNF shells showed pH-sensitive drug loading/releasing properties, which suggest potential for a range of therapeutic and biomedical app