Integrated Janus cellulosic composite with multiple thermal functions for personalized thermal management.

The effective integration of multiple thermal functions into one material is highly attractive in personal thermal management, taking the complex application environment into consideration. Herein, a multifunctional Janus cellulosic composite encompassing superior electrical heating, energy storage, thermal insulation, and infrared camouflage performance was firstly developed by integrating Janus cellulose nanofibers (CNF) aerogel, polypyrrole (PPy), and polyethylene glycol (PEG). In practice, the active heating-thermal regulation layer (PPy@CNFphilic-PEG) of multifunctional Janus cellulosic composite is faced inward to provide heating on-demand through the joint action of the electrically conductive PPy and thermally regulative PEG. The outward-facing hydrophobic aerogel layer (CNFphobic) serves as the thermal insulator, which simultaneously enables infrared camouflage by reducing heat loss to the environment via infrared radiation. This work presents an effective and facile strategy toward multifunctional Janus materials for efficient personal thermal management, showing great promise for potential applications, such as thermal comfort, infrared camouflage, and security protection.

Synthetic semicrystalline cellulose oligomers as efficient Pickering emulsion stabilizers.

Nanocellulose are promising Pickering emulsion stabilizers for being sustainable and non-toxic. In this work, semicrystalline cellulose oligomers (SCCO), which were synthesized from maltodextrin using cellobiose as primer by in vitro enzymatic biosystem, were exploited as stabilizers for oil-in-water Pickering emulsions. At first, the morphology, structure, thermal and rheological properties of SCCO suspensions were characterized, showing that SCCO had a sheet morphology and typical cellulose-Ⅱ structure with 56 % crystallinity. Then the kinetic stabilities of emulsions containing various amounts of SCCO were evaluated against external stress such as pH, ionic strength, and temperature. Noting that SCCO-Pickering emulsions exhibited excellent stabilities against changes in centrifugation, pH, ionic strengths, and temperatures, and it was also kinetically stable for up to 6 months. Both SCCO suspensions and their emulsions exhibited gel-like structures and shear-thinning behaviors. These results demonstrated great potential of SCCO to be applied as nanocellulosic emulsifiers in food, cosmetic and pharmaceutical industries.

Antibacterial phase change microcapsules obtained with lignin as the Pickering stabilizer and the reducing agent for silver.

This paper provides a novel and facile method to synthesize antibacterial phase change microcapsules (microPCMs) decorated with silver particles, where lignin was acting as both the Pickering stabilizer and the reducing agent for silver. First lignin Pickering emulsions at various oil-to-water ratios and lignin loading were prepared. Then, n-eicosane encapsulated in polyurea (PU) shells was prepared via interfacial polymerization of isophorone diisocyanate (IPDI) and ethylene diamine/diethylene triamine (EDA/DETA) in a Pickering emulsion stabilized by lignin particles. The results showed that the lignin particles were embedded in the microPCMs shell. These lignin particles were utilized to reduce silver ions, resulting in silver particles decorated microPCMs (Ag/lignin microPCMs). The resulting Ag/lignin microPCMs exhibited a well-defined core-shell spherical morphology with high phase-transition enthalpy (177.6 J/g), high encapsulation efficiency (69.0%) and good thermal durability. As well, the Ag/lignin microPCMs presented good antibacterial activity, showing great potential in industrial applications such as biomedical, textile and construction areas.

Lignin assisted Pickering emulsion polymerization to microencapsulate 1-tetradecanol for thermal management.

This work explored the use of Pickering emulsion stabilized by lignin nanoparticles (LNPs) to microencapsulate 1-tetradecanol (TDA) via polymerization of acrylates for thermal management. The morphology and thermal performance of the resulting microcapsules were explored using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). A highest encapsulation ratio of 81.4% and melting enthalpy of 190 J/g could be achieved when the core/shell mass ratio was 2:1, and 10 wt% of the crosslinking monomer pentaerythritol tetraacrylate (PETRA) was used. Results of the leakage and accelerated thermal cycling tests showed that the microcapsules had good thermal and chemical stability. When the microcapsules were combined with gypsum, an effective thermal storage composite was obtained, showing good potential for thermal management in the construction field.