Scheme 3. The flowchart of the whole technology.

High-entropy effect is a novel design strategy to optimize properties and explore novel materials. In this work, (La1/5Nd1/5Sm1/5Ho1/5Y1/5)NbO4 (5RNO) high-entropy microwave dielectric ceramics were successfully prepared in the sintering temperature range of 1210-1290 � via the solidphase reaction route, and medium-entropy (3RNO and 4RNO) ceramics were compared. The effects of entropy on crystal structure, phase transition, and dielectric performances were evaluated. Entropy increase yields a significant increase in the phase transition temperature (from monoclinic fergusonite to tetragonal scheelite structure). Optimal microwave dielectric properties were achieved in the high-2 entropy ceramics (5RNO) at the sintering temperature of 1270 °C for 4 h with a relative density of 98.2%, and microwave dielectric properties of εr = 19.48, Q×f = 47,770 GHz, τf = -13.50 ppm/°C. This work opens an avenue for the exploration of novel microwave dielectric materials and property optimization via entropy engineering.

No abstract

The introduction of 1, 1, 3, 3‐tetramethyl guanidine groups with degree of substitution of 0.18 into cellulose can tailor the solubility of cellulose in water, which leads to a general and robust development of biopolymer‐based biodegradable and biocompatible material for phase‐transfer of hydrophobic biocompatible nanoparticles to aqueous solution. Fourier transform infrared spectroscopy shows the successful ligand exchange between small molecules and 1, 1, 3, 3‐tetramethyl guanidine functionalized cellulose during the phase transfer. Transmission electron microscope images of the original and transferred nanoparticles confirm the success of the phase transfer without obvious agglomeration occurred. The transferred nanoparticles possessed their own unique properties such as surface plasmon resonance, magnetism, up‐conversion fluorescence.

No abstract