The present disclosure provides a method for preparing biopolymer particles, said method comprising a membrane emulsification of a dispersed phase into a continuous phase wherein the dispersed phase comprises the biopolymer in a solvent, and wherein passing the dispersed phase through the membrane forms an emulsion of the biopolymer in the continuous phase; and a phase inversion with an anti-solvent to form particles of the biopolymer; wherein prior to (b), the emulsion is cooled to a temperature, T1. Also provided are biopolymer particles obtained from the method.

A method for producing a resin particle dispersion includes: obtaining a phase-inverted emulsion by adding a neutralizer to a resin solution prepared by dissolving a resin having an acid value in an organic solvent to thereby neutralize the resin and then adding an aqueous medium to the resulting resin solution to subject the resin to phase inversion emulsification; and removing the organic solvent from the phase-inverted emulsion. In the course of obtaining the phase-inverted emulsion, a maximum agitation power per unit mass (kg) of the resin when the resin solution containing the aqueous medium added thereto is agitated to perform the phase inversion emulsification is from 0.4 W to 20 W inclusive.

Compositions containing a first reactant; an emulsion comprising a surfactant and silicon dioxide (SiO.sub.2) nanoparticles; and a carrier fluid containing a second reactant and methods of making. When the first and second reactants react, they generate heat. At a first time, the emulsion surrounds the first reactant, and the carrier fluid with the second reactant surrounds the emulsion. At a second time, the emulsion surrounds a first portion of the first reactant; and a second portion of the first reactant surrounds the emulsion.