Study of the influence of the parameters of the preparation process on the structure of a highly porous copolymer of styrene and divinylbenzene

The effect of polymerization parameters and drying temperature on the structure of a porous styrene-divinylbenzene copolymer obtained on the basis of highly concentrated emulsions was investigated. The structure of this material consisted of two types of pores: voids with an average size of 3.5±0.3 μm and holes in the pore walls with an average size of 0.7±0.2 μm. It was determined that both in materially initiated and radiation polymerization, porous copolymers of styrene and divinylbenzene with the same structure are formed.

Development of Structured Sunflower Oil Systems for Decreasing Trans and Saturated Fatty Acid Content in Bakery Creams

In this work, the design of low moisture (10%) oil/water emulsions based on sunflower oil were investigated, as well as their application in a bakery cream as a conventional fat replacer. The emulsions were dehydrated to reach 10% moisture content, achieving highly concentrated vegetable oil gel emulsions of different consistencies and qualities. Physical properties of the dried emulsions were evaluated by texture, microstructure, and oil loss determination. The reformulated bakery creams with the dried emulsions obtained from 47% oil showed better spreadability, viscosity, and viscoelasticity properties. A shortening replacement with the dried emulsion obtained from 70% initial oil caused a negative impact on the creams’ consistency, with lower viscosity and lower hysteresis area, revealing a weakness of structure. This research provided new knowledge about the structuration of vegetable oils through concentrated emulsions and their application as a source of healthy fat in creams for bakery applications.

Unraveling driving regimes for destabilizing concentrated emulsions within microchannels

There are four regimes to the destabilization of concentrated emulsions: (i) coalescence, (ii) emulsion bursts, (iii) a simultaneous combination of the first two mechanisms; and (iv) compaction of droplet network that leads to fracture-like behavior.

A multi-component lattice Boltzmann approach to study the causality of plastic events

Using a multi-component lattice Boltzmann (LB) model, we perform fluid kinetic simulations of confined and concentrated emulsions. The system presents the phenomenology of soft-glassy materials, including a Herschel–Bulkley rheology, yield stress, ageing and long relaxation time scales. Shearing the emulsion in a Couette cell below the yield stress results in plastic topological re-arrangement events which follow established empirical seismic statistical scaling laws, making this system a good candidate to study the physics of earthquakes. One characteristic of this model is the tendency for events to occur in avalanche clusters, with larger events, triggering subsequent re-arrangements. While seismologists have developed statistical tools to study correlations between events, a process to confirm causality remains elusive. We present here, a modification to our LB model, involving small, fast vibrations applied to individual droplets, effectively a macroscopic forcing, which results in the arrest of the topological plastic re-arrangements. This technique provides an excellent tool for identifying causality in plastic event clusters by examining the evolution of the dynamics after ‘stopping’ an event, and then checking which subsequent events disappear. This article is part of the theme issue ‘Fluid dynamics, soft matter and complex systems: recent results and new methods’.