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Coarsening and kinetic arrest of colloidal systems undergoing spinodal decomposition (SD) is a conserved motif for forming hierarchical, bicontinuous structures. Although the thermodynamic origins of SD in colloids are widely known, the microstructural processes responsible for its coarsening and associated dynamics en route to arrest remain elusive. To better elucidate the underlying large-scale microdynamical processes, we study a colloidal system with moderate-range attractions which displays characteristic features of arrested SD, and study its dynamics during coarsening through a combination of differential dynamic microscopy and real-space tracking. Using these recently developed imaging techniques, we reveal directly that the coarsening arises from collective dynamics of dense domains, which undergo slow, intermittent, and ballistic motion. These collective motions indicate interfacial effects to be the driving force of coarsening. The nature of the gelation enables control of the arrested length scale of coarsening by the depths of quenching into the spinodal regime, which we demonstrate to provide an effective means to control the elasticity of colloidal gels.

Curcumin nanoemulsions (Cur-NEs) were developed with various surfactant concentrations by using high pressure homogenization and finally applied to the commercial milk system. Characterization of Cur-NEs was performed by measuring the droplet size and polydispersity index value at different Tween 20 concentrations. The morphology of the Cur-NEs was observed by confocal laser scanning microscopy and transmission electron microscopy. Antioxidant activity and in vitro digestion ability were tested using 2,2-diphenyl-1-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, pH-stat method, and thiobarbituric acid reactive substances assays. Cur-NEs were found to be physically stable for 1 mo at room temperature. The surfactant concentration affects particle formation and droplet size. The mean droplet size decreased from 122 to 90 nm when surfactant concentration increased 3 times. Cur-NEs had shown an effective oxygen scavenging activity. Cur-NEs-fortified milk showed significantly lower lipid oxidation than control (unfortified) milk and milk containing curcumin-free nanoemulsions. These properties make Cur-NEs suitable systems for the beverage industry.

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