Polyglycerol-poly(ε-caprolactone) block copolymer as a new semi-solid polymeric emulsifier to stabilize O/W nanoemulsions

Abstract

This work introduces a new polymeric emulsifier, polyglycerol-block-poly(ε-caprolactone), to prepare and stabilize oil-in-water nanoemulsions through the formation of a semi-solid interphase between oil and water. Nanoemulsions are prepared using representative silicone and ester oils, which are widely used for commercial consumer products. The block copolymer is homogeneously solubilized in a mixture of oil and ethanol at 70°C, and the organic solution is dispersed in water using a conventional homogenizer. Stable nanoemulsions of 220-280 nm in mean diameter are spontaneously generated. The block copolymer is reorganized at the interface to form a robust semi-solid polymeric barrier that can prevent the entrapped oil from diffusing out to the aqueous phase. The barrier exhibits excellent stability against mechanical stresses, allowing nanoemulsions to be very stable during repeated freeze/thaw cycles. This work suggests that polyglycerol-based block copolymers can be a new promising polymeric emulsifier for stabilization of nanoemulsions of various oils.

Methods for producing microstructured hydrogels for targeted applications in biology

“…Owing to the benefit of amphipathy for stabilizers to migrate to and assemble at the phase interface, block copolymers are commonly used due to the versatility of having both hydrophilic and hydrophobic polymer chains conjugated in the same molecule. The capability of these materials to form semisolid structures and crystals impart both yield stress to the phases involved and stability against mechanical stress in the interface, so the coalescence is delayed and there is inherent steric repulsion of the polymer-covered domains [197,198]. Hydrophobic polymers such as poly(caprolactone), poly(lactide), and poly(hydroxypropyl methacrylate) and hydrophilic polymers like poly(glycerol) and poly(ethylene oxide) are the most commonly used combination for producing the copolymer emulsifiers [198][199][200].…”

Nanoemulsions of Chamomile and Cumin Essential Oils: As an Alternative Bio-rational Control Approach against the Red Flour Beetle, Tribolium castaneum

“…The nanoemulsion physicochemical properties the average droplet size, viscosity (cP), polydispersivity (PDI), zeta Potential (mV) and conductivity (mS/cm) were characterized. The droplet size and viscosity were determined by the dynamic laser scattering method (Zetasizer Nano ZS90) (Jun et al, 2015). The zeta potential and polydispersivity index were determined by photon correlation spectroscopy using the kit ZetaPlus (Zhermack, Badia Polesine, Italy), (Arancibia et al, 2017).…”

Polyglycerol Hyperbranched Polyesters: Synthesis, Properties and Pharmaceutical and Biomedical Applications

“…Jun et al synthesized linear PGCL using glycidol, instead of glycerol, which was reacted with ε-caprolactone. In this case, in order to avoid the formation of multi-arm polymers, the hydroxyl group had to be initially protected, and the copolymers were prepared in a three-stage procedure (Scheme 12) [216][217][218]. Ethoxyethyl glycerol ether (EEGE) was synthesized initially from glycidol and ethyl vinyl ether using p-toluenesulfonic acid as a catalyst.…”