Recent Advances in the Emulsion Solvent Evaporation Technique for the Preparation of Nanoparticles and Nanocapsules

Abstract

The emulsion solvent evaporation technique is a method for preparing nanoparticles and nanocapsules that are particularly adapted for applications requiring materials with high purity and low toxicity, such as for biomedicine or electronics. We discuss here new important advances concerning the elucidation of the mechanism of nanoparticle formation, and the synthesis of nanoparticles with new structures or from new polymers.

Preparation and characterization of 100% bio-based polylactic acid/palmitic acid microcapsules for thermal energy storage

“…Unlike emulsion polymerization, no monomer, initiator or catalyst is used. Hence, it allows the fabrication of microspheres with high purity [ 39 ]. In general, the fabrication process involves four main steps: (1) dissolution of PA and PLA in DCM; (2) emulsification of this organic phase (i.e., dispersed phase), in a continuous aqueous phase of deionized water containing PVA; (3) extraction and evaporation of solvent from the dispersed phase, which transform the dispersed phase into solid microspheres (i.e., microPCM); and (4) recovery and drying of microPCM to eliminate residual solvent and emulsifier.…”

A triblock terpolymer vs. blends of diblock copolymers for nanocapsules addressed by three independent stimuli

“…41 This technique has been successfully applied for synthesis of NCs from different polymers including functional block copolymers 42 and for the encapsulation of various payloads. 43 The final morphology of a colloidal system consisting of different non-miscible phases strongly depends on the interfacial tension between these phases. 44 A triblock terpolymer and hexadecane (a non-solvent for the copolymer) were dissolved in dichloromethane containing a small amount of Nile-Red (NR) and then mixed with a basic aqueous solution of cetyltrimethylammmonium chloride (CTMA-Cl) by stirring and ultrasonication to form a miniemulsion (Fig.…”

Advanced stimuli-responsive polymer nanocapsules with enhanced capabilities for payloads delivery

“…The driving force for successful encapsulation is the ideal phase separation between the stimuli-responsive polymer and the payload or the solution containing the payload in miniemulsion droplets, no matter induced by polymerization, 30 a condensation reaction, 31 or by solvent evaporation. 32 In the three different approaches, the formation of the PNCs and the encapsulation of payload are realized simultaneously. Meanwhile, the PNC quantity is easy to scale up by increasing the feed.…”

“…36 The miniemulsion-solvent evaporation technique is another facile method to encapsulate payloads in stimuliresponsive PNCs. 32 This technique is particularly interesting to fabricate stimuli-responsive PNCs with high purity and low toxicity that can find applications in biomedicine 37 or for upconversion. 38 In direct miniemulsion, the pre-synthesized polymer, hydrophobic payload, and a non-solvent for polymer are well mixed in a "good" solvent to form miniemulsion droplets under ultrasonication (approach II in Fig.…”