Emulsions
are mixtures of two immiscible liquids in which droplets of one are
dispersed in a continuous phase of the other. The most common emulsions
are oil–water systems, which have found widespread use across
a number of industries, for example, in the cosmetic and food industries,
and are also of advanced scientific interest. In addition, the past
decade has seen a significant increase in both the design and application
of nonaqueous emulsions. This has been primarily driven by developments
in understanding the mechanism of effective stabilization of oil-in-oil
(o/o) systems, either using block copolymers (BCPs) or solid (Pickering)
particles with appropriate surface functionality. These systems, as
highlighted in this review, have enabled emergent applications in
areas such as pharmaceutical delivery, energy storage, and materials
design (e.g., polymerization, monolith, and porous polymer synthesis).
These o/o emulsions complement traditional emulsions that utilize
an aqueous phase and allow the use of materials incompatible with
water. We assess recent advances in the preparation and stabilization
of o/o emulsions, focusing on the identity of the stabilizer (BCP
or particle), the interplay between stabilizer and oils, and highlighting
applications and opportunities associated with o/o emulsions.
The
spontaneous zwitterionic copolymerization (SZWIP) of 2-oxazolines
and acrylic acid affords biocompatible but low molecular weight linear N-acylated poly(amino ester)s (NPAEs). Here, we present
a facile one-step approach to prepare functional higher molar mass
cross-linked NPAEs using 2,2′-bis(2-oxazoline)s (BOx). In the
absence of solvent, insoluble free-standing gels were formed from
BOx with different length n-alkyl bridging units,
which when butylene-bridged BOx was used possessed an inherent green
fluorescence, a behavior not previously observed for 2-oxazoline-based
polymeric materials. We propose that this surprising polymerization-induced
emission can be classified as nontraditional intrinsic luminescence.
Solution phase and oil-in-oil emulsion approaches were investigated
as means to prepare solution processable fluorescent NPAEs, with both
resulting in water dispersible network polymers. The emulsion-derived
system was investigated further, revealing pH-responsive intensity
of emission and excellent photostability. Residual vinyl groups were
shown to be available for modifications without affecting the intrinsic
fluorescence. Finally, these systems were shown to be cytocompatible
and to function as fluorescent bioimaging agents for in vitro imaging.
We present a new biscarboxylic acid acrylate, which is used for the synthesis of double hydrophilic EDTA-mimicking block copolymers capable of self-assembly upon zirconium complexation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.