Bicontinuous Block Copolymer Microparticles through Hydrogen-Bonding-Mediated Dual Phase Separation between Polymer Segments and Fluorinated Additives.

Bicontinuous microparticles have advanced transport, mechanical, and electrochemical properties and show promising applications in energy storage, catalysis, and other fields. However, it remains a great challenge to fabricate bicontinuous microparticles of block copolymers (BCPs) by controlling the microphase separation due to the extremely narrow region of a bicontinuous structure in the phase diagram. Here, we demonstrate a strategy to balance the phase separation of BCPs and fluorinated additives at different length scales in emulsion droplets, providing a large window to access bicontinuous microparticles.

Dynamic Electrostatic Interfacial Engineering for Block Copolymer Microparticles with Reversible Structures.

Responsive nanoparticle surfactants (NPSs) can dynamically and reversibly modulate the interfacial interactions between incompatible components, which are essential in the interfacial catalysis, corrosion, and self-assembly of block copolymers (BCPs). However, NPSs with stimuli-responsive behavior often involve tedious chemical synthesis and surface modifications. Herein, we propose a strategy to in situ construct a kind of dynamic and reversible NPSs by the interfacial electrostatic interaction between the negatively charged nanoparticles (NPs) and the positively charged homopolymers.

Shaping Block Copolymer Microparticles by Positively Charged Polymeric Nanoparticles.

Shape-transforming block copolymer (BCP) microparticles have attracted extensive attention due to their promising applications in nanotechnology, biomedicines, interfacial science, and other fields. As their performance is highly associated to their shape and structure, it is very important to realize the precise control of particle shape. In this report, a method is proposed to regulate the shape and structure of polystyrene-b-polydimethoxysiloxane (PS-b-PDMS) microparticles by using positively charged core-crosslinked nanoparticles (CNPs) as a cosurfactant, combining with cationic surfactant cetyltrimethylammonium bromide (CTAB).

Dopamine-Substituted Multidomain Peptide Hydrogel with Inherent Antimicrobial Activity and Antioxidant Capability for Infected Wound Healing.

Wound infection can cause a delay in wound healing or even wound deterioration, threatening patients' lives. The excessive accumulation of reactive oxygen species (ROS) in infected wounds activates a strong inflammatory response to delay wound healing. Therefore, it is highly desired to develop hydrogels with inherent antimicrobial activity and antioxidant capability for infected wound healing.

Shaping Block Copolymer Microparticles by pH-Responsive Core-Cross-Linked Polymeric Nanoparticles.

Block copolymer microparticles with controllable morphology have drawn widespread attention owing to their promising applications in photonic materials, energy storage, and other areas. Hence, it is highly desired to achieve a controllable transformation of microparticle morphology. In this work, we report a simple method to shape the morphology of polystyrene--poly(dimethylsiloxane) (PS--PDMS) microparticles, by employing core-cross-linked polymeric nanoparticles (CNPs) as cosurfactants which are synthesized through cross-linking P4VP segment of PS--poly(4-vinylpyridine) (PS--P4VP).

Responsive Photonic Crystal Microcapsules of Block Copolymers with Enhanced Monochromaticity.

Self-assembly of block copolymers (BCPs) has been developed as a promising approach for constructing photonic crystal (PC) microspheres for dynamic optical modulation. However, high curvature in the center of microspheres usually distorts the periodic core structure, leading to an inconsistency of photonic bandgap and poor monochromaticity of structural color. Herein, we report a simple yet robust strategy for fabricating responsive PC microcapsules of polystyrene--poly(2-vinylpyridine) through self-emulsification strategy.

Kinetic Control of Length and Morphology of Segmented Polymeric Nanofibers in Microfluidic Chips.

In this work, we report an approach to prepare segmented polymer nanofibers (SPNFs) composed of rodlike subunits by kinetically controlled self-assembly of polystyrene--poly(4-vinylpyridine)-based supramolecules in microfluidic chips. The length and morphology of the SPNFs could be effectively adjusted by changing the total flow rate () and the molar ratio () of 4-vinylpyridine (4VP) unit to a hydrogen-bonding molecule, 3--pentadecyphenol. Moreover, the subunits of SPNFs could transform from short rods to spheres when the interfacial tension between PS core and solvent increased.

Surface engineering of magnetic iron oxide nanoparticles by polymer grafting: synthesis progress and biomedical applications.

Magnetic iron oxide nanoparticles (IONPs) have wide applications in magnetic resonance imaging (MRI), biomedicine, drug delivery, hyperthermia therapy, catalysis, magnetic separation, and others. However, these applications are usually limited by irreversible agglomeration of IONPs in aqueous media because of their dipole-dipole interactions, and their poor stability. A protecting polymeric shell provides IONPs with not only enhanced long-term stability, but also the functionality of polymer shells.

Flow-Induced Micellar Morphological Transformation in Microfluidic Chips under Nonequilibrium State: From Aggregates to Spherical Micelles.

Self-assembly of block copolymers (BCPs) in microfluidic chips is a versatile yet effective route to produce micellar aggregates with various controllable sizes and morphologies. In this study, the morphological transformation of the BCP of polystyrene--poly(4-vinylpyridine) (PS--P4VP) assemblies from irregular aggregates to multicompartment micelles and ultimately to ordered spherical micelles is demonstrated in microfluidic chips. Our experimental and computational simulation results indicate that the transverse diffusion of solvents plays an important role in the morphological transformation of PS--P4VP assemblies in the confined flow condition.

Chemically Responsive Photonic Crystal Hydrogels for Selective and Visual Sensing of Thiol-Containing Biomolecules.

Intracellular thiols (e.g., cysteine, homocysteine, and glutathione) play critical roles in biological functions.

Segmental Janus nanoparticles of polymer composites.

We demonstrate a facile yet robust "plasma etching and grafting" strategy to prepare Janus nanoparticles (NPs) coated with binary polymer brushes on two different sides. The ratio of the two types of polymer ligands can be tailored by tuning the plasma etching power.

Regulation of Drug Release by Tuning Surface Textures of Biodegradable Polymer Microparticles.

Generally, size, uniformity, shape, and surface chemistry of biodegradable polymer particles will significantly affect the drug-release behavior in vitro and in vivo. In this study, uniform poly(d,l-lactic-co-glycolide) (PLGA) and PLGA-b-poly(ethylene glycol) (PLGA-b-PEG) microparticles with tunable surface textures were generated by combining the interfacial instabilities of emulsion droplet and polymer-blending strategy. Monodisperse emulsion droplets containing polymers were generated through the microfluidic flow-focusing technique.