Uniform Microparticles with Controllable Highly Interconnected Hierarchical Porous Structures

Abstract

A simple and versatile strategy is developed for one-step fabrication of uniform polymeric microparticles with controllable highly interconnected hierarchical porous structures. Monodisperse water-in-oil-in-water (W/O/W) emulsions, with methyl methacrylate, ethylene glycol dimethacrylate, and glycidyl methacrylate as the monomer-containing oil phase, are generated from microfluidics and used for constructing the microparticles. Due to the partially miscible property of oil/aqueous phases, the monodisperse W/O/W emulsions can deform into desired shapes depending on the packing structure of inner aqueous microdrops, and form aqueous nanodrops in the oil phase. The deformed W/O/W emulsions allow template syntheses of highly interconnected hierarchical porous microparticles with precisely and individually controlled pore size, porosity, functionality, and particle shape. The microparticles elaborately combine the advantages of enhanced mass transfer, large functional surface area, and flexibly tunable functionalities, providing an efficient strategy to physically and chemically achieve enhanced synergetic performances for extensive applications. This is demonstrated by using the microparticles for oil removal for water purification and protein adsorption for bioseparation. The method proposed in this study provides full versatility for fabrication of functional polymeric microparticles with controllable hierarchical porous structures for enhancing and even broadening their applications.

Electric Field Assisted Microfluidic Platform for Generation of Tailorable Porous Microbeads as Cell Carriers for Tissue Engineering

“…In particular, we demonstrate for the first time an excellent control over both the internal porous texture of the beads and their dimensions. We note that previous microfluidic approaches to fabricate porous microbeads suffered from polydispersity of the pores, provided no control over bead dimensions or otherwise were not suitable to tissue engineering applications due to material constraints . The presented method, thanks to its high reproducibility, flexibility in terms of achievable particle morphologies, and potential versatility in terms of processable biomaterials, significantly advances the current state‐of‐the‐art of porous microparticle synthesis and may open new routes in minimally invasive tissue engineering.…”

Monolithic supermacroporous hydrogel prepared from high internal phase emulsions (HIPEs) for fast removal of Cu 2+ and Pb 2+

“…Among the commonly used methods including direct templating, block copolymer selfassembly, and direct synthesis [27,28], freeze-drying is the simplest way to prepare aligned porous inorganic, organic and composite materials [29][30][31]20], but the pore size and pore structure can't be easily tuned via freeze-drying. From an application perspective, the direct templating methodology is a versatile approach to product highly porous polymers with connected pores and tunable pore size [32][33][34], such as high internal phase emulsion (HIPEs) technique. This is a biphasic system with the volume fraction of the discontinuous phase as high as above 74.05%.…”

Size‐Dependent Phase Separation in Emulsion Droplets

“…Hydrogels, made of varieties of polymers, are classified as "smart" materials, owing to their responsivenesst oe xternal stimuli such as pH and temperature. [1,2] Hydrogels with complex structures such as core-shell, hollow,J anus, and multilayered structuresh ave many applications in cosmetics, [3,4] drug delivery, [5,6] oil recovery, [7][8][9] and cell encapsulation. [1,10] Compared with previous microfluidics methods for creatingd ouble or higher order emulsions, whichr elied on complicated microfluidic devices with accurate surface wettability that is tedious and difficult to construct, [11][12][13][14] the phase separationt echnique promises to be af acile and reliable way to produce monodisperse, high-order emulsions with complex structures on the order of one to hundreds of micrometers.…”