One‐step Preparation of Monodisperse Multifunctional Macroporous Particles through a Spontaneous Physical Process

Abstract

Macroporous particles that combine the property features of spherical structures and porous materials are expected to find use over micro- and macroscopic length scales from miniaturized systems such as cell imaging, drug and gene delivery to industrial applications. However, the capacity for de novo design of such materials is still limited. Here, a spontaneous process to fabricate monodisperse multifunctional macroporous particles (MMMPs) by high internal phase emulsion templating is reported. An interesting physical phenomenon involving self-emulsification and synergistic effects between nanoparticles and amphiphilic diblock copolymers is observed in this process. These MMMPs, featured with tailor-made pore structures, pH responsiveness, and magnetic response, could be used as stimuli-responsive carriers for multiple functional molecules with a high loading and releasing efficiency. This new understanding regarding the underlying phenomena that control self-emulsification behavior and synergistic action in emulsion systems provides a unique outlook and a novel approach to the design of potentially multifunctional porous materials for controllable release and delivery processes.

Discovery and Insights into Organized Spontaneous Emulsification via Interfacial Self-Assembly of Amphiphilic Bottlebrush Block Copolymers

“…As a result, droplets showing uniform diameters are eventually formed when approaching an equilibrium state. For comparison, the packing parameter of the linear BCP surfactant can vary significantly from droplet to droplet due to their flexible polymer chain conformation and random packing at the interface, leading to the disordered porous morphologies with a wide pore size distribution. − ,, Upon evaporation for 165 min, the oil phase is nearly dried and ordered arrangements of the water nanodroplets are achieved. The concentrated suspension of nearly uniform water droplets crystallizes, driven by entropy, which is similar to that of colloids crystallization: the free volume of hard spheres is greater than that of the disordered state resulting in higher entropy in the ordered state .…”

“…In situ observation of the structure formation clearly shows the permeation of water into the oil phase forming W/O droplets of varied size, dynamic equilibrium yielding uniform sizes, self-organization producing well-ordered droplet arrays, and solidification leading to hexagonal closest packed (HCP) porous morphologies. The thermodynamically favorable process is called organized spontaneous emulsification (OSE), which is different from the kinetically controlled formation of the disordered porous structures. ,, The highly extended molecular conformation of BBCP surfactants results in uniform droplets via their ordered arrangement at the W/O interface. Moreover, the contour length of the BBCP backbone exhibits great influence on the obtained pore diameter, and a small increase in the degree of polymerization (DP) leads to a significant increase in the pore size.…”

“…The thermodynamically favorable process is called organized spontaneous emulsification (OSE), which is different from the kinetically controlled formation of the disordered porous structures. 16,25,27 The highly extended molecular conformation of BBCP surfactants results in uniform droplets via their ordered arrangement at the W/O interface. Moreover, the contour length of the BBCP backbone exhibits great influence on the obtained pore diameter, and a small increase in the degree of polymerization (DP) leads to a significant increase in the pore size.…”

Designing Internal Hierarchical Porous Networks in Polymer Monoliths that Exhibit Rapid Removal and Photocatalytic Degradation of Aromatic Pollutants

“…[ 8 ] Contrarily, solid colloidal particles can also stabilize the interface between two different phases even at a relatively low concentration, leading to a Pickering emulsion. [ 9–12 ] A variety of materials such as silica, [ 13–15 ] metal‐organic‐frameworks (MOFs), [ 16–18 ] graphene oxides, [ 19–21 ] and metal oxides [ 22,23 ] has been used as Pickering emulsifiers; they are well dispersed in a continuous phase and bound to the surface of the interface, which forms stable layers to sustain the internal droplets. In contrast to conventional HIPEs, Pickering HIPEs have some advantages: i) they require a small amount of solid particles to maintain the emulsion system (e.g., below 10 wt%) [ 13–23 ] and ii) the emulsifier particles can be designed using diverse monomeric species or further functionalized via post‐polymerization modification.…”

Preparation of Magnetic-Fluorescent Bifunctional Microrods as a Drug Delivery System via One-Step Electrospraying

“…However, the magnetic DDS was poor in real-time tracking and observation and cannot be detected during the delivery process. Therefore, the method of combining fluorescent materials with magnetic targeting technology in DDS came into being, and the magnetic-fluorescent composite DDS received widespread attention [6][7][8]. With magnetic targeting and fluorescent labeling functions, the DDS could realize the integration of diagnosis and treatment such as biological imaging and drug delivery [9,10].…”