RESUMO
We successfully developed a novel and simple method for preparation of monodisperse thermo-sensitive poly(N-isopropylacrylamide) (PNIPAM) hollow microcapsules at the interface of water-in-oil (W/O) single emulsions at a temperature below the lower critical solution temperature (LCST) of PNIPAM. The prepared PNIPAM microcapsules are featured with hollow structures and thin membranes, high monodispersity, excellent reversible thermo-sensitivity and fast response to environmental temperature. This approach exhibits great interests in preparing monodisperse thermo-sensitive microcapsules for encapsulating bioactive materials or drugs requiring mild encapsulation conditions, because of the flexibility in choosing substances being dissolved in the aqueous phase. The preparation methodology demonstrated in this study provides a unique approach for preparing monodisperse hollow polymeric microcapsules with W/O single emulsions.
Assuntos
Acrilamidas/química , Cápsulas/química , Transição de Fase , Polímeros/química , Resinas Acrílicas , Emulsões/química , Microscopia Eletrônica de Varredura , Tamanho da PartículaRESUMO
A microfluidic approach is developed to fabricate monodisperse alginate microcapsules with oil cores, which have the potential to be a brand-new type of vehicles for encapsulating, storing and/or transferring lipophilic drugs or active ingredients/chemicals. The alginate microcapsules with oil cores are generated in a microcapillary microfluidic device using monodisperse oil-in-water-in-oil (O/W/O) double emulsions as templates. All the as-prepared alginate microcapsules and the encapsulated oil droplets are satisfactorily spherical. Both the alginate microcapsule size and the thickness of alginate membrane can be easily controlled by modulating the dimensions of microfluidic device and the flow rates of solutions, because the outer diameter of the O/W/O double emulsion templates and the size of their inner oil cores can be controlled independently by adjusting the inner diameters of emulsification tubes and the flow rates of different solutions. The as-fabricated monodisperse micro-egg-like core-shell alginate microcapsules with oil cores may open new possibilities for engineering novel functional materials.
Assuntos
Alginatos/química , Cápsulas/química , Técnicas Analíticas Microfluídicas/instrumentação , Óleos/química , Emulsões/química , Desenho de Equipamento , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Técnicas Analíticas Microfluídicas/métodos , Tamanho da PartículaRESUMO
We have successfully developed a novel and simple method to controllably prepare monodisperse poly(hydroxyethyl methacrylate-methyl methacrylate) (poly(HEMA-MMA)) microspheres with two distinct structures using single emulsions as templates. By employing a microfluidic emulsification approach to fabricate monomer-contained oil-in-water (O/W) emulsions as templates, and introducing proper initiators and different types of porogens, poly(HEMA-MMA) microspheres with hollow or porous structure are prepared in a controllable way. The shell thickness of hollow microspheres or the porosity of porous microspheres is controllably achieved by simply adjusting the porogen concentration. The prepared poly(HEMA-MMA) microspheres with controllable hollow or porous structures are favored for various potential applications. Furthermore, by using the simple preparation methodology proposed in this study, fabrication of monodisperse porous microspheres or hollow microcapsules with other materials can also be easily achieved.