Macroporous uniform azide- and alkyne-functional polymer microspheres with tuneable surface area: synthesis, in-depth characterization and click-modification

Abstract

A series of uniform, macroporous poly(styrene-co-divinylbenzene) microspheres with diameters ranging from 6.6 0.6 to 8.6 0.2 mm was prepared in a multistep procedure involving precipitation polymerization synthesis of polystyrene seed particles, swelling of seed particles with plasticiser and porogen, and polymerization of styrene–divinylbenzene (S–DVB) inside the seed particles. Particles prepared with varying DVB feed ratios had comparable diameters (as evidenced by scanning electron microscopy) with specific surface areas increasing with DVB content from 11 to 467 m2 g1 (measured by nitrogen adsorption). Residual double bonds were converted into azide functionality (through HBr addition and bromo-azide substitution) or alkyne functionality (Br2 addition followed by double elimination) which allowed for CuAAC-click chemistry conjugation with reagents carrying the respective complimentary alkyne or azide functional groups including the fluorescent dye derivatives 7-nitro-4-(prop-2-ynylamino)benzofuran (NBD-alkyne) and Rhodamine B hexylazide synthesised for this purpose. Efficiency of chemical transformations was determined using a combination of CHN and IC elemental analyses, solid state NMR spectroscopy, FT-IR spectroscopy, Raman spectroscopy, and confocal scanning fluorescence microscopy. Although the respective second steps in each modification route (substitution and elimination) suffered from lower yields (35%), porous particles with azide loadings of up to 0.71 mmol g1 and alkyne loadings of up to 0.78 mmol g1 were prepared. Confocal laser scanning microscopy on Rhodamine B-labelled microspheres indicated functionalization throughout the particles featuring a core–shell structure with higher functionalization in the outer layer of particles. Results are expected to contribute to the development of advanced, well-defined, macroporous particles with high, chemically accessible surface areas

Synthesis of monodisperse poly(styrene-co-divinylbenzene) microspheres with binary porous structures and application in high-performance liquid chromatography

“…Silica gel, zeolite, activated carbon, porous metal, and porous polymeric materials have been widely used as stationary phase of chromatographic separation, ion exchange resin, catalyst support, and aerospace research has been done to study various properties of monodisperse polystyrene microspheres with porous structures [5][6][7][8][9]. Different kinds of multistage methods, such as activated swelling [10,11], seeded emulsion polymerization [12], precipitation polymerization [13], template imprinting [14,15], and membrane techniques [16,17] have been developed to prepare the monodisperse porous polystyrene particles.…”

Reactive Precursor Particles as Synthetic Platform for the Generation of Functional Nanoparticles, Nanogels, and Microgels

“…A similar procedure was reported using polystyrene particles with divinylbenzene and a porogen as additive. After polymerization, residual double bonds were converted into azide or alkyne functionalities, which allowed “click” chemistry conjugation with the CuAAC counterpart ligand . In general, this procedure creates a micro‐ or macroporous structure, enabling the inner and outer functionalization of the respective particles.…”

“…After polymerization, residual double bonds were converted into azide or alkyne functionalities, which allowed "click" chemistry conjugation with the CuAAC counterpart ligand. [71] In general, this procedure creates a micro-or macroporous structure, enabling the inner and outer functionalization of the respective particles. With this, "clickable" platforms can be generated for the conjugation of multiple molecules such as catalyst, biomacromolecules, or therapeutics.…”

Preparation of morphology-controllable PGMA-DVB microspheres by introducing Span 80 into seed emulsion polymerization

“…GMA and DVB were selected as monomer and crosslinker to synthesize microspheres due to its good ability to swell seed beads. [30][31][32][33] While different amount of Span 80 was added to the reaction system, hollow, microporous or macroporous structure microspheres could be formed. Additionally, the shape and uniformity of the obtained microspheres were greatly improved compared with previous reports.…”