Preparation of monodisperse magnetic polystyrene microspheres and its surface chemical modification

Regioselective Seeded Polymerization in Block Copolymer Nanoparticles: Post‐Assembly Control of Colloidal Features

Post‐assembly modifications are efficient tools to adjust colloidal features of block copolymer (BCP) particles. However, existing methods often address particle shape, morphology, and chemical functionality individually. For simultaneous control, we transferred the concept of seeded polymerization to phase separated BCP particles. Key to our approach is the regioselective polymerization of (functional) monomers inside specific BCP domains. This was demonstrated in striped PS‐b‐P2VP ellipsoids. Here, polymerization of styrene preferably occurs in PS domains and increases PS lamellar thickness up to 5‐fold. The resulting asymmetric lamellar morphology also changes the particle shape, i.e., increases the aspect ratio. Using 4‐vinylbenzyl azide as co‐monomer, azides as chemical functionalities can be added selectively to the PS domains. Overall, our simple and versatile method gives access to various multifunctional BCP colloids from a single batch of pre‐formed particles.

Investigation on the Controllable Synthesis of Colorized and Magnetic Polystyrene Beads With Millimeter Size via In Situ Suspension Polymerization

A series of colorized and magnetic polystyrene/Fe₃O₄ (PS/Fe₃O₄) composite beads with millimeter size are successfully synthesized by introducing hydrophobic Fe₃O₄via in situ suspension polymerization of styrene for the first time. Effects of the hydrophobic Fe₃O₄ content, stirring speed, and surfactant dosage on the macromorphology and particle size of PS/Fe₃O₄ beads are systematically investigated to realize the controllable synthesis. Moreover, three kinds of hydrophobic pigments are also employed to synthesize colorized polystyrene, which demonstrates the versatility, simplicity, and wide applicability of the proposed method. Scanning electron microscopy (SEM) and element mapping (EM) images demonstrated that the hydrophobic Fe₃O₄ is well dispersed in the polystyrene matrix. Thermogravimetric analysis (TGA) shows that the resultant PS/Fe₃O₄ beads possess a better thermal stability than neat PS. PS/Fe₃O₄ beads have a promising application in the fields of colorized extruded PS board, colorized expanded PS foam particle, and board.

Synthesis of Sponge-Like Material for the Extraction of Fluoroquinolones in Milk

The new sponge material was prepared by the copolymerization of polystyrene and methacrylic acid. The polystyrene seed was prepared by two-step seed swelling polymerization. Scanning electron microscopy images showed that the sponge material were clumps with porous morphologies. The adsorption behaviour of the sponge material was analysed by detecting pefloxacin and enfloxacin in milk samples. Under the optimized conditions, good linearity was obtained in the range 0.05-10.0 μg g−1, with a correlation coefficient (r2) of ≥ 0.9991. The recoveries at three spiking levels ranged from 85.6 to 106.9% with relative standard deviations (RSDs) of ≤6.6%. The sponge material could be applied to the rapid screening of Pefloxacin and enfloxacin in complicated milk-product matrices.