Conjugated Microporous Polymer Hybrid Microparticles for Enhanced Applicability in Silica-Boosted Diclofenac Adsorption

Diclofenac (DCF) is one of the most widespread and consumed analgesics, thereby causing contamination of water bodies on a global scale. A common approach to tackle this pressing issue is the adsorption of DCF exploiting highly hydrophobic polymers. However, controlling the morphology of such polymers is essential. Adsorption capacities of the presented conjugated microporous polymer (CMP) in bulk-form, for DCF (q(sat)) are as low as 13.0 mg g(-1) despite exhibiting additional nitrogen moieties to specifically target DCF. Herein, an approach to drastically increase the DCF adsorption by increasing the accessible hydrophobic surface area by coating it around mesoporous silica microspheres is shown. These microspheres do not attribute to the adsorption of DCF themselves, but increase the accessibility of the CMP. Simultaneously, the applicability of the hybrid material is enhanced through higher wettability and more facile separation. As a consequence, an effective adsorbent is formed featuring an adsorption of up to 422 mg DCF per 1 x g CMP for the optimized silica/monomer ratio - comparable to expensive state-of-art materials. As the approach combines the advantages of the nano- and the micro-dimension and does not depend on the actual adsorbent material, it holds great potential for general adsorption problems requiring highly engineered systems.