Bottom‐Up Meets Top‐Down: Patchy Hybrid Nonwovens as an Efficient Catalysis Platform

Abstract

Heterogeneous catalysis with supported nanoparticles (NPs) is a highly active field of research. However, the efficient stabilization of NPs without deteriorating their catalytic activity is challenging. By combining top-down (coaxial electrospinning) and bottom-up (crystallization-driven self-assembly) approaches, we prepared patchy nonwovens with functional, nanometer-sized patches on the surface. These patches can selectively bind and efficiently stabilize gold nanoparticles (AuNPs). The use of these AuNP-loaded patchy nonwovens in the alcoholysis of dimethylphenylsilane led to full conversion under comparably mild conditions and in short reaction times. The absence of gold leaching or a slowing down of the reaction even after ten subsequent cycles manifests the excellent reusability of this catalyst system. The flexibility of the presented approach allows for easy transfer to other nonwoven supports and catalytically active NPs, which promises broad applicability.

Coaxial Electrospinning Formation of Complex Polymer Fibers and their Applications

“…Schöbel et al. recently immobilized AuNPs on the surface of core‐sheath fibers consisting of PS and patchy worm‐like crystalline core micelles (wCCM) sheath . By simply immersing into preformed citrate‐stabilized AuNP solution, AuNPs are evenly and strongly attached to patches on core‐sheath fiber surface.…”

Recent progress in block copolymer crystallization

“…Solution assembly of triblock terpolymers also has led to interesting advances in the field of BCP crystallization. In most cases, CDSA was used to form worm‐like micellar structures with crystalline cores of either PE or PFS . While the current focus of CDSA research is related to controlled micelle growth and hierarchical assembly, triblock terpolymers provide another opportunity to tailor the corona of the micelle to form “patchy” morphologies on the micelle surface .…”

“…PS‐ b ‐PE‐ b ‐PMMA and PS‐ b ‐PFS‐ b ‐PMMA BCPs were assembled in solution to monitor the CDSA process and to create micelles with tunable, multicomponent coronas. Similar to micelles grown from mixing diblock copolymers that co‐crystallize, the central PE forms the crystalline core with two different solvophilic blocks around the exterior.…”

“…The PS block was selectively stained with RuO 4 . Finally, the researchers were able to selectively assemble gold nanoparticles into PMMA domains by functionalizing the methacrylate with N , N ‐dialkylethylenediamines . PFS B‐block copolymers with PS and PMMA terminal blocks also formed patchy coronas with PS or PMMA domains .…”

Enabling Heterogeneous Gold Catalysis with Patchy Micelles

“…[1] More recently,i ncreasingly complex morphologies have become accessible using av ariety of methods.M ulticompartmental or "patchy" BCP micelles with segmented cores or coronas have attracted considerable attention with respect to their hierarchical assembly and potential applications in uptake and release based on the presence of chemically different environments in close proximity. [2][3][4] In ar ecent Communication in Angewandte Chemie, [5] Greiner,S chmalz, and co-workers report ab eautifully designed catalytic system based on cylindrical BCP micelles with ac orona consisting of patches with different surface chemistries.O ne type of patch selectively binds catalytically active nanoparticles (NPs) and prevents their aggregation and subsequent loss of activity.The other is used to facilitate their surface incorporation into anonwoven matrix of electrospun polymer fibers,which enables recycling by permitting facile separation of the catalyst from the products.…”