Enhanced UV Penetration and Cross-Linking of Isoporous Block Copolymer and Commercial Ultrafiltration Membranes using Isorefractive Solvent.

Amphiphilic block copolymers are promising candidates for the fabrication of ultrafiltration membranes with an isoporous integral asymmetric structure. The membranes are typically fabricated by the combination of block copolymer self-assembly and the non-solvent-induced phase separation (SNIPS) process resulting in isoporous integral asymmetric membranes. Certainly, all these membranes lack thermal and chemical stability limiting the usage of such materials.

Thermally and Chemically Stable Isoporous Block Copolymer Membranes.

Ultrafiltration (UF) membranes, particularly membranes fabricated from self-assembled diblock copolymers, hold promise in wastewater treatment, dairy, and food industries. Membrane development goals involve combining a highly porous selective layer with a narrow pore size distribution with a mechanically stable supporting layer to achieve constant flux. To date, isoporous integral asymmetric membranes have been formed either as flat sheets or hollow fibers, and a surface-selective layer determines membrane separation performance.

Self-Assembly of Large Magnetic Nanoparticles in Ultrahigh Molecular Weight Linear Diblock Copolymer Films.

The development of diblock copolymer (DBC) nanocomposite films containing magnetic nanoparticles (NPs) with diameters () over 20 nm is a challenging task. To host large iron oxide NPs (FeO, = 27 ± 0.6 nm), an ultrahigh molecular weight (UHMW) linear DBC polystyrene--poly(methyl methacrylate) (PS--PMMA) is used as a template in the present work.

Self-Assembly in ultrahigh molecular weight sphere-forming diblock copolymer thin films under strong confinement.

Ultrahigh molecular weight (UHMW) diblock copolymers (DBCs) have emerged as a promising template for fabricating large-sized nanostructures. Therefore, it is of high significance to systematically study the influence of film thickness and solvent vapor annealing (SVA) on the structure evolution of UHMW DBC thin films. In this work, spin coating of an asymmetric linear UHMW polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) DBC is used to fabricate thin films, which are spherically structured with an inter-domain distance larger than 150 nm.

Anionic Copolymerization Enables the Scalable Synthesis of Alternating (AB) Multiblock Copolymers with High Molecular Weight in /2 Steps.

Based on the highly disparate reactivities of isoprene (I, = 25.4) and 4-methylstyrene (4MS, = 0.007) in the anionic copolymerization in nonpolar media, a general strategy for the rapid and scalable synthesis of tapered multiblock copolymers with an extremely steep gradient has been developed.

One-Step Anionic Copolymerization Enables Formation of Linear Ultrahigh-Molecular-Weight Block Copolymer Films Featuring Vivid Structural Colors in the Bulk State.

Ultrahigh-molecular-weight (UHMW) tapered block copolymers (BCPs) consisting of polyisoprene- block-poly(4-methylstyrene) featuring overall molar masses in the range of 1101-2033 kg mol ( M) are synthesized via a convenient one-step anionic copolymerization protocol. The obtained UHMW BCPs are investigated by differential scanning calorimetry, size exclusion chromatography, and H NMR spectroscopy. Microphase separation for the UHMW BCPs in the bulk state is investigated by transmission electron microscopy (TEM) measurements and scanning electron microscopy (SEM), revealing well-ordered lamellar and spherical domains with large domain sizes in the range of 100-200 nm.