Nanostructured block copolymer (BCP) thin films constitute an elegant tool to generate periodic patterns with periodicities ranging from a few nanometers to hundreds of nanometers. Such well-organized nanostructures are foreseen to enable next-generation nanofabrication research with potent applications in the design of functional materials. This valuable platform is, however, limited by the geometric features attainable from diblock copolymer architectures. Therefore, strategies to enrich the variety of structures are gaining momentum [1,2]. In particular, we have demonstrated that precise interface manipulations and iterative self-assembly of BCP layers can lead to morphological variety [3]. We have also developed a method based on immobilized nanostructured BCP layers which yielded to the generation of non-native BCP nanostructures through “responsive layering”. Accordingly, design rules have been established in order to finely control the resulting non-native BCP structures by tuning the BCP morphology, domain spacing and interfacial and topographical fields between the different layers [4,5]. We demonstrated that the change of the interfacial energy between the nanostructured BCP films, associated to the topography inherent to the immobilization of the underneath BCP layer, leads to a controlled registration of the upper BCP layer with respect to the underlying one.

Diblock copolymers are of significant interest due to their potential as templates for patterned surfaces over large areas, useful in various nanofabrication applications (1). To achieve precise control of the order-disorder transition temperature (TODT) (temperature below which self-assembly occurs) and the domain spacing, a strategy can be to use binary blends of block copolymers of similar nature but different molecular weights (2,3). This study systematically investigated order-disorder transition and microdomain structure in binary mixtures of poly(styrene-block-methyl methacrylate) (PS-b-PMMA) copolymers in bulk and thin film. Two molar masses were used, 28 and 34 kg/mol. Binary mixtures with various compositions were prepared via solvent evaporation. Thin films (80 nm) were obtained by spin-coating the copolymers solutions on a grafted layer of random P(S-r-MMA). The temperature of the order-disorder transition of the binary mixtures in the weak segregation regime was precisely determined using in situ grazing incidence small-angle X-ray scattering (GISAXS) for films and small-angle X-ray scattering (SAXS) for bulk samples. The evolution of the TODT as a function of the blend composition follows a simple mixing rule.

Their proficiency in transport modulation of ionic species positions mesoporous silica-polymer hybrid nanomaterials as essential elements in advanced energy management, sensing, and molecular sieving systems. The unparalleled precision of biological systems in ion transport arises from pore architectures honed at the nanoscale and structurally optimized to meet the specific requirements of the migrating ions. To approach nature’s precision in designing nanostructures, the plasmonic near-field of Au nanospheres was harnessed as directing unit, enforcing local polymer placement in silica membranes. Immobilized at specified layer height of double-layered mesoporous silica (MPS) thin-films, the Au nanospheres served as photoactive moiety, initiating visible light-induced, photoiniferter-mediated reversible-addition-fragmentation chain-transfer (RAFT) polymerization [1]. Plasmon-induced RAFT polymerization and local polymer formation were revealed through ATR-IR spectroscopy and fluorescence microscopy upon fluorophore colorization. Selective plasmon-induced polymerization in a system of dual photoreactivity demanded exclusive photoexcitation of the Au nanospheres, evading the iniferter’s bathochromically shifted wavelength regime of photoactivity relative to its absorption profile, and was achieved through direct laser writing. While fine mechanics paired with beam diameters down to 7 µm enable the advanced lateral precision in polymer placement through laser writing [2], longitudinal control over polymer placement along the light path through the technique remains unattained. Combining the lateral precision of laser writing with photoactive near-field modes anchored at defined positions along the film height, we present a strategy to acquire control over spatial placement of functional polymer through direct laser writing which lays a foundation toward directed ionic motion through membranes.

Energy storage is vital in this day and age, particularly for storing clean energy produced from renewable resources. In order to meet this ever growing demand and enhance sustainability in this field, more efficient and cleaner materials must be generated. Ionic liquids (ILs) are defined as liquid electrolytes with a melting point below 100 ⁰C.[1] Compared to many organic solvents, ILs exhibit properties such as higher ionic conductivity and thermal stability, and can be used to generate so-called ionogels, which are a class of materials that offer much promise in the way of improving energy storage for future generations. Ionogels are typically generated as a result of immobilisation of ionic liquid within a crosslinked matrix, such as polymers. For the synthesis of ionogels, polymer concentrations are commonly required to be >10% w/w to induce gelation, which can reduce the effect of the electrochemical properties provided by the IL. Herein, we present for the first time, a reversible addition fragmentation chain transfer polymerisation-induced self-assembly (RAFT-PISA) formulation in ionic liquid that yields block copolymer nanoparticles such as spheres, worms, and vesicles. Most importantly, this new IL PISA formulation facilitates the in situ formation of worm ionogel electrolyte materials at copolymer concentrations ≥5% w/w via efficient and convenient synthesis routes without the need for organic co-solvents, crosslinkers, post-polymerisation purification or processing. Additionally, we exemplify the electrochemical properties and thermal stability of these ionogels, which are shown to be comparable to that of the ionic liquid alone, demonstrating their potential as gel electrolytes.[2]

Nanoporous polymers are two-phase materials composed of a polymer phase and nanoscale pores or cells. Positioned at the forefront of materials and polymer science, these materials exhibit a unique combination of properties due to the effects of molecular confinement within the polymer and other structural changes related to their nanoscale architecture. In addition to their low density, nanoporous polymers demonstrate enhanced mechanical properties, reduced thermal conductivity, and a high surface area. One of the main challenges in their production is the generation and stabilization of nanometric cells.
This study presents the strategy of using block copolymers to produce nanoporous polymers with a controlled structure through CO2 gas dissolution foaming. In particular, this paper explores two main approaches: first, the use of block copolymer micelle nanostructuring as a template to generate nanometric cells, and second, nucleation induced by the addition of the block copolymer without micelle formation. Both approaches present advantages and limitations. This work presents the results of two example systems based on polymethylmethacrylate (PMMA) and polystyrene (PS). Properties of the generated materials are also presented. The results support that this fabrication strategy is the most promising for large-scale production of nanoporous polymers.

Carbon nanotubes (CNTs) were incorporated into poly(lactic acid) (PLA)/thermoplastic polyurethane (TPU) blends, with an epoxy compound (ADR) acting as a compatibilizer, to form the blend-based nanocomposites. Scanning electron microscopy results showed a sea-island morphology in PLA/TPU (7:3) blend and a co-continuous morphology in PLA/TPU (5:5) blend. The addition of ADR improved the compatibility between PLA and TPU; the added CNTs were mainly distributed in the TPU phase. Differential scanning calorimetry results revealed that the inclusion of ADR inhibited PLA-TPU crystallization due to the improved interfacial interactions, and CNTs hardly facilitated the crystallization of PLA-TPU in the composites. Thermogravimetric analysis revealed the thermal stability improvement of the blends after CNT loading, up to 9°C and 14°C increase at 5 wt.% and 80 wt.% loss, respectively, at 3 phr CNT loading in the PLA/TPU (5:5) blend. The elongation at break (EB) and impact strength (IS) of PLA were improved significantly after forming the blends, especially with ADR incorporation. EB and IS of the PLA/TPU (5:5) blend-based composite increased by up to 70 and 3.4 times, respectively, compared with PLA. Rheological property measurements indicated the formation of a (pseudo)network structure of CNTs in the composites. The inclusion of CNTs improved evidently the anti-dripping performance of the blends in burning tests. The electrical resistivity of the blends decreased by up to seven orders of magnitude at 3 phr CNT loading.