The statistical anionic copolymerization of isoprene (I) and styrene (S) is commonly used to synthesize tapered block copolymers, enabling control of the phase behavior by adjusting the order–disorder transition temperature, T ODT. Alkyllithium initiation in hydrocarbons is known to afford tapered block copolymers of I and S in one step. The effect of tetrahydrofuran (THF) on the copolymerization kinetics and the resulting copolymers was systematically investigated by increasing the [THF]/[Li] ratio from 0 to 2500 (0 to 29%vol THF). For this purpose, in situ near-infrared (NIR) spectroscopy was employed as a versatile and fast method to track the highly accelerated consumption of the individual monomers. Changes in the I/S comonomer sequence and in the polyisoprene (PI) regioisomers, caused by variation of the THF concentration, were independently determined via NMR and in situ NIR spectroscopy. Reactivity ratios were determined as a function of the [THF]/[Li] ratio. They revealed a gradual reversal from r I ≫ r S over r I ≈ r S to r I ≪ r S. Corresponding changes in the copolymer composition profile up to a complete inversion are evident in thermal properties and morphologies. Although all copolymers possess the same comonomer composition (50%mol = 57%vol polystyrene (PS) units), small-angle X-ray scattering and transmission electron microscopy give evidence of a wide variation in bulk morphologies depending on the gradient profile. Overall, the phase diagram is symmetric, and the succession of phases bears certain similarities to the PI-b-PS case. This is discussed in terms of the increasing incompatibility of PS with 3,4-PI and the more symmetric polymer conformational parameter. The degree of segregation, as well as the nanodomain structure, was found to control the mechanical properties, showing a remarkably different viscoelastic response leading to either hard/brittle or ductile/soft materials. The accessibility of tailored gradient profiles, as well as their in-depth understanding by simply using THF as a microstructural modifier, opens a variety of possible applications. As an example, the synthesis of a PI-selective hydrogenated tapered triblock, possessing a THF-modified, phase-compatibilizing tapered block incorporated in the well-established SIS block architecture, is presented.

The statistical anionic copolymerisation of the biobased monomer β-myrcene with styrene in cyclohexane was investigated via in-situ near-infrared (NIR) spectroscopy, focusing on the influence of the modifiers (i.e., Lewis bases)...

Metallopolymers are a unique class of functional materials because of their redox-mediated optoelectronic and catalytic switching capabilities and, as recently shown, their outstanding structure formation and separation capabilities. Within the present study, (tri)block copolymers of poly(isoprene) (PI) and poly(ferrocenylmethyl methacrylate) having different block compositions and overall molar masses up to 328 kg mol are synthesized by anionic polymerization. The composition and thermal properties of the metallopolymers are investigated by state-of-the-art polymer analytical methods comprising size exclusion chromatography, H NMR spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. As a focus of this work, excellent microphase separation of the synthesized (tri)block copolymers is proven by transmission electron microscopy, scanning electron microcopy, energy-dispersive X-ray spectroscopy, small-angle X-ray scattering measurements showing spherical, cylindrical, and lamellae morphologies. As a highlight, the PI domains are subjected to ozonolysis for selective domain removal while maintaining the block copolymer morphology. In addition, the novel metalloblock copolymers can undergo microphase separation on cellulose-based substrates, again preserving the domain order after ozonolysis. The resulting nanoporous structures reveal an intriguing switching capability after oxidation, which is of interest for controlling the size and polarity of the nanoporous architecture.

The development of compartments for the design of cascade reactions in a local space requires a selective spatiotemporal control. The combination of enzyme-loaded polymersomes with enzymelike units shows a great potential in further refining the diffusion barrier and the type of reactions in nanoreactors. Herein, pH-responsive and ferrocene-containing block copolymers were synthesized to realize pH-stable and multiresponsive polymersomes. Permeable membrane, peroxidase-like behavior induced by the redox-responsive ferrocene moieties and release properties were validated using cyclovoltammetry, dye TMB assay, and rupture of host–guest interactions with β-cyclodextrin, respectively. Due to the incorporation of different block copolymers, the membrane permeability of glucose oxidase-loaded polymersomes was changed by increasing extracellular glucose concentration and in TMB assay, allowing for the chemoenzymatic cascade reaction. This study presents a potent synthetic, multiresponsive nanoreactor platform with tunable (e.g., redox-responsive) membrane properties for potential application in therapeutics.

functional inks; in this way, substrates may be patterned with functional materials and tailored nanoparticle arrays may be generated. An ideal additive lithographic substrate patterning technique would allow the execution of an unlimited number of parallel large-area ink deposition steps characterized by short cycle times without process-intrinsic interruptions caused, for example, by ink depletion. However, stateof-the-art substrate patterning techniques do not meet this requirement. Contactless ballistic pattering methods including inkjet printing, aerosol jet printing [2] and laser-induced forward transfer [3] can, in principle, be carried out continuously because ink can continuously be supplied to the substrate. However, these methods involve serial pixel-by-pixel writing associated with limitations regarding patternable areas and/or throughput. Additive substrate patterning by microcontact printing [4] and variations thereof such as polymer pen lithography (PPL), [5] capillary force lithography, [6] wet lithography, [7] and particle transfer printing [8] are parallel and allow simultaneous patterning of large substrate areas. However, these methods involve transfer of ink coated on the outer surfaces of solid elastomeric stamps to substrates. Consequently, ink depletion in the course of successive stamp-substrate contacts results in deteriorating quality of the stamped patterns. Automated stamping devices for parallel additive surface manufacturing would be commercially available, [9] but stamping needs to be interrupted after a limited number of stamping steps to recoat Patterned substrates for optics, electronics, sensing, lab-on-chip technologies, bioanalytics, clinical diagnostics as well as translational and personalized medicine are typically prepared by additive substrate manufacturing including ballistic printing and microcontact printing. However, ballistic printing (e.g., ink jet and aerosol jet printing, laser-induced forward transfer) involves serial pixelby-pixel ink deposition. Parallel additive patterning by microcontact printing is performed with solid elastomeric stamps suffering from ink depletion after a few stamp-substrate contacts. The throughput limitations of additive stateof-the art patterning thus arising may be overcome by capillary stampingparallel additive substrate patterning without ink depletion by mesoporous silica stamps, which enable ink supply through the mesopores anytime during stamping. Thus, either arrays of substrate-bound nanoparticles or colloidal nanodispersions of detached nanoparticles are accessible. Three types of model inks are processed: 1) drug solutions, 2) solutions containing metallopolymers and block copolymers as well as 3) nanodiamond suspensions representing colloidal nanoparticle inks. Thus, aqueous colloidal nanodispersions of stamped drug nanoparticles, regularly arranged ceramic nanoparticles by post-stamping pyrolysis of stamped metallopolymeric precursor nanoparticles and regularly arranged nanodiamond nanoaggregates are obtained. Capillary sta...

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Stimuli-responsive mesoporous silica films were prepared by evaporation-induced self-assembly through the physical entrapment of a functional metalloblock copolymer structuring agent, which simultaneously served to functionalize the mesopore. After end-functionalization with a silane group, the applied functional metalloblock copolymers were covalently integrated into the silica mesopore wall. In addition, they were partly degraded after the formation of the mesoporous film, which enabled the precise design of accessible mesopores. These polymer–silica hybrid materials exhibited remarkable and gating ionic permselectivity and offer the potential for highly precise pore filling design and combination with high-throughput printing techniques. This in situ functionalization strategy of mesoporous silica using responsive metalloblock copolymers has the potential to improve how we approach the design of complex architectures at the nanoscale for tailored transport. This functionalization strategy paves the way for a variety of technologies based on molecular transport in nanoscale pores, including separation, sensing, catalysis, and energy conversion.

Block copolymers (BCPs) in the bulk state are known to self-assemble into different morphologies depending on their polymer segment ratio. For polymers with amorphous and crystalline BCP segments, the crystallization process can be influenced significantly by the corresponding bulk morphology. Herein, the synthesis of the amorphous-crystalline BCP poly(dimethyl silacyclobutane)-block-poly(2vinyl pyridine), (PDMSB-b-P2VP), by living anionic polymerization is reported. Polymers with overall molar masses ranging from 17 400 g to 592 200 g mol −1 and PDMSB contents of 4.8-83.9 vol% are synthesized and characterized by size-exclusion chromatography and NMR spectroscopy. The bulk morphology of the obtained polymers is investigated by means of transmission electron microscopy and small angle X-ray scattering, revealing a plethora of self-assembled structures, providing confined and nonconfined conditions. Subsequently, the influence of the previously determined morphologies and their resulting confinement on the crystallinity and crystallization behavior of PDMSB is analyzed via differential scanning calorimetry and powder X-ray diffraction. Here, fractionated crystallization and supercooling effects are observable as well as different diffraction patterns of the PDMSB crystallites for confined and nonconfined domains.