This review provides a new perspective on the role of the state-of-the-art polymers of intrinsic microporosity (PIMs) in key energy-intensive membrane-based gas separations including O2/N2, H2/N2, ...H2/CH4, CO2/CH4, H2S/CH4, C2H4/C2H6, and C3H6/C3H8 applications. A general overview on the gas separation properties of novel PIM materials developed in the past 15 years is presented with updated performance maps on the latest pure-gas 2015 O2/N2, H2/N2, and H2/CH4 permeability/selectivity upper bounds. Specifically, functionalized ladder PIMs and polyimides of intrinsic microporosity (PIM-PIs) are discussed targeting at high-performance, plasticization-resistant membranes for demanding acid gas (CO2 and H2S) removal from CH4 in natural gas and olefin/paraffin separations. Experimental CO2/CH4 performance data of nearly 70 polymeric membrane materials available in the literature were gathered and plotted for the first time on the Robeson plot, from which a mixed-gas 2018 CO2/CH4 upper bound was proposed to provide guidance for future membrane materials development. A number of PIMs have demonstrated outstanding performances in O2/N2, H2/N2, and H2/CH4 separations, and several functionalized PIMs have shown great promises in CO2/CH4 separation under realistic mixed-gas conditions. The potential of PIMs materials and their derivatives for H2S/CH4, C2H4/C2H6, and C3H6/C3H8 separations are underexplored, and significant efforts are needed to develop stable and high-performance materials under mixed-gas conditions. Ultimately, fabricating PIMs materials into defect-free, inexpensive, thin-film composite or integrally-skinned asymmetric membranes is paramount to their successful large-scale commercialization.
The inert nature of most commercial polymers and nanomaterials results in limitations of applications in various industrial fields. This can be solved by surface modifications to improve ...physicochemical and biological properties, such as adhesion, printability, wetting and biocompatibility. Polymer functionalization allows to graft specific moieties and conjugate molecules that improve material performances. In the last decades, several approaches have been designed in the industry and academia to graft functional groups on surfaces. Here, we review surface decoration of polymers and nanomaterials, with focus on major industrial applications in the medical field, textile industry, water treatment and food packaging. We discuss the advantages and challenges of polymer functionalization. More knowledge is needed on the biology behind cell–polymer interactions, nanosafety and manufacturing at the industrial scale.
Capillary electromigration is a well-established commercial group of analytical techniques, and, alike other column separation systems, it often benefits from a preceding sample preparation step. ...This step not only improves the analytical performance of many methods and prolongs the equipment's life span, but it also makes some determinations possible. A remarkable sample preparation technique is molecular imprinting technology: by creating tailored polymers able to ‘select’ the targeted analytes, matrix effects are severely diminished. This review aims to provide an overview of all the published works that combine capillary electrophoresis and molecularly imprinted polymers (MIP). Although a literature search produced around 130 published analytical methodologies and 5 patents, authors believe that there is still plenty of room for interesting developments. Works ranged from the analysis of pesticides to pharmaceuticals or hormones, being the most common instrumental detection spectrophotometric. The combination between MIP and electrophoresis can be divided into two main categories depending on where the MIPs are placed within the analytical ‘pipeline’: off-column and in-column. Off-column consisted of MIP batch application previous to capillary injection. In-column approaches are more complex, and can be divided into coating, monolith, packed (these three being considered capillary electrochromatography), and dispersed particles (affinity capillary electrophoresis).
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Photopolymerization is an effective method to covalently cross-link polymer chains that can be shaped into several biomedical products and devices. Additionally, polymerization reaction may induce a ...fluid–solid phase transformation under physiological conditions and is ideal for in vivo cross-linking of injectable polymers. The photoinitiator is a key ingredient able to absorb the energy at a specific light wavelength and create radicals that convert the liquid monomer solution into polymers. The combination of photopolymerizable polymers, containing appropriate photoinitiators, and effective curing based on dedicated light sources offers the possibility to implement photopolymerization technology in 3D bioprinting systems. Hence, cell-laden structures with high cell viability and proliferation, high accuracy in production, and good control of scaffold geometry can be biofabricated. In this review, we provide an overview of photopolymerization technology, focusing our efforts on natural polymers, the chemistry involved, and their combination with appropriate photoinitiators to be used within 3D bioprinting and manufacturing of biomedical devices. The reviewed articles showed the impact of different factors that influence the success of the photopolymerization process and the final properties of the cross-linked materials.
Nowadays, ion-exchange membranes have numerous applications in water desalination, electrolysis, chemistry, food, health, energy, environment and other fields. All of these applications require high ...selectivity of ion transfer, i.e., high membrane permselectivity. The transport properties of ion-exchange membranes are determined by their structure, composition and preparation method. For various applications, the selectivity of transfer processes can be characterized by different parameters, for example, by the transport number of counterions (permselectivity in electrodialysis) or by the ratio of ionic conductivity to the permeability of some gases (crossover in fuel cells). However, in most cases there is a correlation: the higher the flux density of the target component through the membrane, the lower the selectivity of the process. This correlation has two aspects: first, it follows from the membrane material properties, often expressed as the trade-off between membrane permeability and permselectivity; and, second, it is due to the concentration polarization phenomenon, which increases with an increase in the applied driving force. In this review, both aspects are considered. Recent research and progress in the membrane selectivity improvement, mainly including a number of approaches as crosslinking, nanoparticle doping, surface modification, and the use of special synthetic methods (e.g., synthesis of grafted membranes or membranes with a fairly rigid three-dimensional matrix) are summarized. These approaches are promising for the ion-exchange membranes synthesis for electrodialysis, alternative energy, and the valuable component extraction from natural or waste-water. Perspectives on future development in this research field are also discussed.
The process of mucoadhesion involving a polymeric drug delivery platform is a complex one that includes wetting, adsorption and interpenetration of polymer chains amongst various other processes. The ...success and degree of mucoadhesion bonding is influenced by various polymer-based properties such as the degree of cross-linking, chain length and the presence of various functional groupings. The attractiveness of mucosal-targeted controlled drug delivery of active pharmaceutical ingredients (APIs), has led formulation scientists to engineer numerous polymeric systems for such tasks. Formulation scientists have at their disposal a range of
in vitro and
in vivo mucoadhesion testing setups in order to select candidate adhesive drug delivery platforms. As such, mucoadhesive systems have found wide use throughout many mucosal covered organelles for API delivery for local or systemic effect. Evolution of such mucoadhesive formulations has transgressed from first-generation charged hydrophilic polymer networks to more specific second-generation systems based on lectin, thiol and various other adhesive functional groups.
Protection from and removal of chemical warfare agents (CWAs) from the environment remains a global goal. Activated charcoal, metal oxides, metal organic frameworks (MOFs), polyoxometalates (POMs) ...and reactive polymers have all been investigated for CWA removal. Composite polymeric materials are rapidly gaining traction as versatile building blocks for personal protective equipment (PPE) and catalytic devices. Polymers are inexpensive to produce and easily engineered into a wide range of materials including films, electro-spun fibers, mixed-matrix membranes/reactors, and other forms. When containing reactive side-chains, hydrolysis catalysts, and/or oxidative catalysts polymeric devices are primed for CWA decontamination. In this review, recent advances in reactive polymeric materials for CWA removal are summarized. To aid in comparing the effectiveness of the different solid catalysts, particular attention is paid to the stoichiometric ratio of reactive species to toxic substrate (CWA or CWA simulant).
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•Reactive polymers (RPs) readily decontaminate chemical warfare agents (CWAs).•RPs function as solid forms of the long-known liquid or surfactant decontaminants.•RPs can now contain metal- and enzyme-based catalysts as well as reactive moieties.•Most RPs remove nerve agents but some also remove blistering agents as well.
The recent developments in using iridium(III) complexes as phosphorescent emitters in electroluminescent devices, such as (white) organic light‐emitting diodes and light‐emitting electrochemical ...cells, are discussed. Additionally, applications in the emerging fields of molecular sensors, biolabeling, and photocatalysis are briefly evaluated. The basic strategies towards charged and non‐charged iridium(III) complexes are summarized, and a wide range of assemblies is discussed. Small‐molecule‐ and polymer‐based materials are under intense investigation as emissive systems in electroluminescent devices, and special emphasis is placed on the latter with respect to synthesis, characterization, electro‐optical properties, processing technologies, and performance.
Phosphorescent iridium(III) complexes as emissive species in various recent applications are reviewed. The developments in the synthesis and application of these Ir(III) complexes are discussed. Here, special attention is drawn to polymer‐containing materials. Ir(III) emitters are highlighted as key materials in the areas of OLEDs, light‐emitting electrochemical cells, sensors, water‐splitting technology, and biolabeling.
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•Development of a flow microdevice with programmable in situ hydrogel formation.•Utilization of Fe-alginate hydrogel as the electric stimuli-responsive material.•On-demand release of ...Fe2+ ions for controlled reactive radical formation.•Portable microfluidic device for continuous BPA degradation at the pollution source.•Model-based design for iterative optimization and process intensification.
An innovative electrochemical microreactor leveraging redox-responsive hydrogels for the targeted removal of organic pollutants has been presented in this study. The centrepiece is a redox-responsive alginate hydrogel cross-linked with iron ions, capable of controlling the release of Fe ions by an external electrical stimulus. The Fe ions were used to activate persulfate, leading to the formation of reactive sulfate and hydroxyl radicals in situ. The system was tested for the continuous degradation of organic pollutants by radical oxidation using bisphenol A (BPA) as a model system. This unique, responsive feature of the alginate hydrogel enables its modulation and thus the removal of BPA on demand. In continuous operation, a BPA removal efficiency of over 94 % was achieved, demonstrating the enormous potential of microfluidic setup for the environmental remediation of various organic pollutants. By tailoring the process conditions, such as the residence time, even a complete removal of BPA was achieved. The robust and portable design should enable the utilization of such a system at the site of contamination. Due to the efficient process control achieved through microfluidic design, the study further delves into the adaptability of this system to different environmental matrices and showcases its potential as a promising solution to the increasing global threat of water pollution. Thereby, this research opens up new strategies for niche-oriented pollution management, including model-based design approaches. The CFD model was applied to simulate and optimize process conditions, enabling further process intensification.
Heterochain polymers such as DNA and proteins are abundant in nature, but they are not ubiquitous in man‐made polymers due to the synthetic difficulties. Traditional polymerization methodologies ...including chain polymerization, step‐growth polymerization, and coordination polymerization all show obvious drawbacks in synthesizing heterochain polymers. The alkyne multicomponent polymerizations (MCPs) developed in the early 2000s open a new door for the synthesis of conjugated heterochain polymers with diverse structures and unique properties. This review presents the progress in novel heterochain polymers constructed by alkyne‐based MCPs in the last three years. The unique properties and high‐tech applications brought by heteroatoms and MCPs are summarized and perspectives on future directions are also discussed.
Functional heterochain polymers, such as DNA and proteins, are abundant and essential in nature, but are not ubiquitous among man‐made polymers due to the synthetic difficulties. The alkyne multicomponent polymerizations initiated in the early 2000s open a new door for the synthesis of conjugated heterochain polymers with diverse structures and unique properties.
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