From carbonyl to sulfonyl: Unlocking advanced polymers with SuFEx-enabled “macroisosteres”

Composite polymer-concrete beams represent new modern structures that can take an advantage of the polymer's practical tensile properties and combine them with the concrete's favourable compressive properties. Drawing on this knowledge, a set of polymer beams acting compositely with a concrete slab was designed and manufactured. The aim of the research was to utilise the low weight and high strength of the polymer I-sections and combine them with the high stiffness of the concrete slab, which forms the upper part of the cross-section. The advantage of fibre-reinforced polymer (FRP) beams is their anisotropy, where the strength of the material is increased by placing the fibres uniformly in one direction, and the composite elements are then stressed in the most reinforced direction. To ensure the interaction between the polymer element and the concrete slab, strip shear connectors of a precisely defined shape were developed and utilised. The designed composite beam simulates a pre-cast component that can be applied in bridge structures for short and medium spans. The pre-cast beams were subjected to four-point bending. Apart from the overall deflections of the structure, the stresses in the cross-section of the composite material and the relative deformations/strains on the surface of the concrete part of the cross-section were monitored during the test. The whole experiment yielded new results in both laboratory and theoretical respects, not only regarding the interaction of materials with distinct characteristics but also the properties of composites per se.

Nerve system diseases like Parkinson's disease, Huntington's disease, Alzheimer's disease, etc. seriously affect thousands of patients' lives every year, making them suffer from pains and inconvenience. Recently, bio‐interfaces between neural cells/tissues and polymer based biomaterials attracted worldwide attention due to the ability of polymer based biomaterials to serve as nerve conduits, drug carriers and neurites guidance platform in neuroregeneration. The role that bio‐interface played and the way it interacted with neural tissues and cells have been thoroughly investigated by the researchers. In this paper we mainly focus on reviewing the bio‐interface between nerve tissues/cells and advanced functional biocompatible polymers, such as conducting polymers and advanced carbon composite materials. These advanced polymers can provide combined interfacial stimulations including interfacial external neurotrophic factors (NTFs) delivery, electrical stimulation, surface guidance and molecules decoration to lesion cells and tissues to promote neuroregeneration in vitro and in vivo, and have contributed greatly to nerve diseases therapy. At the end of this review, the criteria of polymer based biomaterials utilized in neuroregeneration are summarized and the perspectives for future development of bio‐interfaces are also discussed.

Oral route of drug administration is typically the initial option for drug administration because it is both practical and affordable. However, major drawback of this route includes the release of drug at a specified place thus reduces the bioavailability. This could be overcome by utilising the gastroretentive drug delivery system (GRRDS). Prolonged stomach retention improves bioavailability and increases solubility for medicines that are unable to dissolve in high pH environments. Many recent advancements in the floating, bio adhesive, magnetic, expandable, raft forming and ion exchange systems have been made that had led towards advanced form of drug delivery. From the past few years, floating drug delivery system has been most commonly utilised for the delivery of drug in a delayed manner. Various polymers have been utilised for manufacturing of these systems, including alginates, chitosan, pectin, carrageenan’s, xanthan gum, hydroxypropyl cellulose, carbomer, polyethylene oxide and sodium carboxy methyl cellulose. Chitosan, pectin and xanthan gum have been found to be most commonly used polymers in the manufacturing of drug inclusion complex for gastroretentive drug delivery. This study aimed to define various types and advanced polymers as well as also highlights recent advances and future perspectives of gastroretentive drug delivery system.

Maxillofacial defects result from trauma and cancer surgery and affect the quality of the life. Various prostheses are used for craniomaxillofacial reconstruction, which improves the aesthetics and functions to improve the quality of life. The use of various reconstruction biomaterials has been studied for decades. Broadly, biomaterials that are used in the human body are classified as metals, ceramics, and polymers. Although Ti alloy biomaterials are used widely, they present some limitations, for instance, they can interfere with growth in children, interfere in radiological imaging, hypersensitivity to cold stimulation, and stress shielding. Recently, the use of various polymeric biomaterials has increased due to the favorable biomechanical properties of materials that have provided alternatives to treat patients in clinics and have also provided therapeutic approaches for maxillofacial applications. Various polymers have been utilized for the reconstruction of the midface, orbit, temporomandibular joint, and cranial defects with varying success. In addition, advanced polymers are being used in tissue engineering in dentistry as a tissue growth scaffold, and cell and extracellular matrix support. Polymeric materials can be modified to improve their mechanical and biological properties. Herein, the authors present recent and advanced polymers and their uses in maxillofacial and craniofacial reconstruction.

Low‐density polyethylene (LDPE), a polymer extensively utilized in a variety of applications, was constrained by its insufficient rigidity and antibacterial properties in medical stents. When LDPE and the vanillin/furfurylamine benzoxazine (V‐fa) monomer were combined to create the PE‐Bz composite, the rigidity and antimicrobial properties of the resulting material demonstrated a remarkable enhancement. PE‐Bz composites provided outstanding toughness and a significant improvement in rigidity, with tensile strength increased by 25.4% and impact strength enhanced by 10.2%. The rising rigidity was further validated through an elevation in melting peak temperature, a 10.7°C rise in α‐relaxation temperature, and a 60.36% rise in complex viscosity. The rigidity is related to the entanglement effect. The larger the entanglement density of the PE‐Bz composite molecules, the more significant the improvement of rigidity. The molecular dynamics simulations showed the mean square displacement and free fraction volume of the PE‐Bz composite molecular chains similarly decreased, further verifying the above experimental results. Furthermore, as established by scanning electron microscopy, the plate coating method, the in vitro toxicity testing, and the laser confocal scanning microscope, PE‐Bz composites possessed exceptional broad‐spectrum, long‐acting antibacterial properties and biocompatibility. These findings provided insightful guidance for the sensible design of a novel advanced polymer, the PE‐Bz composite, with enhanced rigidity and antimicrobial activity.

In this work the structure, the chemical composition and properties of advanced polymers are studied. Production methods and techniques are discussed, as well as the scientific research that led to their discovery. Examples of their application are reported, highlighting the contribution of advanced polymers both in the development of other scientific fields (such as medicine, natural sciences, biology, aeronautics), as well as in the discovery of new methods of industrial production. Emphasis is given to the possibilities provided by nanotechnology for the creation of innovative polymers and hybrid organic/inorganic or composite materials. The concept of colour, according to the quantum theory and the theory of molecular orbitals, is investigated and the colour–structure direct relation of objects is realized. The categories, the structure and chemical composition of dyestuffs that are used to colorize advanced polymers are determined. The methods of creating self-coloured polymers and their properties are described. Τhe advantages provided by the control οf significant parameters during production procedure are pointed out. Examples of self-coloured advanced polymers and their corresponding applications in significant production sectors are listed and positive effects of their use in the protection of environment and living organisms are mentioned.

Energy storage systems made from abundant materials are essential for the transition to a more sustainable economy. Although today lithium-ion batteries (LIBs) are the most popular battery technology, the growing demand and low availability of lithium, as well as the use of cobalt and other rare metals raise questions about the sustainability and long-term viability of LIB as the only energy storage solution. The high abundance of sodium content and relative similarity to LIBs, allows the sodium ion batteries (SIBs) to be considered as alternative for stationary energy storage [1]. However, the widespread adoption of SIB technology is hampered by many challenges, including the relatively low energy density compared to LIB. Lower energy density electrodes, such as Na2FeP2O7, are generally stable during cycling [2], while many higher energy density electrodes, such as NaxMnO2, have had a shorter cycle life [3]. In this work we show several possible solutions how to improve the electrochemical properties of the SIBs made of these cathode materials.The promising cathode material Na2FeP2O7 was studied to improve its electrical conductivity, which is often low in the case of sodium pyrophosphates. Solution synthesis was used to prepare pristine Na2FeP2O7 and Na2FeP2O7/C composite cathode materials for sodium-ion batteries, using glucose as a carbon source. While the pristine Na2FeP2O7 displays capacity of only 45 mAh/g due to the relatively large grain size, the addition of carbon increases the capacity to up to 92 mAh/g (95% of the theoretical 97 mAh/g capacity) with excellent rate capability, as 44 mAh/g capacity is still retained even at 20 C (1.94 A/g) current. The optimal content of carbon was found to be 4.8%. The initial capacity of 81 mAh/g is fully retained after 500 cycles at 1 C, indicating excellent cycle life of Na2FeP2O7/C. Electrochemical measurements were carried out in 1 M NaClO4 salt in propylene carbonate as electrolyte and show that the addition of 5 wt.% fluoroethylene carbonate solid electrolyte interphase stabilizing additive greatly benefits the rate and cycling performance of Na2FeP2O7/C as measured in half-cells [4].Na0,67MnO2 is another compound that is widely studied as cathode materials in sodium ion batteries. Currently polyvinylidene fluoride (PVDF) is the most popular binder choice. In our study, a novel tetrabutylammonium (TBA) alginate binder is used to prepare a Na0,67MnO2 electrode for sodium-ion batteries with improved electrochemical performance. The ageing of the electrodes has been characterized. TBA alginate-based electrodes are compared to PVDF and Na alginate-based electrodes and show favorable electrochemical performance, with gravimetric capacity values of up to 164 mAh/g, which is 6% higher than measured for the electrode prepared with PVDF binder. TBA alginate-based Na0,67MnO2 electrodes also display good rate capability and improved cyclability and their solid–electrolyte interface is similar to that of PVDF-based electrodes. As the only salt of alginic acid soluble in non-aqueous solvents, TBA alginate emerges as a good alternative to PVDF binder in battery applications where the water-based processing of electrode slurries is not feasible, such as the demonstrated case with Na0,67MnO2 [5].Overall, we have shown that binder and electrolyte selection can significantly improve the electrochemical properties of electrode materials for SIBs.The financial support of projects No. 1.1.1.2/VIAA/1/16/166 “Advanced materials for sodium Ion batteries” and No. lzp-2020/1-0391 “Advanced polymer – ionic liquid composites for sodium-ion polymer batteries” is greatly acknowledged. Institute of Solid-State Physics, University of Latvia as the Center of Excellence has received funding from the European Union's Horizon 2020 Framework Program H2020-WIDESPREAD-01–2016-2017-Teaming Phase 2 under grant agreement No. 739508, project CAMART2. Vaalma, C.; Buchholz, D.; Weil, M.; Passerini, S. A cost and resource analysis of sodium-ion batteries. Nat. Rev. Mater. 2018, 3, 18013.Jin, T.; Li, H.; Zhu, K.; Wang, P.-F.; Liu, P.; Jiao, L. Polyanion-type cathode materials for sodium-ion batteries. Chem. Soc. Rev. 2020, 49, 2342.Lyu, Y.; Liu, Y.; Yu, Z.-E.; Su, N.; Liu, Y.; Li, W.; Li, Q.; Guo, B.; Liu, B. Recent advances in high energy-density cathode materials for sodium-ion batteries. Sustain. Mater. Technol. 2019, 21, e00098.Kucinskis, G.; Nesterova, I.; Sarakovskis, A.; Bikse, L.; Hodakovska, J.; Bajars, G. Electrochemical performance of Na2FeP2O7/C cathode for sodium-ion batteries in electrolyte with fluoroethylene carbonate additive. J. Alloys Compd. 2022, 895, 162656.Kucinskis, G.; Kruze, B.; Korde, P.; Sarakovskis, A.; Viksna, A.; Hodakovska, J.; Bajars, G. Enhanced Electrochemical Properties of Na67MnO2 Cathode for Na-Ion Batteries Prepared with Novel Tetrabutylammonium Alginate Binder. Batteries 2022, 8, 6. Figure 1

This paper presents the design of filters and antennas in advanced polymers based on a new material called RXP. Integration capability of the RXP and the performance of WLAN filter design have been verified through the measurement data presented in this paper. Simulated results of 60GHz filters and antennas are also included in this paper. RXP provides low cost and promising high performance advanced polymer solution for wireless applications operating around microwave and millimeter frequencies.

Polymeric membranes are an emerging field in recent years and it has drawn the attention of researchers, owing to the scarcity of drinking water as well as the utility of membranes in different fields rather than water purification. Here, we present an overview of the current - advancements and strategies which have been used to augment the separation mechanisms in polymeric membranes including membrane fouling, permeability, stability, etc. For this purpose, the new trend in membranes is the incorporation of nanomaterials into the polymeric matrices which shows superior properties compared to the virgin polymeric membrane. Various nanomaterials and different approaches have been put forward which shows immense promise in the separation technologies, especially for water treatment processes. This chapter represents a detailed view of the current progress of polymeric nanocomposite membranes for the treatment and purification of water. Though several nanocomposite membranes have been reported till now, here the main focus is on how nanomaterials help in reducing membrane fouling as well as how they help to enhance the permeability of the membrane

Construction of fluorescent polymeric nano-thermometers for intracellular temperature imaging: A review

Combining disparate material constituents into a single composite material has the exciting potential to not only achieve 'best of both worlds' properties, but to find true synergy achieving "better than both worlds" improvements. In the case of polymer systems, this method may be used to produce a material with the advantages of polymers (ex. light weight, flexibility, sustainable processing) while overcoming their low fracture toughness or insulative properties through the addition of metallic or ceramic particles. Using a variety of alignment techniques, it is possible to create microstructures demonstrating synergetic outcomes in both fracture toughness and thermal conductivity compared to either system constituent alone. However, these properties are highly dependent on the microstructure of the reinforced polymers, with qualities like packing and filler alignment playing significant roles. In this thesis work, we investigate the role of these microstructures, specifically global and local filler orientation and spatial positioning, on fracture toughness and thermal conductivity. Toward fracture toughness, we leverage the existing understanding that global alignment of ceramic reinforcement in polymers creates anisotropy with a strong and weak axis of fracture toughness. We study a variety of local alignment patterns designed to exploit toughness anisotropies created by oriented ceramics, a paradigm shift from conventional composite design where the optimal orientation is co-alignment of the ceramic long axis with applied global stress. We explain how localized orientation of ceramic within polymers can achieve moderate gains in strength and stiffness (e.g. 1.25x) as well as tremendous gains in fracture toughness (e.g. 5x). Toward thermal conductivity, we investigate the role of orientation and percolation within polymers filled with phononic ceramics, particularly how the onset of percolation can be tuned through ceramic-filler orientation. This thesis offers details on newly developed percolation models to describe and understand conductivity within these materials. Furthermore, we investigate a compelling class of thermally conductive, electrically insulative hexagonal boron nitride filled polymers that can achieve conductivities of 12 W/(m*K) (a 60x improvement over pure polymer). Overall, this thesis further establishes the importance of controlling microstructure in the forms of particle orientation and spatial positioning, demonstrating new fundamental scientific contributions including understanding the strengthening and toughening mechanisms enabled by local particle control and developing improved percolation models. In addition, this thesis offers breakthrough applications including herringbone architectures which amplify toughness and thermal composites achieving 60x thermal conductivity of base polymers. --Author's abstract

Self-assembled membranes are of vital importance in biological systems e.g. cellular and organelle membranes, however, more focus is being put on synthetic self-assembled membranes not only as an alternative for lipid membranes but also as an alternative for lithographic methods. More investigations move towards self-assembly processes because of the low-cost preparations, structural self-regulation and the ease of creating composite materials and tunable properties. The fabrication of new smart membrane materials via self-assembly is of interest for delivery vessels, size selective separation and purification, controlled-release materials, sensors and catalysts, scaffolds for tissue engineering, low dielectric constant materials for microelectronic devices, antireflective coatings and proton exchange membranes for polymer electrolyte membrane fuel cells. Polymers and nanoparticles offer the most straightforward approaches to create membrane structures. However, alternative approaches using small molecules or composite materials offer novel ultra-thin membranes or multi-functional membranes, respectively. Especially, the composite material membranes are regarded as highly promising since they offer the possibility to combine properties of different systems. The advantages of polymers which provide elastic and flexible yet stable matrices can be combined with nanoparticles being either inorganic, organic or even protein-based which offers pore-size control, catalytic activity or permeation regulation. It is therefore believed that at the interface of different disciplines with each offering different materials or approaches, the most novel and interesting membrane structures are going to be produced. The combinations and approaches presented in this review offer non-conventional self-assembled membrane materials which exhibit a high potential to advance membrane science and find more practical applications.

Aqueous phase polymeric corrosion inhibitors: Recent advancements and future opportunities

Proteins contain a level of complexity-secondary and tertiary structures-that polymer chemists aim to imitate. The bottom-up synthesis of protein-mimicking polymers mastering sequence variability and dispersity remains challenging. Incorporating polymers with predefined secondary structures, such as helices and π-π stacking sheets, into block copolymers circumvents the issue of designing and predicting one facet of their 3D architecture. Block copolymers with well-defined secondary-structure elements formed by covalent chain extension or supramolecular self-assembly may be considered for localized tertiary structures.In this Account, we describe a strategy toward block copolymers composed of units bearing well-defined secondary structures mixed in a "plug-and-play" manner that approaches a modicum of the versatility seen in nature. Our early efforts focused on the concept of single-chain collapse to achieve folded secondary structures through either hydrogen bonding or quadrupole attractive forces. These cases, however, required high dilution. Therefore, we turned to the ring-opening metathesis polymerization (ROMP) of [2.2]paracyclophane-1,9-dienes (pCpd), which forms conjugated, fluorescent poly(p-phenylenevinylene)s (PPVs) evocative of β-sheets. Helical building blocks arise from polymers such as poly(isocyanide)s (PICs) or poly(methacrylamide)s (PMAcs) containing bulky, chiral side groups while the coil motif can be represented by any flexible chain; we frequently chose poly(styrene) (PS) or poly(norbornene) (PNB). We installed moieties for supramolecular assembly at the chain ends of our "sheets" to combine them with complementary helical or coil-shaped polymeric building blocks.Assembling hierarchical materials tantamount to the complexity of proteins requires directional interactions with high specificity, covalent chain extension, or a combination of both chemistries. Our design is based on functionalized reversible addition-fragmentation chain-transfer (RAFT) agents that allowed for the introduction of recognition motifs at the terminus of building blocks and chain-terminating agents (CTAs) that enabled the macroinitiation of helical polymers from the chain end of ROMP-generated sheets and/or coils. To achieve triblock copolymers with a heterotelechelic helix, we relied on supramolecular assembly with helix and coil-shaped building blocks. Our most diverse structures to date comprised a middle block of PPV sheets, parallel or antiparallel, and supramolecularly or covalently linked, respectively, end-functionalized with molecular recognition units (MRUs) for orthogonal supramolecular assembly. We explored PPV sheets with multiple folds achieved by chain extension using alternating pCpd and phenyl-pentafluorophenyl β-hairpin turns. Using single-molecule polarization spectroscopy, we showed that folding occurs preferentially in multistranded over double-stranded PPV sheets. Our strategy toward protein-mimicking and foldable polymers demonstrates an efficient route toward higher ordered, well-characterized materials by taking advantage of polymers that naturally manifest secondary structures. Our studies demonstrate the retention of distinct architectures after complex assembly, a paradigm that we believe may extend to other polymeric folding systems.

Recent years have witnessed an explosion of interest in the application of polymers as the substrates for various electronic and display devices. The advantages of polymers are their mechanical flexibility, light weight, enhanced durability, roll-to-roll fabrication and low cost compared with rigid materials (such as silicon and glass). Hybrid polymers have drawn great attention because they offer the opportunity to prepare high-performance multifunctional advanced materials through the combination of properties of organic and inorganic segments. Recently, a new approach to construction of nanohybrid materials based on polyhedral oligomeric silsesquioxne (POSS) as an inorganic moiety has attracted a lot of interest. Double-decker-shaped silsesquioxane (DDSQ) is a new family of silsesquioxane consisting of nanometer-sized Si-O-Si cage structure functionalized with a wide variety of organic groups. DDSQ-based hybrid polymer (Double-decker-shaped polysilsesquioxane, DDPSQ) possesses many fascinating properties such as high thermal stability, good mechanical properties, low dielectric constant, excellent transparency, excellent flexibility and so on. Due to these fascinating properties, DDPSQ can be used as a potential candidate substrate for various flexible electronic devices. For such applications drawing of conductive metal (Au, Cu, Ag) patterns on a DDPSQ substrate is required. Herein, we have described fabrication of Ag microwiring with submicron resolution on a DDPSQ film by laser direct writing. The line width of the Ag-wiring fabricated by this laser direct-write maskless technique can be controlled flexibly by changing the objective lens magnification and the focusing point. With an objective lens magnification 100x, Ag microwiring with a line width of about 5 μm has been achieved. The Ag-wiring shows an excellent adhesion to DDPSQ surface as evaluated by Schotch tape test. The resistivity of the Ag-wiring is determined to be 4.3 × 10-6 Ω cm ,which is comparable that of bulk Ag (1.6 × 10-6 Ω cm).