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Molybdenum disulfide nanosheets (MoS2 NSs) has great promising in the field of optical biosensor due to its unique optical transparency and semiconducting properties. In this work, supramolecule ca...

A novel epoxy cyclohexane-based polyurethane material was synthesized from a self-made epoxy cyclohexane-tetrahydrofuran (CHO-THF) co-polyether. Due to the special rigid six-membered ring skeleton in the polyether molecular chain, the polyurethane materials have excellent mechanical properties, good optical transparency and weather resistance. In this paper, the synthesis process of the epoxy cyclohexane-based polyurethane material was studied and the properties of the material were tested. The results showed that curing parameters R value had effects on the mechanical properties and optical transparency of the material.

Polydimethylsiloxane (PDMS) is the predominant material used for organ-on-a-chip devices and microphysiological systems (MPSs) due to its ease-of-use, elasticity, optical transparency, and inexpensive microfabrication. However, the absorption of small hydrophobic molecules by PDMS and the limited capacity for high-throughput manufacturing of PDMS-laden devices severely limit the application of these systems in personalized medicine, drug discovery, in vitro pharmacokinetic/pharmacodynamic (PK/PD) modeling, and the investigation of cellular responses to drugs. Consequently, the relatively young field of organ-on-a-chip devices and MPSs is gradually beginning to make the transition to alternative, nonabsorptive materials for these crucial applications. This review examines some of the first steps that have been made in the development of organ-on-a-chip devices and MPSs composed of such alternative materials, including elastomers, hydrogels, thermoplastic polymers, and inorganic materials. It also provides an outlook on where PDMS-alternative devices are trending and the obstacles that must be overcome in the development of versatile devices based on alternative materials to PDMS.

The optical transparency of palladium layers is studied in the wavelength range of 0.5–1.1 μm in air and gas mixtures containing hydrogen in concentrations from 0.1 to 100 vol %. The layers were deposited on glass substrates by thermal evaporation in vacuum. The Bouguer law is fulfilled for layers with thicknesses of the order of 450 A. The layers with thicknesses exceeding 1200 A disintegrate in 100% hydrogen. An abrupt increase in the transparency of palladium layers typical for first-order phase transitions was observed at a hydrogen concentration between 1 and 10%. The rate of the hydrogen-induced change in the transparency of layers linearly increases with increasing hydrogen concentration in the gas mixture.

We use indium tin oxide (ITO), one of the representative resistive materials, for the implementation of a metamaterial electromagnetic (EM) absorber with a high absorbance in a wide frequency range. Highly symmetrical split ring resonators made of ITO film are deposited on the polyethylene terephthalate with transparent and flexible features, and such a configuration causes the proposed absorber to be insensitive to polarization and incidence angles. The proposed absorber, with a profile of only 0.171λ, exhibits a wideband absorbance of 7.2 GHz to 27 GHz, with a 90% absorption criterion. A prototype is built, and all the computed expectations from the full-wave EM simulations in this work are verified experimentally.

Conductive poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is widely used for practical applications such as energy conversion and storage devices owing to its good flexibility, processability, high electrical conductivity, and superior optical transparency, among others. However, its hygroscopic character, short durability, and poor thermoelectric performance compared to inorganic counterparts has greatly limited its high-tech applications. In this work, PEDOT:PSS/SnO2 nanocomposites have been prepared via a simple, low cost, environmentally friendly method without the use of organic solvents or compatibilizing agents. Their morphology, thermal, thermoelectrical, optical, and mechanical properties have been characterized. Electron microscopy analysis revealed a uniform dispersion of the SnO2 nanoparticles, and the Raman spectra revealed the existence of very strong SnO2-PEDOT:PSS interactions. The stiffness and strength of the matrix gradually increased with increasing SnO2 content, up to 120% and 65%, respectively. Moreover, the nanocomposites showed superior thermal stability (as far as 70 degrees C), improved electrical conductivity (up to 140%), and higher Seebeck coefficient (about 80% increase) than neat PEDOT:PSS. On the other hand, hardly any change in optical transparency was observed. These sustainable nanocomposites show considerably improved performance compared to commercial PEDOT:PSS, and can be highly useful for applications in energy storage, flexible electronics, thermoelectric devices, and related fields., Comunidad de Madrid

The art of origami has emerged as an engineering tool with ever increasing potential, but the technique is typically limited to soft and deformable materials. Glass is indispensable in many applications, but its processing options are limited by its brittle nature and the requirement to achieve optical transparency. We report a strategy that allows making three dimensional transparent glass with origami techniques. Our process starts from a dynamic covalent polymer matrix with homogeneously dispersed silica nanoparticles. Particle cavitation and dynamic bond exchange offer two complementary plasticity mechanisms that allow the nanocomposite to be permanently folded into designable geometries. Further pyrolysis and sintering convert it into transparent three dimensional glass. Our method expands the scope of glass shaping and potentially opens up its utilities in unexplored territories., Glass is indispensable but its processing options are limited. Here the authors extend origami techniques to shaping three-dimensional transparent glass by introducing physical cavitation and chemical dynamic bond exchange in the pre-glass polymer-silica nanocomposites.

The authors of the published title paper (Bull. Mater. Sci. 2020 43 17) claim to have grown a resorcinol-doped potassium hydrogen phthalate (RKHP) crystal by a slow evaporation method. It was reported that the organic dopant enhances the second harmonic generation efficiency (SHG) of potassium hydrogen phthalate (KHP). In this letter to Editor, many points of criticism concerning the crystal growth and the characterization of the so-called RKHP crystal are discussed to prove that the published original paper is erroneous.

Rheumatoid arthritis (RA) belongs to the most often occurring autoimmune diseases in the world. For serological diagnosis, IgM auto-antibodies directed against the Fc portion of IgG referred to as rheumatoid factor are used as biomarkers. The autoantibody detection is usually done by ELISA. Such assays are reliable but are not suitable for point-of-care testing in contrast to lateral flow assays. Here, we report the development of a lateral flow assay based on carboxylated fluorescence-encoded poly(methyl methacrylate) nanoparticles. Poly(methyl methacrylate) is a non-toxic plastic with an excellent biocompatibility and high optical transparency which promises especially high sensitive fluorescence detection thereby leading to very sensitive assays. We could detect a positive signal in samples with a nephelometric reading down to 0.4 U/mL. By analyzing 30 sera of patients with a RA diagnosis and 34 sera of healthy test subjects we could confirm positive ELISA results in 72% of all cases and negative ELISA results in 97% of all cases.

Thin fims in the Zr−B−N system possessing optical transparency have been studied. It is established that increase in the volume fraction of nitrogen in the gas mixture and, hence, in the concentration of nitrogen in the coatings leads to an increase in their optical transmission due to the formation of a BN phase.

Summary Digital health promises a paradigm shift for medicine where biomarkers in individuals are continuously monitored to improve diagnosis and treatment of disease. To that end, a technology for minimally invasive quantification of endogenous analytes in bodily fluids will be required. Here, we describe a strategy for designing and fabricating hydrogel microfilaments that can penetrate the skin while allowing for optical fluorescence sensing. The polyacrylamide formulation was selected to provide high elastic modulus in the dehydrated state and optical transparency in the hydrated state. The microfilaments can be covalently tethered to a fluorescent aptamer to enable functional sensing. The microfilament array can penetrate the skin with low pain and without breaking, contact the dermal interstitial fluid, and be easily removed from the skin. In the future, hydrogel microfilaments could be integrated with a wearable fluorometer to serve as a platform for continuous, minimally invasive monitoring of intradermal biomarkers., Graphical Abstract, Highlights • Polyacrylamide hydrogel microfilaments were fabricated via replica molding • Microfilaments are stiff, when dehydrated, and optically transparent, when hydrated • Fluorescent aptamer can be tethered to hydrogel matrix for in situ analyte sensing • Microfilaments penetrate skin with low pain and contact interstitial fluid, Bioelectronics; Polymers; Biomedical Materials

A new aromatic diamine, 10,10-bis[4-(4-amino-3-trifluoromethylphenoxy)phenyl]-9( 10H)-anthrone (BATFPA), has been synthesized from anthrone via three-step procedure. Low-temperature polycondensation of BATFPA with various aromatic dicarboxylic acid chlorides produced novel fluorinated polyamides with moderate to high inherent viscosities of 0.75–1.03 dL/g while the weight-average molecular weight and number-average molecular weight were in the range of 66,000–74,000 and 37,000–41,000, respectively. Nearly, all the polymers were readily soluble in polar solvents, such as N,N-dimethyl acetamide (DMAc), N-methyl-2-pyrrolidinone, pyridine, and tetrahydrofuran, and afforded transparent, light-colored, and flexible films upon casting from DMAc solvent. These polymers had glass transition temperatures of 249–309°C, 10% weight loss temperatures of 486–517°C, and char yields of 53–61% at 800°C under nitrogen. All polymers were amorphous and their films exhibited tensile strengths of 64–86 MPa, tensile moduli of 1.8–2.2 GPa, and elongation at break of 10–18%. These polymers had dielectric constants ranging from 3.25 to 3.76 (100 Hz), low moisture uptake in the range of 0.72–1.18%, and high transparency with an ultraviolet–visible absorption cutoff wavelength in the 360–378 nm range.

The discovery of a general strategy for organizing functional proteins into stable nanostructures with the desired dimension, shape, and function is an important focus in developing protein-based self-assembled materials, but the scalable synthesis of such materials and transfer to other substrates remain great challenges. We herein tackle this issue by creating a two-dimensional metal-protein hybrid nanofilm that is flexible and cost-effective with reliable self-recovery, stability, and multifunctionality. As it differs from traditional metal ions, we discover the capability of Sn2+ to initiate fast amyloid-like protein assembly (occurring in seconds) by effectively reducing the disulfide bonds of native globular proteins. The Sn2+-initiated lysozyme aggregation at the air/water interface leads to droplet flattening, a result never before reported in a protein system, which finally affords a multifunctional 2D Sn-doped hybrid lysozyme nanofilm with an ultralarge area (e.g., 0.2 m2) within a few minutes. The hybrid film is distinctive in its ease of coating on versatile material surfaces with endurable chemical and mechanical stability, optical transparency, and diverse end uses in antimicrobial and photo-/electrocatalytic scaffolds. Our approach provides not only insights into the effect of tin ions on macroscopic self-assembly of proteins but also a controllable and scalable synthesis of a potential biomimic framework for biomedical and biocatalytic applications.

Perovskite oxide SrVO3 (SVO) is a transparent conductor with excellent optical and electrical properties. Most of the previous works have focused on (001)-oriented SVO thin films. As an alternative to tin-doped indium oxide (ITO), the other orientations of SVO thin films are important to be considered as well. In the present work, the optical and electrical properties of (111)-oriented SVO epitaxial films have been investigated. Excellent electrical conductivity (2.92 × 104 S cm−1) and optical transparency (56.6%) have been demonstrated, which are comparable to those of ITO and expand the applications of epitaxial SVO thin films in other orientations as transparent conducting oxide.

Metal-organic framework (MOF) nanosheets have attracted extensive attention due to their remarkable properties, such as nanoscale and tunable thickness, adjustable structure and function, high-aspect-ratio, large surface area, more exposed accessible active site, favorable mechanical flexibility, and optical transparency. This article aims to review the latest developments in MOF nanosheets. Firstly, the assortments of the synthetic methods of MOF nanosheets will be introduced. Then, the wide applications and utilization of these ultrathin MOF nanosheets in the fields of electronics, gas separation, catalysis, sensors, energy storage/transfer, and as enzyme inhibitors will also be explored. Finally, the prospects and challenges of MOF nanosheets will be presented.

Due to remarkable electronic property, optical transparency, and mechanical flexibility, monolayer molybdenum disulfide (MoS2) has been demonstrated to be promising for electronic and optoelectroni...

Microfluidics has become recognized as a powerful platform technology with a wide range of applications in various fields, such as biology, biomedicine, chemistry and environment. To achieve higher performance, microfluidic devices are required to have superior optical transparency; mechanical, chemical and thermal stability; as well as easy design and fabrication. All of these requirements make glass as an attractive and ideal material for the fabrication of microfluidic devices due to its excellent characteristics in optical, mechanical, thermal, electrical and chemical aspects in comparison to other materials (e.g., silicon and polydimethylsiloxane). In order to give preliminary guidance for researchers from different backgrounds, we provide a comprehensive overview of the fabrication methods for glass-based microfluidic devices as well as various applications based on different types of glass. This review takes into account recent advances in the fabrication of microfluidics, such as, liquid glass and ultra-thin glass, so as to provide a full understanding of the latest research trend in this area. Finally, some remaining challenges facing the field are summarized, and potential prospects for future work with an emphasis on both emerging techniques are discussed.

Combining organic and inorganic components at a nanoscale is an effective way to obtain high performance coating materials with excellent chemical and physical properties. This review focuses on recent approaches to prepare hybrid nanostructured waterborne coating materials combining the mechanical properties and versatility of silica as the inorganic filler, with the flexural properties and ease of processing of the polymer matrix. We cover silica-polymer coupling agents used to link the organic and inorganic components, the formation of hybrid films from these silica-polymer nanostructures, and their different applications. These hybrid nanostructures can be used to prepare high performance functional coatings with different properties from optical transparency, to resistance to temperature, hydrophobicity, anti-corrosion, resistance to scratch, and antimicrobial activity.

The simultaneous attainment of high strength and high toughness of transparent cellulose nanofibril (CNF) film can expedite its uses in advanced applications. In this work, a wood-inspired strategy is proposed to address the conflict between strength and toughness by using natural derived lignosulfonic acid (LA) as a reinforcing additive. Only 1 wt% LA addition can double the toughness (11.0±1.3 MJ/m3) of pure CNF film. Consequently, the as-prepared CNF/LA-1 nanocomposite film not only exhibits superior mechanical properties (23.6±1.3 MJ/m3 toughness, 249±6 MPa strength, and 15.4±1.4 % strain), but also maintains an excellent optical transparency of 91.2 % (550 nm). Furthermore, the mechanism for simultaneously enhancing strength and toughness is essentially attributed to the improved hydrogen bonding between CNF-OH and LA-SO3H and effective energy dissipation system. This work provides a green and effective approach to prepare strong yet tough and transparent biodegradable CNF film for high-end applications.

One of the beneficial effects of non-digestible oligosaccharides (NDOs) is their anti-inflammatory effects on host animals. While conventional animal studies require that analysis be done after samples have been taken from the host, zebrafish larvae are optically transparent upon hatching and this provides an opportunity for observations to be made within the living zebrafish larvae. This study aimed to take advantage of the optical transparency of zebrafish larvae to study the nitric oxide (NO) reducing effects of NDOs through the use of lipopolysaccharide (LPS) from Salmonella enterica serovar (ser.) Enteritidis (S. Enteritidis) to induce cardiac NO production. Prior to running the above experiment, an acute toxicity assay was conducted in order to determine the appropriate concentration of oligosaccharides to be used. The oligosaccharides tested consisted of oligosaccharides which were extracted from palm kernel cake with a degree of polymerization (DP) equal to or less than six (OligoPKC), commercial mannanoligosaccharide (MOS) and commercial fructooligosaccharide (FOS). Acute toxicity test results revealed that the OligoPKC has a LC50 of 488.1 μg/ml while both MOS and FOS were non-toxic up to 1,000 μg/ml. Results of the in vivo NO measurements revealed that all three NDOs were capable of significantly reducing NO levels in LPS stimulated zebrafish embryos. In summary, at 250 μg/ml, OligoPKC was comparable to MOS and better than FOS at lowering NO in LPS induced zebrafish larvae. However, at higher doses, OligoPKC appears toxic to zebrafish larvae. This implies that the therapeutic potential of OligoPKC is limited by its toxicity.

Poly (amic acid) s (PAAs) were synthesized using 4,4&prime, (hexafluoroisopropyl-idene) diphthalic anhydride (6FDA) and two types of diamines&mdash, bis(3-aminophenyl) sulfone (BAS) and bis(3-amino-4-hydroxyphenyl) sulfone (BAS-OH). Two series of transparent polyimide (PI) hybrid films were synthesized by solution intercalation polymerization and thermal imidization using various concentrations (from 0 to 1 wt%) of organically modified clay Cloisite 30B in PAA solution. The thermo-mechanical properties, morphology, and optical transparency of the hybrid films were observed. The transmission electronic microscopy (TEM) results showed that some of the clays were agglomerated, but most of them showed dispersed nanoscale clay. The effects of -OH groups on the properties of the two PI hybrids synthesized using BAS and BAS-OH monomers were compared. The BAS PI hybrids were superior to the BAS-OH PI hybrids in terms of thermal stability and optical transparency, but the BAS-OH PI hybrids exhibited higher glass transition temperatures (Tg) and mechanical properties. Analysis of the thermal properties and tensile strength showed that the highest critical concentration of organoclay was 0.50 wt%.

The zebrafish embryo is a vertebrate well suited for visualizing nanoparticles at high resolution in live animals. Its optical transparency and genetic versatility allow noninvasive, real-time observations of vascular flow of nanoparticles and their interactions with cells throughout the body. As a consequence, this system enables the acquisition of quantitative data that are difficult to obtain in rodents. Until now, a few studies using the zebrafish model have only described semiquantitative results on key nanoparticle parameters. Here, a MACRO dedicated to automated quantitative methods is described for analyzing important parameters of nanoparticle behavior, such as circulation time and interactions with key target cells, macrophages, and endothelial cells. Direct comparison of four nanoparticle (NP) formulations in zebrafish embryos and mice reveals that data obtained in zebrafish can be used to predict NPs' behavior in the mouse model. NPs having long or short blood circulation in rodents behave similarly in the zebrafish embryo, with low circulation times being a consequence of NP uptake into macrophages or endothelial cells. It is proposed that the zebrafish embryo has the potential to become an important intermediate screening system for nanoparticle research to bridge the gap between cell culture studies and preclinical rodent models such as the mouse.

Based on the aromatic diamine monomer containing di-tert-butylbenzene and methyl groups, this work proposes its polymerization with four different dicarboxylic acids. The prepared polyamides (PA 3a–3d) were characterized by GPC, FTIR, 1H NMR, mechanical, thermal, optical and gas separated techniques. They exhibited high solubility and good optical transparency. Their optical transmittance at 450 nm wavelength was in the range of 81.4%–86.8%, and the cutoff wavelength was in the range of 327–352 nm. The membranes also had good mechanical properties with tensile strength of 79.7–91.4 MPa, elongations at breaks of 9.0–10.9% and initial modulus of 1.5–1.9 GPa. Meanwhile, these membranes possessed good thermal properties with glass transition temperature (Tg) values of 226–246 °C. The permeability of CH4, N2, and CO2 for these membranes was tested by constant pressure-variable volume method. The PA 3d containing tert-butyl moiety in the diacid units exhibited highest permeability (PCO2 = 31.4 and PN2 = 1.9) whereas PA 3c containing hexafluoroisopropylidene moiety exhibited highest selectivity (CO2/CH4 = 22.2).

High quality tissue-mimicking phantoms (TMPs) have a critical role in the preclinical testing of emerging modalities for diagnosis and therapy. TMPs capable of accurately mimicking real tissue in Magnetic Resonance guided Focused Ultrasound (MRgFUS) applications should be fabricated with precise T1 and T2 relaxation times. Given the current popularity of the MRgFUS technology, we herein performed a systematic review on the MR relaxation properties of different phantoms types. Polyacrylamide (PAA) and agar based phantoms were proven capable of accurately replicating critical thermal, acoustical, and MR relaxation properties of various body tissues. Although gelatin phantoms were also proven factional in this regard, they lack the capacity to withstand ablation temperatures, and thus, are only recommended for hyperthermia applications. Other gelling agents identified in the literature are Poly-vinyl alcohol (PVA), Polyvinyl Chloride (PVC), silicone, and TX-150/ TX-151; however, their efficacy in thermal studies is yet to be established. PAA gels are favorable in that they offer optical transparency enabling direct visualization of coagulative lesions. On the other hand, agar phantoms have lower preparation costs and were proven very promising for use with the MRgFUS technology, without the toxicity issues related to the preparation and storage of PAA materials. Remarkably, agar turned out to be the prominent modifier of the T2 relaxation time even for phantoms containing other types of gelling agents instead of agar. This review could be useful in manufacturing realistic MRgFUS phantoms while simultaneously indicating an opportunity for further research in the field with a particular focus on the MR behavior of agar-based TMPs.

9,9-Bis(4-aminophenyl)xanthene (BAPX) was prepared simply and effectively via one-pot, two-step procedure using xanthenone and aniline as main substrates. The monomer BAPX was reacted with six aromatic dianhydrides in N, N-dimethylacetamide (DMAc) to yield the corresponding polyimides (PIs) via the poly(amic acid) precursors and subsequent thermal or chemical imidization. The resulting PIs exhibited good thermal stability with glass transition temperatures of 308–348°C, initial decomposition temperatures of 470–510°C, 10% weight loss temperatures of 540–565°C, and char yields of 55–59% at 800°C in nitrogen, respectively. All polymers were amorphous and readily soluble in organic solvents such as N-methyl-2-pyrrolidone and DMAc. The PI films had tensile strengths of 71–92 MPa, tensile moduli of 1.91–2.35 GPa, and elongations at break of 5–13%. Meanwhile, these polymer films also had high optical transparency with a cutoff wavelength in the range of 367–415 nm, lower dielectric constants (3.02–3.34 at 10 MHz), and low water uptake of 0.30–0.52%.

Stretchable and transparent electrodes (STEs) are vital and indispensable in developing optoelectronic devices aiming for next-generation flexible electronics. However, the fabrication of high-performance electrodes with both good stretchability and transparency is still challenging. To balance the conductivity and stretchability trade-offs in previously reported STEs, the STEs with embedded metal nickel (Ni) meshes in polydimethylsiloxane (PDMS) in this study are designed and tested. The STEs show high optical transparency (81.6%), high stretchability (40%) and low resistance (0.44 Ω). We can further improve the mechanical stretchability of the STEs by designing the Ni mesh patterns, while still maintaining optical and electrical properties.. In addition, this fabrication strategy versatile without sophisticated processing procedures, opening possibility for high-throughput, large-volume, and low-cost production, which would lead to potential applications in wearable medical equipment and transparent electronic devices.

Here, we develope a kind of biobased transparent polyimides (PIs) with excellent solubility and mechanical properties by using myo-inositol derived diamines. Two biobased diamines M1 and M2 were synthesized through a protection reaction of –OH units of myo-inositol followed by the substitution and subsequent reduction reactions. Myo-inositol based PIs were prepared via the microwave-assisted polymerization of biobased diamines and commercial dianhydrides. These PIs were soluble in various common solvents even in CH2Cl2 and acetone at room temperature. The biobased PIs also showed good optical transparency with T450nm values of over 82%. Moreover, all the PI films possessed outstanding mechanical properties with tensile modulus of over 3.5 GPa, which was higher than that of most of petroleum-based PIs. In addition, the PI films containing –OH units were obtained via a simple deprotection reaction of myo-inositol based PIs.

Graphene-on-semiconductor has been proved to be a quality heterojunction with efficient photoelectric conversion. In this work, we constructed Schottky junction solar cells by combing graphene woven fabrics (GWFs) and n-doped single crystal silicon, and examined the performance of solar cells when GWFs of different meshes were used. Sparse GWFs possessed high optical transparency but led to poor carrier collection, whereas dense GWFs could collect carriers efficiently but generated too few photo carriers due to low transparency. The GWFs with an optimal mesh could provide a good balance between the generation and collection of photo-induced carriers to deliver high power conversion efficiency. Keywords: Graphene, Heterojunction, Solar cell

The paper deals with Hf–B–Si–C–N films deposited onto Si and SiC substrates using pulsed magnetron co-sputtering of a single B4C–Hf–Si target (at fixed 15% Hf and 20% Si fractions in the target erosion area) in argon–nitrogen gas mixtures. We focus on the effect of the nitrogen fraction in the gas mixture (in the range from 0% to 50%) and of the voltage pulse length (50 μs and 85 μs with the corresponding duty cycle of 50% and 85%, respectively) on the structure and properties of the films. We show that an increasing nitrogen fraction in the gas mixture and consequently in the films (up to 52 at.%) results in a strong amorphization of the film structure, decrease in the film hardness, and rapid rise in the electrical resistivity and the optical transparency of the films. Very high oxidation resistance in air even up to 1500 °C is demonstrated for two sufficiently hard (20–22 GPa) Hf–B–Si–C–N films: the electrically conductive Hf7B23Si22C6N40 film and the optically transparent Hf6B21Si19C4N47 film, both with a contamination level

A facile and versatile spin-coating method was adopted to fabricate transparent omniphobic coatings by infiltrating fluorinated lubricant into the uniform polytetrafluoroethylene nanoparticulate film. The lubricant-infused surfaces display excellent liquid repellency, good optical transparency, and show outstanding performance in self-cleaning, anti-corrosion, and anti-icing. Importantly, the liquid repellency of the omniphobic surfaces still prevails after various mechanical damages.

Two isomers of conventional cis-dicyclohexyl-3,3′,4,4′-tetracarboxylic dianhydride (4,4′-HBPDA), i.e. dicyclohexyl-2,3′,3,4′-tetracarboxylic dianhydride (3,4′-HBPDA) and dicyclohexyl-2,2′,3,3′-tetracarboxylic dianhydride (3,3′-HBPDA), were prepared through a four-step procedure. The data from single crystal X-ray diffraction revealed that 3,3′-HBPDA possessed higher structural rigidity/linearity than 4,4′-HBPDA. The one-step polycondensation of isomeric HBPDAs with commercial diamines enabled the synthesis of alicyclic polyimides. The isomer effects of the dianhydrides on the properties of resulting polyimides were studied in detail. For certain diamines, 3,3′-HBPDA-derived polyimides possessed higher glass transition temperatures (Tg) and better dimensional stability compared with those from 4,4′-HBPDA and 3,4′-HBPDA. These phenomena could be attributed to the higher structural rigidity/linearity of 3,3′-dicyclohexyl-tetracarboxydiimide, and restricted rotation of 3-substituted cyclohexylimide. Owing to the asymmetric structures and suppressed rotation of 3-substituted cyclohexylimides, 3,4′-HBPDA-based polymers exhibited higher Tg, improved dimensional stability, and enhanced solubility compared with 4,4′-HBPDA-based ones. Furthermore, all the isomeric HBPDA-derived polyimides were essentially colorless with excellent optical transparency in the UV–Visible region. The excellent overall properties of polyimides from 3,3′-HBPDA and 3,4′-HBPDA made them promising candidate materials for optoelectronic applications.

Cellulose diacetate (CDA) composite films were synthesized by incorporation of nanofibrillated celluloses (NFCs), using a casting/evaporation technique. Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM) characterization indicated the presence of interaction and certain compatibility between CDA and NFCs. The CDA and NFCs were converted to cellulose II by an alkaline treatment which resulted in the formation of all cellulose composite (ACC) films, as indicated by the FTIR and XRD characterization. Significant changes were observed in their structural, thermal, mechanical, and optical transparency properties. The SEM images revealed the excellent compatibility among the constituents of the ACC films. The tensile strength, Young's modulus, and strain at break of the ACC films with 15wt% NFCs content were increased to 102.3MPa, 5.8GPa, 14.7% respectively. This work provides a promising pathway for manufacturing high performance ACC materials.

A novel and thermally stable aluminum phosphate Li6Na3Sr14Al11P22O90 (1) has been achieved by using a solid-state molten method, which contains an oxo-centered trinuclear cluster and an anti-Lowenstein's rule Al–O–Al linkage and is constructed from two types of (3,6)-connected kgd layers [Al(Al3O)(PO4)7]25− and [Al(PO4)2]3−. The good optical transparency in the whole UV range and excellent thermal stability make the title compound a potential optical window material.

Polymers, derived from bio-derived resources, have gained considerable momentum because of a lower dependence over conventional fossil-based resources without compromising the materials' thermo-mechanical properties. Unique characteristics of organic and inorganic materials can be incorporated by a combination of both to obtain hybrid materials. We have recently developed a series of transparent biopolyimides (BPI) from a biologically derived exotic amino acid, 4-aminocinnamic acid (4ACA) to yield 4-amino truxillic ester (4ATA ester) derivatives. In the present research, the polyimide-precursor was subjected to sol–gel polycondensation reactions with silicon-alkoxide followed by annealing under vacuo to yield a biopolyimide-silica hybrid. The biopolyimide structures (4ATA acid/ester) and their silica hybrids thermo-mechanical, electrical and optical performance were evaluated. It was found that the biopolyimide with 4ATA(ester) yields thermo-mechanically robust films with very high electrical stability as well as optical transparency, plausibly due to the uniform dispersion of the silica particles in the biopolyimide matrix.

In this study, a novel diamine monomer, 4-(4-trifluoromethylthiophenyl)-2,6-bis(4-aminophenyl)pyridine (FTPAP) was synthesized through two-step reaction from 4-trifluoromethylthiobenzaldehyde and 4-nitroacetophenone as raw materials, and then the structure of FTPAP was characterized by Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance, and mass spectrometry. A series of fluorinated polyimides were prepared from FTPAP with five commercial dianhydrides, namely, pyromellitic dianhydride, biphenyl tetracarboxylic dianhydride, oxydiphtahalic anhydride, benzophenone tetracarboxylic dianhydride, and 4,4′-(hexafluoroisopropylidene) diphthalic anhydride. The structure and performance of the fluorinated polymers were fully characterized by FTIR, differential scanning calorimetry, thermogravimetric analysis, and wide-angle X-ray diffraction (WAXD). The inherent viscosity of polymers ranged from 0.41 to 1.45 dL g−1. These polymers displayed good solubility in polar aprotic solvents, such as N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, and N-methyl-2-pyrrolidone, at room temperature or on heating. Furthermore, they exhibited outstanding thermal stability with glass transition temperatures beyond 305°C, and the temperature of 10% weight loss was in the range of 514–573°C with more than 56% residue at 800°C under nitrogen. Moreover, they showed high optical transparency with the cutoff wavelengths in the range of 385–457 nm and excellent hydrophobic property with contact angle in the range of 82.8–97.6°. In addition, the results of WAXD indicated that all of the polymers presented amorphous structure.

Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) has high optical transparency in the visible light range and low-temperature processing condition, making it one of the most widely used polymer hole transport materials inverted perovskite solar cells (PSCs), because of its high optical transparency in the visible light range and low-temperature processing condition. However, the stability of PSCs based on pristine PEDOT:PSS is far from satisfactory, which is ascribed to the acidic and hygroscopic nature of PEDOT:PSS, and property differences between PEDOT:PSS and perovskite materials, such as conductivity, work function and surface morphology. This review summaries recent efficient strategies to improve the stability of PEDOT:PSS in PSCs and discusses the underlying mechanisms. This review is expected to provide helpful insights for further increasing the stability of PSCs based on commercial PEDOT:PSS.

It is still a challenge to explore self-healable and reprocessable polysiloxane elastomer with improved mechanical strength and superior transparency. In this work, a self-healable and reprocessable polysiloxane elastomer with fine mechanical strength and optical transparency is facilely constructed by thiol-ene photopolymerization between thiol-functionalized silicone resin (MDT-SH) and vinyl-terminated polysiloxane and diboronic ester. The UV radiation intensity, molecular structure of MDT-SH and thiol/ene molar ratio play an important role in the thiol-ene photopolymerization and mechanical properties of polysiloxane elastomer. The damaged elastomer is completely repaired at 80 °C after 3 h, and the waste elastomer can be reprocessed into new items with 90% recovery of mechanical property. More importantly, its transmittance at 400–800 nm is higher than 95%, and it is almost unaffected by the healing process. This self-healable, transparent and tough polysiloxane elastomer has the potential to develop flexible electronics and wearable devices.

Optical properties and morphology of polymer films based on diglycidyl ether of bis-phenol A and on natural compound 3,5,7,30 ,40 epentahydroxyflavone (quercetin) using UVevis spectroscopy, scanning electron microscopy and powder X-ray diffraction methods have been investigated. The influence of ordering degree of the polymers, flexibility of their chains, intensity of intermolecular interaction between the quercetine moieties on the polymers' morphology was discussed. It is shown that all the quercetine-based polymer films are transparent at visible and near infrared regions beginning from 420 to 450 nm. Low optical transparency in the short-wavelength region can be explained the self-absorption of quercetin moieties in the polymer chains Досліджено оптичні властивості та морфологію полімерних плівок на основі дигліціділового ефіру біс-фенолу А та природного з'єднання 3,5,7,3′,4′–пентагідроксифлавону (кверцетину) за допомогою УФ–віс-спектроскопії, скануючої електронної мікроскопії та порошкової дифракції рентгенівських променів. Розглянуто вплив ступеня упорядкування полімерів, гнучкості їх ланцюгів, інтенсивності міжмолекулярної взаємодії між кверцетинними муетами на морфологію полімерів. Показано, що всі полімерні плівки на основі кверцетину прозорі у видимих і ближніх інфрачервоних областях, починаючи від 420 до 450 нм. Низькою оптичною прозорістю в короткохвильової області можна пояснити самопоглинання кверцетинових муетів в полімерних ланцюгах.

Highly refractive and transparent polyphosphonates with varying aromatic backbones have been synthesised by polycondensation of phosphonic dichlorides and diols, significantly expanding the reported scope of these intrinsic high refractive index polymers. The polyphosphonates display excellent thermal properties, with thermal stability up to 450 °C and tuneable glass transition temperatures ranging from 41 to 214 °C by terminating the polymer with different alcohols. The polymers synthesised also possess excellent optical properties, with low UV cut off points and high refractive indices up to 1.66, the highest reported for this type of polymer. We also report Abbe numbers for this class of polymers for the first time; all are high (>22), making these polymers excellent potential candidates for a range of optical applications.

The structure-property relationship of partially aliphatic copolyimides has been studied for the development of flexible, transparent polyimide films. A structurally rigid cycloaliphatic dianhydride and three aromatic dianhydrides having different structural flexibility were reacted with 4,4′-oxydianiline to prepare the copolyimides. In order to control the balance between aromaticity and aliphaticity and between rigidity and flexibility of the copolyimides, the molar ratio of the dianhydrides was varied. Polyimide properties such as viscosity, solubility, optical transparency, color, dielectric constants, film flexibility and thermal stability are influenced by aromaticity/aliphaticity and/or flexibility/rigidity of the monomers.

This paper shows that tailorable polymeric scaffolds on a molecular scale could be achieved through the ring opening reaction of a three-membered N-heterocyclic compound, aziridine. Aziridine is incorporated into an elastomeric polymer backbone (here, PDMS) through Pt(0)-catalyzed hydrosilylation, retaining attractive features such as optical transparency and elastic properties compared to conventional PDMS. The resulting aziridine-containing PDMS is chemoselectively and regio-specifically post-modified through an orthogonal ring opening reaction of the aziridine and takes advantage of the wide substrate scope of aziridine chemistry.

This communication reports the synthesis of CC functionalized oleophilic carbon dots (FOCDs). The as-prepared FOCDs could enhance the stability of optical polymer against UV aging while no obvious effect on optical transparency.

In order to obtain highly optical transparency polyimides, two novel aromatic diamine monomers containing pyridine and kinky structures, 1,1-bis[4-(5-amino-2-pyridinoxy)phenyl]diphenylmethane (BAPDBP) and 1,1-bis[4-(5-amino-2-pyridinoxy)phenyl]-1-phenylethane (BAPDAP), were designed and synthesized. Polyimides based on BAPDBP, BAPDAP, 2,2-bis[4-(5-amino-2-pyridinoxy)phenyl]propane (BAPDP) with various commercial dianhydrides were prepared for comparison and structure-property relationships study. The structures of the polyimides were characterized by Fourier transform infrared (FT-IR) spectrometer, wide-angle X-ray diffractograms (XRD) and elemental analysis. Film properties including solubility, optical transparency, water uptake, thermal and mechanical properties were also evaluated. The introduction of pyridine and kinky structure into the backbones that polyimides presented good optical properties with 91–97% transparent at 500 nm and a low cut-off wavelength at 353–398 nm. Moreover, phenyl pendant groups of the polyimides showed high glass transition temperatures (T g) in the range of 257–281 °C. These results suggest that the incorporating pyridine, kinky and bulky substituents to polymer backbone can improve the optical transparency effectively without sacrificing the thermal properties.