Host Polymer Research Articles

Material Aspects of Thin-Film Composite Membranes for CO2/N2 Separation: Metal–Organic Frameworks vs. Graphene Oxides vs. Ionic Liquids

Thin-film composite (TFC) membranes containing various fillers and additives present an effective alternative to conventional dense polymer membranes, which often suffer from low permeance (flux) and the permeability–selectivity tradeoff. Alongside the development and utilization of numerous new polymers over the past few decades, diverse additives such as metal–organic frameworks (MOFs), graphene oxides (GOs), and ionic liquids (ILs) have been integrated into the polymer matrix to enhance performance. However, achieving desirable interfacial compatibility between these additives and the host polymer matrix, particularly in TFC structures, remains a significant challenge. This review discusses recent advancements in TFC membranes for CO2/N2 separation, focusing on material structure, polymer–additive interaction, interface and separation properties. Specifically, we examine membranes operating under dry conditions to clearly assess the impact of additives on membrane properties and performance. Additionally, we provide a perspective on future research directions for designing high-performance membrane materials.

Discrete Macrocyclic Polymer Hosts-Induced Cascade Luminescence Enhancement and Application in Bioimaging.

The integration of polymers, supramolecular macrocycles and aggregation-induced emission (AIE) molecules provides numerous possibilities for constructing various functional supramolecular systems. Herein, we constructed supramolecular assembled systems based on discrete macrocyclic polymer hosts via the cooperation of hydra-headed macrocycles containing two or three pillar[5]arene units (defined as P2, P3), the block polymer F127 and AIE molecules (alkyl-cyano modified tetraphenylethene, alkyl-triazole-cyano modified 9,10-distyrylanthracene, defined as TPE-(CN)4 and DSA-(TACN)2). Compared with the binary assembly between hydra-headed hosts or F127 and AIE molecules, cascaded supramolecular assembly-induced emission enhancement (SAIEE) in aqueous solution was achieved in discrete macrocyclic polymer-based supramolecular assembled systems. Considering the cascaded SAIEE performance, we have successfully applied discrete macrocyclic polymer-based supramolecular assembled systems to bioimaging and constructed an artificial light-harvesting system (LHs) to explore more potential applications. The supramolecular assembly form of discrete macrocyclic polymers hosts and AIE molecules proposed in this work provides new inspiration for the construction and application of high-performance supramolecular luminescent systems.

Cellulose acetate-based polymer electrolyte for energy storage application with the influence of BaTiO3 nanofillers on the electrochemical properties: A progression in biopolymer-EDLC technology

The bio-based solid polymer electrolyte serves as a promising choice for the next generation of energy storage devices to meet the requirement of green chemistry. In the current research, a green plasticized magnesium ion-conducting biopolymer electrolyte was developed using simple solution casting method for Electric Double Layer Capacitors (EDLC) applications. The biopolymer Cellulose Acetate (CA) as the host polymer, with varying concentrations of BaTiO3 as the nanofiller, Mg(CF3SO3)2 as the ionic dopant, and PEG as the plasticizer. A 2 wt% addition of BaTiO3 to the biopolymer electrolyte exhibits maximum conductivity measuring 2.4 × 10−3 S/cm. Linear Sweep Voltammetry (LSV) analysis demonstrates maximum stability voltage of 3.51 V. The ionic transference number (tion) and (tMg2+) were determined to be 0.99 and 0.41 respectively. The fabricated EDLC device with the same electrolyte showed polarisation curve without any noticeable peaks in the Cyclic Voltammetry (CV) plot, indicating no redox reactions occurring at the electrode-electrolyte interface. Galvanostatic Charge Discharge (GCD) results showed excellent coulombic efficiency, stability and Energy Density and Power Density performance over 2000 cycles. The incorporation of BaTiO3 into biopolymer membranes presents a viable approach towards sustainable energy storage solutions by enhancing the energy storage capacity of EDLC devices.

Effect of succinonitrile on the structural, ion conductivity, and dielectric properties of PVDF‐HFP based solid polymer electrolytes

AbstractA detailed account of the poly(vinylidene difluoride‐co‐hexafluoropropylene) (PVDF‐HFP)/succinonitrile (SN)/lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) based solid polymer electrolytes (SPEs) of various compositions is reported. SN is incorporated as plasticizer, while LiTFSI is employed as the source of lithium ions. Fourier transfer infrared (FTIR) spectroscopy reveals the formation of polar and electroactive γ crystal phase by PVDF in pristine PVDF‐HFP and the prepared SPE films. FTIR further confirms the interaction between the host polymer and the salt and between the salt and the plasticizer. The interaction between the salt and plasticizer suggests that SN not only offers the plasticization effect but also facilitates salt dissociation. The ion conductivity increases with increasing salt content up to 20 wt% but beyond that concentration a decline in ion conductivity is observed, which could be attributed to the ion pair association or cluster formation due to the excess salt concentration that reduces the availability of free ions and ultimately leads to the reduction in ion conductivity. After including SN in the SPE formulation, electrochemical impedance spectroscopy reveals a substantial increase in room temperature ion conductivity of the SPE from ~1.08 × 10−5 S cm−1 for pristine SPE with 20 wt% salt to ~2.7 × 10−4 S cm−1 for plasticized SPE with 40 wt% SN and 20 wt% salt. This is attributed to the plasticizing effect of SN that enhances ion mobility through the matrix and to the increased charge carrier concentration (SN facilities salt dissociation). The fabricated SPEs exhibit a significant enhancement in ion conductivity with increasing temperature and the maximum ion conductivity of 1.1 × 10−3 S cm−1 is attained at 393 K by plasticized SPE with 40 wt% SN content. The ion conductivity of all the prepared SPEs follows the temperature dependent Arrhenius behavior, suggesting the thermally activated ion hopping mechanism of ionic conduction. Further, the plasticized SPEs display near unity ion transference number indicating the predominance of the ionic mode of conduction. The dielectric and electric modulus analysis reveal a faster relaxation phenomenon and hence higher ion conductivity of the prepared SPEs with increasing salt and plasticizer content.

The Transformative Role of Nano-SiO2 in Polymer Electrolytes for Enhanced Energy Storage Solutions

In lithium–polymer batteries, the electrolyte is an essential component that plays a crucial role in ion transport and has a substantial impact on the battery’s overall performance, stability, and efficiency. This article presents a detailed study on developing nanostructured composite polymer electrolytes (NCPEs), prepared using the solvent casting technique. The materials selected for this investigation include poly(vinyl chloride) (PVC) as the host polymer, lithium bromide (LiBr) as the salt, and silica (SiO2) as the nanofiller. The addition of nano-SiO2 dramatically enhanced the ionic conductivity of the electrolytes, with the highest value of 6.2 × 10−5 Scm−1 observed for the sample containing 7.5 wt% nano-SiO2. This improvement is attributed to an increased amorphicity resulting from the interactions between the polymer, salt, and filler components. A structural analysis of the prepared NCPEs using X-ray diffraction revealed the presence of both crystalline and amorphous phases, further validating the enhanced ionic transport. Additionally, the thermal stability of the NCPEs was found to be excellent, withstanding temperatures up to 334 °C, thereby reinforcing their potential application in lithium–polymer batteries. This work explores the electrochemical performance of a fabricated lithium-ion-conducting primary electrochemical cell (Zn + ZnSO4·7H2O|PVC: LiBr: SiO2|PbO2 + V2O5), which demonstrated an open circuit voltage of 2.15 V. The discharge characteristics of the fabricated cell were thoroughly studied, showcasing the promising potential of these NCPEs. With the support of superior morphological and electrical properties, as-prepared electrolytes offer an effective pathway for future advancements in lithium–polymer battery technology, making them a highly viable candidate for enhanced energy storage solutions.

Judd-Ofelt analysis and temperature sensing properties of polyethylmethacrylate (PEMA) networks doped with CdNb2O6: Er3+/Yb3+ phosphors

Research on the sensitivity of temperature measurements and optical thermometry involving rare earth ions has been an area of interest in the field of photonics and materials science. Introducing polymer networks as a new host material has an important role due to their properties including a versatile and stable environment for rare earth ions and rapid response in temperature detection. In this work, linear and crosslinked polyethylmethacrylate (PEMA) networks doped with Er3+/Yb3+ (1.5 mol % Er3+, 2 mol% Yb3+) synthesized by free-radical crosslinking polymerization with 0.1 EMA (weight %) at 60 °C were used to investigate direct and indirect optical bandgap energies and Urbach energy from UV–Visible spectra. The Judd-Ofelt (JO) approach was employed to analyze parameters Ωt (t = 2,4,6), spontaneous transition probabilities (Α), branching ratios (β) and radiative lifetimes (τ) as a function of linear and crosslinked PEMA doped nano-crystalline CdNb2O6: Er3+/Yb3+. The stimulated emission cross-sections of the transitions 2H11/2⟶4I15/2, 2S3/2⟶4I15/2 and 2F9/2⟶4I15/2 of Er3+/Yb3+ were calculated by two different methods; Fuchtbauer-Ladenburg formula and modified theory, respectively. The gain bandwidth cross-section product for the 2H11/2⟶4I15/2 was found to be 162.06. 10−28cm3, 260.94. 10−28cm3 and 461.20. 10−28cm3 of Er3+/Yb3+ embedded in linear, low and high crosslinked PEMA samples, respectively. JO parameters and stimulated emission cross-sections increased; therefore, radiative lifetimes decreased by increasing crosslinking content. In addition, the temperature dependence of upconversion (UC) luminescence was monitored under 975 nm excitation. The fluorescence intensity ratio (FIR) method examined the temperature sensing under two thermally coupled levels at 525 and 548 nm. The maximum sensitivities obtained from the FIR technique within the 300–650 K temperature range shifted to lower temperatures with increasing crosslinker content. Hence, linear and crosslinked polymer hosts doped rare-earth ions can be candidates for remote temperature sensors across various fields.

Fabrication and Properties of in Situ Cross‐Linked Supramolecular Gel Based on Host‐Guest Interaction

AbstractWater‐cut control is critical to efficient reservoir development. In this investigation, a host‐guest inclusion polymer gels system with self‐assembly features was constructed stemming from the host‐guest recognition mechanism. Subsequently, the elements affecting polymer viscosity were discussed. Eventually, the injectivity and plugging performance of the host‐guest inclusion system were measured by core displacement tests. The results indicated that the optimum synthesis temperature of the host polymer and guest polymer were 30 °C and 40 °C, separately, and the optimum total monomer content should be 20 wt%. The polymer system had excellent thickening properties and shearing resistance resulting from host‐guest inclusion interaction and physical hydrophobic association. Meanwhile, it had better plugging performance than host polymer or guest polymer alone. This profile control agent system provides a novel method for settling deep profile control in oilfields.

Enhanced Dielectric, Thermal, Energy Storage, Quality Factor, Impedance, and Conductivity Properties of Novel PVDF/PAN/ZrO2 Polymer Nanocomposites for Flexible Electronics Applications

ABSTRACTIn this study, novel polymer nanocomposite films based on polyvinylidene fluoride/polyacrylonitrile/zirconium dioxide (PVDF/PAN/ZrO2) were prepared using a solution casting technique. The structural modifications and morphological properties were analyzed by x‐ray diffraction (XRD) and high resolution scanning electron microscopy (HRSEM). The obtained results verified the filler‐polymer interactions and uniform dispersion of the ZrO2 filler in the host polymers (PVDF and PAN). Thermal stability of up to 46% leftover residue for 30% ZrO2 nano‐filler loading in the blend polymer nanocomposite was analyzed by thermogravimetric analysis (TGA). The dielectric properties such as dielectric constant and dielectric loss values and impedance, Q‐factor, and AC conductivity were analyzed using an impedance analyzer. The decrement in impedance with increasing nano‐filler content with improved dielectric, thermal, Q‐factor, energy density and conductivity properties signifies the prepared novel PVDF/PAN/ZrO2 polymer nanocomposite as an effective material for flexible electronics applications.

Ion Conduction Mechanism in Polymer Blend Electrolyte Films

AbstractThis paper presents the development of the blend polymer solid electrolyte films (BPSE) for potential applications in electrochemical devices. Two host polymers, polyvinyl alcohol (PVA) and polymethyl methacrylate (PMMA), along with the salt KI, are employed to create the solid polymer electrolytes (SPEs). The synthesis involves varying the weight percentage of salt within the SPEs to investigate its impact on the material properties. Conductivity measurements are conducted using AC impedance spectroscopy, unveiling the conductivity behavior of the BPSEs. Additionally, surface morphology is characterized using polarized optical microscopy (POM) at 10 pixel resolution, offering a detailed examination of the film's microstructure. This comprehensive study not only contributes to the understanding of the fundamental properties of BPSEs but also opens avenues for their utilization in various electrochemical applications.

Impact of TBAI Doping on the Optical and Dielectric Features of PVC/MoO3/NiMoO4/PANI Polymer Composite for Optoelectronic and Energy Storage Applications

Poly (vinyl chloride, PVC)/MoO3/NiMoO4/polyaniline (PANI)/x wt% tetrabutylammonium iodide (TBAI) polymers were formed using casting and hydrothermal methods. The present study examined the nanocomposites’ structural, electrical, and optical features comprising PVC/MoO3/NiMoO4/PANI/x wt%TBAI polymers. X-ray diffraction and scanning electron microscopy were used to investigate the structure and morphology of different samples. The influence of different amounts of TBAI on the linear and nonlinear optical features of PVC/MoO3/NiMoO4/PANI/x wt%TBAI polymers was explored. Adding MoO3/NiMoO4/PANI.TBAI reduced the direct and indirect optical band gaps to their minimum values (3.88, 3.04) eV and (3.58, 2.13) eV, respectively. Doped polymer with MoO3/NiMoO4 has the highest refractive index value. Only PVC filled with MoO3/NiMoO4 exhibits the highest non-linear optical parameters within the visible range. The fluorescence intensity and emitted colors influenced by the kind of dopant. The dielectric constant and ac conductivity values of the host polymer were affected by the amount of TBAI. The maximum energy density value was observed in PVC/MoO3/NiMoO4/PANI/10 wt%TBAI polymer. The Cole-Cole plot demonstrated an irregular shift for doped samples relative to the undoped. The obtained results nominated the nanocomposite films of PVC/MoO3/NiMoO4/PANI/x wt%TBAI to be used in diverse electric and optoelectrical applications.

Piezoelectric Energy Harvesting in Poly(vinylidene Fluoride‐co‐hexafluoropropylene)/Barium Titanate Nanofibers and Ultrasonic Assisted Piezocatalytic Degradation of Ciprofloxacin

AbstractAn innovative approach has been adopted through the synthesis of a cost‐effective ferroelectric host polymer, which was integrated with Barium Titanate (BaTiO3) to develop an efficient electrospun Polyvinylidene Fluoride‐Hexafluoropropylene/BaTiO3 (PVdF‐HFP/BaTiO3) nanocomposite (PBT), designated for energy harvesting and piezocatalytic applications. FT‐IR affirmed the existence of the crystalline β‐phase within the nanofibers. SEM images showed that nanofiber diameter decreases as applied voltage is increased in electrospinning. The BaTiO3 nanoparticles were scattered evenly in PBT, but at lower voltages, they aggregate. PBT showed enhanced piezoelectric performance under higher voltage conditions, registering a maximum piezoelectric output of ~7.7 V and an output current of 0.77 μA. Moreover, the composite exhibited a power density of 14.15 mW/m2 at a load resistance of 20 MΩ. Fabricated piezoelectric nanogenerator (PENG) demonstrated practical utility in flexible electronics, notably in charging capacitors of 0.47 μF and 1 μF. Additionally, the piezocatalytic degradation of the antibiotic ciprofloxacin (CIP) was effectively achieved using the electrospun nanofibers, with an impressive degradation rate of up to 99.6 % within 30 minutes under acidic conditions, and the material displayed notable reusability, maintaining up to 95.5 % efficiency after five cycles. DFT calculations and COMSOL simulations alongside a comparative examination of the electronic properties of PBT.

Enabling robust near-infrared afterglow polymers through cascade energy transfer

Near-infrared afterglow materials, which can significantly reduce background fluorescence and improve penetration in living organisms, are vital for precision imaging. However, the practicability of near-infrared afterglow materials has been hindered by their short lifetime and low luminescence quantum efficiency. Herein, we propose an effective strategy for doping water-soluble afterglow polymer host materials with fluorescent dyes, leveraging the step-by-step Förster energy transfer principle to realize near-infrared afterglow. Benefiting from the ultralong lifetime of 4.2 s and high quantum efficiency of 20.1 % for the blue host PAMCz as well as efficient cascade energy transfer efficiency of 83.3 %, the developed NIR afterglow exhibits luminescence peaked at 750 nm, a lifetime of 1.4 s, and a quantum efficiency of 17.1 %. A successful demonstration of near-infrared afterglow biological imaging with a penetration depth of 3.4 mm and signal-to-background ratio of 48.3, has been established. These advancements expand the scope of near-infrared afterglow materials by combining an ultralong lifetime with high quantum efficiency, providing a roadmap for designing robust near-infrared materials.

Intramolecular Through‐Space Charge‐Transfer Effect for Achieving Room‐Temperature Phosphorescence in Amorphous Film

AbstractOrganic emitters that exhibit room‐temperature phosphorescence (RTP) in neat films have application potential for optoelectronic devices, bio‐imaging, and sensing. Due to molecular vibrations or rotations, the majority of triplet excitons recombine rapidly via non‐radiative processes in purely organic emitters, making it challenging to observe RTP in amorphous films. Here, a chemical strategy to enhance RTP in amorphous neat films is reported, by utilizing through‐space charge‐transfer (TSCT) effect induced by intramolecular steric hindrance. The donor and acceptor groups interact via spatial orbital overlaps, while molecular motions are suppressed simultaneously. As a result, triplets generated under photo‐excitation are stabilized in amorphous films, contributing to phosphorescence even at room temperature. The solvatochromic effect on the steady‐state and transient photoluminescence reveals the charge‐transfer feature of involved excited states, while the TSCT effect is further experimentally resolved by femtosecond transient absorption spectroscopy. The designed luminescent materials with pronounced TSCT effect show RTP in amorphous films, with lifetimes up to ≈40 ms, comparable to that in a rigid polymer host. Photoluminescence afterglow longer than 3 s is observed in neat films at room temperature. Therefore, it is demonstrated that utilizing intramolecular steric hindrance to stabilize long‐lived triplets leads to phosphorescence in amorphous films at room temperature.

Spectroscopic study of wemple-didomenico empirical formula and taucs model to determine the optical band gap of dye-doped polymer based on chitosan: Common poppy dye as a novel approach to reduce the optical band gap of biopolymer

This study investigates the effect of a natural dye extracted from common poppy (Papaver rhoeas) waste flowers on the optical properties of chitosan (CS) films. The extraction of natural dyes from waste flowers can be considered a new field for research in green chemistry. CS films are flexible and biodegradable but have low optical activity and band gap, limiting their applications in optical devices. The doped CS polymer with different concentrations of Papaver rhoeas dye exhibited enhanced optical properties. Also, 30 % glycerol was added as a plasticizer to omit film brittleness. The FTIR examinations is helpful to propose a mechanism that explains the interaction of the dye with the host polymer. The UV–vis spectroscopic examination establish that the optical characteristics of the films can be modified by adjusting the dye concentration. Furthermore, optical absorption properties are described using the Tauc non-direct transition model, revealing an approximate optical band gap of 1.64 eV. This band gap defines the energy required for electron transitions, elucidating the material’s electronic characteristics. The extinction coefficient (k) and refractive index (n) of the CS-doped films’ shows a dispersion behavior at visible regions of EM radiation. The Wemple-DiDomenico single oscillator model was used to investigate the n dispersion and determine the oscillator energy equivalent to the optical band gap. Additionally, calculations have been performed on optical dielectric properties and optical conductivity. The Urbach energy was measured and used to detect the structure of the films. The findings underscore the potential applications of these natural dye-doped CS films in eco-friendly materials and optical devices.

Black phosphorus film as Q-switcher in neodymium-doped fiber laser

We present the successful development of a 1089.4 nm Q-switched laser employing a neodymium-doped fiber (NDF) as the active fiber and black phosphorus (BP) as the saturable absorber (SA). The BP SA was fabricated by inserting BP compound into a polyvinyl alcohol (PVA) host polymer, exhibiting a saturable absorption of 2.8 %. Integrated into an NDFL ring cavity, the SA modified the cavity loss, enabling the production of Q-switched pulses. With an increase in the 808 nm pumping power from 108.6 to 155.9 mW, the laser output pulse duration decreased from 3.74 to 3.54 μs, while the repetition rate improved from 40.6 to 51.0 kHz. The laser demonstrated a stable pulse train output, with a fundamental frequency signal to background noise ratio of 45.78 dB. The highest pulse energy of 1.3 nJ was recorded at 155.9 mW pump power. To the best of our knowledge, this represents the first utilization of BP as a SA or Q-switcher within an NDFL cavity.

Polyvinylidene fluoride‐co‐hexafluoropropylene polymer gel electrolyte‐enabled dye‐sensitized solar cell for sustainable energy

AbstractDeveloped specifically to address leakage and stability concerns inherent in liquid electrolytes, this study presents a significant advancement in polymer gel electrolyte (PGE) formulation by combining potassium iodide (KI), ammonium iodide (AI) salts, and polyvinylidene fluoride‐co‐hexafluoropropylene (PVDF‐co‐HFP) as a host polymer. The tape casting method was employed to deposit the standard TiO2 paste as the photoanode and platinum paste as the counter electrode. N3 dye was incorporated, and PVDF‐co‐HFP was used as the PGE between the electrodes. The conductivity of PGE was measured by using a digitized conductivity meter. The quasi solid‐state solar cell (QS‐DSSC) assembled using single salts (KI, and AI), and mixed cations PGE was examined via photocurrent–voltage characteristics, and electrochemical impedance spectroscopy. The augmented ionic conductivity directly influences the efficiency of DSSCs. Notably, incorporating a mixed salt (KI + AI) within the PGE enhances ionic conductivity compared to single‐salt‐based counterparts. The resultant DSSCs using mixed salt PGE exhibit a Voc of 600 mV, Jsc of 1.01 mA/cm2, FF of 0.6089, and an efficiency of 0.369%, outperforming those using KI or AI. This highlights the perceptible advantages of employing this innovative electrolyte composition to enhance solar cell performance.

Vanadium Aluminium Carbide Saturable Absorber in Passively Q-switched Erbium-doped Fibre Laser

Following the success of graphene saturable absorber (SA) in the development of passively Q-switched fibre lasers within the past decade, research on two-dimensional (2-D) nanomaterials SAs have shown a significant rise in demands. Nonetheless, there have been several unavoidable setbacks due to the nature of certain nanomaterials, in terms of optical, electronic and physical properties up until the reveal of transition metal carbide (MXene) nanomaterials. These metal-ceramic materials exhibit excellent optical and electrical properties as well as outstanding physical characteristics. However, their synthesis processes involve hazardous and highly acidic chemicals, which drove the researchers to adopt their precursors— ternary nanolaminate carbides (MAX phases) nanomaterials with a simpler and more exquisite fabrication process. This paper presents a passively Q-switched erbium-doped fibre laser (EDFL) with the utilisation of a MAX phases nanomaterial, vanadium aluminium carbide (V4AlC3) as SA. The V4AlC3 SA was fabricated through the solution casting technique with polyvinyl alcohol as the host polymer. The V4AlC3 SA was then integrated into a passively Q-switched EDFL configuration. The performance of V4AlC3 SA as a Q-switcher was determined with the assistance of an optical spectrum analyser (OSA), mixed domain oscilloscope (MDO), and optical power meter (OPM). The maximum pulse repetition rate and minimum pulse width were 54.37 kHz and 6.43 ms, respectively. The minimum repetition interval was 18.33 ms and the duty cycle was 0.326. The highest attained output power was 2.5 mW. Through calculation, the maximum pulse energy and peak power were identified as 45.246 nJ and 6.602 mW. The extensively gigantic pulses in nanosecond duration at 1560.16 nm was accomplished by the V4AlC3 SA, thus proving its stability which also signifies good applications especially those acquiring stable high power and energy.

Fabrication of free standing nano-SiO2 incorporated solid polymer electrolytes based on poly(vinyl) chloride

AbstractFree standing nanocomposite polymer electrolytes (NCPEs) based on the polymer host poly(vinyl) chloride (PVC) were successfully prepared using the solution casting technique. Lithium nitrate (LiNO3) and nano-sized silica (SiO2) (< 100 nm) were employed as the electrolyte and filler, respectively. Impedance studies revealed a maximum ionic conductivity value of 1.226 × 10−4 S/cm at room temperature for the PVC/LiNO3 with 5 wt.% nano-SiO2. X-ray diffraction (XRD) analysis verified the sample’s amorphous nature. Dielectric permittivity and relaxation time values were consistent with impedance results. Additionally, parameters such as diffusion coefficient, mobile concentration, and mobility were evaluated for the prepared samples. Differential scanning calorimetry (DSC) studies confirmed a change in glass transition temperature (Tg) of PVC/LiNO3/SiO2 sample. The scanning electron micrograph (SEM) images revealed a honeycomb morphology, indicating ease of Li+ ion transportation.

Time-Dependent Color-Changing Room-Temperature Phosphorescence Materials with Mutual Achievement between Guest and Host Molecules.

Host-guest doping strategy has gradually become the mainstream in constructing organic room-temperature phosphorescence (RTP) materials. The two-component doped system typically emits monochromatic phosphorescence dominated by the guest molecule, which also means that the intrinsic phosphorescence emission of the host molecule is not well utilized. In this work, a time-dependent color-changing RTP material is constructed based on host-guest doped system, in which the initial yellow phosphorescence stems from the isoquinoline-pyrazole guest and the final cyan phosphorescence originates from the intrinsic emission of the polymer host. The phenomenon of the strong interaction between host and guest molecules leading to their respective intrinsic phosphorescence provides new design inspiration for designing and developing two-component doped materials with RTP properties of color variation over time.

Modulation between capacitor and conductor for a redox-active 2D bis(terpyridine)cobalt(II) nanosheet via anion-exchange

Ionic polymers are intriguing materials whose functionality arises from the synergy between ionic polymer backbones and counterions. A key method for enhancing their functionality is the post-synthetic ion-exchange reaction, which is instrumental in improving the chemical and physical properties of polymer backbones and introducing of the functionalities of the counterions. Electronic interaction between host polymer backbone and guest ions plays pivotal roles in property modulation. The current study highlights the modulation of responses to external electric field in cationic bis(terpyridine)cobalt(II) polymer nanofilms through anion-exchange reactions. Initially, as-prepared chloride-containing polymers exhibited supercapacitor behaviour. Introducing anionic metalladithiolenes into the polymers altered the behaviour to either conductive or insulative, depending on the valence of the metalladithiolenes. This modulation was accomplished by fine tuning of charge-transfer interactions between the bis(terpyridine)cobalt(II) complex moieties and redox-active anions. Our findings open up new avenue for ionic polymers, showcasing their potential as versatile platform in materials science.