Solution Casting Research Articles

Physicochemical characterization, antioxidant and antimicrobial activities of chitosan film containing Sauropus androgynus extract prepared by solution casting and supercritical impregnation

Sauropus androgynus extract (SAE) was incorporated with chitosan to produce solution casting film (SAE-SCF) and supercritical impregnation film (SAE-SIF). The physicochemical characterization and biological activities of SAE-SCF and SAE-SIF films were evaluated and compared. In terms of total phenolic content (TPC) and total flavonoids content (TFC), SAE-SCF (TPC: 49.14–71.88 mg GAE/g; TFC: 32.73–57.05 mg QE/g) obtained higher results than SAE-SIF (TPC: 8.40–18.90 mg GAE/g; TFC: 1.97–12.34 mg QE/g). FTIR results confirmed the interaction between SAE-active compounds and chitosan via hydrogen bonding and electrostatic interaction. Due to the formation of hydrogen bonding or cross-linking effects in SAE-chitosan film, the light opacity (1.748–3.375 AU), water vapor permeability (2.87–3.92 × 10−11 g m−1.s−1.Pa−1), and mechanical properties (tensile strength; 8.65-15.72 MPa; elongation at break: 7.95–13.25%) were enhanced compared to neat chitosan film, with SAE-SCF showing higher performances than SAE-SIF. The antioxidant activities of both films were evaluated using ABTS (IC50: 55.98–97.85 μg/mL) and DPPH assays (IC50: 53.68–143.04 μg/mL), with SAE-SCF showing higher inhibition of free radicals than SAE-SIF. The ferric-reduction power was recorded (28.17–94.95 Trolox μmol/mL), and SAE-SCF achieved a higher reduction power than SAE-SIF. In antimicrobial analysis, SAE-SCF demonstrated the best reduction of viable growth of all tested foodborne microorganisms. Overall, the functional performance of SAE-SCF is better than SAE-SIF in all tested aspects. The results revealed the potential of SAE-SCF to be utilized as a food packaging material.

Synthesis of MnO@Fe2O3 core-shell doped PVA/PVP polymeric nanocomposites for electronic and optoelectronic devices: Mechanical, electrical, and optical properties

Abstract The aqueous solution cast method was utilized to create biodegradable nanocomposite of polymers (PNC) films from a poly (vinyl alcohol) / poly (vinyl pyrrolidone) blend (70/30 wt%) and MnO@Fe2O3 nFs. The dislocation density, particle size, and interplanar distance were all calculated. The PNC films' surface shape changes from smooth to porous and somewhat rough because of the nanosized MnO@Fe2O3 particles' dispersion in the blend matrix, which diminishes the blended crystallites' size. The composite film's tensile strength increased from 9.45 MPa for the pure (PVA-PVP) film to 22.35 MPa due to the addition of 6 wt% MnO@ Fe2O3. The optical band gap decreases from 5.26 and 4.84 eV for pure (PVA/PVP) blend direct and indirect energy band gap to 5.18 and 4.71 eV for comparable values of 6wt% MnO@Fe2O3 nFs. Up to 6 wt% MnO@Fe2O3 concentration, PNC films' dielectric permittivity first declines, but it is substantially identical to the pure polymer blend matrix. The PNC sheet's dielectric permittivity increases nonlinearly with temperature, although its DC conductivity follows the Arrhenius law. Laser power was attenuated by (PVA- PVP)/MnO@Fe2O3 for both He-Ne and solid-state green laser beams. When the MnO@Fe2O3 concentration in the blend matrix rises to 6 wt%, the output power for lasers with 532 nm and 650 nm wavelengths drops from 5.49 to 2.4 mW and 19.8 to 9.4 mW, respectively. The findings suggest that nanocomposites exist and are widely recommended for optoelectronics, microelectronics, radiation detection, and several other uses.

Homogeneous CaAlg/PES hybrid ultrafiltration membranes prepared with in situ ionic crosslinking and phase inversion method

Calcium alginate hydrogel/polyethersulfone (CaAlg/PES) hybrid membranes were synthesized via combining in situ ion crosslinking with phase conversion method. Once the Sodium alginate (NaAlg) uniformly dispersed in the casting solution contacted with Ca2+ dissolved in coagulation bath solution in the phase conversion membrane formation process, nanoscale CaAlg hydrogel was in situ formed through ion exchange and evenly dispersed in the membrane matrix. FT-IR and XPS were adopted to confirm the formation of CaAlg hydrogel distributed in PES membrane matrix. SEM, AFM, BET analysis and contact Angle analyzer were all used to characterize the surface changes of morphology, roughness and hydrophilicity in detail. Specific separation performance was also evaluated and compared by cross-flow ultrafiltration tests. Comprehensive analysis of the measured properties of all obtained membranes, when the content of NaAlg was 1.5 wt%, the CaAlg/PES hydrogel membrane M32 had the most excellent performance. The pure water flux increased from 1967 to 2193 L/m2hMPa, rejection rate of BSA was up to 99.87 %, and RFR value was almost 76.83 % after 4 cycles BSA filtration. XPS characterization of the membrane after filtration for 72 hours showed that the retention rate of Ca (2 P) reached 95 %, which further proved the stability of the membrane operation.

Tannic acid-reinforced soy protein/oxidized tragacanth gum-based multifunctional hemostatic film for regulation of wound healing

With recent advances in the field of tissue engineering, composite films with biocompatibility, antimicrobial properties, and wound healing properties have gained potential applications in the field of wound dressings. In this research work, composite films of soy protein (S)/oxidized tragacanth gum (G) were successfully made using the solution casting process. The metal-organic framework containing curcumin (MOF) with concentrations of 5 and 10 wt% and tannic acid (TA) with concentrations of 6 and 12 wt% were entered into the polymer film. Surface morphology with scanning electron microscope (FE-SEM), thermal stability, mechanical properties, chemical structure, antioxidant, water absorption, cell viability, antibacterial activity, and biodegradability of the prepared films were investigated in laboratory conditions. In addition, the toxicity of the films in the cell environment was investigated, and the results showed that cell growth and proliferation improved in the presence of the prepared films, especially films SG/MOF10/TA6 and SG/MOF10/TA12 due to the presence of TA and MOF containing curcumin. Also, the antibacterial activity of the films showed that the presence of tannic acid and curcumin in the structure of the films increases their ability against pathogens. According to the obtained results, the newly produced nanocomposite film (SG/MOF10/TA12) has a high potential to be used for wound dressing due to its favorable characteristics and was considered the optimal film.

Metal-Ligand Bonds Based Reprogrammable and Re-processable Supramolecular Liquid Crystal Elastomer Network.

Dynamic covalent bonds endow liquid crystal elastomers (LCEs) with network rearrangeability, facilitating the fixation of mesogen alignment induced by external forces and enabling reversible actuation. In comparison, the bond exchange of supramolecular interactions is typically too significant to stably maintain the programmed alignment, particularly under intensified external stimuli. Nevertheless, the remaking and recycling of supramolecular interaction-based polymer networks are more accessible than those based on dynamic covalent bonds, as the latter are difficult to completely dissociate. Thus, preparing an LCE that possesses both supramolecular-like exchangeability and covalent bond-level stability remains a significant challenge. In this work, we addressed this issue by employing metal-ligand bonds as the crosslinking points of LCE networks. As such, mesogen alignment can be repeatedly encoded through metal-ligand bond exchange and stably maintained after programming, since the bond exchange rate is sufficiently slow when the programming and actuation temperatures are below the bond dissociation temperature. More importantly, the metal-ligand bonds can be completely dissociated at high temperatures, allowing the LCE network to be dissolved in a solvent and reshaped into desired geometries via solution casting. Building on these properties, our LCEs can be fabricated into versatile actuators, such as reversible folding origami, artificial muscles, and soft robotics.

Metal‐Ligand Bonds Based Reprogrammable and Re‐Processable Supramolecular Liquid Crystal Elastomer Network

AbstractDynamic covalent bonds endow liquid crystal elastomers (LCEs) with network rearrangeability, facilitating the fixation of mesogen alignment induced by external forces and enabling reversible actuation. In comparison, the bond exchange of supramolecular interactions is typically too significant to stably maintain the programmed alignment, particularly under intensified external stimuli. Nevertheless, remaking and recycling of supramolecular interaction‐based polymer networks are more accessible than those based on dynamic covalent bonds, as the latter are difficult to completely dissociate. Thus, preparing an LCE that possesses both supramolecular‐like exchangeability and covalent bond‐level stability remains a significant challenge. In this work, we addressed this issue by employing metal‐ligand bonds as the crosslinking points of LCE networks. As such, mesogen alignment can be repeatedly encoded through metal‐ligand bond exchange and stably maintained after programming, since the bond exchange rate is sufficiently slow when the programming and actuation temperatures are below the bond dissociation temperature. More importantly, the metal‐ligand bonds can be completely dissociated at high temperatures, allowing the LCE network to be dissolved in a solvent and reshaped into desired geometries via solution casting. Building on these properties, our LCEs can be fabricated into versatile actuators, such as reversible folding origami, artificial muscles, and soft robotics.

Enhancement of antifouling and separation properties of poly(m-phenylene isophthalamide) hybrid ultrafiltration membrane using highly crystalline poly(heptazine imide) nanosheets

A highly crystalline phase g-C3N4, namely poly (heptazine imide) (PHI) was synthesized using molten salts. A high-performance ultrafiltration membrane was prepared by blending PHI nanosheets with Poly(m-phenylene isophthalamide) (PMIA) to obtain casting solution, and further prepared by phase conversion method. Hybrid PMIA membranes were prepared by incorporating 0.02–0.10 wt% of PHI, which were further characterized by SEM, AFM, XRD, FTIR, XPS, TGA and surface zeta potential. The hydrophilicity, water flux, and rejection of bovine serum albumin (BSA) of the membrane significantly increased. For instance, the water permeability of M4 (264.6 Lm−2h−1bar−1) was about 2.3 times that of bare PMIA membrane (113.6 Lm−2h−1bar−1), while maintaining a BSA rejection of 94.7 % for a 1000 mgL−1 BSA feed solution. Moreover, the M4 membrane showed excellent antifouling performance with a flux recovery rate of up to 88.7 % and lower irreversible fouling of 11.3 %. This study may provide reference for the modulation of highly crystalline g-C3N4 structure and its application in membrane fabrication for water treatment.

Insights into the effect of carboxylated cellulose nanocrystals on mechanical and barrier properties of gelatin films for flexible packaging applications

In this study, gelatin/carboxylated cellulose nanocrystal (cCNC) bionanocomposite films were developed as an eco-friendly alternative to non-biodegradable flexible plastic packaging. Cellulose nanocrystals were modified by 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation (cCNC) to strategically interact with amino groups present in the gelatin macromolecular backbone. Gelatin/cCNC bionanocomposite films (0.5–6.0 wt% cCNC) obtained by solution casting were transparent to visible light while displayed high UV-blocking properties. The chemical compatibility between gelatin and cCNC was deepened by electrostatic COO−/NH3+ interactions, as detected by FTIR spectroscopy and morphologically indicated by scanning electron microscopy (SEM). Accordingly, Young's modulus and tensile strength of films were largely increased by 80 and 64 %, respectively, specifically near the cCNC percolation threshold (4 wt%), whereas the water vapor permeability (WVP) was reduced by 52 % at the optimum 6.0 wt% cCNC content in relation to the non-reinforced gelatin matrix (0.10 vs. 0.18 g H2O mm m−2 h−1 kPa−1). The oxygen transmission rates (OTR) of the gelatin/cCNC bionanocomposites were < 0.01 cm3 m-2 day−1, making them technically competitive to most promising biopolymers like polycaprolactone (PCL) and poly(lactic acid) (PLA). This study reveals how TEMPO-oxidized cellulose nanocrystals can broaden the performance of biodegradable gelatin films for use in packaging. The gelatin/cCNC bionanocomposites also represent an effective approach for designing newly sustainability-inspired flexible materials from the surface modification of nanocelluloses targeting specific interactions with protein structures.

Preparation of a high performance PES/PES-OH Loose nanofiltration membrane based on reactive porogen

Loose nanofiltration membranes (LNF) have wide applications in the field of precise separation of small organic molecules. However, high separation precision of organic molecules with salts and a high water flux are still the challenges in the commercial applications of LNF membranes. In the current work, polyethersulfone (PES)/hydroxylated polyethersulfone (PES-OH) LNF membranes were synthesized by nonsolvent-induced phase separation (NIPS) based on reactive porogen (butyl dicarbonate, BDC) for the first time. The reactive porogen was decomposed to produce nanobubbles during heat-treated casting solution and phase inversion in HCl coagulation. It was found that the heat-treatment temperature of the casting solution was higher, the viscosity of the solution at 20 °C was higher due to the existence of more nanobubbles from BDC decomposition in the casting solution. Moreover, heat-treatment temperature had decisive impacts on the structure and separation property of the formed LNF membranes as nanobubbles actually acted as pore-forming agents. The HCl coagulation/immersion baths also promoted the BDC decomposition to produce the nanobubbles and improved the transmembrane water flux without sacrificing rejection and separation precision performance. The synthesized LNF membrane had a pore diameter approximately 3.81 nm, with a flux up to 200.2 L·m−2·h−1. Direct Black 38 shows a rejection of > 99 %, whereas NaCl shows a rejection of < 5 %, exhibiting a good separation accuracy and found superior to the separation performance in the literature. This research result has offered a novel approach for the preparation of superior performance LNF membranes, which can be utilized for precise separation.

Reduced dielectric loss of MXene/PVDF composites with adding MnO2 nanorods

To reduce the dielectric loss of MXene/PVDF composites near the percolation threshold, a MnO2/MXene hybrid structure was successfully synthesized via an ultrasonic-assisted solution process, and MnO2/MXene/PVDF composite films were prepared by a solution casting method. The effects of different amounts of MnO2 nanorods on the microstructure, thermal stability, dielectric properties and mechanical properties of the composite films were investigated. At 1 kHz, the dielectric constant of 7 wt% MnO2/MXene/PVDF is 37.3, and the dielectric loss is as low as 0.05. The electric modulus curve, Nyquist curve and equivalent analog circuit of the composites revealed strong interface polarization and microcapacitance effects in the composites. In addition, the composite films exhibit excellent mechanical properties, and the storage modulus of the composite film loaded with 10 wt% MnO2 is 1990.5 MPa, which is 3.44 times that of pure PVDF. This study confirms that incorporating MnO2 nanorods into MXene/PVDF composites is an effective approach for fabricating high-performance dielectric composites.

Physical and Functional Properties of Poly (Lactic Acid)/Paprika Oleoresin Films for Food Packaging Application

Background: Paprika oleoresin is a compound extracted from paprika, with functional properties, mainly due to its fatty acid composition and carotenoid profile. The effect of these compounds on PLA composite films has not been investigated. Objective: The objective of this study is to evaluate the effect of paprika oleoresin at different concentrations on the surface color, UV barrier, mechanical barrier, water vapor barrier, hydrophobicity, paprika oleoresin release and antibacterial properties of PLA-based composite films. Method: Functional poly(lactic acid)-based films incorporating paprika oleoresin extract (POE) at three levels (0.01%, 0.03% and 0.06%) were prepared using a solution casting method. Results: The paprika oleoresin showed an excellent compatibility with the PLA, as a uniform dispersion was observed. Moreover, the addition of POE improved properties such as elasticity (increase of 62%) and water vapor permeability (decrease of 69%). However, compared to the control film (polylactic acid), the solubility of the polylactic acid and paprika oleoresin extract films was found to be significantly increased. As the POE content increased, the color intensity of the PLA films became lighter orange-yellow. The film composed by PLA/ POE (0.06%) also presented significant bacterial inhibition for Staphylococcus aureus. In addition, the films demonstrated total carotenoid release in food-simulating liquids. Conclusion: Functional PLA/POE films can be a good alternative to replace traditional food packaging.

Electrospun Quasi‐Composite Polymer Electrolyte with Hydoxyl‐Anchored Aluminosilicate Zeolitic Network for Dendrite Free Lithium Metal Batteries

AbstractAll‐solid‐state lithium metal batteries have reshaped emerging safe battery technologies. However, their low metal ion transport and unstable electrode electrolyte interface make their mass production a huge question. To bridge the emerging solid state and traditional liquid electrolytes, we focus on Quasi‐Composite Polymer electrolytes (QCPE). Herein, we develop QCPE with active 3D alumino‐silicate zeolitic ion conduction pathways embedded in a polymer matrix using two techniques‐ solution casting and electrospinning. Electrospun QCPE outperforms Solution cast QCPE by achieving high amorphous behavior. Prompt elimination of solvent during electrospinning decreases bulk resistance and increases its ionic conductivity. The Zeolitic pathway anchored by hydroxyl groups of PVA polymer acts as a highway for Li+ ions. It exhibits highly stable platting stripping vs Li+/Li for 450 hours with low overpotential, confirming the interfacial compatibility and dendrite‐free cycling at lithium metal anode. Controlled lithium‐ion nucleation regulated by evenly distributed zeolitic pathway is an interesting front of this work. To test QCPE's performance in Lithium metal battery (LMB), the electrospun QCPE is used to fabricate LMB with LiFePO4 cathode. This battery system delivered a high capacity of 155 mAh g−1 at 0.1 C. In addition to the high performance, electrospun QCPE production is scalable at an industrial scale.

Chitosan Based Zinc and Copper Nanoparticles: Synthesis, Characterization and Antibacterial Activity Investigation

Chitosan biopolymer has been used as a key supporting material for the synthesis of metallic nanoparticles (MNPs) due to its exceptional qualities, which include good capping and stabilizing capabilities, biocompatibility, biodegradability, eco-friendliness, polycationic and non-toxicity. In this study, chitosan-based metal nanoparticles, such as copper nanoparticles (Chi-Cu NPs) and zinc nanoparticles (Chi-Zn NPs) have been synthesized, characterized and checked for their bacteriological properties. The solution casting method has been employed to produce metal nanoparticles based on chitosan. FTIR, TGA, and SEM analysis were employed to characterize the produced nanoparticles. The produced materials are nanomaterials with a size range of 1-100 nm, as demonstrated by the SEM photograph. The generated nanoparticles showed increased antimicrobial activity. Chi-Zn NPs have zones of inhibition of 38, 31, 30 and 39 and Chi-Cu NPs have zones of inhibition of 32, 36, 37 and 32 mm against Pseudomonas aeruginosa, Salmonella bovismorbificans, Salmonella typhi and Escherichia coli bacteria, respectively. Whereas the standard medication kanamycin have zones of inhibition 22, 22, 20 and 20 against those bacteria, respectively. Journal of Engineering Science 15(1), 2024, 45-57

Fabrication, structure and optical characteristics of CuO/polymer nanocomposites materials for optical devices

The films of P(4ClAni)/CuO, which formed of mixing poly 4-chloroaniline P(4ClAni) by CuO, were fabricated by the casting solution method. The XRD confirmed the successful prepration of the P(4ClAni)/CuO films. Additionally, the effect of CuO on the optical characteristics was determined. The CuO increased the refractive index from 1.09 for P(4ClAni) to 1.11 for P(4ClAni)/CuO-1, and 1.19 for P(4ClAni)/CuO-3, respectively, while the oscillation energy E0 dropped from 4.29 eV for P(4ClAni) to 3.57 eV for P(4ClAni)/CuO-1, 3.12 eV for P(4ClAni)/CuO-2, and 3.06 eV for P(4ClAni)/CuO-3. The charge transfer between P(4ClAni) and CuO increased optical conductivity as the CuO ratios increased. This suggests that modifications in the electronic structure of the composite due to the interactions between P(4ClAni) and CuO. Also, the plasma frequency increased from 0.87 x 1012 s−1 to 2.32 x 1012 s−1. These changes in optical parameters occurred when the polarization of the P(4ClAni)/CuO was altered. The study elucidated the advantages of incorporating CuO nanoparticles as fillers in improving the properties of P(4ClAni) structures. The obtained results indicate the P(4ClAni)/CuO composites were sucessfuly fabricated with novel characteristics that can be applied in flexible optical devices.

Improving Multi-pixel Visual Quality of Invariant Visual Cryptography Scheme

A visual cryptography scheme (VCS) splits the secret image into several shares. Stacking a certain number of shares will reveal the secret image. The principle algorithm (deterministic algorithm) retains the size of shares, and the revealed image is at least double the size of the secret image with good visual quality. In contrast, the probabilistic algorithm has the size of the revealed image equal to that of the secret image with the noisily revealed image. Multi-pixel algorithm cast solutions for the trade off problems between the good visual quality and the non-expansion size of the revealed image. In this paper, we introduce new algorithms for multi-pixel to improve the quality of preceding algorithms, generalize the multi-pixel algorithm, provide evidence of the best form of multi-pixel, and contribute to the thin line problem.

NIR-driven intense UV upconversion films for non-contact high-efficiency prevention of bacterial infections

Bacterial infections on wounds imposes a significant limitation to the wound healing. Although the conventional drug antibacterial dressing is employed for hindering bacterial infection, the inevitable microbial resistance and secondary damage severely limit the quality and speed of wound healing. Herein, the NIR-driven intense UV upconversion (UC) BaLu2F8:80%Yb3+/0.5%Tm3+ microcrystals are, for the first time, designed and fabricated into solid sterilization film to protect the wounds from infections. Equipped with excessive Yb3+ sensitizers, the emission of Yb3+/Tm3+ co-doped monoclinic BaLu2F8 matrix achieve a 175-fold enhancement at the UV band. The UV UC microcrystals was further fabricated into a NIR-to-UV sterilization film with a diameter of 1.5 cm and a thickness of 150 μm using solution casting method, which can efficiently destroy 97 % of E. coli with a NIR irradiation of 5 minutes. Due to the outstanding penetrability of NIR irradiation, the sterilization film under 4 layers gauze dressing can be activated to produce UV photons. The in-vivo mouse tests demonstrate the well-designed NIR-to-UV sterilization film can speed up the wound healing by high-efficient inhibiting E. coli infection under the irradiation of 980 nm NIR laser. The non-contact NIR-driven UV sterilization film require no more drugs and dressing exchange, thus entirely eliminating the effect of microbial resistance and secondary damage from conventional drug dressing. Our work provides a new alternative for constructing highly-efficiency sterilization dressing through the utilization of NIR-to-UV optical conversion materials.

Mechanical Properties and Crystallinity of Specific PLA/Cellulose Composites by Surface Modification of Nanofibrillated Cellulose.

Polylactic acid (PLA) has inherent drawbacks, such as its amorphous structure, which affect its mechanical and barrier properties. The use of nanofibrillated cellulose (NFC) mixed with PLA for the production of composites has been chosen as a solution to the above problems. A PLA/NFC composite was produced by solution casting. Before use, the cellulose was modified using a silane coupling agent. The composite films were investigated via X-ray diffraction, as well as by mechanical, physical, thermal analyses and by differential scanning calorimeter. The crystallinity was four times that of pure PLA and the water vapor transmission rate decreased by 76.9% with the incorporation of 10 wt% of NFC. The tensile strength of PLA/NFC blend films increased by 98.8% with the incorporation of 5 wt% of NFC. The study demonstrates that the addition of NFC improved the properties of PLA. This provides a solid foundation for the enhancement of the performance of PLA products.

Impact of Starch-Based Bioplastic Film Reinforced with Alkaline Treated Lemongrass Fibre and Lemongrass Essential Oil on the Barrier and Mechanical Properties

Bioplastic has been gaining interest over the years to replace the used of synthetic plastic especially in food packaging application due to its biodegradable nature and non-toxicity feature. However, their lack in mechanical properties and water sensitivity retards it wide application. In this research, starch-based composite bioplastics film is prepared using solution casting method, which composed of alkaline treated lemongrass fibre (2-10 wt%) and lemongrass essential oil (1-3%) as the reinforcement material. Fiber characterization was conducted to evaluate the structural, thermal and morphology of the treated fibre. The effect reinforcement on barrier and mechanical properties of the bioplastic film was investigated. Results indicated that treated lemongrass fibre improve the surface texture of lemongrass fibre that enables it to integrate well with the starch matrix. It can be observed by the improvement of mechanical properties of reinforced bioplastic film up to 2.5MPa. Th incorporation of lemongrass essential oil significantly enhanced barrier properties of the reinforced bioplastic by reducing the water uptake up to 30%. Findings indicate that the starch-based bioplastic were suitable for food packaging application.

Lithium-Rich Porous Aromatic Framework Doped Quasi-Solid Polymer Electrolyte for Lithium Battery with High Cycling Stability.

Lithium-ion batteries (LIBs) have revolutionized the energy storage landscape and are the preferred power source for various applications, ranging from portable electronics to electric vehicles. The constant drive and growth in battery research and development aim to enhance their performance, energy density, and safety. Advanced lithium batteries (LIBs) are considered to be the most promising electrochemical storage devices, which can provide high specific energy, volumetric energy density, and power density. However, the trade-off between ionic conductivity and cycling stability is still a major contradiction for SPEs. In this work, a novel hydroxylated PAF-1 was designed and synthesized through post-modification, and the lithium-rich single-ion porous aromatic framework PAF-1-OLi was thereafter prepared by lithiation, achieved with a specific surface area to be 155 m2 g-1 and a lithium content of 2.01 mmol g-1. PAF-1-OLi, lithium bis(trifluoromethanesulfony)limine (LiTFSI), and poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) were compounded to obtain PAF-1-OLi/PVDF by solution casting, which had good mechanical, thermodynamic, and electrochemical properties. The ion conductivity of PAF-1-OLi/PVDF infiltrated with plasticizer was 2.93 × 10-4 S cm-1 at 25 °C. The tLi+ was 0.77, which was much higher than that of the traditional dual-ion polymer electrolytes. The electrochemical window of PAF-1-OLi/PVDF can reach 4.9 V. The Li//PAF-1-OLi/PVDF//LiFePO4 battery initial discharge specific capacity was 147 mAh g-1 and reached 134.9 mAh g-1 after 600 cycles with a capacity retention rate of 91.2%, demonstrating its good cycling stability. The anionic part of lithium salt was fixed on the framework of PAF-1 to increase the Li+ transfer number of PAF-1-OLi/PVDF. The lithium-rich PAF-1-OLi and the LiTFSI provided abundant Li+ sources to transfer, while PAF-1-OLi helped to form a continuous Li+ transport channel, effectively promoting the migration of Li+ in the PAF-1-OLi/PVDF and effectively improving the Li+ conductivity. This study afforded a novel polymer electrolyte based on lithium-rich PAF-1-OLi, which has excellent electrochemical performance, providing a new choice for the polymer electrolyte of lithium batteries.

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.