Biobased polyester versus synthetic fiberglass casts for treating stable upper limb fractures in children: a randomized controlled trial.

BACKGROUND: Stable upper limb fractures, such as radius, ulna, or distal humerus fractures, are common pediatric orthopedic traumas that are traditionally managed with cast immobilization. The commonly used synthetic fiberglass cast is light and water resistant but may promote skin itchiness during casting, which is a common complaint of patients. In addition, these diisocyanate-based casts have been proven to be toxic and may cause asthma. Herein, we introduce a novel biobased polyester cast to compare its clinical outcomes and patient satisfaction with conventional synthetic fiberglass casts. METHODS: From Feb 2022 to Nov 2022, we undertook a single-center prospective randomized trial involving 100 children with cast-immobilized stable upper limb fractures. These patients were randomized into either biobased polyester or synthetic fiberglass groups. All patients were regularly followed up till the cast removal which occurred approximately 3-4 weeks after immobilizing. Objective clinical findings and subjective patient questionnaire were all collected and analyzed. RESULTS: According to the radiographs taken on the day of cast removal, there was no loss of reduction in both groups. The incidence of skin problems was 3.4 times higher in the synthetic fiberglass group than in the biobased polyester group. For the subjective questionnaire, the biobased polyester cast was preferred in every sub-item. CONCLUSIONS: Our study strongly suggested that the novel biobased polyester cast provides matching stability to conventional fiberglass casts and improves patient satisfaction in an eco-friendlier and safer way. TRIAL REGISTRATION: ClinicalTrials.gov Protocol Registration and Results System ( https://www. CLINICALTRIALS: gov/ ; ID: NCT06102603; Date: 26/10/2023).

Hierarchical 3D Snowflake-like Iron Diselenide: A Robust Electrocatalyst for Furaltadone Detection.

An electrocatalyst with a large active site is critical for the development of a high-performance electrochemical sensor. This work demonstrates the fabrication of an iron diselenide (FeSe2)-modified screen-printed carbon electrode (SPCE) for the electrochemical determination of furaltadone (FLD). It has been prepared by the facile method and systematically characterized with various microscopic/spectroscopic approaches. Due to advantageous physiochemical properties, the FeSe2/SPCE showed a low charge-transfer resistance value of 200 Ω in 5.0 mM [Fe(CN)6]3-/4- containing 0.1 M KCl. More importantly, the FeSe2/SPCE exhibited superior catalytic performance compared to the bare SPCE for FLD sensing based on the electrochemical response in terms of a peak potential of -0.44 V (vs Ag/AgCl (sat. KCl)) and cathodic response current of -22.8 µA. Operating at optimal conditions, the FeSe2-modified electrode showed wide linearity from 0.01 to 252.2 µM with a limit of detection of 0.002 µM and sensitivity of 1.15 µA µM-1 cm-2. The analytical performance of the FeSe2-based platform is significantly higher than many previously reported FLD electrochemical sensors. Furthermore, the FeSe2/SPCE also has a promising platform for FLD detection with high sensitivity, good selectivity, excellent stability, and robust reproducibility. Thus, the finding above shows that the FeSe2/SPCE is a highly suitable candidate for the electrochemical determination of glucose levels for real-time applications such as in human urine and river water samples.

Bio-based poly(hexamethylene 2,5-furandicarboxylate-co-2,6-naphthalate) copolyesters: a study of thermal, mechanical, and gas-barrier properties.

A series of poly(hexamethylene 2,5-furandicarboxylate-co-2,6-naphthalate) copolyesters were synthesized using various amounts of poly(hexylene 2,5-furandicarboxylate) (PHF) and poly(hexylene 2,6-naphthalate) (PHN) via melt polymerization. The effects of introducing 2,6-naphthalene dicarboxylic acid (NDCA) on the thermal, mechanical, and gas-barrier properties were investigated. When the NDCA content was less than 30 mol%, the temperatures of crystallization (Tc) and melting (Tm) decreased as the amount of NDCA was increased owing to disturbance of the polymer-chain regularity. When the NDCA content was above 50 mol%, the Tc and Tm of the materials increased as the NDCA content was increased, showing that the dominant crystallization behavior varied from 2,5-furandicarboxylic acid to NDCA. Hence, the glass transition temperature (Tg) increased as the NDCA content was increased, which was attributed to the incorporation of NDCA with a more rigid naphthalate structure compared with the furan ring. The gas-barrier properties of the samples were observed to improve with the introduction of NDCA; this tendency could be explained by the ß-relaxation behavior and free volume values of the samples in the amorphous state. The activation energy (Ea) of ß-relaxation increased with the NDCA content, indicating that higher amounts of energy were needed to trigger the onset of long-range molecular motions. Free-volume calculations of the polymer structure showed that the introduction of NDCA hindered the space for gas penetration. For these reasons, the gas-barrier properties were improved and evaluated.

Synthesis and Characterization of Size-Controlled Titania Nanorods through Double Surfactants.

A synthetic technique based on a two-step sol-gel hydrothermal method using cetyltrimethylammonium bromide (CTAB) and triblock copolymer PEO106-PPO70-PEO106 (F127) as double surfactants with the assistance of three amines (ethylamine (EA), diethylamine (DEA), and triethylamine (TEA)) for fabrications of anatase titania nanorods is proposed. The formation and growth mechanisms of TiO2 crystals are described. We discovered that crystal size reduces with an increase in the number of alkyl substituents on the nitrogen of amines because the steric hindrance of the bulky alkyl substituent around nitrogen suppresses the nucleation and crystal growth rate. The size of titania from 80 to 220 nm is modulated with concentrations of EA, DEA, and TEA. The amines are considered as catalysts for morphological evolution of TiO2 crystals. The results indicate that the incorporation of double surfactants (F127-CTAB) has a dual role, acting as a chelating agent for titania against external forces and a capping agent inhibiting the three-dimensional growth of TiO2 crystals.

Influence of asymmetric substituent group 2-methyl-1,3-propanediol on bio-based poly(propylene furandicarboxylate) copolyesters.

A series of bio-based poly(propylene-co-2-methyl-1,3-propanediol 2,5-furandicarboxylate) (PPMF) copolyesters, with various compositions from poly(propylene 2,5-furandicarboxylate) (PPF) to poly(2-methyl-1,3-propylene 2,5-furandicarboxylate) (PMePF), were synthesized by conventional melt polymerization. The effects of the substituent group to PPF on the thermal properties, mechanical properties, and gas barrier properties were analyzed by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), tensile testing, and the oxygen permeation test. The introduction of the methyl group with a hydrogen atom altered the thermal behavior and gas barrier properties of copolyesters, suggesting that the glass temperature (Tg) and the melting temperature (Tm) were decreased as the 2-methyl-1,3-propanediol (MPO) content increased. PPF exhibited the highest Tm and Tg of 175.9 °C and 83.0 °C with a melting enthalpy (ΔHm) of 38.6 J g-1, and poly(2-methyl-1,3-propylene 2,5-furandicarboxylate) formed as an amorphous polyester. Moreover, the effect of a substituent methyl group on the barrier properties was attributed to ß relaxation and fraction free volume, which could be raised by replacing the methyl group with a hydrogen atom for PPF, weakening the barrier properties.

Bio-based thermoplastic poly(butylene succinate-co-propylene succinate) copolyesters: effect of glycerol on thermal and mechanical properties.

Poly(butylene succinate-co-propylene succinate) (PBSPS) was polymerized using succinic acid, 1,4-butanediol, 1,3-propanediol, and glycerol (GC). The PBSPS copolyester with a BS/PS ratio of 7/3 has a low melting point (Tm, 80 °C) and crystallization temperature (Tc, 20 °C) in addition to excellent thermal stability with a thermal degradation temperature (Td) above 300 °C. Isodimorphism was observed for 30-50 mol% PS, lowering Tm and Tc. The featured crystalline lattices (021) and (110) of PBS at 2θ = 21.5° and 22.5° gradually disappeared with PS content greater than 50 mol% and transformed into a PPS crystalline lattice at 2θ = 22.3°. Young's modulus decreased with increasing PS content due to crystallinity loss. Wide-angle X-ray diffraction demonstrated that the chain movement regularity was affected by the GC content, reducing the crystallinity. The PBSPS copolyesters were elastic with 0.001 mol% GC but became rigid with GC content greater than 0.01 mol%. The chain conformation was flexible for 0.001-0.01 mol% GC and exhibited an irregular steric architecture for 0.02-0.03 mol% GC due to more GC acting as nodes. Thus, the thermal and mechanical properties of the synthesized bio-based PBSPS copolyesters can be controlled by adjusting the GC content; therefore, such copolyesters are suitable for medical support, coating, and phase-change material applications.

Impact of constitution of the terthiophene-vinylene conjugated side chain on the optical and photovoltaic properties of two-dimensional polythiophenes.

The effects of the spatial arrangement of the conjugated side chains of two-dimensional polymers on their optical, electrochemical, molecular-packing, and photovoltaic characteristics were investigated. Accordingly, novel polythiophenes with horizontally (PBTTTV-h) and vertically (PBTTTV-v) grafted terthiophene­vinylene (TTV) conjugated side chains were synthesized that display two and one UV-vis peaks, respectively; the difference is due to the different constitutions of the conjugated side-chains. Because the spatial arrangement affects the molecular self-assembly, PBTTTV-h shows stronger crystallinity than PBTTTV-v, which enhances the charge mobility in devices. Moreover, PBTTTV-h has a lower HOMO energy level (−5.49 eV) than PBTTTV-v (−5.40 eV). Bulk heterojunction solar cells fabricated from PBTTTV-h/PC71BM and PBTTTV-v/PC71BM exhibit power conversion efficiencies of 4.75% and 4.00%, respectively, and Voc values of 800 and 730 mV, respectively, under AM1.5G illumination (100 mW cm(−2)). Thus, the architecture of the TTV conjugated side chains affects the optical, electrochemical, and photovoltaic properties; this study provides more ideas for improving 2-D conjugated polymers for semiconductor devices.

Synthesis and rheological characterization of water-soluble glycidyltrimethylammonium-chitosan.

In this study, chitosan (CS) grafted by glycidyltrimethylammonium chloride (GTMAC) to form GTMAC-CS was synthesized, chemically identified, and rheologically characterized. The Maxwell Model can be applied to closely simulate the dynamic rheological performance of the chitosan and the GTMAC-CS solutions, revealing a single relaxation time pertains to both systems. The crossover point of G' and G" shifted toward lower frequencies as the CS concentration increased but remained almost constant frequencies as the GTMAC-CS concentration increased, indicating the solubility of GTMAC-CS in water is good enough to diminish influence from the interaction among polymer chains so as to ensure the relaxation time is independent of the concentration. A frequency-concentration superposition master curve of the CS and GTMAC-CS solutions was subsequently proposed and well fitted with the experimental results. Finally, the sol-gel transition of CS is 8.5 weight % (wt %), while that of GTMAC-CS is 20 wt %, reconfirming the excellent water solubility of the latter.

Simple bone cysts of the proximal humerus presented with limb length discrepancy: A case report.

BACKGROUND: Simple bone cysts (SBC) are benign tumor-like bone lesions typically identified in children. While SBC may lead to growth disturbances or growth arrest, such cases are uncommon. The mechanisms behind these observations remain unclear. Additionally, research on the etiology of SBC remains inconclusive, and there has been no consensus on the appropriate timing and methodology for treatment. CASE SUMMARY: Here, we present our experience in the successful surgical management of a 10-year-old girl with SBC, who presented with a pathological fracture complicated by malunion of the displaced fracture, varus deformity, and limb length discrepancy. We hypothesized two possible etiologies for the patient's growth arrest and subsequent humerus varus deformity: (1) Direct disruption of the physis by fluid from the cyst itself; and (2) damage to the epiphysis due to repetitive pathological fractures associated with SBC. In addressing this case, surgical intervention was undertaken to correct the proximal humerus varus deformity. This approach offered the advantages of simultaneously correcting angular abnormalities, achieving mild limb lengthening, providing definitive SBC treatment, and reducing the overall treatment duration. CONCLUSION: As per current literature, acute correction of acute angular deformity in proximal humeral SBC is not well comprehended. However, in this specific case, acute correction was considered an optimal solution.

Synthesis of High-Value Bio-Based Polyamide 12,36 Microcellular Foams with Excellent Dimensional Stability and Shape Recovery Properties.

The search for alternatives to petroleum-based thermoplastic polyamide elastomers (TPAEs) has recently drawn great interest. In this study, a bio-massed TPAE, PA12,36, was synthesized using 1,12-dodecanediamine (DDA) and fatty dimer acid (FDA, PripolTM1009) precursors via catalyst and solvent-free melt polycondensation. The molecular structure and molecular weight of the PA12,36 were characterized by 1H NMR, FTIR, and GPC. PA12,36 displayed a low melting temperature of 85.8 °C, an initial degradation temperature of 425 °C, and a glass-transition temperature of 30.4 °C, whereas it sustained satisfactory tensile strength (10.0 MPa) and superior strain at break (1378%). Furthermore, PA12,36 was foamed by supercritical CO2, and the cell size, cell density, and porosity were determined. The entangled long-chained FDA component generated a physically crosslinked network, which promoted the melt viscosity of PA12,36 against elongations of foam cell growth and increased foamability significantly. As a result, uniform structured cellular foams with a cell diameter of 15-24 µm and high cell density (1011 cells/cm3-1012 cells/cm3) were successfully achieved. The foaming window was widened from 76 to 81 °C, and the expansion ratio was increased from 4.8 to 9.6. Additionally, PA12,36 foam with a physically crosslinked structure presented a better creep shape recovery percentage (92-97.9%) and sturdier dimensional stability. This bio-based PA12,36 foam is a promising candidate to replace petroleum-based thermoplastic elastomer foams for engineering applications, particularly shoe soles.

One-pot synthesis of liquid photocrosslinkable poly(l-lactide) with terminal triacrylate.

We synthesized a poly(l-lactide)-pentaerythritol triacrylate (PETA) polymer modified with acrylic trifunctional groups using a one-pot method based on ring-opening polymerization of l-lactide and PETA. We calculated the molecular weight and structure of PLA-PETA using gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) (1H, 13C, heteronuclear multiple bond correlation [HMBC]) spectroscopy. Photocrosslinking PLA-PETA using the Omnirad 1173 photoinitiator yielded a transparent sample with 91% crosslinkage. The crosslinked sample was analyzed using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and thermomechanical analysis (TMA) to determine its thermal properties and thermal expansion coefficient. In vitro cell toxicity tests showed an average cell viability >90%, indicating that the PLA-PETA polymer had good biocompatibility with cells after photocrosslinking.

Influence of Cross-Linking and Crystalline Morphology on the Shape-Memory Properties of PET/PEN/PCL Copolyesters Using Trimesic Acid and Glycerol.

PCL-based biodegradable shape-memory polymers (SMPs) are limited in strength, which restricts their practical applications. In this study, a series of novel SMPs, composed of poly(ethylene terephthalate) (PET), poly(ethylene naphthalate) (PEN), and poly(ε-caprolactone) (PCL), were synthesized and cross-linked using planar (benzene-1,3,5-tricarboxylic acid, BTC) or non-planar (glycerol, GC) cross-linkers via the one-pot method. The influence of different kinds of cross-linkers and hard segments of copolyesters on the thermal properties, crystallization behavior, mechanical properties, shape-memory performance, and degradability was investigated by FT-IR, 1H-NMR, DSC, DMA, TGA, XRD, tensile test, intrinsic viscosity measurement, and in vitro enzymatic degradation test. The results indicate that the tensile strength of the copolyester can be significantly improved from 27.8 to 53.2 MPa by partially replacing PET with PEN while maintaining its shape-memory characteristics. Moreover, a small amount of cross-linking modification leads to higher temperature sensitivity, improved shape recovery rate at third round (Rr(3) = 99.1%), and biodegradability in the cross-linked PET/PEN/PCL shape-memory polymers. By changing the crystallization morphology and cross-linking forms of the material, we have developed a shape-memory polymer with both high strength and a high shape recovery rate, which provides a new strategy for the development of shape-memory materials.

Synthesis and Characterization of Poly(DL-lactide) Containing Fluorene Structures.

9,9-bis[4-(2-hydroxy-3-acryloyloxypropoxy)phenyl]fluorene (BPF) hydroxyl groups (-OH) were used as initiators in the ring-opening polymerization reaction with DL-lactide monomers at different molar ratios to synthesize a Poly(DL-lactide) polymer containing bisphenol fluorene structure and acrylate functional groups (DL-BPF). The polymer's structure and molecular weight range were analyzed using NMR (1H, 13C) and gel permeation chromatography. DL-BPF was then subjected to photocrosslinking using the photoinitiator Omnirad 1173, resulting in the formation of an optically transparent crosslinked polymer. Characterization of the crosslinked polymer involved analyzing its gel content, refractive index, thermal stability (via differential scanning thermometry (DSC) and thermogravimetric analysis (TGA)), as well as conducting cytotoxicity tests. The crosslinked copolymer exhibited a maximum refractive index of 1.5276, a maximum glass transition temperature of 61.1 °C, and cell survival rates higher than 83% in the cytotoxicity tests.

In-situ formation of niobium oxide - Niobium carbide - Reduced graphene oxide ternary nanocomposite as an electrochemical sensor for sensitive detection of anticancer drug methotrexate.

Engineering the nanostructure of an electrocatalyst is crucial in developing a high-performance electrochemical sensor. This work exhibits the hydrothermal followed by annealing synthesis of niobium oxide/niobium carbide/reduced graphene oxide (NbO/NbC/rGO) ternary nanocomposite. The oval-shaped NbO/NbC nanoparticles cover the surface of rGO evenly, and the rGO nanosheets are interlinked to produce a micro-flower-like architecture. The NbO/NbC/rGO nanocomposite-modified electrode is presented here for the first time for the rapid and sensitive electrochemical detection of the anticancer drug methotrexate (MTX). Down-sized NbO/NbC nanoparticles and rGO's high surface area provide many active sites with a rapid electron transfer rate, making them ideal for MTX detection. In comparison to previously reported MTX sensors, the developed drug sensor exhibits a lower oxidation potential and a higher peak current responsiveness. The constructed sensors worked analytically well under optimal conditions, as shown by a low detection limit of 1.6 nM, a broad linear range of 0.1-850 µM, and significant recovery findings (∼98 %, (n = 3)) in real samples analysis. Thus, NbO/NbC/rGO nanocomposite material for high-performance electrochemical applications seems promising.

Radiographic outcomes of the treatment of complex femoral shaft fractures (AO/OTA 32-C) with intramedullary nailing: a retrospective analysis of different techniques.

OBJECTIVES: To assess the results of open versus closed reduction in intramedullary nailing (IMN) for complex femoral fractures (Arbeitsgemeinschaft für Osteosynthesefragen Foundation/Orthopaedic Trauma Association [AO/OTA]: 32-C) and to determine the factors involved in bone healing. METHODS: This retrospective study involved 47 consecutive patients with complex femoral diaphyseal fractures who underwent reduction and fixation. RESULTS: All open-reduction and 12 closed-reduction patients (52.17%) had an anatomical-to-small gap. The closed-small group had the highest bone union rate (100%), followed by the open-reduction (79.17%) and closed-large groups (72.73%); intergroup differences were significant. The closed-small group had the shortest mean union time (7.31 months), followed by the open-reduction group (7.58 months). The closed-large group had a significantly longer union time (9.75 months) than those in the closed-small and open-reduction groups. Femoral radiographic union scores in the closed-small and open-reduction groups were similar at three timepoints; scores were higher than those in the closed-large group, with a significant difference 6 and 9 months post-operatively. CONCLUSION: IMN with closed reduction for complex femoral shaft fractures had better outcomes and fewer complications versus open reduction. For unsatisfactory closed reduction outcomes (i.e., residual gap >10 mm), minimally invasive techniques or open reduction with minimal stripping should be considered.

A Rapid Thermal Absorption Rate and High Latent Heat Enthalpy Phase Change Fiber Derived from Bio-Based Low Melting Point Copolyesters.

A series of poly(butylene adipate-co-hexamethylene adipate) (PBHA) copolymers with different content of 1,4-cyclohexanedimethanol (CHDM) was synthesized via one-step melt polymerization. The PBHA copolymer with 5 mol% CHDM (PBHA-C5) exhibited a low melting point (Tm) and high enthalpy of fusion (∆Hm) of 35.7 °C and 43.9 J g-1, respectively, making it a potential candidate for an ambient temperature adjustment textile phase change material (PCM). Polybutylene terephthalate (PBT) was selected as the matrix and blended at different weight ratios of PBHA-C5, and the blended samples showed comparable Tm and ∆Hm after three cycles of cooling and reheating, indicating good maintenance of their phase changing ability. Samples were then processed via melt spinning with a take-up speed of 200 m min-1 at draw ratios (DR) of 1.0 to 3.0 at 50 °C. The fiber's mechanical strength could be enhanced to 2.35 g den-1 by increasing the DR and lowering the PBHA-C5 content. Infrared thermography showed that a significant difference of more than 5 °C between PBT and other samples was achieved within 1 min of heating, indicating the ability of PBHA-C5 to adjust the temperature. After heating for 30 min, the temperatures of neat PBT, blended samples with 27, 30, and 33 wt% PBHA-C5, and neat PBHA-C5 were 53.8, 50.2, 48.3, 47.2, and 46.5 °C, respectively, and reached an equilibrium state, confirming the temperature adjustment ability of PBHA-C5 and suggesting that it can be utilized in thermoregulating applications.

Naphthalene Diimide-Based Donor-Acceptor-Donor Small Molecules as Metal-Free Organocatalysts for Photocatalytic CO2 Reaction.

The application of organic small molecules as metal-free photocatalysts for light-driven photoreduction of carbon dioxide (CO2) has seldom been explored. This work developed four naphthalene diimide (NDI)-derived donor-acceptor-donor small molecules with different numbers of thiophene units, namely, NDI-2T, NDI-TT, NDI-4T, and NDI-6T, as metal-free photocatalysts to catalyze the reduction of CO2 under irradiation with an air mass 1.5G solar simulator at one-sun intensity. The structure-property relationship was investigated by exploring the effects of the electron-donating ability of the donor units on the optical properties, redox potential, electron-hole distribution, and exciton lifetime. NDI-6T exhibited the most red-shifted absorption, longest exciton lifetime, and strongest electron-hole separation. However, the large upshift in oxidation potential because of the elevated electron-donating ability of the hexathiophene unit significantly reduced the driving force for catalyst regeneration, leading to poor catalytic performance. Alternatively, NDI-4T possessed proper redox potentials, reduced charge-transfer resistance, and excellent photocurrent intensity; therefore, it effectively converted CO2 to a single product of CO in the presence of water as an electron donor without a sacrificial reagent or cocatalyst with a product yield of 168.6 µmol gcat-1 24 h-1, which was considerably higher than those of NDI-TT (111.9 µmol gcat-1 24 h-1), NDI-2T (88.4 µmol gcat-1 24 h-1), and NDI-6T (40.5 µmol gcat-1 24 h-1). This study provides a practical guideline for the molecular design of conjugated organic molecules as promising photocatalysts for CO2 photoreduction.

Highly Stretchable Fully Biomass Autonomic Self-Healing Polyamide Elastomers and Their Foam for Selective Oil Absorption.

Renewable polymers with self-healing ability, excellent elongation, hydrophobicity, and selective oil absorption attributes are of interest for an extensive range of applications, such as e-skin, soft robots, wearable devices, and cleaning up oil spills. Herein, two fully renewable eco-friendly polyamide (PA)-based self-healing elastomers (namely, PA36,IA, and PA36,36) were prepared by a facile and green one-pot melt polycondensation of itaconic acid (IA), PripolTM 1009, and PriamineTM 1075 monomers. The molecular structures of these PAs were analyzed by FITR, 1H NMR, and 13C NMR. The distinct structure of these PAs shows superior strain values (above 2300%) and high ambient temperature autonomous self-healing ability. Interestingly, the synthesized renewable PA36,36 showed zero water absorption values and hydrophobic properties with a contact angle of θ = 91° compared to the synthesized PA36,IA and other previously reported PAs. These excellent attributes are due to the low concentration of amide groups, the highly entangled main chains, the intermolecular diffusion, the manifold dangling chains, and the numerous reversible physical bonds within the renewable PAs. Furthermore, the hydrophobic properties may aid in the selective oil absorption of the PA36,36-based foam, for which PA36,36 foam is produced by the green supercritical carbon dioxide (scCO2) batch foaming process. The PA36,36 foam with a microporous cellular structure showed better absorption capacity and high stability in repeated use. Due to these advantages, these bio-based PAs have potential for the production of eco-friendly self-healing materials, superabsorbent foams, and other polymeric materials.

Low-Mass Liquid Crystalline Materials Blended in Recycled Thermoplastic Polyester Elastomer for Corrosion Inhibitor Application.

In this work, the development and application of multicomponents obtained from recycled polyethylene terephthalate (r-PET) waste and monotropic liquid crystals as anticorrosion coatings are reported. The r-PET raw material was alcoholyzed and reproduced as a thermoplastic polyester elastomer (TPEE) with different amounts (n%, n = 0, 1, 3, and 5) of 1,6-hexanediamine (HDA). Then, a fluorine-containing liquid crystal (4-cyano-3-fluorophenyl 4-ethylbenzoate (4CFE)) was incorporated into the TPEE mixture via solvent blending to modify and enhance the water resistance. The adhesion behavior of the coating on glass and iron substrates was evaluated by cross-cut tests and immersion tests in aqueous NaCl. In the corrosion resistance measurements, all of the coating samples fabricated with 10 ± 1 mm thickness were less active toward electrochemical corrosion (PEF% > 99%) than the bare iron plate, indicating that our work provided better protection against corrosion of the iron plate.

Antibacterial Activity and Protection Efficiency of Polyvinyl Butyral Nanofibrous Membrane Containing Thymol Prepared through Vertical Electrospinning.

Human safety, health management, and disease transmission prevention have become crucial tasks in the present COVID-19 pandemic situation. Masks are widely available and create a safer and disease transmission-free environment. This study presents a facile method of fabricating masks through electrospinning nontoxic polyvinyl butyral (PVB) polymeric matrix with the antibacterial component Thymol, a natural phenol monoterpene. Based on the results of Japanese Industrial Standards and American Association of Textile Chemists and Colorists methods, the maximum antibacterial value of the mask against Gram-positive and Gram-negative bacteria was 5.6 and 6.4, respectively. Moreover, vertical electrospinning was performed to prepare Thymol/PVB nanofiber masks, and the effects of parameters on the submicron particulate filtration efficiency (PFE), differential pressure, and bacterial filtration efficiency (BFE) were determined. Thorough optimization of the small-diameter nanofiber-based antibacterial mask led to denser accumulation and improved PFE and pressure difference; the mask was thus noted to meet the present pandemic requirements. The as-developed nanofibrous masks have the antibacterial activity suggested by the National Standard of the Republic of China (CNS 14774) for general medical masks. Their BFE reaches 99.4%, with a pressure difference of <5 mmH2O/cm2. The mask can safeguard human health and promote a healthy environment.