Polymer Technology Research Articles

Molecularly imprinted ratiometric electrochemical sensor based on 3D-1D MoS2@CNTs hetero-nanoflower for selective detection of trimethoprim

Trimethoprim (TMP) is a broad-spectrum antibiotic that is frequently found residue in the environment and food. An innovative electrochemical sensor was proposed for the detection of trimethoprim with high selectivity, sensitivity and reproducibility through the integration of the flower-like MoS2@CNTs heterostructure as substrate, molecular imprinted polymer (MIP) technology as recognition, and the ratiometric strategy between trimethoprim and ferrocene (Fc) for quantitative. The recognition reaction of TMP by MIP-MoS2@CNTs sensor was assumed as an irreversible electrochemical oxidation reaction controlled by a combination of adsorption-diffusion process with two electrons and protons. With the incorporation of Fc during detection, a satisfying linear relationship of ITMP/IFc and the concentration of TMP was achieved, indicating a detection concentration ranging from 50 to 3000 nmol·L−1 with a detection limit of 27.01 nmol·L−1. In addition, the MoS2@CNTs MIP ratiometric sensor exhibited good stability for 20 days and excellent reproducibility with a relative standard deviation of 1.06 %, which was lower than 3.89 % of single signal. The practical feasibility of the sensor was detected in water samples with recovery rates of 98.62 ∼ 107.47 % and fish samples with recovery rates of 98.93 ∼ 105.45 %. Overall, the developed MIP ratiometric sensor provides a versatile system with easy operation and great potential for detecting small hazardous molecules in the environment and food products.

Editorial: Polymers in geotechnical and geoenvironmental engineering

Editorial: Polymers in geotechnical and geoenvironmental engineering

Microstructured Cantilever Probe on Optical Fiber Tip for Microforce Sensor

Benefiting from the great advances of the femtosecond laser two-photon polymerization (TPP) technology, customized microcantilever probes can be accurately 3-dimensional (3D) manufactured at the nanoscale size and thus have exhibited considerable potentials in the fields of microforce, micro-vibration, and microforce sensors. In this work, a controllable microstructured cantilever probe on an optical fiber tip for microforce detection is demonstrated both theoretically and experimentally. The static performances of the probe are firstly investigated based on the finite element method (FEM), which provides the basis for the structural design. The proposed cantilever probe is then 3D printed by means of the TPP technology. The experimental results show that the elastic constant k of the proposed cantilever probe can be actively tuned from 2.46 N/m to 62.35 N/m. The force sensitivity is 2.5 nm/µN, the Q-factor is 368.93, and the detection limit is 57.43 nN. Moreover, the mechanical properties of the cantilever probe can be flexibly adjusted by the geometric configuration of the cantilever. Thus, it has an enormous potential for matching the mechanical properties of biological samples in the direct contact mode.

FFKM combines high-temperature performance with exceptional low compression set

UK-based Precision Polymer Engineering Ltd (PPE) has developed a perfluoroelastomer (FFKM) sealing material that combines the ability to operate and perform well at a high temperature with exceptional low compression set.

Embracing Sustainability: The World of Bio-Based Polymers in a Mini Review.

The proliferation of polymer science and technology in recent decades has been remarkable, with synthetic polymers derived predominantly from petroleum-based sources dominating the market. However, concerns about their environmental impacts and the finite nature of fossil resources have sparked interest in sustainable alternatives. Bio-based polymers, derived from renewable sources such as plants and microbes, offer promise in addressing these challenges. This review provides an overview of bio-based polymers, discussing their production methods, properties, and potential applications. Specifically, it explores prominent examples including polylactic acid (PLA), polyhydroxyalkanoates (PHAs), and polyhydroxy polyamides (PHPAs). Despite their current limited market share, the growing awareness of environmental issues and advancements in technology are driving increased demand for bio-based polymers, positioning them as essential components in the transition towards a more sustainable future.

Revolutionizing polymer engineering for Photodetectors: A Machine Learning-Assisted paradigm for rapid materials discovery

Polymers are appealing candidates for photoelectric applications because of their intrinsic characteristics include flexibility in substrate compatibility, ease of manufacturing, room temperature operating conditions, and adaptable optoelectronic properties. In present study, we have used the machine learning (ML) for property prediction and polymer designing. Multiple ML models are trained. 10,000 novel polymers are generated using automatic method. The synthetic accessibility of the chosen polymers is predicted. Structural similarity among the selected polymers is also calculated that indicated good structural similarity among the chosen polymers. By effectively identifying and optimizing novel polymers, the implemented methods substantially increase the chances of uncovering superior materials suited for advanced applications.

Fabrication of robust polyamide 6 with local cross‐linked structure via dynamic vulcanization

AbstractPolyamide 6 (PA6) is a widely used thermoplastic engineering polymer, and the toughening modification for PA6 is always a main research topic. Meanwhile, the rigidity and heat resistance of PA6 usually deteriorate. To address this conflict, an epoxy compound (EGDE‐GA) was designed and synthesized and used to modify PA6 by dynamic vulcanization in twin‐screw extruder. EGDE‐GA is a linear molecule with a flexible molecular structure, which is favorable to toughening of PA6, and epoxy groups of EGDE‐GA can form local cross‐linked structure to improve the rigidity and retain the heat resistance of PA6. At the loading of 20 wt% of EGDE‐GA, the modified PA6 (PA6/EGDE‐GA 20) exhibited very high elongation at break and notched impact strength, which were increased by 413% and 520%, respectively, compared to those of PA6. The tensile strength was 61.4 MPa, which was higher than that of PA6. The heat deflection temperature remained almost unchanged. The results showed that the modified polymers may possess the high toughness without sacrificing the original rigidity by building the local crosslinked structure using dynamic vulcanization. The findings provide a feasible method for reusing and upcycling PA6 and other polymers with higher value and wider use in the industry.Highlights The polyamide 6 (PA6) is toughened via dynamic vulcanization. The toughness of modified PA6 is increased by 520% compared with pure PA6. The toughened PA6 exhibits higher tensile strength than that of pure PA6. The toughened PA6 maintains its rigidity and heat resistance.

Smart Janus cotton fabrics prepared via mist polymerization for moisture and thermal management

The construction of Janus structures on cotton fabrics can endow the fabrics with dynamic multifunctional properties. However, because of the large pores between fabric fibers, the formation of Janus structures by grafting different functional coatings on the double surfaces of cotton fabrics via dipping technology is difficult. To construct Janus structures on cotton fabrics, mist polymerization and “grafting-through” polymerization technologies were used to graft polylauryl methacrylate and a heat-shrinkable thermosensitive antibacterial polymer on the inside and outside surfaces of the cotton fabric, respectively. The as-formed Janus cotton fabric demonstrated excellent antibacterial durability. Even after subjecting the Janus fabric to 70 laundering cycles, its bacterial rates against Escherichia coli and Staphylococcus aureus were > 93.0 %. Compared with the pristine cotton fabric, when the ambient temperature is high or low, the Janus fabric can adjust the skin temperature within 5 min by approximately ±3.0 °C. Additionally, the fabric exhibited excellent waterproof and moisture permeability properties. The Janus cotton fabrics prepared by the proposed strategy possess significant potential for applications in the field of wearable textiles.

Efficacy and safety of durable versus biodegradable polymer drug-eluting stents in patients with acute myocardial infarction complicated by cardiogenic shock

The clinical impact of different polymer technologies in newer-generation drug-eluting stents (DESs) for patients with acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) remains poorly understood. We investigated the efficacy and safety of durable polymer DESs (DP-DESs) compared with biodegradable polymer DESs (BP-DESs). A total of 620 patients who underwent percutaneous coronary intervention with newer-generation DESs for AMI complicated by CS was divided into two groups based on polymer technology: the DP-DES group (n = 374) and the BP-DES group (n = 246). The primary outcome was target vessel failure (TVF) during a 12-month follow-up, defined as a composite of cardiac death, myocardial infarction, or target vessel revascularization. Both the DP-DES and BP-DES groups exhibited low stent thrombosis rates (1.3% vs. 1.6%, p = 0.660). The risk of TVF did not significantly differ between the two groups (34.2% vs. 28.5%, hazard ratio [HR] 0.94, 95% confidence interval [CI] 0.69–1.29, p = 0.721). This finding remained consistent after adjustment with inverse probability of treatment weighting (28.1% vs. 25.1%, HR 0.98, 95% CI 0.77–1.27, p = 0.899). In AMI patients complicated by CS, the risk of a composite of cardiac death, myocardial infarction, or target vessel revascularization was not significantly different between those treated with DP-DESs and those treated with BP-DESs.Trial registration: RESCUE registry, https://clinicaltrials.gov/ct2/show/NCT02985008, NCT02985008.

Bio-based, closed-loop chemical recyclable aromatic polyamide from 2,5-furandicarboxylic acid: Synthesis, high performances, and degradation mechanism

The resource and environmental challenges posed by the extensive use and disposal of plastics have increased the urgency of research into plastic recycling and the hunt for bio-based alternative feedstocks. As one of the five general engineering polymers, polyamide has not yet been systematically explored in terms of its recycling performance or mechanism, especially aromatic polyamides. In addition, research on novel structured bio-based aromatic polyamides has not received sufficient attention due to the harsh polymerization conditions. In this work, bio-based fully aromatic polyamides based on 2,5-furandicarboxylic acid (FDCA) was successfully synthesized through the acyl chloride method, exhibiting thermal, mechanical, and barrier properties comparable to or superior to those of fossil derived isophthalic acid based polyamides. Moreover, both synthesized polyamides could be hydrolyzed in alkaline environments through the cleavage of amide bonds, as demonstrated by molecular dynamics simulations. The presence of furan rings lowered the energy barrier of hydrolysis as compared to benzene rings. Furthermore, a simple and efficient acidification followed by filtration approach with high recovery yields was developed to recover initial monomers from degradation solutions, thus achieving closed-loop chemical recovery of two polyamides. This work will further expand the application of bio-based feedstock, FDCA, and open new avenues for polyamide recycling research.

In-situ polymerization of PANI nanocone array on PEN nanofibrous membranes for solar-driven interfacial evaporation

Solar-driven interfacial evaporation (SDIE) holds great potential for desalination, but it also poses challenges to application performance. Herein, a novel polyaniline (PANI) modified polyarylene ether nitrile (PEN) electrospun nanofibrous membranes (PANI@PEN) was developed by introducing PDA and CTAB, which increased the polymerization amount of PANI and controlled its morphology by sequential in-situ polymerization, aiming to enhance its SDIE comprehensive performance. This unique structure can generate multiple diffuse reflections under sunlight, resulting in the highest water evaporation rate of the nanofibrous membrane at 1.822 kg m−2 h−1, while evaporation rate at 1.527 kg m−2 h−1 for a 3.5 wt% sodium chloride solution. Due to the good flexibility of PEN polymer substrate, the obtained membranes can be easily arched, showcasing an interesting ability to collect salt through salt deposition. Meanwhile, PEN also provides a robust skeleton, endowed PANI@PENs with corrosion-resistant, capable of desalination in acidic media, purifying heavy metal ion solutions through evaporation, as well as good mechanical properties for reusability. The study potentially provides a strategy for utilizing dopamine and CTAB loaded on high-performance polymer nanofibrous membranes and the convenient in-situ polymerization to generate advanced photothermal PANI. This strategy paves a way to enable high-performance engineering polymer, PEN, with solar-thermal evaporation capabilities, further opening its potential applications in seawater desalination and industrial wastewater purification.

In situ synthesis of novel trans‐1, 4‐polyisoprene/isotactic polybutene reactor blends with multi‐component structure

AbstractIn this paper, a series of novel trans‐1, 4‐polyisoprene/isotactic polybutene (TPI/iPB) in‐reactor blends were synthesized by isoprene and butene sequential two‐stage polymerization technology with spherical TiCl4/MgCl2 type Ziegler‐Natta catalyst. The components, structures, and properties of the as‐obtained TPI/iPB reactor blends were characterized by gel permeation chromatography, Fourier transform Infrared spectroscopy, and differential scanning calorimetry. The active trans‐1, 4‐polyisoprene (TPI) particles obtained in the initial isoprene polymerization by the Z‐N catalyst can be acted as microreactors to initiate butene polymerization subsequently. The TPI/iPB reactor blends with varied components were in situ synthesized within the reactor. The preparative‐temperature rising elution fractionation (p‐TREF) technique was used to fractionate the TPI/iPB reactor blends based on the elution temperature ranged from −40°C to 90°C. The weight distribution and microstructure of each fraction were investigated. The reactor blends are composed of crystallizable high trans‐1, 4‐uint polyisoprene obtained from the first‐stage isoprene polymerization, high isotactic polybutene obtained from the second‐stage butene polymerization and TPI‐b‐iPB block copolymer with different sequence structure obtained from the initial time of the second stage. This work is expected to propose the possible polymerizations of a‐olefins and conjugated dienes by using heterogeneous Ziegler‐Natta catalyst and provide a kind of novel rubber/plastic reactor blend materials.Highlights The first synthesis of the trans‐1, 4‐polyisoprene/isotactic polybutene reactor blends. p‐TREF technique was used to analyze the composition of TPI/iPB reactor blends. Detailed structure characterization of the fractions including GPC and NMR TPI‐b‐iPB block copolymer can be obtained through the sequential polymerization. Rubber/plastic reactor blend materials were fabricated by the Z‐N catalyst.

Cage Nanofillers' Influence on Fire Hazard and Toxic Gases Emitted during Thermal Decomposition of Polyurethane Foam.

Polyurethane (PUR), as an engineering polymer, is widely used in many sectors of industries. However, the high fire risks associated with PUR, including the smoke density, a high heat release rate, and the toxicity of combustion products limit its applications in many fields. This paper presents the influence of silsesquioxane fillers, alone and in a synergistic system with halogen-free flame-retardant compounds, on reducing the fire hazard of polyurethane foams. The flammability of PUR composites was determined with the use of a pyrolysis combustion flow calorimeter (PCFC) and a cone calorimeter. The flammability results were supplemented with smoke emission values obtained with the use of a smoke density chamber (SDC) and toxicometric indexes. Toxicometric indexes were determined with the use of an innovative method consisting of a thermo-balance connected to a gas analyzer with the use of a heated transfer line. The obtained test results clearly indicate that the used silsesquioxane compounds, especially in combination with organic phosphorus compounds, reduced the fire risk, as expressed by parameters such as the maximum heat release rate (HRRmax), the total heat release rate (THR), and the maximum smoke density (SDmax). The flame-retardant non-halogen system also reduced the amounts of toxic gases emitted during the decomposition of PUR, especially NOx, HCN, NH3, CO and CO2. According to the literature review, complex studies on the fire hazard of a system of POSS-phosphorus compounds in the PUR matrix have not been published yet. This article presents the complex results of studies, indicating that the POSS-phosphorous compound system can be treated as an alternative to toxic halogen flame-retardant compounds in order to decrease the fire hazard of PUR foam.

Application of Life Cycle Assessment to Analysis of Fibre Composite Manufacturing Technologies in Shipyards Industry

Life cycle assessment (LCA) is used to evaluate the environmental load of fibre composite manufacturing technologies in the shipyards industry in a frame of the Fibre4Yards (Horizon 2020) project. This paper is focused on the LCA of fibre-reinforced polymer (FRP) technologies used to produce all elements of the floating unit, i.e., the conventional vacuum infusion technology for the deck panel and adaptive mould process for superstructure panels, ultraviolet (UV) curved pultrusion process for the production of stiffeners, hot stamping technology for brackets, and three-dimensional (3D) printing and automatic tape placement (ATP) for pillars. Environmental impact was assessed based on standard indicators: Global Warming Potential, water consumption, and fossil resource scarcity. The results indicate that the total carbon footprint of analysed FRP technologies is mainly produced by the type of the materials applied rather than by the amount of energy consumed during the process.

Polymer composite materials and technologies used in sports industry: a review

The article provides a review of scientific and technical literature, including Russian and foreign periodicals, patents for inventions in the field of creating products for the sports industry from polymer composite materials. The technologies and technical solutions used to achieve the assigned tasks, the advantages and disadvantages of using the methods are considered. It is shown that the use of modern achievements in materials science, a new generation of materials and advanced technologies can contribute to the achievement of high sports results.

Reduction of mesoporous poly(ether ether ketone) materials, preserving pore size

AbstractPoly(ether ether ketone) (PEEK) is an important high‐performance engineering polymer that is used extensively in numerous engineering applications that require chemical, solvent and thermal resistance. These attributes make PEEK attractive for the preparation of porous materials and membranes. Chemical modifications of preformed porous PEEK materials can expand the utilization of PEEK in a range of applications. It is desirable to carry out chemical functionalization without affecting the preformed porous structure or the degree of polymer crystallinity responsible for the sought‐after properties. We report here on the heterogeneous functionalization of preformed mesoporous PEEK materials with hydroxyl groups using sodium borohydride as a reducing agent in a poly(ethylene glycol)/tetrahydrofuran solvent mixture. The pore structure of functionalized materials was characterized, and the degree of modification with functional groups was measured as a function of reaction protocol. The methodology was applied to the preparation of porous PEEK materials in the form of beads and hollow fibers that differed in semicrystalline morphology and pore structure. The degree of surface modification by –OH groups in reduced PEEK (PEEK‐OH) porous materials was determined quantitatively by measuring the carbocation adduct concentration formed upon the dissolution of PEEK‐OH in sulfuric acid using UV–visible spectroscopy. Bis(4‐(4‐methoxyphenoxy)phenyl)methanone was used to optimize the reaction condition protocol. The degree of crystallinity and pore structure of the functionalized articles were largely preserved following modification. © 2024 Society of Industrial Chemistry.

On‐Surface Isomerization of Indigo within 1D Coordination Polymers

AbstractNatural products are attractive components to tailor environmentally friendly advanced new materials. We present surface‐confined metallosupramolecular engineering of coordination polymers using natural dyes as molecular building blocks: indigo and the related Tyrian purple. Both building blocks yield identical, well‐defined coordination polymers composed of (1 dehydroindigo : 1 Fe) repeat units on two different silver single crystal surfaces. These polymers are characterized atomically by submolecular resolution scanning tunnelling microscopy, bond‐resolving atomic force microscopy and X‐ray photoelectron spectroscopy. On Ag(100) and on Ag(111), the trans configuration of dehydroindigo results in N,O‐chelation in the polymer chains. On the more inert Ag(111) surface, the molecules additionally undergo thermally induced isomerization from the trans to the cis configuration and afford N,N‐ plus O,O‐chelation. Density functional theory calculations confirm that the coordination polymers of the cis‐isomers on Ag(111) and of the trans‐isomers on Ag(100) are energetically favoured. Our results demonstrate post‐synthetic linker isomerization in interfacial metal‐organic nanosystems.

On-Surface Isomerization of Indigo within 1D Coordination Polymers.

Natural products are attractive components to tailor environmentally friendly advanced new materials. We present surface-confined metallosupramolecular engineering of coordination polymers using natural dyes as molecular building blocks: indigo and the related Tyrian purple. Both building blocks yield identical, well-defined coordination polymers composed of (1 dehydroindigo : 1 Fe) repeat units on two different silver single crystal surfaces. These polymers are characterized atomically by submolecular resolution scanning tunnelling microscopy, bond-resolving atomic force microscopy and X-ray photoelectron spectroscopy. On Ag(100) and on Ag(111), the trans configuration of dehydroindigo results in N,O-chelation in the polymer chains. On the more inert Ag(111) surface, the molecules additionally undergo thermally induced isomerization from the trans to the cis configuration and afford N,N- plus O,O-chelation. Density functional theory calculations confirm that the coordination polymers of the cis-isomers on Ag(111) and of the trans-isomers on Ag(100) are energetically favoured. Our results demonstrate post-synthetic linker isomerization in interfacial metal-organic nanosystems.

A self-stiffening compliant intracortical microprobe

Utilising a flexible intracortical microprobe to record/stimulate neurons minimises the incompatibility between the implanted microprobe and the brain, reducing tissue damage due to the brain micromotion. Applying bio-dissolvable coating materials temporarily makes a flexible microprobe stiff to tolerate the penetration force during insertion. However, the inability to adjust the dissolving time after the microprobe contact with the cerebrospinal fluid may lead to inaccuracy in the microprobe positioning. Furthermore, since the dissolving process is irreversible, any subsequent positioning error cannot be corrected by re-stiffening the microprobe. The purpose of this study is to propose an intracortical microprobe that incorporates two compressible structures to make the microprobe both adaptive to the brain during operation and stiff during insertion. Applying a compressive force by an inserter compresses the two compressible structures completely, resulting in increasing the equivalent elastic modulus. Thus, instant switching between stiff and soft modes can be accomplished as many times as necessary to ensure high-accuracy positioning while causing minimal tissue damage. The equivalent elastic modulus of the microprobe during operation is ≈ 23 kPa, which is ≈ 42% less than the existing counterpart, resulting in ≈ 46% less maximum strain generated on the surrounding tissue under brain longitudinal motion. The self-stiffening microprobe and surrounding neural tissue are simulated during insertion and operation to confirm the efficiency of the design. Two-photon polymerisation technology is utilised to 3D print the proposed microprobe, which is experimentally validated and inserted into a lamb’s brain without buckling.

Molecular engineering of cross-linked polymers based on camphor substituted quinoxaline and 2,5-dithiophen-2-yl-pyrrole for efficient electrochromic energy storage devices

In this work, two donor–acceptor monomers SNSCQH and SNSCQF consisting of two 2,5-dithiophen-2-yl-pyrrole units and camphor substituted quinoxaline-based linkers were developed for electrochromic and energy storage applications. The cross-linked conjugated polymer thin films PSNSCQH and PSNSCQF were successfully prepared through electrochemical polymerization of the corresponding monomers and deposited on ITO substrates, which exhibited remarkable electrochromic performance, involving large optical contrast over 50 %, short response time less than 1.5 s, and high coloration efficiency over 220 cm2/C. Moreover, both PSNSCQH and PSNSCQF demonstrated large areal specific capacitance, with values of 9.27 mF/cm2 and 10.13 mF/cm2 at a current density of 0.1 mA/cm2, respectively. Additionally, electrochromic energy storage devices based on PSNSCQH and PSNSCQF thin films in a sandwich configuration were fabricated, enabling visualization of the energy storage state through color changes. This study provided valuable insights into the behavior of cross-linked two-dimensional conjugated polymers with intermolecular interactions between layers for electrochemical devices.