Polymerization Process Research Articles

Maize‐derived zein/acrylic hybrid emulsion for superior skin adhesion and water resistance in cosmetic adhesives

AbstractWaterborne acrylic emulsions are considered suitable materials for cosmetic skin adhesives because of their positive attributes, such as their safe water‐based polymerization process and low volatile‐organic‐compound emissions. The significant challenge of inadequate water resistance in emulsion adhesives, which is primarily caused by the excess surfactants retained at the interface of emulsion particles upon film formation, necessitates urgent resolution for their viable application as cosmetic adhesives. Zein, a corn‐derived protein, possesses hydrophobic amino acids that provide exceptional water‐repellent characteristics. Therefore, zein is expected to exhibit a remarkable skin‐adhesion attribute. This paper presents the introduction of a pioneering zein/acrylic hybrid emulsion exhibiting remarkable skin adhesion and water resistance, which was achieved through the use of zein, a corn‐derived protein. After formation, the zein/ sodium dodecyl sulfate (SDS) complex can unfold the zein chain, thereby enhancing skin adhesion, while concurrently inhibiting surfactant migration to enhance water resistance. The zein/SDS complex was introduced into the Pre‐emulsion (PE) manufacturing process during emulsion polymerization. As expected, the zein/acrylic hybrid emulsion demonstrated favorable skin adhesion and a notable improvement in water resistance. This approach presents a promising avenue for the practical application of emulsion nanoparticles as eco‐friendly cosmetic adhesives, offering excellent durability and skin adhesion through the utilization of naturally derived proteins.

A universal method for preparing biomass derived topologically defective carbons with superior catalytic performance in cationic radical polymerization

This study aims to develop a universal preparation method for biomass-derived topologically defective carbons and reveal the catalytic mechanism of such carbons for cationic radical polymerization. Firstly, bamboo fiber-derived topologically defective carbon (BFTC) is prepared by an ammonia-assisted heat treatment method. BFTC can significantly promote the chemical oxidative polymerization of 3-aminophenylboronic acid (a typical cationic radical polymerization process) and obtain high molecular weight products, which is mainly attributed to the rich topological defect structure of BFTC. Secondly, the ammonia-assisted heat treatment method is applied to two other biomasses, and the derived carbons have similar microstructure and chemical composition to BFTC, indicating the universality of this method at the material preparation level; meanwhile, these derived carbons also exhibit excellent catalytic properties when they promote 3-aminophenylboronic acid (ABA) polymerization, which further confirms the universality of this method from the perspective of material properties. Finally, research on the catalytic mechanism shows that there is an interaction based on partial electron transfer between the topological defects of the carbon catalyst and ABA or ABA-derived radical. This effect promotes the rapid derivatization of ABA into cationic radical, and also improves the stability of the radical, thereby achieving efficient polymerization of ABA around the topological defect active center. Therefore, this study confirms the universality of the ammonia-assisted heat treatment method to prepare biomass-derived topologically defective carbon, and such defective carbons are likely to serve as catalysts for cationic radical polymerization.

Ultrahighly Li-selective nanofiltration membranes prepared via tailored interfacial polymerization

Nanofiltration (NF) membrane-based separation has gained significant attention as an efficient technology for recovering lithium (Li) from salt-lake brines. However, many previously developed NF membranes are not commercially feasible because they lack sufficient Li selectivity and require the use of new monomers/chemicals or complicated fabrication processes. Herein, we propose a commercially viable method to fabricate ultrahighly Li-selective polyamide (PA) membranes by carefully tailoring a conventional interfacial polymerization process using an established piperazine (PIP)/trimesoyl chloride monomer system. The use of excess PIP endowed the fabricated membrane with enhanced PA crosslinking density and a positive surface charge, reinforcing both its size and Donnan exclusion mechanisms. Furthermore, the addition of benzyltributylammonium chloride, a cationic surfactant, to the PIP solution effectively improved the water permeance of the membrane without impairing its magnesium ion (Mg2+) rejection by loosening its PA network while enhancing its positive surface charge. Consequently, our tailor-made PA membranes with the proper pore structures and strong positive surface charges exhibited ultrahigh Li+/Mg2+ selectivity of up to 150 (under single-salt conditions) and 887 (under mixed-salt conditions), significantly outperforming commercial and other reported laboratory-made NF membranes. Our strategy provides a facile and effective means to manufacture Li-selective membranes with high commercial viability.

Self-catalysed frontal polymerisation enables fast and low-energy processing of fibre reinforced polymer composites

Frontal polymerisation has the potential to bring unprecedented reductions in energy demand and process time to produce fibre reinforced polymer composites. Production of epoxy-based fibre reinforced polymer parts with high fibre volume content, commonly encountered in industry, is however hindered by the heat sink created by the fibres and the mould, overcoming the heat output of the chemical reaction, thus preventing front propagation. We propose a novel self-catalysed frontal polymerisation manufacturing method based on the integration of thin resin channels in thermal contact with the composite stack as a strategy for low-energy production of high fibre volume fraction polymer composites without the need for a continuous energy input. Frontal polymerisation inside the resin channel proceeds faster and preheats the fabric stack, thus catalysing the process. Parts with up to 60% fibre content are successfully produced independently of the sample thickness. Fillers added within the resin channels provide means to tailor the frontal polymerisation process kinetics. The parts have a significantly higher glass transition temperature than those produced in a conventional oven, and comparable mechanical properties while energy consumption is reduced by over 99.5%.

431 Defective uromodulin polymerization and peptide excretion in a natural canine model of kidney stones

OBJECTIVES/GOALS: Using a natural canine model of kidney stone disease, we previously identified a pathogenic variant in the uromodulin gene (UMOD) that imparts a dramatic risk for calcium oxalate (CaOx) stones. This study was designed to characterize the effects of the pathogenic variant on uromodulin processing, specifically polymerization and peptide excretion. METHODS/STUDY POPULATION: Uromodulin polymerization status and peptides were measured in random urine samples from CaOx stone-forming dogs with the pathogenic UMOD variant and breed-, sex-, and age-matched healthy control dogs. Polymerization status was determined using an ultracentrifugation protocol and Western blotting in 6 CaOx cases and 3 controls; relative abundance of the polymerizing and nonpolymerizing forms was evaluated. Uromodulin peptide abundances were measured by LC-MS/MS with 4 dogs per group; results were summed to determine total uromodulin peptide excretion for each dog, and individual peptide abundances were calculated as a percentage of the total. Polymerization status and peptides were compared between groups. RESULTS/ANTICIPATED RESULTS: Dogs with the pathogenic UMOD variant had abnormalities in both uromodulin polymerization and peptide processing. The polymerization data showed that the polymerizing form of uromodulin was abundant in all healthy controls but absent or severely reduced in most dogs with the variant. In contrast, nonpolymerizing uromodulin was detected in all dogs with no observed difference between those with and without the variant. The peptidomics data showed that stone-forming dogs with the pathogenic UMOD variant lacked a peptide cleavage site, resulting in the loss of two common peptides that terminate at that site and the presence of longer peptides that span the site. DISCUSSION/SIGNIFICANCE: These findings implicate uromodulin polymerization and peptide processing defects in kidney stone risk. Future studies will define the mechanisms through which these defects affect stone formation, ultimately informing development of novel preventative therapies.

Investigating and characterizing electrical properties of polypyrrole/SiO2/FePS3 nanocomposite

AbstractNovel nanocomposites of polypyrrole (PPy) embedded in silica (SiO2) and iron phosphorus trisulphide (FePS3) nanoparticles have been fabricated. The nanocomposite's dielectric characteristics have been examined in relation to temperature ranges of 25–200°C and frequency ranges of 0.1–7 MHz. Fourier‐transform infrared spectroscopy (FTIR), x‐ray diffraction (XRD), scanning electron microscopy (SEM–EDX), transmission electron microscope (TEM), and dielectric measurements have all been used to evaluate the prepared nanocomposite. The monoclinic crystal structure of the prepared FePS3 and PPy/SiO2/FePS3 nanocomposite is confirmed by XRD, EDX, and TEM studies. The FePS3 is perfectly layered structure in the SEM image, and FePS3 and SiO2 particles are well intercalated, creating novel nanocomposites of two nanoparticle phases that served as a union network during the polymerization process. The IR spectrum shows that PPy is a dopant in the interlayer area of FePS3. The splitting major peak (570 cm−1) of FePS3 is visible at around 640 and 560 cm−1. The high AC conductivity values indicated that the combination of FePS3/SiO2 nano‐matrix contains PPy at high packing densities and confirming the semiconducting properties of the nanocomposite to be used in several electronic applications.

Preparation of cholesterol-imprinted polymer for selective adsorption of cholesterol from gastrointestinal mimicking solution.

The purpose of this study is to synthesize a highly selective adsorbent to remove cholesterol, one of the most important causes of cardiovascular diseases, from the intestinal mimic solution (IMS). For this purpose, cholesterol imprinted polymers were synthesized by suspension polymerization method using the molecular imprinting technique. In the first step, the functional monomer MATyr with hydrophobic character was synthesized. Then, the cholesterol-MATyr monomer precomplex was formed and the polymerization process was carried out by adding cross-linkers with the comonomer HEMA. The synthesized polymer poly(2-hydroxyethyl methacrylate-N-methacryloyl-(L)-tyrosine methylester) poly(HEMA-MATyr) was characterized by FTIR and SEM. The cholesterol adsorbing behavior of the synthesized poly(HEMA-MATyr) microbeads adsorbent was investigated at different initial concentrations, different temperatures, and adsorption times. The maximum adsorption capacity of microbeads was determined as 56.67 mg/g at a concentration of 2.5 mg/L. The amount of cholesterol adsorbed in the IMS was found as 83.07 mg/g polymer, which indicates that 92% of the cholesterol in the medium was adsorbed. The selectivity behavior of the cholesterol imprinted polymer was carried out with the stigmasterol and estradiol molecules, which are similar in structure, molecular weight, and character to the cholesterol molecule. The chol-imprinted polymeric beads were 21.38 and 10.08 fold more selective for cholesterol compared to estradiol and stigmasterol steroids used as competitor agents respectively. Kinetic and isotherm calculations of the synthesized cholesterol imprinted polymer were made and reusability experiments were carried out.

Synthesis of HfC nanowires on carbon fibers by a novel catalyst-assisted pyrolysis using HfCl4 as precursor

The synthesis of hafnium carbide nanowires (HfCNWs) on carbon fibers was successfully achieved by employing HfCl4 and furfuryl alcohol as precursor materials, facilitated by Ni-assisted catalytic pyrolysis. In the polymerization and cross-linking processes of furfuryl alcohol, hafnium cations play a crucial role, leading to the atomic-level amalgamation and effectively enhancing the reactivity of the Hf-O-C system. The nucleation of HfCNWs takes place at 1300 °C, followed by growth through a solid-liquid-solid (SLS) mechanism. Carbon fibers were uniformly coated with tens micrometer-long HfCNWs having an approximate diameter of 500 nm. Notably, the tips of these HfCNWs exhibited clean surfaces free of Ni catalyst particles, indicating their root growth model. This novel catalyst-assisted pyrolysis method holds great potential for enabling cost-effective large-scale production of transition metal carbide nanowires.

Utilizing municipal solid waste incineration bottom ash and volcanic tuff to produce geopolymer materials

Large volumes of municipal solid waste incineration bottom ash (MSWIBA) are produced annually in China; however, their improper disposal causes serious ecological and environmental problems. This study investigated the feasibility of using MSWIBA and volcanic tuff to produce geopolymers. The effects of the MSWIBA content, silicon–sodium molar ratio, and alkali equivalent on the uniaxial compressive strength (UCS) and bulk density of the geopolymer samples were examined using single-factor and optimization tests. The test results showed that the UCS and bulk density of the geopolymer decreased as the MSWIBA content increased, whereas they increased as the alkali equivalent increased. As the silicon–sodium molar ratio increased, the UCS first increased and then decreased, and the change in bulk density was limited. In the final geopolymer preparation, the MSWIBA content was 17.85%, the silicon–sodium molar ratio was 1.71, and the alkali equivalent was 9.49%. According to X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, energy-dispersive spectrometry, and nuclear magnetic resonance analyses, the main phases of the geopolymer under the final preparation parameters were quartz, sanidine, calcite, orthoclase, gismondine, and illite. During the geological polymerization process, a large amount of CNASH gel was generated and attached to the surface of the particles or filled the pores between the particles, resulting in a pore size of 0.01–1 μm. The heavy metals in the geopolymers exhibited a good stabilization effect owing to the CNASH gel. Except for Cd, which posed a medium risk, the remaining heavy metals posed low or no risk.

Polymer-encapsulated Sm-doped nano-hydroxylapatite and its antibacterial property☆

Hydroxylapatite (HAp), owing to its excellent biocompatibility, is a promising carrier for lanthanide ions to encourage antibacterial activity. However, hydroxylapatite powder would still require modification to ensure the optimal integration of antibacterial characteristics. In this study, Sm-doped nano-hydroxylapatite (SmHAp) was synthesized by spontaneous mineralization of amorphous SmHAp precursors, which ensures a homogeneous distribution of Sm3+ within bulk SmHAp. Powder X-ray diffraction and its Pawley fitting results for SmHAp indicate the lattice substitution of Ca2+ with Sm3+, resulting in the lattice distortion in SmHAp compared to pure HAp. Meanwhile, polymer-encapsulated Sm-doped nano-hydroxylapatite composite (p_SmHAp) was synthesized by a dual-step polymerization involving UV curing of an outer crust and heat treatment for bulk reaction completion. Irgacure 2959 and a toluene solution of AIBN were used as catalysts for the radical polymerization process. The antibacterial property of p_SmHAp was evaluated by observing the growth of Sporosarcina pasteurii (ATCC 11859) both in the solid and the liquid medium, correlating with the Sm fraction and SmHAp’s crystallinity in p_SmHAp. These bacteriostatic rings' diameters exceed 20 mm, demonstrating that p_SmHAp with a SmHAP/p_SmHAp mass ratio of 0.1 and Sm/(Ca+Sm) molar ratio of 0.05−0.1 effectively releases Sm3+, serving as a strong antibacterial agent.

Situ synthesis and characterization of polypyrrole/ZnO Nanocomposites for optical and photocatalytic activity

In situ polymerisation process used for manufacturing polypyrrole (PPy) nanoparticle-reinforced various doping concentration of zinc oxide (ZnO NPs) nanocomposites. Fourier transform infrared(FTIR), Scanning electron microscopy(SEM), Photo luminescence (PL) and UV-vis spectroscopy was used to characterise the polymer nanocomposite. The ZnO nanoparticles are distributed throughout PPy matrix as shown in the SEM pictures of the nanocomposites. Distinctive peaks of Pure PPy and metal oxide bond of ZnO are as displayed in the FTIR spectra. Optical property of PPy, ZnO and PPy/ZnO was studied by using PL and UV-DRs spectrophotometer. These outcomes demonstrated that the synthesised PZ30 nanoparticles could potentially use in the treatment of wastewater.

A new radical initiation for the ring-opening polymerization of tetrahydrofuran with a radical substitution mechanism

A new radical-Lewis acid system has been discovered to achieve the ring-opening polymerization of tetrahydrofuran. Different types of reaction mechanisms were discovered for the initiation and polymerization processes. The proposed initiation mechanism was studied by MALDI-TOF and ESI-MS as a radical substitution mechanism and polymerization was a coordination-insertion mechanism. And polytetrahydrofuran with high molecular weight (Mn = 14.6 × 104 g mol−1) and narrow molecular weight distribution (PDI = 1.44) could be obtained.

Studying the Structure and Properties of Epoxy Composites Modified by Original and Functionalized with Hexamethylenediamine by Electrochemically Synthesized Graphene Oxide.

In this study, we used multilayer graphene oxide (GO) obtained by anodic oxidation of graphite powder in 83% sulfuric acid. The modification of GO was carried out by its interaction with hexamethylenediamine (HMDA) according to the mechanism of nucleophilic substitution between the amino group of HMDA (HMDA) and the epoxy groups of GO, accompanied by partial reduction of multilayer GO and an increase in the deformation of the carbon layers. The structure and properties of modified HMDA-GO were characterized using research methods such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy and Raman spectroscopy. The conducted studies show the effectiveness of using HMDA-OG for modifying epoxy composites. Functionalizing treatment of GO particles helps reduce the free surface energy at the polymer-nanofiller interface and increase adhesion, which leads to the improvement in physical and mechanical characteristics of the composite material. The results demonstrate an increase in the strength and elastic modulus in bending by 48% and 102%, respectively, an increase in the impact strength by 122%, and an increase in the strength and elastic modulus in tension by 82% and 47%, respectively, as compared to the pristine epoxy composite which did not contain GO-HMDA. It has been found that the addition of GO-HMDA into the epoxy composition initiates the polymerization process due to the participation of reactive amino groups in the polymerization reaction, and also provides an increase in the thermal stability of epoxy nanocomposites.

Multi-Stimuli-Responsive, Topology-Regulated, and Lignin-Based Nano/Microcapsules from Pickering Emulsion Templates for Bidirectional Delivery of Pesticides.

The increasing demand for improving pesticide utilization efficiency has prompted the development of sustainable, targeted, and stimuli-responsive delivery systems. Herein, a multi-stimuli-responsive nano/microcapsule bidirectional delivery system loaded with pyraclostrobin (Pyr) is prepared through interfacial cross-linking from a lignin-based Pickering emulsion template. During this process, methacrylated alkali lignin nanoparticles (LNPs) are utilized as stabilizers for the tunable oil-water (O/W) Pickering emulsion. Subsequently, a thiol-ene radical reaction occurs with the acid-labile cross-linkers at the oil-water interface, leading to the formation of lignin nano/microcapsules (LNCs) with various topological shapes. Through the investigation of the polymerization process and the structure of LNC, it was found that the amphiphilicity-driven diffusion and distribution of cyclohexanone impact the topology of LNC. The obtained Pyr@LNC exhibits high encapsulation efficiency, tunable size, and excellent UV shielding to Pyr. Additionally, the flexible topology of the Pyr@LNC shell enhances the retention and adhesion of the foliar surface. Furthermore, Pyr@LNC exhibits pH/laccase-responsive targeting against Botrytis disease, enabling the intelligent release of Pyr. The in vivo fungicidal activity shows that efficacy of Pyr@LNC is 53% ± 2% at 14 days postspraying, whereas the effectiveness of Pyr suspension concentrate is only 29% ± 4%, and the acute toxicity of Pyr@LNC to zebrafish is reduced by more than 9-fold compared with that of Pyr technical. Moreover, confocal laser scanning microscopy shows that the LNCs can be bidirectionally translocated in plants. Therefore, the topology-regulated bidirectional delivery system LNC has great practical potential for sustainable agriculture.

Emulsion polymerization process: effects of particle nucleation mechanism on properties of acrylic-styrene latex

Emulsion polymerization process: effects of particle nucleation mechanism on properties of acrylic-styrene latex

MiRNA-Responsive 3D DNA walker nanoprobe for intracellular imaging, cell typing, and clinical diagnostics

Achieving reliable miRNA detection and imaging remains a critical and formidable challenge. To address this challenge, we developed a three-dimensional (3D) DNA walker nanoprobe (DWN), derived from a multifunctional molecular beacon with a lipidic moiety. This innovative structure employs a cholesterol-conjugated multifunctional molecular beacon (Chol-MMB) assembled through hydrophobic interactions, thereby bypassing the cumbersome and inefficient process of immobilizing DNA strands onto rigid surfaces. Once the walker nanoprobe enters cells, the binding between the target miRNA and the nanoprobe triggers an intermolecular polymerization process, leading to a conformational change in DWN. This change liberates a walking strand, initiating the walking reaction. As a result, the 3D DNA walker nanoprobe illuminates the fluorophore, enabling precise quantitative analysis. The efficacy of the DWN was demonstrated by the limit of detection of 0.326 fmol for miR-21 with a reaction duration of 1 h. In addition, this strategy effectively differentiates various cells based on the specific miRNA. Further refinement of this method will lead to an efficacious miRNA-based platform for cell typing and liquid biopsy.

Simulation approach to study kinetic heterogeneity of gadolinium catalytic system in the 1,4-cis-polyisoprene production

Abstract This article presents a novel simulation approach for solving the inverse problem of kinetic heterogeneity in polymerization processes, specifically focusing on the production of polyisoprene using a gadolinium chloride solvate-based catalytic system. The proposed method is based on the assumption that the distribution of active centers (ACs) can be described by model distributions. By utilizing primary physicochemical data, such as the polymerization rate and molecular weight distribution, the simulation approach automatically identifies the kinetic parameters, determining the Frenkel statistical parameter and solving the problem of kinetic heterogeneity. The experimental results revealed the presence of at least three distinct types of ACs, each contributing different proportions to the polymerization process. The simulation approach offers valuable insights into the complexities of catalytic systems and their role in polymerization, paving the way for optimizing reaction conditions and advancing industrial polymer synthesis processes. This study marks a significant step forward in understanding and controlling polymerization reactions, with potential implications for the development of innovative materials and industrial applications.

Light-Mediated Polymerization Catalyzed by Carbon Nanomaterials.

Carbon nanomaterials, specifically carbon dots and carbon nitrides, play a crucial role as heterogeneous photoinitiators in both radical and cationic polymerization processes. These recently introduced materials offer promising solutions to the limitations of current homogeneous systems, presenting a novel approach to photopolymerization. This review highlights the preparation and photocatalytic performance of these nanomaterials, emphasizing their application in various polymerization techniques, including photoinduced i) free radical, ii) RAFT, iii) ATRP, and iv) cationic photopolymerization. Additionally, it discusses their potential in addressing contemporary challenges and explores prospects in this field. Moreover, carbon nitrides, in particular, exhibit exceptional oxygen tolerance, underscoring their significance in radical polymerization processes and allowing their applications such as 3D printing, surface modification of coatings, and hydrogel engineering.

Multi-Functional Integration of Phosphor, Initiator, and Crosslinker for the Photo-Polymerization of Flexible Phosphorescent Polymer Gels.

A general approach to constructing room temperature phosphorescence (RTP) materials involves the incorporation of a phosphorescent emitter into a rigid host or polymers with high glass transition temperature. However, these materials often suffer from poor processability and suboptimal mechanical properties, limiting their practical applications. In this work, we developed benzothiadiazole-based dialkene (BTD-HEA), a multifunctional phosphorescent emitter with a remarkable yield of intersystem crossing (ΦISC, 99.83 %). Its high triplet exciton generation ability and dialkene structure enable BTD-HEA to act as a photoinitiator and crosslinker, efficiently initiating the polymerization of various monomers within 120 seconds. A range of flexible phosphorescence gels, including hydrogels, organogels, ionogels, and aerogels were fabricated, which exhibit outstanding stretchability and recoverability. Furthermore, the unique fluorescent-phosphorescent colorimetric properties of the gels provide a more sensitive method for the visual determination of the polymerization process. Notably, the phosphorescent emission intensity of the hydrogel can be increased by the formation of ice, allowing for the precise detection of hydrogel freezing. The versatility of this emitter paves the way for fabricating various flexible phosphorescence gels with diverse morphologies using microfluidics, film-shearing, roll coating process, and two/three-dimensional printing, showcasing its potential applications in the fields of bioimaging and bioengineering.

Multi‐Functional Integration of Phosphor, Initiator, and Crosslinker for the Photo‐Polymerization of Flexible Phosphorescent Polymer Gels

AbstractA general approach to constructing room temperature phosphorescence (RTP) materials involves the incorporation of a phosphorescent emitter into a rigid host or polymers with high glass transition temperature. However, these materials often suffer from poor processability and suboptimal mechanical properties, limiting their practical applications. In this work, we developed benzothiadiazole‐based dialkene (BTD‐HEA), a multifunctional phosphorescent emitter with a remarkable yield of intersystem crossing (ΦISC, 99.83 %). Its high triplet exciton generation ability and dialkene structure enable BTD‐HEA to act as a photoinitiator and crosslinker, efficiently initiating the polymerization of various monomers within 120 seconds. A range of flexible phosphorescence gels, including hydrogels, organogels, ionogels, and aerogels were fabricated, which exhibit outstanding stretchability and recoverability. Furthermore, the unique fluorescent‐phosphorescent colorimetric properties of the gels provide a more sensitive method for the visual determination of the polymerization process. Notably, the phosphorescent emission intensity of the hydrogel can be increased by the formation of ice, allowing for the precise detection of hydrogel freezing. The versatility of this emitter paves the way for fabricating various flexible phosphorescence gels with diverse morphologies using microfluidics, film‐shearing, roll coating process, and two/three‐dimensional printing, showcasing its potential applications in the fields of bioimaging and bioengineering.