Glycol Dimethacrylate Monomers Research Articles

Processable and shape-stable phase change materials with enhanced thermal conductivity of UV-cured NPGDMA aided PEG2000 and BN

Polyethylene glycol (PEG) has several drawbacks, including poor shape stability, low thermal conductivity, and challenges with complex molding. In this work, a rapid and simple approach for producing phase change materials (PCMs) with high thermal conductivity and good shape stability is reported. The neopentyl glycol dimethacrylate (NPGDMA) monomer is polymerized utilizing UV-cured technology, which can offer a cross-linked network to stop PEG2000 leakage and enhance the heat conductivity of the composite by adding BN. The best PEG2000-to-NPGDMA ratio in the PEG2000/NPGDMA/BN PCM is found to be 9:1, taking into account the shape stability and energy storage of the PCMs. The ideal amount of BN to add is 5 wt%, which improves the thermal conductivity by about 52.1 %. According to the DSC test, PEG2000/NPGDMA/BN has a significant capacity for storing heat with a melting enthalpy of up to 139.3 J/g. The PEG2000/NPGDMA/BN composite passed with good thermal cycling performance and no change in group composition after 101 thermal cycles. The prepared PCMs can be formed into complex shapes for use in particular applications.

Porous polymer nanocomposites containing single-walled carbon nanotubes for chromium (VI) removal from water

By using a high internal phase emulsion (HIPE) templating approach, we synthesize functional porous nanocomposites containing single-walled carbon nanotubes (SWCNTs). HIPEs are prepared from an oil phase consisting of 2-ethylhexyl acrylate (2-EHA) and ethylene glycol dimethacrylate (EGDMA) monomers, while the modified SWCNTs are dispersed in the aqueous phase using sodium dodecyl sulfate (SDS) surfactant. The resulting monolithic nanocomposites, denoted as PHIPE/SWCNT, with high porosity and effective functional groups are used for selective Cr(VI) removal from contaminated water. The effects of adsorption parameters such as the initial pH of the solution, adsorbent amount, contact time, and initial Cr(VI) concentration on the removal efficiency are investigated and optimized. The experimental results reveal that Cr(VI) adsorption kinetics and equilibrium in PHIPE/SWCNT are well described by the pseudo-second-order and the Langmuir models, respectively. The maximum adsorption capacity of PHIPE/SWCNT for Cr(VI) is found to be 72.35 mg g−1. The presence of competitive sulfate ions in the aqueous media can have a negative effect on the removal efficiency of the adsorbent. The regeneration studies show that the monolith can be reused several times by simply recovering under basic conditions.

RNA-Polymer Hybrids via Direct and Site-Selective Acylation with the ATRP Initiator and Photoinduced Polymerization.

Combining synthetic polymers with RNA paves the way for creating RNA-based materials with non-canonical functions. We have developed an acylation reagent that allows for direct incorporation of the atom transfer radical polymerization (ATRP) initiator into both short synthetic oligoribonucleotides and natural biomass RNA extracted from torula yeast. The acylation was performed in a quantitative yield. The resulting initiator-functionalized RNAs were used for grafting polymer chains from the RNA by photoinduced ATRP, resulting in RNA-polymer hybrids with narrow molecular weight distributions. The RNA initiator was used for the polymerization of oligo(ethylene oxide) methyl ether methacrylate, poly(ethylene glycol) dimethacrylate, and N-isopropylacrylamide monomers, resulting in RNA bottlebrushes, hydrogels, and stimuli-responsive materials. This approach, readily applicable to both post-synthetic and nature-derived RNA, can be used to engineer the properties of a variety of RNA-based macromolecular hybrids and assemblies providing access to a wide variety of RNA-polymer hybrids.

Synthesis, characterization of cross‐linked poly(ethylene glycol dimethacrylate‐methyl methacrylate‐N‐(1‐phenylethyl) acrylamide) copolymer and removal of copper(II), cobalt(II) ions from aqueous solutions via this copolymer

AbstractThis study investigates the synthesis and evaluation of a new polymeric adsorbent for adsorbing Cu2+ and Co2+ ions from aqueous solutions. In this study, R‐(+)‐methylbenzylamine and acryloyl chloride were used to synthesize N‐(1‐phenylethyl)‐acrylamide (PEA) monomer, and the synthesized PEA was characterized by FTIR, 1H‐NMR and 13C‐NMR. Then, using PEA, ethylene glycol dimethacrylate (EGDMA) and methyl methacrylate (MMA) monomers by radical polymerization reaction, cross‐linked poly(ethylene glycol dimethacrylate‐methyl methacrylate‐N‐(1‐phenylethyl)acrylamide) (poly(EGDMA‐co‐ MMA‐co‐PEA) copolymer was obtained. FTIR, solid‐NMR, and elemental analysis methods were used to characterize the poly(EGDMA‐co‐MMA‐co‐PEA) obtained. Poly(EGDMA‐co‐MMA)‐co‐PEA) copolymer was used as an adsorbent in the final stage of the study to remove copper (Cu2+) and cobalt (Co2+) ions from aqueous solutions. The study examined the effects of various variables including contact time, initial metal ion concentration, and pH on adsorption efficiency. The initial concentration, contact time, and solution pH that were found to be most effective for Cu2+ ion removal were 1000 mg/L, 20 min, and 6, respectively. The ideal working parameters for Co2+ removal were determined to be an initial concentration of 1000 mg/L, a contact period of 50 min, and a solution with a pH of 6. While the adsorption capacity of Cu2+ was 185.44 mg/g at 25°C, the adsorption capacity of Co2+ was 123.76 mg/g under the same conditions. The kinetic data were best described by the theoretical adsorption capacity, which was close to the experimentally determined value for the adsorption of Cu2+ and Co2+ ions, and the pseudo‐second‐order with the highest regression coefficient.

Preparation and optoelectronic characteristics of perovskite module devices in air assisted by polymer inner packaging layern

The preparation of traditional organic-inorganic lead-halogen hybrid perovskite solar cells often requires strict nitrogen glove box conditions, thus hindering their industrial scalability. This study develops a large-area perovskite film formation process and designs a novel device structure to achieve a dual enhancement of module device efficiency and stability in a high humidity air environment (55%). High-quality perovskite thin films are successfully prepared by vacuum extraction in ambient air, followed by a double-end low-temperature photopolymerization process utilizing acrylate monomer molecules for inner encapsulation modification of the freshly formed perovskite thin films. The influences of these techniques on the photoelectric characteristics of perovskite thin films and devices are investigated. The results indicate that uniform and dense perovskite films can be achieved in ambient air with a pumping time of 60 s. By adjusting the concentration of ethylene glycol dimethacrylate monomer molecules used in the low-temperature photopolymerization process, the surface defects on the perovskite film can be effectively controlled. The optimal concentration of 1 mg/mL results in perovskite film with optimal morphology and fluorescence intensity. Furthermore, rigid module device and flexible module device (effective area: 18 cm²), based on the polymer inner encapsulation, demonstrate outstanding outdoor photoelectric conversion efficiencies of 19.51% and 18.17%, respectively (with the highest indoor low-light conversion efficiencies of 34.5% and 30.2%, respectively). Notably, the untreated flexible device exhibits a significant decline in photoelectric conversion efficiency, falling below 50% of the initial value after one month of exposure to air. In contrast, device incorporating the polymer inner encapsulation layer maintains over 90% of their original efficiency, highlighting their excellent humidity resistance stability. Moreover, the polymer encapsulation layer also greatly improves the bending stability of the flexible device. This research paves the way for industrial-scale producing perovskite solar cells and addressing the challenges associated with humidity and large-area fabrication. The findings contribute to advancing perovskite solar cell technology and offering a pathway for high-efficiency and stable devices suitable for practical applications.

Analysis of Monomer Release from Different Composite Resins after Bleaching by HPLC.

(1) Background: This study aimed to examine the effect of bleaching agents on the release of triethylenae glycol dimethacrylate, 2-hydroxyethyl methacrylate, bisphenol A, urethane dimethacrylate, and bisphenol A-glycidyl methacrylate monomers, which are released from different composite resins, using the high-performance liquid chromatography (HPLC) method. (2) Methods: Ninety disc-shaped specimens were produced and immersed in artificial saliva. After different bleaching applications [office type bleaching (OB) and home type bleaching (HB)], the specimens were immersed in a 75 wt% ethanol/water solution, and the released monomers were analyzed by HPLC at predefined time intervals: 1, 7, and 28 days. The Kruskal-Wallis and Mann-Whitney U tests were conducted for statistical analysis (p = 0.05). (3) Results: The monomers were released at all times from all composite specimens. The monomer release was increased over time. The highest monomer release was detected on day 28. Bleaching applications affected monomer release. No statistical difference was found between OB and HB applications (p > 0.05). The most released monomer was Bisphenol-A in all composites. (4) Conclusion: Given that a residual monomer release from composite resins has a toxic effect and that bleaching treatments increase this release, a treatment protocol should be made in accordance with the manufacturer's instructions.

Effects of ionic liquids and dual curing on vat photopolymerization process and properties of 3d-printed ionogels

Ionic liquids (ILs) can facilitate photopolymerization reactions involved in the fabrication of ionogels (IGs). In this study, ILs were immobilized by 3D printing through polymerization of vinyl-monomers in their medium. The effect of ILs on the vat photopolymerization (VP) process was studied. Multiple IL-compatible photopolymer formulations were developed by using EmimBF4, BmimBF4, OmimBF4, and EmimTFSI ionic liquids and photocurable N-vinylpyrrolidone (NVP) and triethylene glycol dimethacrylate (TEGDMA) monomers. The photoinduced radical copolymerization of NVP with TEGDMA was studied using a combination of photo-DSC, Jacobs working curves and FTIR methods. The analysis revealed a dichotomy of IL-based VP as the addition of ILs led to a significant acceleration of polymerization and an increase in the critical exposure energy due to a higher conversion degree necessary for the gelation. Moreover, the Jacobs working curves showed that penetration depth dramatically changed with IL type. Based on these results, overcuring time was calculated and applied in the VP process to ensure that enough monomers were converted in each 3d-printed layer to prevent interlayer cracking. Furthermore, the dual curing approach was applied to achieve the highest possible conversion by adding a thermal initiator (AIBN). Dual curing increased the mechanical properties of ionogels but led to a reduced ionic conductivity due to an inhibition of IL’s mobility. In addition, this study found IL compositions for ionogels demonstrating no shrinkage after photopolymerization and post-curing. We suggest that the outcomes of the present study created a platform for fabricating high-resolution 3d-printed nonvolatile and nonflammable ionogels.

Preparation and characterization of silica based nanoclusters as reinforcement for dental applications

AbstractAs composite resins become the most extensively utilized material in the field of cosmetic and restorative dentistry, several strategies to overcome dental composites' challenges such as long‐term mechanical failure and secondary caries are continuously being developed. Among them, the design of suitable fillers to optimize their clinical performance has been given priority in addressing those shortcomings. In this study, silica‐based nanoclusters were synthesized and used as fillers to prepare UV curable dental composites was assessed. Nanoclusters were prepared by prepolymerization followed by pulverization and sieving of commercial silica nanoparticles with triethylene glycol dimethacrylate monomer. The composites were then made by filling 55:25:20 weight ratio of urethane dimethacrylate, bisphenol A glycidyl methacrylate, and triethylene glycol dimethacrylate, respectively with varying concentration of nanoclusters. The clusters and composites were characterized by SEM, TGA, and FTIR analyzes. The results have shown a significant improvement of physical and mechanical properties in composites containing nanoclusters. Increasing nanocluster concentration caused a reduction in composite polymerization shrinkage, water absorption and solubility as well as limited rise of flexural strength. At 50% filler load, nanoclusters doped composites exhibited higher flexural strength than nanoparticles doped composites. Furthermore, the blending of nanoclusters with nanoparticles as fillers produced the composites having the lowest polymerization shrinkage (2.2%) and the highest flexural strength (113.91 MPa). Overall, the synthesized nanoclusters have shown greater performance in comparison with the current available silica nanoparticles.

An approach for the scalable production of macroporous polymer beads

A tubular co-flow reactor to produce macroporous polymer beads by polymerization of medium and high internal phase emulsion (M/HIPE) templates was developed. This reactor allows for improved production rates compared to tubing based microfluidic devices. Water-in-oil (W/O) M/HIPEs, containing methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDMA) monomers in the continuous phase, were injected into a re-circulating carrier phase. The continuous phase of the emulsion droplets was UV polymerized in situ, resulting in polyM/HIPE beads. The emulsion composition was adjusted to produce poly(MMA-co-EGDMA) porous polymer beads with a protective crust and an interconnected internal pore structure. HCl loaded beads were produced by adding the active ingredient into the dispersed emulsion phase, leading to HCl encapsulation in the porous structure of the beads after polymerization. Even after exposure to ambient conditions for 24 h, 60% of the HCl remained in the beads, indicating good encapsulation efficiencies. Thus, it is possible to use such macroporous beads as delivery vehicles.

Properties of A Model Self-Healing Microcapsule-Based Dental Composite Reinforced with Silica Nanoparticles.

Aim: The purpose of this study was to evaluate the mechanical properties of an experimental self-healing dental composite model (SHDC) composed of SiO2 nanoparticles with varying percentages of triethylene glycol dimethacrylate (TEGDMA) monomer and N,N-dihydroxyethyl-p-toluidine (DHEPT) amine microcapsules. Materials and methods: Microcapsules were prepared by in-situ polymerisation of PUF shells, as explained in our previous work. The model SHDC included bisphenol A glycidyl dimethacrylate (Bis-GMA:TEGDMA) (1:1), 1 wt% phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide (BAPO), 0.5 wt% benzoyl peroxide (BPO) catalyst, 20 wt% silanised silica dioxide (SiO2) (15 nm) and (0, 2.5, 5, 7.5, 10 wt%) of microcapsules (120 ± 45 μm). Light transmission, hardness, degree of conversion (DC), flexural strength and elastic modulus of the SHDC model were measured. Results: The degree of conversion of the SHDC ranged from 73 to 76% 24 h after polymerisation. Hardness measurements ranged from 22 to 26 VHN (p > 0.05); however, the flexural strength was adversely affected from 80 to 55 MPa with increasing microcapsules of up to 10 wt% in the composites (p < 0.05). Conclusion: Only flexural strength decreased drastically ~30% with increasing microcapsules (>10 wt%) in the composites. All other measured properties were not significantly affected. Accordingly, we recommend a stronger composite material that could be created by increasing the filler content distribution in order to achieve a hybrid self-healing composite with enhanced mechanical properties.

Synthesis of uniform submicron poly(lactic acid)-based particles/capsules by radical precipitation polymerization

Poly(l-lactic acid) (PLLA) is a well-known biopolymer, usually synthesized via step-growth or ring-opening polymerization from lactic acid or a lactide monomer, respectively. PLLA microspherical particles are produced by dispersion polymerization with a ring-opening lactide monomer using a particular copolymer chain as a stabilizer. This is not easy to achieve when dehydration is needed. Here, a robust and simple synthesis of a nearly monodisperse, submicron PLLA-based particle/capsule was proposed via radical precipitation polymerization without the use of surfactant. A commercial PLLA was first glycolyzed with ethylene glycol to obtain a low molecular weight glycolyzed PLLA (GPLLA). Then, the GPLLA was copolymerized with methacrylic acid and ethylene glycol dimethacrylate monomers using a benzoyl peroxide initiator. Active sites on the GPLLA backbone were generated by hydrogen abstraction of benzoyloxy radicals that further copolymerized before self-assembly to form the polymer particles. Uniform particle size of about 580 nm with a low polydispersity index (PDI) of 0.012 was obtained. This method was also implemented to produce nearly monodisperse capsules containing linalool. The particle size of PLLA-based capsules was about 280 nm with narrow particle size distribution (PDI of 0.120). The PLLA-based capsules effectively inhibited microbial growth of Staphylococcus aureus, Escherichia coli and Candida albicans and were not toxic to human cells.

Mechanical Properties of Experimental Composites with Different Photoinitiator.

Objective The effect of different photoinitiators on mechanical properties of experimental composites was evaluated. Materials and Methods Resin composites were formulated by using a blend of bisphenol A-glycidyl and triethylene glycol (50/50 wt%) dimethacrylate monomers, and 65 wt% of barium aluminium silicate and silica filler particles. Photoinitiators used were 0.2% camphorquinone (CQ) and 0.8% co-initiator (DMAEMA); 0.2% phenyl-propanedione and 0.8% DMAEMA; 0.1% CQ + 0.1% phenyl propanedione and 0.8% DMAEMA; 0.42% mono(acyl)phosphine oxide (MAPO); and 0.5% bis(acyl)phosphine oxide (BAPO). Specimens ( n = 10) were light cured by using a multiple-emission peak light-emitting diode for 20 seconds at 1,200 mW/cm 2 of irradiance and Knoop hardness and plasticization, depth of cure, flexural strength, and elastic modulus were evaluated. Data were statiscally analyzed at significance level of α = 5%. Results Experimental composites containing MAPO and BAPO photoinitiators showed the highest values of flexural strength, elastic modulus, top surface hardness, and lower hardness reduction caused by alcohol compared with CQ. Composites containing CQ and PPD showed similar results, except for depth of cure and hardness of bottom surface. Conclusion BAPO and MAPO showed higher flexural strength, elastic modulus, hardness on top surface, and lower polymer plasticization to CQ.

Raman spectroscopic study of gamma radiation‐initiated polymerization of diethylene glycol dimethacrylate in different solvents

AbstractIn this work, the degree of conversion and polymerization kinetics of diethylene glycol dimethacrylate (DEGDMA) monomer in different solvents upon gamma irradiation with different doses have been studied by Raman spectroscopy and mass difference measurements. Density functional theory calculations were performed on the monomer and the crosslinked structure to obtain the assignment of Raman peaks to specific bonds. The evolution of the bonding configuration of the structure with dose and the composition of the monomer mixture was investigated. The dependence of the polymerization rate on the solvent type was explained by the mechanism of the polymerization affected by the relative solubility of the components of the monomer mixture. Raman measurements revealed also that there are not fully crosslinked monomer molecules in the polymer matrix.

Surface Integrity of Dimethacrylate Composite Resins with Low Shrinkage Comonomers.

The goal of current research was to investigate the influence of adding low shrinkage “Phene” like comonomers hexaethylene glycol bis(carbamate-isoproply-α-methylstyrene) (HE-Phene) and triethylene glycol bis(carbamate-isoproply-α-methylstyrene) (TE-Phene) on the surface and color characteristics of composite resin. A range of weight fractions (0, 10, 20, 30, 40 wt.%) of HE/TE-Phene monomers were mixed with bisphenol A glycidyl methacrylate (GMA)/triethylene glycol dimethacrylate (TEGDMA) monomer. Experimental composite resins were made by mixing 71 wt.% of silica fillers to 29 wt.% of the resin matrix. A Vickers indenter and glossmeter were used for testing surface hardness (SH) and gloss (SG) at 60°. A chewing-simulator was used to evaluate the surface wear after 15,000 cycles. Color change (∆E) and translucency parameter (TP) were measured using a spectrophotometer. Data showed that HE/TE-Phene monomer had no negative impact (p > 0.05) on surface gloss, wear, color change and translucency of experimental composite resins. Surface hardness was in a reducing direction with the increas in HE/TE-Phene weight fraction (p < 0.05). The study results suggested that incorporating HE/TE-Phene monomers up to 30 wt.% with Bis-GMA/TEGDMA resin did not negatively influence the surface integrity of composite resins except for SH.

TEGDMA (Triethylene Glycol Dimethacrylate) Induces Both Caspase-Dependent and Caspase-Independent Apoptotic Pathways in Pulp Cells.

Monomers leached from resin-based composites (RBCs) may reach intrapulpal concentrations of the millimolar (mM) range, which could contribute to inflammation. The aim of this investigation was to assess the cytotoxicity of triethylene glycol dimethacrylate (TEGDMA) monomers on pulp cells as well as to identify molecular mechanisms leading to apoptosis. Pulp cells were harvested from molars extracted for orthodontic reasons and cultured through an explant method. To assess cytotoxicity, cells underwent a 5-day exposure to 0.75, 1.5, and 3 mM TEGDMA and were subject to cell counting and WST-1 staining. Based on the findings, cells were subsequently exposed to 0.1, 0.2, 0.75, 1.5, and 3 mM TEGDMA for 24 h to uncover the details of apoptosis. Changes in the production or cleavage of the apoptosis-specific proteins caspase-8, caspase-9, caspase-3, caspase-12, and Apoptosis-Inducing Factor (AIF) were measured by Western blot. The 5-day study showed concentration- and time-dependent cytotoxicity. Significant cell death was detected after 24 h with TEGDMA concentrations of 1.5 and 3 mM. One-day exposure to TEGDMA led to the activation of caspase-8, -9, -3, and -12 and an increased AIF production. Results suggest that relevant concentrations of TEGDMA monomers, leached from RBCs, induce apoptosis in pulp cells through both caspase-dependent as well as caspase-independent mechanisms. Endoplasmic reticulum stress and the activation of caspase-independent apoptotic pathways may be further mechanisms by which monomers induce apoptosis in pulp cells.

Towards improving the biocompatibility of prosthetic eyes

Prosthetic eyes are currently manufactured using Poly(methyl methacrylate) (PMMA) which is not an ideal material because it is hydrophobic. While significant research has investigated the benefits of hydrophilic materials for contact lenses, no such research has been carried out on hydrophilic materials for prosthetic eyes until now. In this study, different derivatives of Poly(ethylene glycol) (PEG) monomer and methyl methacrylate (MMA) monomer were grafted to PMMA using copolymerisation. The resulting matrixes were evaluated by water contact angle measurement, 24 h water absorption testing, and colour-difference measurement when exposed to ultraviolet light. The contact angle and water absorption results indicated that ethylene glycol dimethacrylate (EGDMA) grafted PMMA matrix had a better hydrophilic performance than the other matrixes tested. EGDMA is already a minor constituent of the PMMA matrix currently used for manufacturing prosthetic eyes but when the proportion of EGDMA monomer to MMA monomer used in the manufacturing process was increased to 50/50 the hydrophilicity of the matrix was significantly improved.EGDMA-grafted PMMA is inexpensive and comes as a liquid monomer that is easily mixed with the PMMA monomer that ocular prosthetists are familiar with. The mixture requires no special handling beyond the normal safety precautions that apply when using PMMA monomers. In-vitro testing shows that EGDMA-grafted PMMA significantly improves the wettability of PMMA currently used for the manufacture of prosthetic eyes and has the potential to significantly improve wearing comfort and socket health.

Removal of sunset yellow FCF from aqueous solutions using a highly cross-linked PDMA star polymer

The highly cross-linked PDMA star polymer (PDMA-b-PEGDMA) was successfully synthesized by group transfer polymerization (GTP) using 2-(N,N-dimethylamino)ethyl methacrylate (DMA) and cross-linking agent ethylene glycol dimethacrylate (EGDMA) monomers. Highly cross-linked polymer as a huge molecule has many functional groups. Thanks to these properties, dye adsorption performance of this kind of polymer was investigated. Sunset yellow FCF (SY) dye was used to determine whether the polymer showed adsorption properties. The effect of solution pH, dye concentration change and adsorbent amount on adsorption were investigated and the most effective adsorption conditions were determined for polymer. According to these parameters, the reaction rate constants in the dye adsorption of highly cross-linked polymer and the thermodynamic parameters (ΔH°, ΔG° and ΔS°) of the adsorption were calculated. The reaction was spontaneous (ΔG° < 0) at all temperatures (20 °C, 35 °C, and 50 °C). Kinetic of adsorption of SY dye onto polymer was studied, as well as its adsorption isotherm. At the last stage of the study, recovery of the polymer was carried out. The polymer was recovered using the dissolution–precipitation method. Adsorption studies were performed using UV–Vis spectrophotometer. The characterizations of the synthesized highly cross-linked star polymer and the recovered polymer were carried out using proton NMR (1H NMR) spectroscopy and gel permeation chromatography (GPC).

The Development of High-Power LIBs Separators

Separators present the crucial functions of separating the positive and negative electrodes due to the free flow of lithium ions through the liquid electrolyte that fills in their open pore. Separators for liquid electrolyte Lithium-ion batteries can be classified into porous polymeric membranes, nonwoven mats, and cellulose separators. When a lithium-ion battery is being overcharged, it releases the heat and results in the inner-short. The polyethylene (PE) separators used here had shut down at around 135°C to cool the exothermal batteries. To enhance the meltdown temperature of the separator, a PE separator was coated with polymers synthesized from various ethylene glycol dimethacrylate monomers. At the same time, nonwoven mats have the potential to be low cost and thermally stable separators. Furthermore, the lithium-ion phosphate/lithium half cell using cellulose separator exhibited stable charge-discharge capability even at 120 °C. This paper presents an overview of the PE and PP membranes of lithium-ion battery separators, discusses how to solve their disadvantages, and reviews the cellulose-based materials developed for potential application in the lithium-ion battery.

Photografting of polymer monoliths by a crosslinking monomer

The surface of fifteen polymethacrylate monolithic stationary phases has been modified by a post-polymerization UV-initiated grafting reaction with bifunctional poly(ethylene glycol)dimethacrylate monomers. An effect of crosslinking monomer length, its concentration in the modification mixture, and a time of the modification reaction have been selected to control the extent of modification by a design of experiments protocol. Hydrodynamic and kinetic properties of prepared columns were characterized by capillary liquid chromatography. Regression analysis of determined data revealed that there is only a minor effect of modification reaction on column permeability, as it is rather controlled by the composition of the polymerization mixture used to prepare generic monolith. On the other hand, the utilization of shorter crosslinking monomer increased the formation of small pores and minimized mass transfer resistance effect. Both column efficiency and mass transfer resistance also improved when a lower concentration of crosslinking monomer in the modification mixture was used. Photografting modification decreased a negative effect of mass transfer resistance related to a crosslink density gradient and allowed fast isocratic separations of dopamine metabolism-related compounds. Developed preparation protocol might be further utilized in the preparation of monolithic stationary phases in microfluidic devices.

Characterization of luminescent monodisperse microparticles prepared by gamma radiation-initiated polymerization

Abstract Fluorescent microparticles have been prepared by gamma radiation-initiated precipitation polymerization of diethylene glycol dimethacrylate monomer with ethyl propionate solvent and fluorescein isothiocyanate isomer-I (FITC) fluorophore. Different FITC concentrations and irradiation conditions were used, and their effect on the particle properties was studied. The samples were characterized by scanning electron microscopy, Raman and photoluminescence spectroscopies. Our results showed that the size of the microspheres is dependent on the composition of the monomer mixture. The uniformity of the microparticles decreases with increasing FITC concentration, relative to the monomer. Changes in the emission spectrum of the FITC were also observed after irradiation. The gamma irradiation-initiated polymerization was found to be a promising and simple technique to prepare luminescent spherical microparticles.