Poly Ethylene Glycol Dimethylacrylate Research Articles

Shedding light on the initial growth of ZnO during plasma-enhanced atomic layer deposition on vapor-deposited polymer thin films

Interest in atomic layer deposition (ALD) processes on polymer substrates is fueled by the increasing rise of organic electronics and polymer-based nanodevices. This study provides new insights into the initial growth and interface formation during plasma-enhanced ALD (PE-ALD) of ZnO on poly ethylene glycol dimethylacrylate (pEGDMA) and poly 2-hydroxyethyl methacrylate (pHEMA) thin films, both deposited by initiated chemical vapor deposition (iCVD). In-situ spectroscopic ellipsometry showed that PE-ALD growth on the investigated polymers is a result of two competing processes: plasma etching of the polymer substrate and ZnO nucleation and growth. During the first 10–15 ALD cycles, polymer etching was found to prevail until at a certain point (depending on plasma power and type of polymer) ZnO growth takes over and the regime of linear ALD growth is entered. On pHEMA, though more sensitive to etching, ZnO film formation starts early on, whereas on pEGDMA, subsurface nucleation and island growth appear to dominate the initial stage of deposition. Despite the initial etching, resulting ZnO films are smooth and of comparable structural quality to those grown on silicon. These findings contribute to a deeper understanding of PE-ALD growth on polymers providing knowledge essential for the successful development of new processes and applications.

Ionic Liquid-Supported Interpenetrating Polymer Network Flexible Solid Electrolytes for Lithium-Ion Batteries

In this report, we have prepared the imidazolium-based ionic liquid-incorporated interpenetrating polymer network (IPN) electrolyte membrane containing cellulose triacetate with polyethylene glycol dimethyl acrylate and polyethylene oxide by the UV-induced polymerization method. A facile IPN electrolyte membrane appears to be homogeneous in nature with high mechanical strength, excellent thermal stability, and exhibits optimum ionic conductivity of the order of 2.84 × 10–3 S cm–1. The oxidative stability of the IPN electrolyte membrane is observed up to 5.2 V at room temperature, which is attributed to immobilized ion networks provided by the imidazolium ionic liquid. The IPN electrolyte membrane is galvanostatically cycled having battery configuration Li/IPN EM/LiFePO4, which shows the first discharge capacity of 110 mA h g–1 at 0.05 C with 93.65% Coulombic efficiency at room temperature. The cell shows discharge capacities of about 85, 82, and 76 mA h g–1 at 0.1, 0.2, and 1 C rates, respectively. The ionic liquid-incorporated IPN electrolyte membrane provides a promising system for stabilizing lithium electrodeposition and fabricating high-performance lithium-ion batteries. Finally, IPN electrolyte membranes could be a potential electrolytes for next-generation high-power and safer solid-state battery technology.

UV Radiation Crosslinking of Acrylated Palm Olein (APO) Copolymer Resins for 3D Printing

Generally, only a few especially acrylic monomers have photoabsorption characteristics to allow for effective stereolithography (STL) to take place. Biomaterial product from palm oil, Acrylated Palm Olein (APO), is seen as an ideal alternative to petroleum-based polymers due the diminishing petrochemical supply and abundant of the natural polymer in the market. In this study, APO as a biopolymer is introduced to synthetic polymers Polyethylene Glycol Dimethylacrylate (PEGDMA) and Polyethylene Glycol Diacrylate (PEGDA), separately. All three polymers offer photoabsorption characteristics that enable them to be the resins for ultraviolet (UV) 3D printing. The crosslinking of both copolymers is optimized by comparing two different UV radiation techniques; UV cured machine and UV STL 3D printer. The degree of crosslinking for both APO-co-PEGDMA and APO-co-PEGDA through gel fraction analysis are studied and compared with their prepolymer resins. As predicted, the maximum degree of crosslinking of APO-co-PEGDMA and APO-co-PEGDA samples are achieved from the fabrication of samples by 3D printing and recorded at 67.50% and 59.50% respectively, comparing to the samples cured by UV cure machine, which recorded maximum crosslinking percentage at only 21.31%. Further analysis is done using swelling test to study water absorption capacities of copolymers and results shows that APO-co-PEGDMA able to retain water at maximum of 42.47% and APO-co-PEGDA at 52.02% from the 3D printed samples, and recorded lowest readings at 22.82% and 25.56% respectively. UV cured samples are recorded to have lowest readings at 3.89% for APO-co-PEGDMA, and 4.23% for APO-co-PEGDA. Fourier Transform Infrared (FTIR) Spectroscopy confirmed the successful crosslinked of the copolymers. Analysis of FTIR shows that there are presence of new peaks and shifting of peaks, indicating that APO is crosslinked with PEGDMA backbone as well as PEGDA backbone. These also suggest that both polymers are suitable to be incorporated with APO as new photopolymer resins, fabricated using UV radiation crosslinking, with PEGDMA shown a slightly better result. All results are agreeable with FTIR results.

A cross-linked polymer inclusion membrane for enhanced gold recovery from electronic waste

A cross-linked polymer inclusion membrane (CL-PIM) incorporating the extractant trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl) phosphinate (Cyphos® IL 104) was developed for the first time for the enhanced Au(III) recovery from aqua regia digests of electronic waste (discarded mobile phones). Cellulose triacetate (CTA), poly(vinyl chloride) (PVC) and poly(vinylidene fluoride-co-hexafluropropylene) (PVDF-HFP) were examined as base polymers. The suitability of poly(ethylene glycol) dimethylacrylate (PEGDMA), poly(ethylene glycol) divinyl ether (PEGDVE) and N-ethylmaleimide (NEM) as cross-linking agents, and the possibility of using triarylsulfonium hexafluorophosphate (TASHFP) and 2,2-dimethoxy-2-phenylacetophenone (DMPA) as initiators were investigated. It was demonstrated that the CL-PIMs composed of Cyphos® IL 104 (30 wt%), PVDF-HFP, PEGDMA (base polymer to cross-linking agent ratio 6:4) and DMPA (1 wt%) or TASHFP (2 wt%) transported Au(III) from 2.5 mol L−1 hydrochloric acid solutions twice as fast as their non-CL-PIM counterpart, showing excellent stability over five successive transport experiments. However, in aqua regia feed solutions (6 mol L−1 acidity) only the CL-PIM containing TASHFP was able to achieve complete Au(III) recovery. AFM studies revealed that the PVDF-HFP-based CL-PIMs had a much higher surface contact area when compared to their non-CL counterpart, and this is proposed to be the reason for their superior transport performance. The CL-PIM that showed good transport efficiency in aqua regia was also applied to aqua regia digests of electronic waste from two mobile phones, and Au(III) was selectively recovered in less than 24 h, while other metals present in significantly higher concentrations were not transported.

Astrocytes Decreased the Sensitivity of Glioblastoma Cells to Temozolomide and Bay 11-7082.

Glioblastoma multiforme (GBM) is the most common malignant type of astrocytic tumors. GBM patients have a poor prognosis with a median survival of approximately 15 months despite the “Stupp” Regimen and high tumor recurrence due to the tumor resistance to chemotherapy. In this study, we co-cultured GBM cells with human astrocytes in three-dimensional (3D) poly(ethylene glycol) dimethyl acrylate (PEGDA) microwells to mimic the tumor microenvironment. We treated 3D co- and mono-cultured cells with Temozolomide (TMZ) and the nuclear factor-κB (NF-κB) inhibitor Bay 11-7082 and investigated the combined effect of the drugs. We assessed the expressions of glial fibrillary acidic protein (GFAP) and vimentin that play a role in the tumor malignancy and activation of the astrocytes as well as Notch-1 and survivin that play a role in GBM malignancy after the drug treatment to understand how astrocytes induced GBM drug response. Our results showed that in the co-culture, astrocytes increased GBM survival and resistance after combined drug treatment compared to mono-cultures. These data restated the importance of 3D cell culture to mimic the tumor microenvironment for drug screening.

A 3D Printed Self-Sustainable Cell-Encapsulation Drug Delivery Device for Periocular Transplant-Based Treatment of Retinal Degenerative Diseases.

Self-sustainable release of brain-derived neurotrophic factor (BDNF) to the retina using minimally invasive cell-encapsulation devices is a promising approach to treat retinal degenerative diseases (RDD). Herein, we describe such a self-sustainable drug delivery device with human retinal pigment epithelial (ARPE-19) cells (cultured on collagen coated polystyrene (PS) sheets) enclosed inside a 3D printed semi-porous capsule. The capsule was 3D printed with two photo curable polymers: triethylene glycol dimethacrylate (TEGDM) and polyethylene glycol dimethylacrylate (PEGDM). The capsule’s semi-porous membrane (PEGDM) could serve three functions: protecting the cells from body’s immune system by limiting diffusion (5.97 ± 0.11%) of large molecules like immunoglobin G (IgG)(150 kDa); helping the cells to survive inside the capsule by allowing diffusion (43.20 ± 2.16%) of small molecules (40 kDa) like oxygen and necessary nutrients; and helping in the treatment of RDD by allowing diffusion of cell-secreted BDNF to the outside environment. In vitro results showed a continuous BDNF secretion from the device for at least 16 days, demonstrating future potential of the cell-encapsulation device for the treatment of RDD in a minimally invasive and self-sustainable way through a periocular transplant.

Preparation of Patterned Polymeric Scaffolds by Soft Lithographic Method and their Characterization for Tissue Engineering

Nowadays, cell growth studies on patterned surfaces have received increasing interest due to their cell control and substrate adhesion properties. In this study, patterned scaffolds were prepared by using Soft Lithographic Method. The structural and morphological properties of the prepared materials were analyzed for their use within cell growth systems. Microscope glasses were used as the bottom holder and coated with different polymers; polyethylene glycol dimethyl acrylate (PEG-DMA), polyvinyl chloride (PVC), and polymethyl methacrylate (PMMA) in order to compare the efficiency of the samples on the cell growth. The coated surfaces were patterned using poly (dimethyl siloxane) (PDMS) molds which were fabricated originally as soft materials for pattern transfer and used as stamps and as scaffolds.

A facile method to fabricate an antimicrobial coating based on poly(1-vinyl-3-allylimidazolium iodide) (PAVI) and poly(ethylene glycol) dimethyl acrylate (PEGDMA)

Biomedical device-related infections have been a great concern over the past decades. In this work, cationic macromolecules poly(1-vinyl-3-allylimidazolium iodide) (PAVI) with antibactericidal ability were prepared and grafted on nose clips by surface-initiated polymerization via plasma/autoclaving method. The precursor poly(1-vinylimidazole) was synthesized by surface-initiated polymerization and then quaternarized to form polymeric quaternary ammonia salts which have been commonly used as bactericidal materials. We first synthesized a series of different formulations of cationic PAVI and hydrophilic poly(ethylene glycol) dimethyl acrylate graftings onto nose clips by thermal-initiating polymerization with covalent bonds for antimicrobial surface modification. Antibacterial test results showed that the cationic–hydrophilic coatings exhibited excellent antibacterial behaviors for multidrug-resistant bacteria such as vancomycin-resistant Enterococcus and methicillin-resistant Staphylococcus aureus. The in vitro log reduction value for could reach 6.0 and 8.6, respectively, and the in vivo log reduction value could reach 1.3 and 2.0, respectively. In vitro cytotoxicity indicated that PAVI coatings were non-leachable and exhibited no toxicity toward mammal cells. This rationally designed polycationic antimicrobial coating displayed great potential application in combating implant-associated infections on biomedical devices.

Preparation and characterization of polymers based on PDMS and PEG-DMA as potential scaffold for cell growth

This work describes a soft lithographic method for the generation of patterned both biopolymer and silver with each covered on microscope glass. Because of their biocompatible nature and permeability to gases the biopolymers are convenient for cell culture studies. The microscope glass was covered by polyethylene glycol dimethyl acrylate (PEG-DMA), as biopolymer and patterned by the UV light passing through the printed photomask for the preparation of the PDMS stamps. PDMS stamps were originally fabricated in this work for pattern transfer. Ag and polymer covered on the microscope glass were patterned by using these PDMS stamps. The patterned Ag, PDMS mold and PEG-DMA biopolymer were used as scaffolds and cell growth experiments have been performed on these materials. The degree of cell viability was measured by seeding them with L929 mouse fibroblasts and the number of the cells was measured by neutral red uptake assay. An increase in the number of cells on the material surfaces was observed. The pattern and the cell growth properties were followed by optic microscope. The results obtained from the cell growth was subjected to student's t-test.

Investigating the Influence of HUVECs in the Formation of Glioblastoma Spheroids in High-Throughput Three-Dimensional Microwells.

Glioblastoma (GBM) is the most common form of primary brain tumor with a high infiltrative capacity, increased vascularity, and largely elusive tumor progression mechanism. The current GBM treatment methods do not increase the patient survival rate and studies using two-dimensional (2D) cell cultures and in vivo animal models to investigate GBM behavior and mechanism have limitations. Therefore, there is an increasing need for in vitro three-dimensional (3D) models that closely mimic in vivo microenvironment of the GBM tumors to understand the underlying mechanisms of the tumor progression. In this study we propose to use a 3D in vitro model to overcome these limitations, using poly (ethylene glycol) dimethyl acrylate (PEGDA) hydrogel-based microwells and co-culture GBM (U87) cells and endothelial cells (HUVEC) in the 3D microwells to provide a 3D in vitro simulation of the tumor microenvironment. Furthermore, we investigated the gene expression differences of co-cultures by quantitative real-time PCR. Our results suggested that the relative expression profiles of tumor angiogenesis markers, PECAM1/CD31, and VEGFR2, in co-cultures are consistent with in vivo GBM studies. Furthermore, we suggest that our microwell platform could provide robust and useful 3D co-culture models for high-throughput drug screening and treatment of the GBM.

Synthesis and Performance of Molecular Imprinted Polymers as Drug Release Controller

Molecular imprinted polymers were synthesized using α-methylacrylacid as monomer, acetylsalicylic acid as template. Polyethylene glycol dimethylacrylate was taken as cross-linker. UV-Vis spectrophotometer was used to detect the drug-loading and releasing performances of these polymers. The studies showed that the imprinted polymers could load more drugs than non-imprinted polymer, and exhibited a slower drug-releasing rate than the latter at pH 7.4. The content of cross-linker had influences on drug-loading amounts. The imprinted polymer released few drugs at the buffer solution of pH 1.2.

Effects of polyaniline chain structures on proton conduction in a PEM host matrix

This study examined the effects of the conjugated chain structure of polyaniline (PAn) on proton transport in a proton exchange membrane (PEM) containing a small amount of PAn colloidal particles. The PEM host matrix consisted of a hydrophobic three-component polymer blend (TCPB) of poly(4-vinylphenol- co-methylmethacrylate) P(4-VP-MMA), poly(butyl methacrylate) (PBMA), and Paraloid ® B-82 acrylic copolymer resins; in which a hydrophilic network of 2-acrylamido-2-methyl propanesulfonic acid (AMPS), 2-hydroxyethyl methacrylate (HEMA) and poly(ethylene glycol)dimethylacrylate (PEGDMA) was formed upon embedded polymerization. Colloidal PAn particles were added to the PEM matrix during the embedded polymerization of PEM. Two types of PAn colloidal particles with different chain structures and morphologies were synthesized by inverse miniemulsion polymerization and interfacial polymerization. The PAn(1) particles from inverse miniemulsion polymerization were bar-shaped, contained a higher fraction of quinoid diimine units than the scaffold-like PAn(2) particles from interfacial polymerization, and displayed a strong promotional effect on proton conduction. The oxidation state of the PAn particles was also varied by post-synthesis treatments to evaluate the effect of oxidation state on proton conduction. It was found that a mixed oxidation state such as the emeraldine form of PAn had the best enhancement effect. The PAn loading optimal for proton conductivity enhancement of the composite PEM was determined to be about 2 wt% of PAn(1).

Embedded polymerization driven asymmetric PEM for direct methanol fuel cells

This work reports the fabrication of proton exchange membranes (PEM) with stronger resistance to methanol penetration than Nafion ®117. A three-component acrylic polymer blend (TCPB) consisting of a copolymer of 4-vinylphenol-methyl methacrylate, poly(butyl methacrylate) (PBMA) and a copolymer of methyl methacrylate-ethyl acrylate is used as the methanol barrier. In order to implant a proton source phase within the membrane as homogeneously as possible, the hydrophilic monomers, 2-acrylamido-2-methyl propanesulfonic acid (AMPS), 2-hydroxyethyl methacrylate (HEMA) and poly(ethylene glycol) dimethylacrylate (PEGDMA), are polymerized only after they have been embedded in the TCPB matrix. The embedded polymerization has resulted in an asymmetric membrane structure, in which the hydrophilic network is sandwiched by two layers of matrixes with high percentages of TCPB. As expected, this asymmetric membrane structure exhibits lower methanol uptake than Nafion ®117; and a proton conductivity in the range of 10 −3–10 −4 S/cm, which is dependent on the concentration of the sulfonic acid content. It is suggested that the two external layers in this asymmetric membrane provide primarily methanol-blocking and supporting proton-conducting properties; while the middle layer supplies protons and conserves water. This unique sandwiched PEM structure from embedded polymerization is confirmed by microstructure characterizations and by physical property measurements.