Water-soluble Monomers Research Articles

Electronically Conductive Hydrogels by in Situ Polymerization of a Water-Soluble EDOT-Derived Monomer.

Electronically conductive hydrogels have gained popularity in bioelectronic interfaces because their mechanical properties are similar to biological tissues, potentially preventing scaring in implanted electronics. Hydrogels have low elastic moduli, due to their high water content, which facilitates their integration with biological tissues. To achieve electronically conductive hydrogels, however, requires the integration of conducting polymers or nanoparticles. These “hard” components increase the elastic modulus of the hydrogel, removing their desirable compatibility with biological tissues, or lead to the heterogeneous distribution of the conductive material in the hydrogel scaffold. A general strategy to transform hydrogels into electronically conductive hydrogels without affecting the mechanical properties of the parent hydrogel is still lacking. Herein, a two‐step method is reported for imparting conductivity to a range of different hydrogels by in‐situ polymerization of a water‐soluble and neutral conducting polymer precursor: 3,4–ethylenedioxythiophene diethylene glycol (EDOT‐DEG). The resulting conductive hydrogels are homogenous, have conductivities around 0.3 S m−1, low impedance, and maintain an elastic modulus of 5–15 kPa, which is similar to the preformed hydrogel. The simple preparation and desirable properties of the conductive hydrogels are likely to lead to new materials and applications in tissue engineering, neural interfaces, biosensors, and electrostimulation.

The scale-up of electrochemically mediated atom transfer radical polymerization without deoxygenation

The scale-up of Atom Transfer Radical Polymerization (ATRP) from 15 mL to 15 L (scale-up factor 1000) by galvanostatic simplified electrochemically mediated ATRP (seATRP) is disclosed. An electrochemical O2 scavenging cycle was embedded in the ATRP equilibrium to allow self-degassing of the mixture and avoid impractical deoxygenation procedures. Low volume seATRP of acrylamide in water was optimized by studying various reaction parameters, including the concentrations of scavenger, supporting electrolyte, type of initiator and ligand, and catalyst loading. The target reaction was scaled up from 0.015 L to 15 L. At all volumes and up to 15 L, polymerizations were relatively fast and produced well-defined polyacrylamide with narrow molecular weight (MW) distributions. All reactions were powered by renewable electricity, obtained from a photovoltaic plant. Several water-soluble monomers, including (meth)acrylic acid and methacrylamide, were polymerized at pH ranging from 1.0 to 7.4, without compromising the self-degassing mechanism. These results show a feasible scale-up of seATRP and could foster its adoption by polymer industries promoting a more widespread use of controlled radical polymerizations.

Hydroxysafflower yellow A alleviates HK-2 cells injury in cold hypoxia/reoxygenation via mitochondrial apoptosis

Cold storage for organ preservation in kidney transplantation is a core predisposing factor for delayed graft function and the long-term outcome of transplanted kidneys. Hydroxysafflor yellow A (HSYA) is the most effective water-soluble active monomer in Safflower with a strong property of inhibiting hypoxia and reoxygenation (H/R). However, the evidence concerning the effect of HSYA on H/R in kidney transplantation is limited. To investigate whether HSYA has a protective effect on cold H/R injury，we investigated the possible protective mechanism. Here, we incubated HK-2 cells to establish a cold H/R model and observed HSYA activation in an in vitro model of cold-storage rewarming which included the cell survival rate, cell morphology and ultrastructure, protein expression of Bcl-2, Bax, CytC, Apaf-1, and caspase-3, and status of mitochondrial permeability transformation pores (MPTPs). Our data showed that HSYA pretreatment increased the survival rate of the cells, alleviated mitochondrial damage, decreased the expression of apoptosis-related proteins and inhibited the openness of mitochondrial permeability transformation pores. Our findings suggested that HSYA may be a major predisposing mediator of mitochondrial apoptosis and renal tubular injury in cold storage–associated transplantation and may be an effective therapeutic target for improving graft function and graft survival.

Performance regulation of a thin film composite (TFC) NF membrane by low-temperature interfacial polymerization assisted by the volatilization of n-hexane

Reducing the thickness of the polyamide (PA) layer has been confirmed as a feasible strategy to improve the permeability of the thin film composite (TFC) nanofiltration (NF) membrane. In this study, a novel interfacial polymerization (IP) approach assisted by the volatilization of n-hexane was proposed to promote the formation of a thinner PA layer, in which a small amount of n-hexane was added onto the substrate membrane after aqueous phase immersion and before the organic phase coating, then the temperature of the substrate membrane together with the water-soluble monomer solution would be decreased due to the volatilization of n-hexane. The infrared thermographies demonstrated that 7.8 μL cm−2n-hexane dosage was the most efficient, which can sharply decrease the surface temperature from room temperature (25 °C) to 7.9 °C. The TFC membranes prepared at the lower temperature presented much higher permeability. When PIP concentration was 0.3% w/v, TMC concentration was 0.1% w/v and IP reaction time was 40 s, the PA layer formed at this low temperature was smoother and more hydrophilic. Its thickness was reduced from 26.97 nm to 11.98 nm and water permeability was increased by 50% to 36.7 L m−2 h−1 bar−1 while maintaining Na2SO4 rejection of 96.5%.

High biobased content waterborne latexes stabilized with casein

Growing environmental regulations are enforcing the synthesis of sustainable and ecofriendly materials. While waterborne processes, as emulsion polymerization, allow producing polymeric materials with low solvents emission, the reduction of their carbon footprint can be achieved by replacing petroleum-derived raw materials by biobased reagents. In this scenario, this work aims to synthesize high biobased content waterborne latexes by emulsion polymerization of two partially biobased commercial monomers (2-octyl acrylate, OA, and isobornyl methacrylate, IBOMA) in presence of previously methacrylated casein (bovine milk protein), which acts as a surfmer (i.e., an emulsifier capable of being radically polymerized). The kinetic study of the emulsion polymerization of OA and IBOMA allows optimizing the formulation, thus resulting that the incorporation of a low fraction of a more water soluble monomer is required to reach acceptable polymerization rates and high monomer conversion. The as-obtained films show promising performance in terms of their mechanical properties, resistance to solvents and biodegradability in organic compost, which could pave the way for the synthesis of high biobased (>75%) content binders for waterborne coatings.

A polyesterase from the Antarctic bacterium Moraxella sp. degrades highly crystalline synthetic polymers

The uncontrolled release of plastics in the environment has rendered them ubiquitous around the planet, threatening the wildlife and human health. Biodegradation and valorization of plastics has emerged as an eco-friendly alternative to conventional management techniques. Discovery of novel polymer-degrading enzymes with diversified properties is hence an important task in order to explore different operational conditions for plastic-waste upcycling. In the present study, a barely studied psychrophilic enzyme (MoPE) from the Antractic bacterium Moraxella sp. was heterologously expressed, characterized and its potential in polymer degradation was further investigated. Based on its amino acid composition and structure, MoPE resembled PET-degrading enzymes, sharing features from both mesophilic and thermophilic homologues. MoPE hydrolyzes non-biodegradable plastics, such as polyethylene terephthalate and polyurethane, as well as biodegradable synthetic polyesters, such as polycaprolactone, polyhydroxy butyrate, polybutylene succinate and polylactic acid. The mass fraction crystallinity of the aliphatic polymers tested ranged from 11% to 64% highlighting the potential of the enzyme to hydrolyze highly crystalline plastics. MoPE was able to degrade different types of amorphous and semi-crystalline PET, releasing water-soluble monomers and showed synergy with a feruloyl esterase of the tannase family for the release of terephthalic acid. Based on the above, MoPE was characterized as a versatile psychrophilic polyesterase demonstrating a broad-range plastics degradation potential.

Pretreatment/fractionation and characterization of winery waste streams within an integrated biorefinery concept

The aim of this work was the characterization of the main winery wastes, e.g. vineyard prunings, grape stalks, grape pomace and wine lees, and the utilization of the hydrothermal pretreatment towards selective fractionation and recovery of hemicellulose (and related sugars, furans and acids), increased cellulose enzymatic hydrolysis, and isolation of “surface” and hydrothermal/acid hydrolysis lignin, discussing also the potential valorization of each stream into value-added chemicals. Two varieties from Greece were investigated, i.e. Grenache Rouge (Vitis vinifera L. cv. Grenache Rouge) and Malagouzia (Vitis vinifera L. cv. Malagouzia). Three hydrothermal pretreatment severities were applied, i.e. logRo 3.24, 4.32 and 4.71 (corresponding to 170oC-15 min, 170oC-180 min, and 220oC-15 min), all leading to enhanced enzymatic hydrolysis of cellulose in the vine prunings to glucose. The composition of the recovered aqueous product contained mainly glucan and xylan, which were converted to monomeric sugars and eventually to furans (furfural, HMF) and organic acids (formic, lactic) at more intense conditions. The grape stalks and mainly the grape pomace which comprises of grape skins and seeds, contained less carbohydrates compared to vine prunings, but can be considered as an abundant source of lignin that can provide fast pyrolysis oils enriched in phenolic compounds. Similarly, the extracted surface lignin from the hydrothermally pretreated vine prunings may offer highly phenolic/aromatic bio-oils. The extractives of the parent lignocellulosic wastes (15–50 wt%) contain water soluble sugar monomers and oligo-saccharides and ethanol soluble fatty acids (palmitic, tridecanoic, a-linoleic, oleic, stearic acids). The wine lees can be considered as a source of value-added polyols and phenyl alcohols, such as glycerin (1,2,3-propanotriol), 2,3-butanediol and phenylethyl alcohol.

Systematic synthesis of a series of glycopolymers having N-acetyl-D-glucosamine moieties that can be used for evaluations of lectin—carbohydrate interactions

Four kinds of water-soluble carbohydrate monomers having different methylene numbers of polymerizable aglycons were systematically prepared from N-acetyl-D-glucosamine (GlcNAc). Typical radical polymerization in the presence of ammonium persulfate (APS)—tetramethylethylenediamine (TEMED) in water was applied for the monomers with acryl amide as a regulator for adjusting the average distance between carbohydrate residues, a series of glycopolymers having various densities of GlcNAc residues was obtained. Regulation of the polymers showed two pivotal points: one is the effect of lengths between carbohydrate residues and the polymer backbone and the other one is the influence of average densities of carbohydrates in the glycopolymer. Carbohydrate—protein interaction by means of the glycopolymer library for wheat germ agglutinin (WGA) as a model protein was investigated and the highest Ka value was obtained when the glycopolymer having the longest methylene length and the ratio of 1:10 (sugar unit:acrylamide unit) was used as a substrate.

Orientin Prolongs the Longevity of Caenorhabditis elegans and Postpones the Development of Neurodegenerative Diseases via Nutrition Sensing and Cellular Protective Pathways.

Age is the major risk factor for most of the deadliest diseases. Developing small molecule drugs with antiaging effects could improve the health of aged people and retard the onset and progress of aging-associated disorders. Bioactive secondary metabolites from medicinal plants are the main source for development of medication. Orientin is a water-soluble flavonoid monomer compound widely found in many medicinal plants. Orientin inhibits fat production, antioxidation, and anti-inflammatory activities. In this study, we explored whether orientin could affect the aging of C. elegans. We found that orientin improved heat, oxidative, and pathogenic stress resistances through activating stress responses, including HSF-1-mediated heat shock response, SKN-1-mediated xenobiotic and oxidation response, mitochondria unfolded responses, endoplasmic unfolded protein response, and increased autophagy activity. Orientin also could activate key regulators of the nutrient sensing pathway, including AMPK and insulin downstream transcription factor FOXO/DAF-16 to further improve the cellular health status. The above effects of orientin reduced the accumulation of toxic proteins (α-synuclein, β-amyloid, and poly-Q) and delayed the onset of neurodegenerative disorders in AD, PD, and HD models of C. elegans and finally increased the longevity and health span of C. elegans. Our results suggest that orientin has promising antiaging effects and could be a potential natural source for developing novel therapeutic drugs for aging and its related diseases.

Effect of Brushing Simulation on the Surface Roughness of Two Different Commercially Available Glass Ionomer Cements - An In Vitro Study

Introduction: Glass ionomer cement (GIC) is a restorative material used in dentistry which can also be used as luting cement and for fixing orthodontic appliances. The main components found in GIC are silicon, calcium, sodium and fluoride. In order to improve the toughness of the cement, speed of setting and resistance to wearing, water content of the glass-ionomer cement was replaced by water-soluble polymers or monomer systems. The aim of this study is to evaluate the effect of brushing simulation on the surface roughness of two different commercially available glass ionomer cements.
 Materials and Methods: GC gold label and D Tech are commercially available glass ionomer restorative cements chosen for this present study. 5 samples were prepared from each. The samples were checked for pre-surface roughness using a stylus profilometer and then subjected to brushing. Toothbrush simulator (ZM3.8 SD Mechatronik) with minimum pressure of 3N and a fluoridated toothpaste was used for brushing. Then the post surface roughness was again checked and the results were tabulated and then statistically analyzed using SPSS software.
 Results: Surface roughness was increased after brushing simulation in both GC gold label and D Tech GIC samples. This difference was statistically not significant (paired student t, p value = 0.763).
 Conclusion: D-tech GIC samples had less surface roughness after brushing simulation when compared to GC Gold label samples.

Emulsion-Templated, Magnetic, Hydrophilic-Oleophobic Composites for Controlled Water Removal.

Emulsion-templated, hydrophilic-oleophobic porous materials are promising for the removal of a small amount of water from oil-water mixtures, but the maneuver and complete collection of these porous materials are challenging. Herein, we report the fabrication of magnetic, hydrophilic-oleophobic polyHIPE composites from reactive Fe3O4 nanoparticle-stabilized high internal phase emulsions through simultaneous bulk polymerization of water-soluble monomers and interface-catalyzed polycondensation of 1H,1H,2H,2H-perfluorooctyltriethoxysilane. The resulting composites were hydrophilic-oleophobic, with water droplets rapidly absorbed (within 20 s), and exhibited designable magnetic responsiveness. The hydrophilicity-oleophobicity enabled water to be removed through selective absorption from oil-water mixtures (including surfactant-stabilized water-in-oil emulsions), with a high separation rate over 99%. The magnetic-responsiveness enabled both the dry and the swollen composites to be maneuvered in a remote and contactless manner and to be fully collected. Therefore, the magnetic, hydrophilic-oleophobic polyHIPE composites are excellent candidates for the removal of water from water-oil mixtures with complete collection.

N-heterocyclic Carbene Containing Homogeneous Ru Catalyst for Aqueous Atom Transfer Radical Polymerization of Water-soluble Vinyl Monomers

This report presents aqueous atom transfer radical polymerization (ATRP) of commonly used acrylate monomers in the presence of N-Heterocyclic carbene (NHC) containing homogeneous Ru catalyst in neat water. The newly synthesized Ru catalyst includes NHC, which possesses poly(ethylene glycol) (PEG) as a water-soluble component and benzylidene. The water-soluble Ru catalyst enables the polymerization of acrylamide, [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA), and PEG methyl ether methacrylate. Polymerization with this new catalyst displayed typical ATRP behavior such as a low PDI, a direct linear relationship between molecular weight and conversion, and first-order kinetics. The polySBMA (Mn 335.5 kDa and PDI 1.66) was prepared with 91% conversion at 6 h of reaction time with 0.05 mol% catalyst loading in neat water ([catalyst]:[monomer] = 1:2000 at 80 °C). Without the Ru catalyst, the thermally initiated polymerization displayed uncontrolled polymerization (e.g., non-linear kinetics, high PDI, and too fast or slow polymerizations). The Ru catalyst also demonstrated ATRP of the PEG methyl ether methacrylate in an organic solvent, acetonitrile. More detailed studies of initiator amount, solvent concentration, and catalyst amount effects were performed. In turn, the new ATRP will add prominent value to the polymer science field as an initial example of Ru-benzylidene catalyzed ATRP in neat water. Additionally, this will promote various applications of environmentally benign polymerization as well as applications in the biomedical field with high-cost efficiency.

Ionic supramolecular polymerization of water-soluble porphyrins: balancing ionic attraction and steric repulsion to govern stacking.

We have synthesized novel water-soluble anionic porphyrin monomers that undergo pH-regulated ionic supramolecular polymerization in aqueous media. By tuning the total charge of the monomer, we selectively produced two different supramolecular polymers: J- and H-stacked. The main driving force toward the J-aggregated supramolecular polymers was the ionic interactions between the sulfonate and protonated pyrrole groups, ultimately affording neutral supramolecular polymers. In these J-aggregated supramolecular polymers, amide groups were aligned regularly along polymer wedges, which further assembled in an edge-to-edge manner to afford nanosheets. In contrast, the H-aggregated supramolecular polymers remained anionic, with their amide NH moieties acting as anion receptors along the polymer chains, thereby minimizing repulsion. For both polymers, varying the steric bulk of the peripheral ethylene glycol (EG) units controlled the rates of self-assembly as well as the degrees of polymerization. This steric effect was further tunable, depending on the solvation state of the EG chains. Accordingly, this new family of supramolecular polymers was created by taking advantage of unique driving forces that depended on both the pH and solvent.

Surfactant-free suspension polymerization of hydrophilic monomers with an oil-in-water system for the preparation of microparticles toward the selective isolation of tumor cells

Polymer microparticles, composed of water-soluble hydrophilic monomers, are synthesized via surfactant-free suspension polymerization with an oil-in-water system. Microparticles formed from PMEA have potential as a platform to capture tumor cells.

Styrene-based polymerised high internal phase emulsions using monomers in the internal phase as co-surfactants for improved liquid chromatography.

Poly(styrene-co-divinylbenzene)-based monoliths were prepared from the polymerisation of water-in-monomer high internal phase emulsions, where the water-soluble monomers acrylamide (AAm) or poly(ethylene glycol) diacrylate (PEGDA) (Mw 258) were also included in the 90 vol% internal phase. Both AAm and PEGDA were found to act as co-surfactants, resulting in the obtainment of monoliths with greater homogeneity in some cases. As a result these materials demonstrated significantly improved chromatographic performance for the separation of a standard mixture of proteins using reversed-phase liquid chromatography, in comparison to monoliths prepared with no internal phase monomer. In particular, the columns grafted with PEGDA were capable of separating a more complex mixture consisting of seven components. The inclusion of monomers in the internal phase also allowed for the functionalisation of the monolith's surface where the degree of polymerisation that occurred in the internal phase, which was governed by the monomer content in the internal phase and initiation location, determined whether polymeric chains or a hydrogel were grafted to the surface. A monolith grafted with AAm was also found to be capable of retaining polar analytes as a result of the increase in surface hydrophilicity.

Aqueous-phase synthesis of heterojunction molecular imprinted photocatalytic nanoreactor via stable interaction forces for improved selectivity and photocatalytic property

Common molecular imprinted photocatalysts are usually prepared in highly toxic organic solvent medium, which will be disturbed by water molecules and swelling differences when used for selective recognition in the aqueous phase. In this study, an ionic liquid (IL) was used as the functional monomer and functionalized P25@IL heterojunction molecular imprinted photocatalytic nanoreactor, referred to as imprinted P25@IL nanoreactor, were prepared via the aqueous-phase microwave polymerization strategy. Imidazole-based IL cations can provide π electron clouds, and side chains are easily functionalized and modified, resulting in strong interactions such as π-π and ion dipoles being formed between IL and levofloxacin hydrochloride (LEV), which can overcome the interference of water molecules and achieve better selective adsorption and degradation of LEV in aqueous medium. The selectivity coefficient of imprinted P25@IL nanoreactor relative to P25 and functionalized P25@IL heterojunction molecular non-imprinted photocatalyst (non-imprinted P25@IL photocatalyst) were 2.69 and 2.26, respectively. More importantly, with the formation of IL-P25 heterojunction and surface imprinted layer, the photocatalytic performance of imprinted P25@IL nanoreactor was 2.33 times higher than that of P25. Our findings offer a novel approach to the synthesis of water-soluble functional monomers and the aqueous-phase synthesis of molecular imprinted photocatalytic materials.

Effect of anionic surfactant on the properties of nonionic hydrophobically associating polymer based slick water

A water-soluble nonionic surfactant hydrophobic monomer (AT100) was synthesized by esterification of acryloyl chloride with Triton X-100, after that, a nonionic hydrophobically associating polyacrylamide P(AM-AT100) was synthesized and used as drag reducer. They were characterized by IR and NMR. In fresh water, when the concentration of drag reducer reached 0.3 g·L−1 (so called slick water), the viscosity was 3.86 mm2·s−1 with a drag reduction rate up to 74.7%. After sodium dodecyl sulfate (SDS) was added into the slick water, hydrophobic chains of SDS and hydrophobic units in P(AM-AT100) aggregated and micelles were likely formed, and this process was just like hydrophobic association. The viscosity of the slick water increased significantly, while the drag reduction rate of the mixed system decreased. With SDS concentration at 1.5 g·L−1 and the drag reducer concentration at 0.3 g·L−1, the drag reduction rate was 71.72% and viscosity was 6.25 mm2·s−1, indicating that increasing viscosity had a significantly adverse effect on drag reduction performance. The proppant layup experiment confirmed that the sand-carrying capacity of low-viscosity slick water is limited, so proppant will settle inevitably.

Interfacial Polymerization at the Alkane/Ionic Liquid Interface.

Polymerization at the liquid–liquid interface has attracted much attention for synthesizing ultrathin polymer films for molecular sieving. However, it remains a major challenge to conduct this process outside the alkane–water interface since it not only suffers water‐caused side reactions but also is limited to water‐soluble monomers. Here, we report the interfacial polymerization at the alkane/ionic liquid interface (IP@AILI) where the ionic liquid acts as the universal solvent for diversified amines to synthesize task‐specific polyamide nanofilms. We propose that IP@AILI occurs when acyl chloride diffuses from the alkane into the ionic liquid instead of being triggered by the diffusion of amines as in the conventional alkane–water system, which is demonstrated by thermodynamic partitioning and kinetic monitoring. The prepared polyamide nanofilms with precisely adjustable pore sizes display unprecedented permeability and selectivity in various separation processes.

Transformations of wormlike surfactant micelles induced by a water-soluble monomer

HypothesisWormlike surfactant micelles (WLMs) are prospective as nanoreactors for micellar copolymerization of hydrophilic and hydrophobic monomers. Hydrophilic monomers can destroy WLMs. Large size and cylindrical shape of micelles can be preserved by high salt content favoring closer packing of surfactant heads. ExperimentsThe effect of a water-soluble monomer (acrylamide) on the structure and rheological properties of giant WLMs of an anionic surfactant potassium oleate at different salt content was investigated by combined experimental (SANS, rheometry, fluorescence and NMR spectroscopy, tensiometry) and molecular dynamics simulations studies. FindingsAt low salt content, when WLMs are linear, acrylamide induces their shortening and transformation into spherical micelles as a result of its incorporation into the micellar corona, leading to the drop of viscosity. At high salt content providing branched WLMs, monomer first triggers their transition to long linear chains, which enhances the viscoelasticity, and then to rods. This is the first report showing that the effect of monomer on the rheological properties is quite different for linear and branched micelles. Using branched micelles allows preserving large WLMs at high water-soluble monomer content, which is favorable for their use as nanoreactors for synthesis of copolymers with high degree of blockiness, which give mechanically tough polymer gels.

One-Component DNA Mechanoprobes for Facile Mechanosensing in Photopolymerized Hydrogels and Elastomers

DNA mechanosensors offer unique properties for mechano-adaptive and self-reporting materials, such as programmable bond strength and geometrical strain response, tunable fluorescent strain sensing, interfacing to biological systems, and the ability to store mechanical information. However, the facile incorporation of advanced DNA motifs into polymer networks and achieving robustness in application settings remain difficult. Herein, we introduce one-component DNA mechanoprobes that can be easily polymerized into polymer hydrogels and even elastomers to allow strain-induced fluorescence sensing. The all-in-one mechanoprobe contains a DNA hairpin for programmable force sensing, an internal fluorophore-quencher pair as a reporter, and methacrylamide groups on both ends for rapid and facile photopolymerization into networks based on the nontoxic water-soluble monomer methoxy triethylene glycol acrylate (mTEGA). In addition to mechanosensing hydrogels, we utilize the low Tg of p(mTEGA) to develop the first bulk elastomer materials with DNA force sensors, which show high elasticity and stronger mechanofluorescence. The system makes decisive steps forward for DNA-based mechanoprobes by overcoming the classical multicomponent design of such probes, allowing photopolymerization useful for the design of complex objects or even 3D printing and demonstrating that such motifs may even be useful in dry bulk materials.