Hexyl Acrylate Research Articles

A large scale study of portable sweat test sensor for accurate, non-invasive and rapid COVID-19 screening based on volatile compound marker detection

This study established a novel infield sensing approach based on detection of the volatile compound markers in skin secretions. This was based on analysis of volatile compounds in axillary sweat samples collected from RT-PCR-proven Coronavirus disease 2019 (COVID-19) positive and negative populations using gas chromatography-mass spectrometry (GC–MS). The analysis proposed the possible markers of the monoaromatic compounds and ethyl hexyl acrylate. A portable photo ionization detector (PID) incorporated with the selective material towards the marker compounds was then developed with the pressurized injection approach. This provided the accuracy of 100% in the research phase (n = 125). The developed approach was then applied for screening of 2207 COVID-19 related cases covering the periods of the Alpha, Beta, Delta and Omicron variants of SARS-CoV-2 infection in Bangkok, Thailand. This offered the sensitivity, specificity and accuracy ranges of 92–99, 93–98 and 95–97%, respectively.

Volatiles of different resistant cotton varieties mediate the host preference of Mirid bug Apolygus lucorum.

Cotton, a crucial economic crop, is also the preferred host plant of the mirid bug Apolygus lucorum. In our previous field experiments, we found that cotton cultivars Kelin 08-15 and BR-S-10 (healthy and herbivore-damaged plants) exhibit distinct attraction and repellence to A. lucorum, respectively. However, the key plant volatiles determining attraction or repulsion effects remain unknown. Here, we investigated the volatiles emitted by these two cotton cultivars before and after herbivore infestation. We found that susceptible Kelin 08-15 emitted a greater diversity and quantity of volatiles than those of BR-S-10, with herbivore-damaged cottons releasing more volatile substances. Electroantennogram (EAG) recordings further revealed that 15 representative volatiles identified above could elicited electrophysiological responses in female and male A. lucorum antennae. Among them, behavioral assays showed that two compounds, 1,3-Diethylbenzene and 4-Ethylbenzaldehyde, exhibited attractive properties, whereas six volatiles including Hexyl Acrylate, Cumene, 2,4-Dimethylstyrene, Eucalyptol, Linalool and Butyl Acrylate demonstrated repellent effects on A. lucorum. Taken together, our findings suggest the critical role of volatile compounds in mediating bug-plant interactions and provide a foundation for the development of strategies to prevent and control of A. lucorum in cotton fields.

Synthesis and Characterization of Novel Terpolymers as Viscosity Index Improvers Using Industrial Waste for Iraqi Lubricating Oil

The potential utilization of industrial waste, specifically polyethylene wax, to enhance the efficiency of alkyl acrylate polymers as viscosity index improver (VII) additives in lubricating compositions has been investigated. Four terpolymers (w1, w2, w3, and w4) were synthesized via free radical polymerization, incorporating hexyl acrylate, 1-tetradecene, and industrial waste-sourced polyethylene wax at varying molar ratios. These terpolymers were characterized through gel permeation chromatography (GPC) for molecular weight determination, Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H-NMR) spectroscopy for chemical structure analysis, and thermal gravimetric analysis (TGA) for thermal stability assessment. The study evaluated the efficiency of these terpolymers as viscosity index improvers (VII) in combination with free additives Iraqi lubricating oil (base oil 60). Our results demonstrate the feasibility of significantly enhancing the efficiency of viscosity improvers through the utilization of industrial waste, with improvements proportional to terpolymer concentration. The terpolymer w3, characterized by a balanced molar ratio of 1:1:1, exhibiting the highest degree of efficacy, which gave VI of 206 at 5 wt.% concentration compared with free additive lubricating oil, which gives VI of 98. This study offers promising insights into the sustainable use of industrial waste to improve lubricating compositions.

Highly Frustrated Poly(ionic liquid) ABC Triblock Terpolymers with Exceptionally High Morphology Factors.

In this work, we report the successful synthesis of 17 unique compositions of a poly(ionic liquid) (PIL) ABC triblock terpolymer, poly(S-b-VBMIm-TFSI-b-HA), where S is styrene, VBMIm-TFSI is vinylbenzyl methylimidazolium bis(trifluoromethanesulfonyl)imide, and HA is hexyl acrylate. Nine distinct morphologies were observed, including two-phase and three-phase disordered microphase separated (D2 and D3), two-phase hexagonally packed cylinders (C2), core-shell hexagonally packed cylinders (CCS), three-phase lamellae (L3), two-phase lamellae (L2), core-shell double gyroid (Q230), spheres-in-lamellae (LSI), and a three-phase hexagonal superlattice of cylinders (CSL). The LSI morphology was unambiguously confirmed using small-angle X-ray scattering and transmission electron microscopy. Morphology type significantly impacted the ion conductivity of the PIL ABC triblock terpolymers, where remarkable changes in morphology factor (normalized ion conductivity) were observed with only small changes in the conducting volume fraction, i.e., PIL block composition. An exceptionally high morphology factor of 2.0 was observed from the PIL ABC triblock terpolymer with a hexagonal superlattice morphology due to the three-dimensional narrow, continuous PIL nanodomains that accelerate ion conduction. Overall, this work demonstrates the first systematic study of highly frustrated single-ion conducting ABC triblock terpolymers with a diverse set of morphologies and exceptionally high morphology factors, enabling the exploration of transport-morphology relationships to guide the future design of highly conductive polymer electrolytes.

In vivo Assessment of Diltiazem HCl Immobilized Co-polymeric pH Sensitive Microgels

Novel stimuli responsive coplymeric (2-ethyl hexyl acrylate -co- itaconic acid diltiazem HCl loaded microgels were fabricated and characterized successfully to reduce the degradation of drugs in acidic pH of stomach resulting in reduced bioavailability to minimize dosing frequency and enhance patient compliance. To evaluate the clinical significance, in-vivo studies of recently prepared novel pH sensitive copolymeric microgels are performed and different pharmacokinetic parameters as maximum plasma concentration (Cmax), time to reach the maximum plasma concentration (Tmax), area under the plasma concentration-time curve (AUC 0-?), half-life (t 1/2?) and elimination rate constant (K21) are analyzed. The mean plasma concentration of sustained release DLZ loaded microgels showed higher Tmax for prepared microgels (4.0758±0.22 hrs) than standard drug solution. The half-life t1/2? of test microgels is relatively higher (5.68±5.86 hrs) whereas the Cmax is measured to be 41.06±2.02ng/ml for microgels with AUC0-? calculated as 460.35±39.99 ng.hr/ml. Elimination rate constant K21 for DLZ microgels is 0.18 ± 0.07 hrs-1 for which showed the absorption phase is extended and drug is present for a prolong period of time in the body. This study proved that novel prepared pH sensitive copolymeric p(EHA-co-IA) microgels released model drug in sustained release manner in pH sensitive medium.

Reversible, ultra-strong underwater adhesive based on supramolecular interaction for instant liquid leakage sealing and robust tissue adhesion

Underwater adhesives have great potential applications in biomedical fields. However, it is challenging to realize underwater adhesion due to screening by highly hydrated layer at the interface. To tackle this problem, here we present a novel strategy that combines hydrophobic association and supramolecular interactions to achieve robust adhesion at wet interfaces. Hydrophobic monomers (hexyl acrylate and styrene) are copolymerized with hydrophilic acrylic acid (AAc), and bifunctional host/guest assembly of β-cyclodextrin and adamantane to produce an adhesive. Herein, hydrophobic segments segregate to form hydrophobic microdomains both inside and at the interface. Internal hydrophobic clusters and host–guest interactions serve as physical crosslinks to improve the mechanical properties. Meanwhile, hydrophobic domains at surface play a critical role in expelling water and building a hydrophobic environment to minimize interference from water, where the hydrophilic units form hydrogen bonding, electrostatic attraction, coordination, and cation-π interactions to adhere on the surface. Lap shear tests indicate adhesion strength of about 92 ∼ 116 kPa on glass, copper, plastic, wood, and bone. Such a strong adhesion is independent of environment changes, including pH, PBS and NaCl solutions. More importantly, the adhesive shows excellent adhesion performance for bone, with adhesion strength up to 112.58 kPa in air and 91.51 kPa underwater. The strategy to combine hydrophobic interactions and supramolecular interactions may open a new avenue to the development of new adhesives for underwater adhesion and biological tissue.

Poly(ethylene oxide)-block-poly(hexyl acrylate) Copolymers as Templates for Large Mesopore Sizes─A Detailed Porosity Analysis

Poly(ethylene oxide)-<i>block</i>-poly(hexyl acrylate) Copolymers as Templates for Large Mesopore Sizes─A Detailed Porosity Analysis

Smart Molecularly Imprinted Polymer Based on Liquid Crystals for Herbicide Recognition

This study focuses on the development and characterization of molecularly imprinted thin films in the absence and presence of a liquid crystal monomer, as well as the evaluation of these materials for recognition of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). Molecular imprinted polymers (MIPs) and non-imprinted polymers (NIPs) were prepared by using two functional monomers, n-butylmethacrylate (BMA) and liquid crystalline (LC) 6-(4-cyanophenyl-4′phenoxy) hexyl acrylate (A6OCB). The resulting (MIPs) and (NIPs) materials were characterized by infrared spectroscopy (FTIR), Raman spectroscopy, polarized optical microscopy (POM), and atomic force microscopy (AFM). The entire monomer consumption, as well as the successful loading and extraction of the 2,4-D molecules, were validated by FTIR and Raman analyses. POM and AFM characterization revealed that the percentage of liquid crystal influenced the distribution of the liquid crystal domains and that the MIP films exhibited remarkable porosity. The experimental results revealed that the MIP films had a substantially higher adsorption capacity toward 2,4-D than the NIP materials and that increasing the liquid crystal content increased the adsorption capacity of both the MIP and NIP films. The selectivity tests in the presence of phenoxyacetic acid (POAc) showed that the MIP films exhibited higher affinity for 2,4-D than for the POAc.

Amphiphilic Surface‐Active Methacrylic Urethane Additives for the Design of Photopolymerized Coatings with Great Potential for Marine Fouling‐Release Applications

AbstractAmphiphilic photopolymerized network films are prepared, based on a hexyl acrylate (HA) hydrophobic matrix containing varied amounts of urethane dimethacrylates bearing a hydrophilic poly(ethylene glycol) segment and terminated with hydrophobic, low surface energy groups, i.e., a short perfluorohexyl chain (for EF) or a fluorine‐free heptamethyltrisiloxane group (for ES). These films are extensively characterized in bulk and at the surface by thermal, mechanical, solvent and water uptake, contact angle, and X‐ray photoelectron spectroscopy measurements. On one hand, surface characterizations reveal that the amphiphilic chains of the additives enrich the topmost layer of the films, thus generating a water‐responsive surface. The reconstruction process is found to be faster for the perfluorinated additive EF and slower for the fluorine‐free ES ones. On the other hand, HA provides a hydrophobic matrix with low elastic modulus, dimensional stability, and adhesion to the substrates even after the absorption of water after prolonged immersion. A field immersion trial carried out in a touristic harbor in Leghorn points out that the films, although being ineffective in preventing organism settlement, are easily cleaned by a water jet after three months of immersion, showing a final residual coverage of panels as low as 15%.

Thermal Degradation Studies of Poly(2-ethyl hexyl acrylate) in the Presence of Nematic Liquid Crystals.

The thermal degradation behavior of Poly(2-ethyl hexyl hcrylate) (Poly(2-EHA)), blended with a commercially available nematic liquid crystal (LC) mixture, was investigated by thermal gravimetric analysis (TGA). Different heating rates, ranging from 5 to 200 °C/min, were applied under an inert atmosphere. Based on the TGA results, activation energies (Eα) at different conversion rates (α) were determined using three integral isoconversion methods: Flynn-Wall-Ozawa (FWO), Tang, and Kissinger-Akahira-Sunose (KAS). It can be noticed that the global evolution of these activation energies was the same for the three models. The coefficient of determination R2 presented values generally higher than 0.97. Using these models, the Eα value for the LC remains constant at 64 kJ/mol for all conversions rates. For the polymer Poly(2-EHA), applying the Tang and FWO models, the activation energy presents a variation ranging from 80 kJ/mol, for conversion α = 0.1, to 170 kJ/mol, for α = 0.9. For the third model (KAS), this energy varies between 80 and 220 kJ/mol in the same range of α.

Preparation of functional nanoparticles of mPEG‐b‐P(DMA‐co‐HA) copolymers via polymerization‐induced thermal self‐assembly

AbstractSelf‐assembled polymeric nanoparticles have been of great interest for various biological applications such as drug delivery, catalysis, and biosensing. In this regard, polymerization‐induced self‐assembly (PISA) has been widely explored as a more efficient technique than conventional self‐assembly methods as it can be conducted in one pot and does not require harsh conditions. Recently, a method known as polymerization‐induced thermal self‐assembly (PITSA) has emerged, exploiting the inherent phase transition behavior of thermoresponsive polymers at a critical temperature point to generate thermoresponsive nanoparticles in situ. However, the narrow range of monomers suitable for PITSA limits the design of diverse thermoresponsive nanoparticles, and therefore this process has not yet been explored to its fullest capacity. In this study, we demonstrate the preparation of thermoresponsive nanoparticles based on hydrophilic N,N‐dimethyl acrylamide (DMA) and hydrophobic hexyl acrylate (HA) monomers. This is particularly interesting as these monomers produce non‐responsive homopolymers but display thermoresponsive behavior when copolymerized. The nanoparticles obtained were crosslinked to enable their characterization at room temperature, and further functionalized with a short synthetic antibacterial peptide (WR)3 to demonstrate proof‐of‐concept potential as antimicrobial agents. Overall, this work expands the library of monomers amenable to PITSA for the production of thermoresponsive nanoparticles, contributing to the design of new functional nanoparticles for therapeutic purposes.

Kinetics of UV Radiation-Induced Fast Collapse and Recovery in Thermally Cycled and Rehydrated Light- and Thermo- Double-Responsive Copolymer Films Probed by In Situ Neutron Reflectivity.

The kinetics of UV radiation-induced fast collapse and recovery in thermally cycled and rehydrated light- and thermo- double-responsive copolymer films of poly(oligo(ethylene glycol) methyl ether methacrylate-co-6-(4-phenylazophenoxy)hexyl acrylate), abbreviated as P(OEGMA300-co-PAHA), are probed by in situ neutron reflectivity (NR). The copolymer film is exposed to a thermal treatment starting at a temperature of 60 °C, which is well above its transition temperature (TT = 53 °C) before the temperature is rapidly decreased from 60 to 23 °C. Based on the applied protocol, the initially collapsed P(OEGMA300-co-PAHA) film is rehydrated due to the switching of polymer chains from a more hydrophobic to a more hydrophilic state when the temperature falls below its TT. The whole rehydration process can be divided into 3 stages: D2O absorption, chain rearrangement, and film reswelling. After rehydration, the thermally cycled P(OEGMA300-co-PAHA) film is switched by UV irradiation via setting the UV radiation on and off. Considering the UV-induced collapse and recovery, both processes are slower than those observed in freshly hydrated films without any thermal stimulus history. Therefore, the experienced thermal history of the film should be considered in the design of sensors and detectors based on double-responsive copolymer films.

Experimental studies on the preparation and properties of starch‐graft‐poly(hexyl acrylate) copolymers

AbstractThe preparation and the properties such as the chemical stability, solution properties, moisture absorption, ability to gelation, glass transition temperatures, thermal stabilities and the decomposition course of starch‐graft‐poly(hexyl acrylate) copolymers have been studied. In general, it can be said that as the grafting percent increases the chemical resistance in alkaline, inert, acidic and buffer environments, and the solubility in non‐polar solvents of the copolymers increases. In turn, the solubility in polar solvents decreases compared to the solubility of starch. The Tg of starch‐g‐poly(hexyl acrylate) copolymers is in the range 102–133°C and is much higher than Tg of poly(hexyl acrylate) homopolymer. The thermal stability of all tested copolymers is higher than 274°C (inert conditions) and 230°C (oxidative conditions). In inert conditions, all tested copolymers decompose in two main stages related to pyrolysis combined with the emissions of the following volatiles: CO, CO2, H2O, aldehydes, alcohols, acids, ester, furanes, aliphatic and alkene fragments. In turn, the copolymers decompose in main three stages in oxidative conditions. The emission of CO, CO2, H2O, aldehydes, alcohols, acids, aliphatic, furanes and alcohols as a result of pyrolysis, oxidation, decarboxylation, dehydration, and combustion processes was confirmed.

Emulsion polymerized styrene acrylic/nanocellulose composite coating to improve the strength and hydrophobicity of kraft paper

Improving the mechanical and water repelling property of kraft paper will extend its use for packaging application. In this work, we developed a cellulose nanofiber (CNF)-based colloidal polymer nanocomposite that was used as coating for improving those properties of kraft paper. In this case, the polymer latex was obtained by the mini-emulsion copolymerization of styrene (St), 2-ethyl hexyl acrylate (EHA) initiated by ammonium persulfate. The CNFs were incorporated into the styrene-acrylic copolymer matrix by the in-situ polymerization and ex-situ mixing process keeping the CNF concentration up to 1.0 wt%. All the latexes showed particle size below 100 nm and excellent colloidal stability (Zeta potential > −32 mV) for several months. The nanocomposite films showed improved mechanical properties (tensile strength upto 7.8 MPa, elongation upto 1096 %) than the pristine copolymer. The in-situ prepared nanocomposite at 1.0 wt% CNF showed the highest storage modulus. The latex-coated kraft paper showed improved tensile index (31.0–45.1 Nm/g) compared to the uncoated paper (20.3 Nm/g) and also high hydrophobicity (water contact angle ∼120°) for the ex-situ prepared nanocomposites. The results are quite promising to develop paper-based packaging materials using nanocellulose in combination with synthetic polymers.

Repairable Macroscopic Monodomain Arrays from Block Copolymers Enabled by Photoplastic and Photodielectric Effects

Upon exposure to UV light (120 mW/cm2, λ = 365 nm), a trans-cis isomerization occurs in a cylinder-forming, azobenzene-containing block copolymer of polydimethylsiloxane-b-poly((4(phenyldiazenyl)phenoxy)hexyl acrylate) (PDMS-b-PPHA) that enables the generation of monodomains of healable, long-range ordered arrays of nanoscopic domains over macroscopic distances. The trans-cis isomerization gives rise to a significant increase in the dielectric constant (from 6.52 to 19.8 at 100 Hz, photodielectric behavior) and a dramatic decrease in the Tg (from 54 to 1 °C, photoplastic behavior) of the PPHA block. By combining these characteristics with an in-plane electric field, macroscopic monodomains of near-perfectly aligned cylindrical microdomains are achieved at low temperatures, and a damage repair is clearly uncovered, where the 300 nm wide scratches can be completely healed at 40 °C, leaving a smooth, uniformly thick film where the continuity and orientation of the aligned microdomains are restored. Subsequent exposure to visible light causes a cis-trans isomerization, increasing the matrix Tg to 54 °C, producing highly oriented and aligned PDMS cylindrical microdomains in a PPHA matrix.

A library of new organofunctional silanes obtained by thiol-(meth)acrylate Michael addition reaction.

A simple and efficient method for the synthesis of organofunctional silanes by the thiol-(meth)acrylate addition reaction is presented. At first, systematic studies were carried out to select an optimum initiator/catalyst of the addition reaction for the model reaction involving 3-mercaptopropyltrimethoxysilane (MPTMS) and hexyl acrylate. Photoinitiators (in the presence of UV light energy), thermal initiators (such as aza compound and peroxide) as well as catalysts (primary and tertiary amines, phosphines and Lewis acid) were studied. After selecting an effective catalytic system and optimizing the reaction conditions, reactions between the thiol group (i.e. 3-mercaptopropyltrimethoxysilane) and (meth)acrylates containing various functional groups were carried out. All derivatives obtained were characterized by 1H, 13C, 29Si NMR and FT-IR analysis. In reactions carried out at room temperature, in an air atmosphere and in the presence of dimethylphenylphosphine (DMPP) as a catalyst, quantitative conversions of both substrates were obtained within a few minutes. The library of organofunctional silanes was expanded by compounds (containing various functional groups, i.e. alkenyl, epoxy, amino, ether, alkyl, aralkyl, fluoroalkyl) which were obtained in the thiol-Michael addition of 3-mercaptopropyltrimethoxysilane to a group of organofunctional (meth)acrylic acid esters.

Optical and Electrical Characterization of Polymer Dispersed Nematic Liquid Crystals

Polymer dispersed liquid crystals are composite functional materials having a variety of application ranging from display to smart window. These materials consist of liquid crystal in which micron size droplets of polymer is dispersed. In the present study the effect of different concentration of polymer 2-ethyl hexyl acrylate on optical and electrical properties of nematic liquid crystal 4-cynophenyl 4-n-hexyl benzoate were investigated by various techniques. The investigation of textures at different temperatures was performed by polarizing optical microscopy for the determination of phase transition temperature. The fabry perot scattering studies using low powered laser beam was used for the confirmation of phase transition temperature. Various textures were found according to the orientation of liquid crystal and polymer. The optical and electrical properties of pure liquid crystal were found to enhance after dispersing polymer. Our investigation suggest that after dispersing polymer into nematic liquid crystal, the material shows more stability, less flicking and sticking of image for display applications.

Influence of elongation and desaturation on chemosensory properties in acrylates and their corresponding 1-alken-3-ones

Acrylates as well as 1-alken-3-ones are both known to be odour active substances but are generally identified in different materials. Nonetheless, butyl acrylate and 1-octen-3-one were both found to elicit a similar mushroom-like odour in previous studies. This led to the question of whether acrylates and enones with the same overall chain length generally elicited similar odours and whether they had similar odour thresholds. Overall, most of the investigated substances showed a mushroom-like, geranium-like or fruity odour. In contrast, short chained substances elicited garlic-like, lighter gas-like or glue-like, odour qualities, suggesting a correlation between the odour quality and the overall chain length. The results showed that only between the analogue structures butyl acrylate and 1-octen-3-one as well as hexyl acrylate and 1-decen-3-one could similar odour qualities be observed. All investigated substances showed low odour threshold values in air between 0.0032 ng/lair (1-hexen-3-one) and 55 ng/lair (1-dodecen-3-one). Overall, 1-alken-3-ones revealed a higher dependency on the chain length when compared to their respective acrylates. The introduction of a second terminal double bond led to a decrease of OT values in case of the acrylates and to an increase in case of the ketones that neither contained a second terminal double bond nor a double bond located close to the carbonyl group. Despite their structural similarities, the results suggest that both substance classes are perceived in a different manner and are therefore likely to be recognized by different types of receptors or are related to different activation patterns in multi-receptor stimulation processes.Graphical abstract

Study on the preparation and performance of an electrically controlled dimming film with wide working temperature range

Polymer dispersed liquid crystal (PDLC) films have shown potential applications in various fields such as curtain walls, indoor partitions and smart windows due to their large-area and convenient manufacturing ability. However, the narrow working temperature range limits their outdoor applications, especially in automobiles. In this study, methods to improve the performances of PDLC films at high and low temperatures were explored. Liquid crystals (LCs) with wide temperature range were used and different polymerizable monomers and cross-linking agents matching the LCs were investigated. Results show that the prepared PDLC film has a better contrast ratio of 48 at a high temperature of 90 °C, and fast on-state and off-state response times of 74 ms and 895 ms at −20 °C, respectively, when using hexyl acrylate as monomer and 1,4-butanediol diacrylate as crosslinking agent. This research could promote the application of PDLC films to outdoor scenes like smart windows for automobiles.

Confocal Microscopy Visualizes Particle–Crack Interactions in Epoxy Composites with Optical Force Probe-Cross-Linked Rubber Particles

Brittle fracture often compromises the durability of glassy polymers. This can be mitigated by reinforcing the matrix with a filler, activating a range of toughening mechanisms. Therefore, it is desirable to better understand the mechanical response of polymer composites, but a direct visualization of the mechanical fate of second-phase inclusions upon material fracture was previously unavailable. Here, rubbery poly(hexyl acrylate) particles, cross-linked with an optical force probe (OFP), are dispersed within an epoxy matrix, the material is fractured, and particle–crack interactions are visualized with confocal laser scanning microscopy. The dual-fluorescence character of the OFPs allows the differentiation between particles that remain intact and those that are stressed beyond bond scission upon interaction with a propagating crack. The localized activation of OFPs reveals stress gradients within the particles and crack direction pathways, hence providing a new layer of information over fracture events in polymer composites.