Butyl Acrylate Research Articles

Doping Si/O to enhance interfacial occupancy of demulsifiers for low‐carbon breaking of water‐in‐heavy oil emulsions

AbstractSeparating water‐in‐heavy oil (W/HO) emulsions at low (room) temperature is challenging when exploiting heavy oil. We propose an adaptable strategy for constructing Si/O‐doped demulsifiers. A nonionic demulsifier (APBMP) has been synthesized based on polysiloxane modified by allyl polyether and butyl acrylate. APBMP achieves 95.97% dehydration within 5 min for W/HO emulsions at 288.15 K and complete dehydration in 15 min at 323.15 K. Mechanistic studies found that doping Si/O into the demulsifier molecules increases the number of hydrogen bond sites, which enables the demulsifiers to quickly disperse natural stabilizers (e.g., asphaltenes) and replace them at the oil–water interfacial film. The demulsifiers prefer to occupy the interfacial sites rather than dissolve into the bulk oil or water phases. Driven by hydrogen‐bond‐dominated noncovalent interactions, the oil–water interfacial film is softened, reconstructed, and broken. These findings provide insights into developing novel materials for oil–water separations in a low‐carbon way.

Reactivity Ratios of Biobased Dialkyl Itaconate Radical Polymerizations Derived from In-Line NMR Spectroscopy and Size-Exclusion Chromatography.

Itaconates available from renewable resources constitute a group of monomers that are used in several types of polymerizations. Their use in free-radical polymerizations (FRPs) is still limited due to the low propagation rate coefficients resulting in low polymerization rates and the occurrence of depropagation which is responsible for limited monomer conversion. Since FRP is considered very robust with few requirements concerning monomer purity, it is still interesting to investigate how itaconate FRP may become feasible. For this reason, copolymerizations of itaconates with other monomers well-suited for FRP are considered. In particular, copolymerization with acrylates appears to be interesting because the propagation rate of these monomers is high and depropagation is not operative at common polymerization temperatures. Copolymerizations of dibutyl and dicyclohexyl itaconate with butyl acrylate were performed to determine the copolymerization reactivity ratios required for tailoring copolymer composition. To limit the number of experiments, copolymerizations were carried out until high conversion and consumption of the individual monomers was obtained from 1H NMR spectroscopy and quantitative size-exclusion chromatography.

Electrochemical Properties of Powdery LiNi1/3Mn1/3Co1/3O2 Electrodes with Styrene-Acrylic-Rubber-Based Latex Binders at High Voltage.

Efforts to improve the energy density and cycling stability of lithium-ion batteries have focused on replacing LiCoO2 in cathodes with LiNixMnyCo1-x-yO2. However, reliance on polyvinylidene fluoride (PVdF) as the binder limits the application of the LiNixMnyCo1-x-yO2 composite electrode for lithium-ion batteries. Here, we evaluate the electrochemical properties of a LiNi1/3Mn1/3Co1/3O2 (NMC111) powder electrode formed using a waterborne-styrene-acrylic-rubber (SAR) latex binder combined with sodium carboxymethylcellulose. The composite electrodes prepared with the SAR-based binder copolymerized with the butyl acrylate monomer and styrene exhibited high adhesive strength and excellent cyclability and rate capability. The results of surface analysis via X-ray photoelectron spectroscopy suggested that the electrode with the SAR-based binder is more resistant to electrolyte decomposition during charge and discharge cycling compared with the NMC111 electrode comprising the conventional PVdF binder. The SAR-derived passivation resulted in enhanced capacity retention during long-term cycling tests of both half- and full-cells (NMC111//graphite). An electrode with a higher Ni content, LiNi0.6Mn0.2Co0.2O2 (NMC622), fabricated using the SAR-based binder, retained 87.1% of its capacity after 50 cycles at 4.6 V and exhibited excellent cycling stability.

Isosorbide-Based Acrylic Pressure-Sensitive Adhesives Through UV-Cured Crosslinking with a Balance Between Adhesion and Cohesion.

The development of sustainable pressure-sensitive adhesives (PSAs) from natural biomass resources has attracted increasing attention owing to their non-toxic, biocompatible, and biodegradable features. In this study, a bio-based acrylic PSA with tunable adhesion and cohesion was synthesized by a selective chemical modification of isosorbide-5-acrylate (IA) and its copolymerization with butyl acrylate and acrylic acid through UV-curing crosslinking. During the UV-curing process, the synthesized isosorbide diacrylate ester (IDAE) served as the crosslinker, effectively improving the crosslinking degree of PSA. The impact of IA and IDAE on the mechanical properties of PSA was studied. Moreover, to achieve a balance between adhesion and cohesion, the optimal composition was identified. The addition of IA significantly enhances the stiffness of PSA. Furthermore, the combined effect of IA and IDAE improves the overall adhesion properties of the PSA. The optimal bio-based PSA demonstrates a peel force of 13.9 N/25 mm and a persistent time of 6820 min, promising to replace traditional petroleum-based PSAs.

Cerium Oxide‐Armored Composite Latex Particles by Visible Light Emulsion Photopolymerization: From Synthesis to Film Properties

AbstractCerium dioxide (CeO2) has huge potential in many applications ranging from biochemical engineering to the coating industry. Here, the first example of visible light photo‐mediated Pickering emulsion polymerization of (meth)acrylate monomers is reported using CeO2 nanoparticles (NPs) as solid stabilizer. A ω,ω′−dicarboxylic acid diphenyl disulfide photoinitiator is anchored on the surface of the CeO2 NPs and used to initiate the emulsion polymerization of methyl methacrylate (MMA) and of MMA/n‐butyl acrylate (MMA/BA) under visible light leading to CeO2‐armored latexes. Radicals generated upon light irradiation trigger the formation of polymer chains chemically attached to the CeO2 NPs, promoting their subsequent adsorption on the latex surface. The composite films obtained from the CeO2‐armored P(MMA‐co‐BA) latexes exhibit a unique honeycomb nanostructure with the nanoceria located in the walls giving the materials excellent mechanical, anti‐UV, and photocatalytic properties.

Selective Hydrolysis of Heterooligosaccharides by Poly(acrylate) Gel Catalysts.

Natural glycoside hydrolases are distinguished by their ability to hydrolyze glycosidic bonds with high efficiency and selectivity. This feature is achieved through specific interactions in the active site during catalytic turnover and is not just facilitated by two catalytically active amino acids. Intrigued by these features, a biomimetic α-galactosidase mimic was developed using an empirical catalyst design. Starting with a library of 704 gels of which 250 have a unique composition synthesized from TEGDMA cross-linker and 7 selected monomers, 238 monomodal gels are evaluated for their ability to hydrolyze the 1→6 α-glycosidic bond in the disaccharide melibiose. Among those, 13 polyacrylate gels with the potential for high catalytic activity are identified using spectrophotometric screening assays based on Schiff bases formed with toluidine. The best-performing polyacrylate (gel A) was found to have a 1500-fold higher proficiency to hydrolyze the 1→6 α-glycosidic bond in melibiose over the 1→2 α-glycosidic bond in sucrose, translating to selective hydrolysis of the glycosidic linkages in the trisaccharide raffinose. The matrix of gel A is composed of 25 mol % TEGDMA cross-linker and equimolar amounts of cyclohexyl, butyl, and benzyl acrylate accounting for CH-π and hydrophobic interaction in the surrounding of a hydrolytic binuclear Cu(II) complex. The combined observations underline a paramount influence of matrix-stabilizing effects on the transition state of the hydrolysis of glycosidic bonds and may pave the way for the rapid development of catalysts transforming biomass.

Effect of Hydrophobic Acrylic Monomers with Different Alkyl Side Chain Lengths on Reducing the Glistening of Hydrophobic Acrylic Intraocular Lens Materials

AbstractGlistening is the condensation of water that forms within the intraocular lens (IOL) materials. In this study, a new approach was attempted to reduce the glistening of IOL materials by introducing hydrophobic acrylic monomers with different alkyl side chain lengths into the IOL materials. Various hydrophobic acrylic monomers such as butyl acrylate (BA), 2‐ethylhexyl acrylate (EHA), and dodecyl acrylate (DA) were copolymerized with a hydrophobic acrylic monomer, 2‐phenoxyethyl acrylate, respectively. In this process, we investigated the effect of the alkyl side chain lengths of hydrophobic acrylic monomers on the glistening of hydrophobic acrylic IOL materials. As the content of hydrophobic acrylic monomers (BA, EHA, and DA) increased, the glistening of IOL materials decreased significantly for all hydrophobic acrylic monomers. At the same content of hydrophobic acrylic monomers, the IOL material showed the least content of glistening when copolymerized with DA. However, the IOL material obtained using BA exhibited the largest content of glistening, indicating that the glistening reduction effect was large in the order of DA>EHA>BA. These findings show that the glistening of IOL materials decreases with increasing alkyl side chain lengths of hydrophobic acrylic monomers.

Preparation of low‐temperature self‐crosslinking acrylic resin and its performance research

AbstractAcrylic resin, as a common coating and adhesive, possesses excellent heat resistance, weather resistance, and is inexpensive, making it widely used in industries related to automotive, construction, electronics, fabrics, and other sectors essential to our daily life. Traditional acrylic resin not only pollutes the environment but also poses certain health risks. Therefore, we studied the synthesis of a low‐temperature self‐crosslinking acrylic emulsions were synthesized by free radical solution polymerization using methyl methacrylate (MMA), butyl acrylate (BA), acrylic acid (AA), diacetone acrylamide (DAAM), hydroxypropyl acrylate (HPA), epoxy resin (E‐51) as the monomers, vinyltriethoxysilane (A‐51) as the coupling agent, and adipic dihydrazide (ADH) as the cross‐linking agent. This water‐based acrylic resin undergoes a crosslinking reaction between the carbonyl group of DAAM and the hydrazide group of ADH, substantially improved the drying speed and adhesion compared to unmodified versions, and also improved the thermal stability. The contact angle of the film increased from 72.8° to 86.9° with the increase of the degree of cross‐linking, and the mechanical properties were improved by 60%. This study provides a suitable formulation for preparing water‐based acrylic resins with superior performance.

Multi-Responsive Polymer Nanoparticles: A Versatile Platform for Double-Security Anticounterfeiting and Smart Food Packaging.

Potential applications of colloidal polymer nanoparticles in the preparation of smart inks are investigated by physical incorporation of the oxazolidine molecules. Precise adjusting the polymer chain flexibility and polarity is achieved by controlling the ratio of methyl methacrylate and butyl acrylate monomers in the polymerization reaction. In addition, nanofibrous indicators of acid-base vapors are prepared from the latex nanoparticles. This can be beneficial for creating materials that sense and respond to environmental changes, such as humidity or moisture and acidity. Thermochromic inks are prepared by microencapsulating crystal violet lactone dye (CVL) in polymer matrices to prevent their release into the aqueous media. Combining two distinct systems with varying triggers, such as light and temperature, provides an effective strategy for double-encryption anticounterfeiting and crack and scratch detection and indication applications. Preparing labels impregnated with double-responsive inks, a novel approach is developed for food spoilage detection and preservation indication. Labels are manufactured using polymer nanoparticles, which contain photoluminescent oxazolidine molecules, as well as a trinary mixture of CVL within core-shell latex particles as the thermochromic dye. The combination of these two responsive elements transforms traditional packaging into a dynamic and interactive sentinel for the food it holds.

Interfacial fatigue fracture of pressure sensitive adhesives

Pressure sensitive adhesives (PSAs) are viscoelastic polymers that can form fast and robust adhesion with various adherends under fingertip pressure. The rapidly expanding application domain of PSAs, such as healthcare, wearable electronics, and flexible displays, requires PSAs to sustain prolonged loads throughout their lifetime, calling for fundamental studies on their fatigue behaviors. However, fatigue of PSAs has remained poorly investigated. Here we study interfacial fatigue fracture of PSAs, focusing on the cyclic interfacial crack propagation due to the gradual rupture of noncovalent bonds between a PSA and an adherend. We fabricate a model PSA made of a hysteresis-free poly(butyl acrylate) bulk elastomer dip-coated with a viscoelastic poly(butyl acrylate-co-isobornyl acrylate) sticky surface, both crosslinked by poly(ethylene glycol) diacrylate. We adhere the fabricated PSA to a polyester strip to form a bilayer. The bilayer is covered by another polyester film as an inextensible backing layer. Using cyclic and monotonic peeling tests, we characterize the interfacial fatigue and fracture behaviors of the bilayer. From the experimental data, we obtain the interfacial fatigue threshold (4.6 J/m2) under cyclic peeling, the slow crack threshold (33.9 J/m2) under monotonic peeling, and the adhesion toughness (∼ 400 J/m2) at a finite peeling speed. We develop a modified Lake-Thomas model to describe the interfacial fatigue threshold due to noncovalent bond breaking. The theoretical prediction (2.6 J/m2) agrees well with the experimental measurement (4.6 J/m2). Finally, we discuss possible additional dissipation mechanisms involved in the larger slow crack threshold and much larger adhesion toughness. It is hoped that this study will provide new fundamental knowledge for fracture mechanics of PSAs, as well as guidance for future tough and durable PSAs.

Development of cellulose-supported Pd-nanocatalyst for the heck coupling and michael addition reactions

The development of reusable, bio-resource based nanocatalysts with high turnover numbers (TONs) is essential for increased sustainability in the chemical sector. Herein, cellulose-supported bio-resourced poly(hydroxamic acid) is employed as a ligand in the synthesis of a palladium nanocomposite (PdNc-PHA) that exhibits higher TONs that previously reported similar systems for the Mizoroki-Heck and Michael addition reactions. The PdNc-PHA catalyst was characterised using Fourier transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectrometry (EDX), high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) analyses. Results showed that the PdNc-PHA catalyst exhibits excellent durability and high catalytic activity in the Mizoroki-Heck and Michael addition reactions, leading to high yields of the desired corresponding products. The Mizoroki-Heck reaction of aryl/heteroaryl chlorides with olefins resulted in the production of cross-coupled products, while the Michael addition reaction of phenol/thiophenol and aliphatic cyclic/alicyclic amines with a variety of olefins synthesised the corresponding O-, S-, and N-alkylated products. The recycle and reusability of the catalyst were tested using 4-nitrochlorobenzene and butyl acrylate. The results demonstrated that the catalyst maintained its catalytic activity effectively for up to ten cycles without any noticeable loss in performance. This research represents a promising strategy for efficient catalysis based on bio-waste as a wealth material.

Synthesis and properties of superhydrophobic monomer stearyl methacrylate-modified polyacrylate latex pressure sensitive adhesives

Hybrid surfactants of long carbon chain hydrophobic nonionic emulsifier N-390 and conventional anionic emulsifier CO-436 were utilized in this study to enable successful emulsion polymerization of super-hydrophobic monomer stearyl methacrylate (SMA) together with butyl acrylate (BA), acrylic acid (AA), and 2-hydroxyethyl acrylate (HEA). The influences of SMA on the resulting latex and film properties were thoroughly investigated. Both FTIR and 1H NMR were used to confirm the successful participation of SMA in the emulsion polymerization. The results indicated that with introduction of SMA, the roughness of the latex film increases, while the light transmission decreases. It was also found that with the addition of SMA, contact angle of the latex PSA film increased from 115.1° to 127.2°, while water absorption decreased from 5.76 to 2.89 wt%. DSC curves demonstrated that SMA has participated more in the homopolymerization reaction than in the copolymerization reaction. TGA results showed that the initial decomposition temperature (T5%) of the latex film was increased from 302.8 to 332.7 °C with the increase of SMA dosage from 0 to 20 wt%. Finally, adhesion properties results indicated that loop tack and 180° peel force of the PSA films were decreased from 11.51 to 1.88 N/25 mm and 6.36 to 3.44 N/25 mm, respectively, while shear strength was increased from 732 to 2865 min.

Free-standing polyaniline-reduced graphene oxide (PANI-rGO) thermoelectric films via electrochemical synthesis

Abstract Heat-based energy harvesting is gaining attention as an alternative energy source. Thermoelectric materials (TEs) generate voltages in response to a thermal gradient and conductive polymer-carbon composites have properties that make them favorable for these applications. Polyaniline-reduced graphene oxide (PANi-GO) thermoelectric thin films were fabricated by the electropolymerization of PANi with simultaneous co-deposition of graphene onto fluorine-doped tin oxide (FTO). Poly(butyl acrylate) was spin-coated onto these films as backing support to make a stable free-standing film of PANi-rGO. The free-standing film was formed upon GO reduction which resulted in simultaneous delamination from the FTO electrode. Compositional and morphological data were obtained via Raman microspectroscopy and scanning electron microscopy and the TE properties were measured in terms of the Seebeck coefficient and conductivities from Hall effect measurements. The Seebeck coefficients of the films measured between 6.6 μV K−1 to 13.4 μV K−1, whereas Hall effect conductivities ranged from 0.483 to 2.68 S cm−1. The highest film power factor measured was 0.025 μW m−1K−2. Varying the GO content used in the electropolymerized film did not have a significant effect on the overall TE property though varying the reduction cycle number and voltage resulted in significant changes in the film Seebeck coefficients and conductivities.

Natural Attenuation Potential of Vinyl Chloride and Butyl Acrylate Released in the East Palestine, Ohio Train Derailment Accident.

The East Palestine, Ohio train derailment released toxic vinyl chloride (VC) and butyl acrylate (BA), which entered the watershed. Streambed sediment, surface water, and private well water samples were collected 128 and 276 days postaccident to assess the natural attenuation potential of VC and BA by quantifying biodegradation biomarker genes and conducting microcosm treatability studies. qPCR detected the aerobic VC degradation biomarkers etnC in ∼40% and etnE in ∼27% of sediments collected in both sampling campaigns in abundances reaching 105 gene copies g-1. The 16S rRNA genes of organohalide-respiring Dehalococcoides and Dehalogenimonas were, respectively, detected in 50 and 64% of sediment samples collected 128 days postaccident and in 63 and 88% of sediment samples collected 276 days postaccident, in abundances reaching 107 cells g-1. Elevated detection frequencies of VC degradation biomarker genes were measured immediately downstream of the accident site (i.e., Sulphur Run). Aerobic VC degradation occurred in all sediment microcosms and coincided with increases of etnC/etnE genes and Mycobacterium, a genus comprising aerobic VC degraders. The conversion of VC to ethene and an increased abundance of VC reductive dechlorination biomarker genes were observed in microcosms established with sediments collected from Sulphur Run. All anoxic microcosms rapidly degraded BA to innocuous products with intermediate formation of n-butanol and acrylate. The results indicate that microbiomes in the East Palestine watershed have natural attenuation capacity for VC and BA. Recommendations are made to improve first-response actions in future contaminant release accidents of this magnitude.

Synthesis of Amphiphilic Polyacrylates as Peelable Coatings for Optical Surface Cleaning

Optical instruments require extremely high precision, and even minor surface contamination can severely impact their performance. Peelable coatings offer an effective and non-damaging method for removing contaminants from optical surfaces. In this study, an amphiphilic polyacrylate copolymer (PMLEA) was synthesized via solution radical copolymerization using the lipophilic monomer lauryl acrylate (LA) and hydrophilic monomers ER-10, methyl methacrylate (MMA), and butyl acrylate (BA). The structure and molecular weight of the copolymer were characterized using Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and gel permeation chromatography (GPC). The hydrophilic–lipophilic balance, surface tension, and wettability of the copolymer were analyzed through water titration, the platinum plate method, and liquid contact angle tests. The cleaning performance of the copolymer coating on quartz glass surface contaminants was evaluated using optical microscopy and Ultraviolet-Visible Near-Infrared (UV-Vis-NIR) spectroscopy. The study examined the effect of varying the ratio of LA to ER-10 on the hydrophilicity, lipophilicity, cleaning efficiency, and mechanical properties of the copolymer coating. The results showed that when the mass ratio of LA to ER-10 was 1:2, the synthesized copolymer exhibited optimal performance in removing dust, grease, and fingerprints from quartz glass surfaces. The coating had a tensile strength of 2.57 MPa, an elongation at break of 183%, and a peeling force of 2.07 N m−1.

The Role of Starch Incorporation into Waterborne Acrylic-Hybrid Nanoparticles for Film-Forming Applications.

The use of biopolymers as an alternative to petroleum-based polymers offers a sustainable solution with benefits such as biodegradability and unique functionalities. In this study, starch/zein bioparticles (BPs) obtained by nanoprecipitation were employed to synthesize acrylic polymer/biopolymer waterborne nanoparticles with excellent film formation capability. These hybrid nanoparticle dispersions were obtained through a semibatch emulsion polymerization using the previously synthesized BPs as seed and variable monomeric formulations composed of butyl acrylate and methyl methacrylate. A synergetic effect between acrylic and biopolymer phases was evidenced where the incorporation of BPs had a fundamental role in improving sensitive properties, such as film blocking resistance, while attaining smooth films at room temperature. These excellent film-forming properties of starch/acrylic hybrid latexes without requiring the addition of formulation agents, which depict an important benefit from an environmental viewpoint, demonstrate that they represent a promising alternative for the development of a new generation of eco-friendly binders.

Study on UV-Curable Acrylic Clear Viscoelastic Materials with Grafted Structures

Flexible substrates are crucial for wearable electronic strain sensors, but achieving biocompatibility, low cost, and aesthetic appeal alongside good mechanical performance remains challenging. Acrylic-based clear viscoelastic films (CVFs) are gaining attention due to their excellent transparency and potential for enhanced mechanical properties. This study synthesized copolymers CVF1-4 with varying branch content using soft monomers 2-ethylhexyl acrylate (2-EHA), butyl acrylate (n-BA), and functional monomer acrylic acid (AA). Employing a "grafting-through" strategy, small molecule monomers, ATRP-synthesized oligomer pBA25, and photoinitiator 1,6-hexanediol diacrylate (HDDA) were in-situ polymerized under UV light to form transparent, flexible elastic films CVF1-4. Between -20 to 80 C, CVF1-4 demonstrated excellent mechanical properties such as low modulus (in the kPa range), low glass transition temperature (below -20 C), large deformation (500-600%), and high strain recovery rate (>95%). Among them, CVF3 with 15% branching showed a balanced comprehensive performance, exhibiting primarily elastic behavior at room temperature. Therefore, selecting appropriate molecular composition and grafting structure provides a simple and customizable solution for optimizing CVF properties.

Photo-induced time-dependent controllable wettability of dual-responsive multi-functional electrospun MXene/polymer fibers

Switchable wettability potential in smart fibers is of paramount importance in various applications. Light-induced controllable changes in surface wettability have a significant role in this area. Herein, smart waterborne homopolymer, functional copolymer with different polarity and flexibility, and multi-functional terpolymer particles containing a time-dependent dual-responsive acrylated spiropyran, as a polymerizable monomer, were successfully synthesized through eco-friendly single-step emulsifier-free emulsion polymerization. Presence of 10 wt% of butyl acrylate and dimethylaminoethyl methacrylate relative to methylmethacrylate as functional comonomers decreased the Tg of the samples almost 20 ℃ and increased their polarity. The optical properties of the particles were investigated, and the UV–vis and fluorescence spectroscopy results showed that not only polarity and flexibility of the polymer chains may have a positive effect on improving the optical properties, but also the simultaneous presence of functional groups has a synergistic effect. The smart polymer particles with flexibility and polarity features exhibited higher absorption and emission compared to other samples. Inspired by these findings, multi-functional smart polymer fibers were prepared using the electrospinning method. The smart multi-functional electrospun fibers containing few-layer Ti3C2 MXenes were synthesized to improve the fibers’ properties and change the surface wettability due to the hydrophilic functional groups of MXene. Field-emission scanning electron microscopy images displayed the successful preparation of few-layer MXenes. Smooth and bead-free fibers with bright red fluorescence emission under UV irradiation were shown using fluorescence microscopy. The study on the surface wettability of fibers revealed that UV and visible light irradiation induced reversible time-dependent changes in the wettability of the smart multi-functional MXene/polymer electrospun fibers from hydrophobic to hydrophilic, reaching a water contact angle of 10° from an initial water contact angle of 100° under UV light and also changing to superhydrophilic state with passing time. Upon visible light exposure, the fibers returned to their original state. Furthermore, the fibers demonstrated a high stability over five alternating cycles of UV and visible light irradiation. This study shows that the fabrication of time-dependent smart fibers, utilizing the flexibility and polarity in the presence of MXenes, significantly improves and controls surface wettability changes. The outstanding dynamically photo-switchable wettability of these fibers may offer exciting opportunities in various applications, especially in the separation of oil from water contaminants.

A conductive ionogel with Stretchability, low hysteresis and adjustable adhesion for Air/Underwater mechanosensing

Conductive ionogels based on deep eutectic solvents (DESs) have great application potential in the field of flexible sensors. However, the development of conductive ionogels that are stable under various environmental conditions (such as high and low temperatures, air, and water) remains extremely challenging. In this work, the hydrophobic conductive ionogel BxHyIG was prepared via a one-step photoinitiated copolymerization of butyl acrylate and N-hydroxyethylacrylamide in a hydrophobic DES. The good chemical compatibility between the polymer and DES, as well as the dense and reversible ion–dipole interactions, dipole–dipole interactions and hydrogen bond interactions, endow BxHyIG with satisfactory transparency (80 %), adhesion (polystyrene: 74.56 kPa), mechanical properties (elongation at break: 578 %, tensile strength: 171.25 kPa), a low degree of hysteresis (DH=1.9 %) and conductivity (3.95 × 10-3 S m−1). Strain/pressure sensors and bioelectrodes prepared from ionogels have the characteristics of high sensitivity, fast response and excellent stability and can be used for real-time monitoring of human activities and health status in the atmosphere. In addition, the inherent hydrophobicity of BxHyIG (water contact angle > 110°) can effectively prevent BxHyIG from being eroded and swollen by water, thereby achieving reliable underwater sensing. More importantly, by directly exposing BxHyIG to air or storing it in nitrogen, the surface adhesion of conductive ionogels can be effectively regulated to obtain double-sided, single-sided or even nonadhesive ionogels. Therefore, this study provides new ideas for the development of conductive ionogels that can be applied under various environmental conditions.

Low-tortuosity, high-loading electrodes for fast-charging quasi-solid-state lithium metal batteries

Structural design of electrodes is a widely adopted approach towards enhanced electrochemical performance in various battery systems. However, in quasi-solid-state lithium metal batteries, research has predominantly focused on developing gel polymer electrolytes (GPEs), with limited attention given to utilizing electrodes with specialized structural design. Herein, by exploiting the excellent wettability and permeability of the GPE, high-loading NMC-811 cathodes featuring aligned channels achieved through freeze-casting are integrated with in-situ UV-polymerized poly (butyl acrylate) (PBA). The aligned channels in the freeze-cast electrodes provide low-tortuosity pathways for smooth Li+ transport, facilitating rapid kinetics. Consequently, superior areal capacity can be delivered under high areal current density (e.g. 1 mAh cm−2 at 2 mA cm−2 and 0.7 mAh cm−2 at 3.8 mA cm−2), demonstrating the fast-charging capability of quasi-solid-state lithium metal batteries.