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The conductive PEDOT hollow spheres fabricated by a template-assisted interfacial polymerization serve as promising spacers rendering the MXene film highly capacitive performances. [Display omitted] • The PEDOT HSs are successfully prepared by a template-assisted interfacial oxidation polymerization. • Incorporation of PEDOT HSs between MXene nanosheets yields highly flexible MP film. • The MP film exhibits a forty-folds enhancement in current response and nearly thickness-independent performances with film thickness varying from 10 to 40 μm. • The MP-based polymer-gel supercapacitor retains 90% capacitance and 100% Coulombic efficiency over the 5000 cycles, Sheets stacking of Ti 3 C 2 T x MXene dramatically reduces the ion-accessible sites and brings a sluggish reaction kinetics. While introducing transitional metal oxides or polymers in the MXene films could partially alleviate such issue, their enhanced performances are realized at the expense of electrode conductivity or cycling stability. Herein, we report an alternative spacer of conductive poly(3,4-ethylenedioxythiophene) (PEDOT) hollow spheres (HSs) which are fabricated by a facile template-assisted interfacial polymerization. The Fe3+ ions electrostatically adsorbed on the –SO 3 H groups of the sulfonated polystyrene spheres (S-PS) initiate the polymerization of uniform PEDOT shell, yielding uniform PEDOT HSs after dissolving the S-PS core. Introducing these PEDOT HSs in the MXene film generates the highly flexible MXene-PEDOT (MP) films featuring hierarchically porous network and high conductivity (283 S cm−1). Consequently, specific capacitance of 218 F g−1 at 3 mV s–1, along with a forty-folds decrease in relaxation time constant (1.0 vs 39.8 s) has been achieved. Moreover, the MP film also exhibits nearly thickness-independent capacitive performances with film thickness in the range of 10–46 μm. A maximal energy density of 21.2 μWh cm−2 at 1015 μW cm−2 together with 92 % capacitance retention over 5000 cycles are achieved for the MP-based solid-state supercapacitor. The intrinsic high conductivity, excellent mechanical flexibility and good structure integrity are responsible for such outstanding electrochemical behaviors. [ABSTRACT FROM AUTHOR]

High sulfur content polymeric materials, known for their intriguing properties such as high refractive indices and high electrochemical capacities, have garnered significant interest in recent years for their applications in optics, antifouling surfaces, triboelectrics, and electrochemistry. Despite the high interest, most high sulfur‐content polymers reported to date are either bulk materials or thin films, and there is a general lack of research into sulfur‐rich polymer colloids. Water‐dispersed, sulfur‐rich particles are anticipated to broaden the range of applications for sulfur‐containing materials. In this study, the preparation and size control parameters are presented of an aqueous dispersion of sulfur‐rich polymers with the sulfur content of dispersed particles exceeding 75 wt%. Employing polymeric stabilizers with varying hydrophilic‐lipophilic balance (HLB), along with changing the rank of inorganic polysulfides, allow for the control of particle size in the range of 360 nm – 1.8 µm. The sulfur‐rich colloid demonstrates antioxidant properties in water, demonstrating the potential for the use of sulfur‐rich polymeric materials readily removable, heterogeneous radical scavengers. [ABSTRACT FROM AUTHOR]

Coupling the Si-based anodes with nickel-rich LiNixMnyCo1−x−yO2 cathodes (x ≥ 0.8) in the energy-dense cell prototype suffers from the mechanical instability of the Li-Si alloys, cathode collapse upon the high-voltage cycling, as well as the severe leakage current at elevated temperatures. More seriously, the cathode-to-anode cross-talk effect of transitional metal aggravates the depletion of the active Li reservoir. To reconcile the cation utilization degree, stress dissipation, and extreme temperature tolerance of the Si-based anode||NMC prototype, we propose a gel polymer electrolyte to reinforce the mechanical integrity of Si anode and chelate with the transitional cations towards the stabilized interfacial property. As coupling the conformal gel polymer electrolyte encapsulation with the spatial arranged Si anode and NMC811 cathode, the 2.7 Ah pouch-format cell could achieve the high energy density of 325.9 Wh kg−1 (based on the whole pouch cell), 88.7% capacity retention for 2000 cycles, self-extinguish property as well as a wide temperature tolerance. Therefore, this proposed polymerization strategy provides a leap toward the secured Li batteries. The cycling performance of Li-ion batteries based on silicon and Ni-rich oxide electrodes is limited by undesired phenomena including Si pulverization, cross talk, and interfacial instability. Here, the authors report in-situ polymerization to improve the stability of gel polymer Li-ion batteries. [ABSTRACT FROM AUTHOR]

The rapid and painless dressing change is a global challenge in wound management due to the traditional ways of dressing change often cause secondary damage on newly formed skin tissue. Recently, researchers have shown great interest in the development of on‐demand dissolvable hydrogel dressings that can be rapidly and safely dissolved under specific stimuli. These hydrogel dressings possess multifunctional properties, including injectability, self‐healing capacity, anti‐inflammation, antioxidation, and angiogenesis capabilities, which have successfully promoted healing for various types of wounds. In this review, we summarize current methods for fabricating on‐demand dissolvable hydrogels dressings, which include two strategies: (1) chemical stimuli, involving the introduction of external dissolving agents; (2) physical stimuli, where stimuli are applied without the use of dissolving agents. These approaches can decrease the density of cross‐links, resulting in the dissolution of hydrogel dressings. The advantages and drawbacks of these on‐demand dissolvable hydrogels dressings for promoting wound healing are discussed and addressed. The development and challenges for the clinical application of on‐demand dissolvable hydrogel dressings are prospected. [ABSTRACT FROM AUTHOR]

Employing quasi-solid-state gel polymer electrolyte (GPE) instead of the liquid counterpart has been regarded as a promising strategy for improving the electrochemical performance of Li metal batteries. However, the poor and uneven interfacial contact between Li metal anode and GPE could cause large interfacial resistance and electrochemical Li stripping/plating inhomogeneity, deteriorating the electrochemical performance. Herein, we proposed that the functional component of composite anode could work as the catalyst to promote the in situ polymerization reaction, and we experimentally realized the integration of polymerized-dioxolane electrolyte and Li/Li22Sn5/LiF composite electrode with low interfacial resistance and good stability by in situ catalyzation polymerization. Thus, the reaction kinetics and stability of metallic Li anode were significantly enhanced. As a demonstration, symmetric cell using such a GPE-Li/Li22Sn5/LiF integration achieved stable cycling beyond 250 cycles with small potential hysteresis of 25 mV at 1 mA·cm−2 and 1 mAh·cm−2, far outperforming the counterpart regular GPE on pure Li. Paired with LiNi0.5Co0.3Mn0.2O2, the full cell with the GPE-Li/Li22Sn5/LiF integration maintained 85.7% of the original capacity after 100 cycles at 0.5 C (1 C = 200 mA·g−1). Our research provides a promising strategy for reducing the resistance between GPE and Li metal anode, and realizes Li metal batteries with enhance electrochemical performance. [ABSTRACT FROM AUTHOR]

A general approach to constructing room temperature phosphorescence (RTP) materials involves the incorporation of a phosphorescent emitter into a rigid host or polymers with high glass transition temperature. However, these materials often suffer from poor processability and suboptimal mechanical properties, limiting their practical applications. In this work, we developed benzothiadiazole‐based dialkene (BTD‐HEA), a multifunctional phosphorescent emitter with a remarkable yield of intersystem crossing (ΦISC, 99.83 %). Its high triplet exciton generation ability and dialkene structure enable BTD‐HEA to act as a photoinitiator and crosslinker, efficiently initiating the polymerization of various monomers within 120 seconds. A range of flexible phosphorescence gels, including hydrogels, organogels, ionogels, and aerogels were fabricated, which exhibit outstanding stretchability and recoverability. Furthermore, the unique fluorescent‐phosphorescent colorimetric properties of the gels provide a more sensitive method for the visual determination of the polymerization process. Notably, the phosphorescent emission intensity of the hydrogel can be increased by the formation of ice, allowing for the precise detection of hydrogel freezing. The versatility of this emitter paves the way for fabricating various flexible phosphorescence gels with diverse morphologies using microfluidics, film‐shearing, roll coating process, and two/three‐dimensional printing, showcasing its potential applications in the fields of bioimaging and bioengineering. [ABSTRACT FROM AUTHOR]

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Hyperbranched polymers (HBPs) are widely applied nowadays as functional materials for biomedicine needs, nonlinear optics, organic semiconductors, etc. One of the effective and promising ways to synthesize HBPs is a polyaddition of AB2+A2+B4 monomers that is generated in the A2+CB2, AA′+B3, A2+B′B2, and A2+C2+B3 systems or using other approaches. It is clear that all the foundational features of HBPs that are manufactured by a polyaddition reaction are defined by the component composition of the monomer mixture. For this reason, we have designed a structural kinetic model of AB2+A2+B4 monomer mixture polyaddition which makes it possible to predict the impact of the monomer mixture's composition on the molecular weight characteristics of hyperbranched polymers (number average (DPn) and weight average (DPw) degree of polymerization), as well as the degree of branching (DB) and gel point (pg). The suggested model also considers the possibility of a positive or negative substitution effect during polyaddition. The change in the macromolecule parameters of HBPs formed by polyaddition of AB2+A2+B4 monomers is described as an infinite system of kinetic equations. The solution for the equation system was found using the method of generating functions. The impact of both the component's composition and the substitution effect during the polyaddition of AB2+A2+B4 monomers on structural and molecular weight HBP characteristics was investigated. The suggested model is fairly versatile; it makes it possible to describe every possible case of polyaddition with various monomer combinations, such as A2+AB2, AB2+B4, AB2, or A2+B4. The influence of each monomer type on the main characteristics of hyperbranched polymers that are obtained by the polyaddition of AB2+A2+B4 monomers has been investigated. Based on the results obtained, an empirical formula was proposed to estimate the pg = pA during the polyaddition of an AB2+A2+B4 monomer mixture: pg = pA = (−0.53([B]0/[A]0)1/2 + 0.78)υAB2 + (1/3)1/2([B]0/[A]0)1/2, where (1/3)1/2([B]0/[A]0)1/2 is the Flory equation for the A2+B4 polyaddition, [A]0 and [B]0 are the A and B group concentration from A2 and B4, respectively, and υAB2 is the mole fraction of the AB2 monomer in the mixture. The equation obtained allows us to accurately predict the pg value, with an AB2 monomer content of up to 80%. [ABSTRACT FROM AUTHOR]

This document discusses the shaping and structuring of polymer gels and their applications in various fields. The document highlights the fabrication of gels with well-defined shapes and spatially controlled structures, as well as the measurement and analysis of their properties. It also explores the practical applications of these advancements in biomedical and food technology. The contributions in the document cover topics such as the creation of muscle tissue, the fabrication of collagen tube gels, the use of hydrogels for drug delivery, and the formation of supramolecular gels. The document emphasizes the potential for diverse applications and the alignment of these advancements with biological and biomedical objectives. [Extracted from the article]

The traditional two‐component Ziegler‐Natta catalyst has low catalytic activity when initiating ring‐opening metathesis polymerization (ROMP) and is unstable and easy to generate polymerization gels. Therefore, it is necessary to add a third group of ligands with appropriate steric hindrance to improve the catalytic activity of the catalyst. The effects of ligands′ steric hindrance and other reaction conditions on the catalytic activity of tungsten hexachloride (WCl6) as catalyst and aluminum triethyl (AlEt3) as co‐catalyst were investigated. The results showed that the size of the ligands′ steric hindrance affected the catalytic activity of ROMP, and the small steric hindrance caused the polymerization rate to be too fast, which was easy to produce gels, and when the steric hindrance of the ligands was too large, its solubility was not good, which was not conducive to the normal polymerization. When stearyl alcohol was selected as the ligand, the highest catalytic activity was 3123 mol cycloolefin polymer (COP)/mol W, and the reaction speed of polymerization was also the fastest and the complete transformation only needed 30 min when the ligand/W was 25. It was found that the polymerization reaction was stable without gels and the obtained polymer molecular weight was appropriate, 17.8 kDa, under the conditions of Al/W=80, reaction temperature 60 °C, monomer concentration 10 w/v %, catalyst/monomer 5*10−4 : 1, chain transfer agent/monomer 0.005 : 1. [ABSTRACT FROM AUTHOR]

Geopolymers with a zeolite‐like structure are attractive inorganic binder materials for addressing the critical challenge of reducing the carbon footprint of the cement industry. Despite many efforts, the exact geopolymerization mechanism remains a topic of investigation. In the present work, we determined the dimerization processes between Si/Al‐bearing monomers through metadynamics. The free energy profiles were obtained using ab initio constrained molecular dynamics simulations. The results reveal that metastable pentacoordinate states formed after exposure to the alkaline medium, followed by the release of the hydroxyl on the rotational axis. The presence of Al(OH)4− monomers would significantly reduce the reaction barriers of dimerization, implying that Al(OH)4− monomers promote the crosslinking degree of the geopolymer gel. Increasing the pH value of the alkali‐activated solution would facilitate the reaction between Si‐bearing monomers and Al(OH)4− monomers. However, the reaction between anionic Si‐bearing monomers presents a much higher barrier because of intensive electrostatic repulsion. Therefore, increasing the pH value decreases the Si/Al ratio of the geopolymer gel at the initial stage, which is consistent with the experimental results. This study refines the understanding of the oligomerization process of aluminosilicates by ab initio molecular simulations. [ABSTRACT FROM AUTHOR]

Gel polymer electrolytes (GPEs) are considered as a promising solution to replace organic liquid electrolytes for safer lithium (Li) batteries due to their high ionic conductivity comparable to liquid electrolytes, no risk of leakage, and high flexibility. However, poor interfacial contact between electrodes and GPEs leads to high interfacial impedance and unsatisfactory electrochemical performance. The emerging in situ synthesized GPEs can fully infiltrate into porous electrodes and form intimate interfaces, improving interfacial contact and electrochemical performance. This perspective covers recent advances of in situ GPEs in design, synthesis, and applications in lithium (Li) batteries. Polyester and polyether‐based GPEs are mainly discussed followed by a brief introduction of GPEs with other polymer matrices, such as poly(ionic liquid)s, cyanoethyl polyvinyl alcohol, poly(vinyl acetal) and single‐ion conductors. Then, the recent progress in Li batteries using in situ GPEs are summarized, including Li‐ion battery, Li‐metal battery, Li‐sulfur battery, and Li‐air battery. Finally, the remaining challenges and future perspectives of in situ GPEs are discussed. We hope this perspective can offer guidance for in situ synthesis of GPEs and facilitate their applications in high‐performance Li batteries. [ABSTRACT FROM AUTHOR]

Nanotechnology has attracted increasing interest in various research fields for fabricating functional nanomaterials. In this study, we investigated the effect of poly(vinyl alcohol) (PVA) addition on the formation and thermoresponsive properties of poly(N-isopropyl acrylamide)-based nanogels in aqueous dispersion polymerizations. During dispersion polymerization, PVA appears to play three roles: (i) it bridges the generated polymer chains during polymerization, (ii) it stabilizes the formed polymer nanogels, and (iii) it regulates the thermoresponsive properties of the polymer nanogels. By regulating the bridging effect of PVA via changing the PVA concentration and chain length, the size of the obtained polymer gel particles was maintained in the nanometer range. Furthermore, we found that the clouding-point temperature increased when using low-molecular weight PVA. We believe that the knowledge gained in this study regarding the effect of PVA concentration and chain length on nanogel formation will aid in the future fabrication of functional polymer nanogels. [ABSTRACT FROM AUTHOR]

As shale gas recovery progresses to deep layers, the wellbore instability during drilling in applications of oil-based drilling fluids (OBFs) becomes increasingly severe. This research developed a plugging agent of nano-micron polymeric microspheres based on inverse emulsion polymerization. Through the single-factor analysis with respect to the permeability plugging apparatus (PPA) fluid loss of drilling fluids, the optimal synthesis conditions of polymeric microspheres (AMN) were determined. Specifically, the optimal synthesis conditions are as follows: the monomer ratio of 2-acrylamido-2-methylpropanesulfonic acid (AMPS): Acrylamide (AM): N-vinylpyrrolidone (NVP) were 2:3:5; the total monomer concentration was 30%; the concentrations and HLB values of emulsifier (Span 80: Tween 60) were 10% and 5.1, respectively; the oil–water ratio of the reaction system was 1:1; the cross-linker concentration was 0.4%. The polymeric microsphere (AMN) produced via the optimal synthesis formula had the corresponding functional groups and good thermal stability. The size distribution of AMN ranged mainly from 0.5 to 10 μm. The introduction of AMND in OBFs can increase the viscosity and yield point of oil-based drilling fluids and slightly decrease the demulsification voltage but significantly reduce high temperature and high pressure (HTHP) fluid loss and permeability plugging apparatus (PPA) fluid loss. The OBFs with 3% polymeric microsphere dispersion (AMND) reduced the HTHP and PPA fluid loss by 42% and 50% at 130 °C, respectively. In addition, The AMND maintained good plugging performance at 180 °C. The AMN particles can block leakoff channels of artificial cores, effectively prevent the invasion of oil-based drilling fluids into formations and suppress pressure transfer. OBFs with 3% AMND enabled the corresponding equilibrium pressure to decrease by 69%, compared with that of the OBFs. The polymeric microspheres had a wide particle size distribution. Thus, they can well match leakage channels at various scales and form plugging layers via compression–deformation and packed accumulation, so as to prevent oil-based drilling fluid from invading formations and improve wellbore stability. [ABSTRACT FROM AUTHOR]

Fluorescent nanocomposite gels have attracted increasing attention due to their excellent optical properties, as well as enhanced mechanical strength originating from the nanoparticles. At present, two‐step methods are usually employed, where fluorescent nanoparticles are firstly prepared, followed by mixing with gel precursor to achieve the final products after gelation, which suffer from the disadvantages of a tedious and time‐consuming process. Thus, the development of a facile strategy is highly desirable, which still remains an obstacle. Herein, a new one‐pot synthesis method towards robust fluorescent nanocomposite gels via frontal polymerization (FP) is proposed, where small molecular precursors (citric acid (CA) and urea, or L‐cysteine) and gel precursor (vinyl monomers) are mixed together as co‐reactants. During the FP process, a lot of heat release gives rise to the generation of carbonized polymer dots (CPDs). Thus, companying with the propagating of the polymerization, the production of fluorescent CPDs/gel composite is completed. In addition, as a nanofiller, CPDs dramatically enhance the mechanical property of the CPDs/gel composite. This work proposes a new fast and efficient one‐pot strategy for the production of CPDs/gel composite, which will guide the development of high‐performance polymer nanocomposites through an in situ synchronous reaction fashion. [ABSTRACT FROM AUTHOR]

Fluorophore is essential to enable the fluorescence and optical switching in most of polymer gels. Herein, a novel concept is proposed to develop a fluorophore‐free organogel that is capable of generation of blue fluorescence at transparent state, while it proceeds with optical switching from blue to purple upon phase transition into non‐transparent state in water. Ammonium persulphate (APS) is utilized to initiate co‐crosslinking of hydrophilic acrylamide (AM) and hydrophobic 2,2,3,4,4,4‐hexafluorobutyl acrylate (HFBA) in dimethyl sulphoxide (DMSO) to give organogel of AM@HFBA at 80 °C. APS decomposes to generate not only radicals, but also ammonium bisulfate (ABS) during heating, in which the elements of ABS produce blue fluorescence (λ = 440 nm), excited by UV light (λ = 365 nm). After the phase transition into non‐transparent state, light‐reflection behavior at the phase‐transitioned surface triggers the optical switching of the organogel from blue to purple under UV light. The optical switching is patternable and reversible, which enables the applications of organogel of AM@HFBA for information encoding/encryption and optical‐switchable soft actuators. This method is universal to achieve fluorescence and optical switching for free radical polymerization‐based gel systems as long as they are initiated by APS in DMSO. [ABSTRACT FROM AUTHOR]

The current commercial Gel Polymer Electrolyte (GPE) products are generally made of synthetic and non-biodegradable materials. In addition, some of these polymers require toxic reagents and complex synthesis processes. The purpose of this research is to manufacture GPE membrane products using biodegradable raw materials, a combination of Hydroxy Ethyl Cellulose (HEC), Carboxymethyl Chitosan (CMCs), and Sodium Alginate (SA) with lithium salt as the electrolyte source. The methods start from the fabrication/synthesis of biodegradable GPE membranes in various compositions, then LiOH is added as an electrolyte source and glutaraldehyde as a crosslinking agent using a solution casting technique. The mechanical membrane testing (tensile strength and elongation) and characterization were carried out using XRD, SEM, and FTIR. Based on mechanical tests carried out, variations in HEC 50%: SA 50% has the highest tensile strength value of 81.4255 MPa and the lowest elongation value of 11.68%. The results of XRD analysis in the presence of a typical peak in the HEC: SA variation was 11.56°, which could affect the strength of the electrolytepolymer gel membrane (GPE). The results of SEM analysis proved that the HEC: SA variation has a porous morphology that can affect the ion absorption capacity in lithium-ion battery applications. The results of FTIR analysis proved that there are functional groups S=O, CH, CO, NH, OH, and COC in the three membranes (SA, CMCs, and HEC). [ABSTRACT FROM AUTHOR]

Quercetin, as one of the most biologically active natural flavonoids, is widely found in various vegetables, fruits and Chinese herbs. In this work, molecularly imprinted polymer (MIP) was synthesized through surface molecular imprinting technology with sol-gel polymerization mechanism on SiO2 at room temperature using quercetin as the template, SiO2 as the supporter, 3-aminopropyltriethoxysilane (APTES) as the functional monomer, and tetraethoxysilane (TEOS) as the cross-linker. The prepared MIP was characterized via scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR) and nitrogen adsorption measurements to validate its surface morphology, structure and functionality. SEM images revealed that the morphology of MIP was rough and spherical with the particle size of 260 nm larger than that of the support SiO2. In the FTIR spectra of MIP, the band around 1499 cm−1 and 2932 cm−1 were assigned to N−H and C-H groups, respectively. The results indicated that the imprinted polymer layers were grafted on the surface of SiO2 and the MIP had been successfully prepared. Since the specific surface area and pore volume of MIP were markedly higher than those of NIP and SiO2 and were 52.10 m2 g−1 and 0.150 cm3 g−1, respectively, it was evident that the imprinting process created corresponding imprinted cavities and porosity. The MIP for adsorbing quercetin was evaluated by static adsorption experiment. The results indicated that the adsorption equilibrium could be reached within 90 min and the maximum adsorption capacity was as high as 35.70 mg/g. The mechanism for adsorption kinetics and isotherm of MIP for quercetin was proved to conform the pseudo-second-order kinetics model (R2 = 0.9930) and the Freundlich isotherm model (R2 = 0.9999), respectively, revealing that chemical adsorption and heterogeneous surface with multilayer adsorption dominated. In contrast to non-imprinted polymer (NIP), the MIP demonstrated high selectivity and specific recognition towards quercetin whose selectivity coefficients for quercetin relative to biochanin A were 1.61. Furthermore, the adsorption capacity of MIP can be maintaining above 90% after five regeneration cycles, indicating brilliant reusability and potential application for selective adsorption of quercetin. [ABSTRACT FROM AUTHOR]

Polymer electrolytes (PEs) have been thoroughly investigated due to their advantages that can prevent severe problems of Li-ion batteries, such as electrolyte leakage, flammability, and lithium dendrite growth to enhance thermal and electrochemical stabilities. Gel polymer electrolytes (GPEs) using in situ polymerization are typically prepared by thermal or UV curing methods by initially impregnating liquid precursors inside the electrode. The in situ method can resolve insufficient interfacial problems between electrode and electrolyte compared with the ex situ method, which could led to a poor cycle performance due to high interfacial resistance. In addition to the abovementioned advantage, it can enhance the form factor of bare cells since the precursor can be injected before polymerization prior to the solidification of the desired shapes. These suggest that gel polymer electrolytes prepared by in situ polymerization are a promising material for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Radical‐mediated thiol‐ene polymerizations (RMTEPs) conducted under typical emulsion polymerization conditions were studied with the aim of determining how various experimental parameters impact particle nucleation and growth. These colloids are unusual since they are made by step‐growth polymerizations, which can be thermally initiated in an aqueous emulsion system. Four pairs of thiol‐ene monomers were used to probe how composition impacts the nucleation loci. Kinetic studies were carried out to understand how monomer conversion, molecular weight, and particle size change throughout the reaction. Additionally, the number of particles formed as a function of surfactant and initiator concentrations were studied and this data, along with information from dye partition experiments, were used to determine polymer colloid nucleation mechanisms and how monomer/polymer structure impacts nucleation processes. Within the four pairs of monomers studied, three proceeded via homogeneous nucleation (via chain collapse in the aqueous phase), while one pair, which gave the highest degree of crosslinking, underwent heterogeneous nucleation (nucleation occurs in the micellar phase). Possible factors that impact which nucleation mechanism dominates a given set of monomers, such as crosslink density, water solubility, and thiol/ene reactivity, is discussed, although no clear set of delineating guidelines can be offered with this current set of data. [ABSTRACT FROM AUTHOR]

Soft colloidal macromolecular structures with programmable chemical functionalities, size, and shape are important building blocks for the fabrication of catalyst systems and adaptive biomaterials for tissue engineering. However, the development of the easy upscalable and template‐free synthesis methods to obtain such colloids lack in understanding of molecular interactions that occur in the formation mechanisms of polymer colloids. Herein, a computer simulation‐driven experimental synthesis approach based on the supramolecular self‐assembly followed by polymerization of tailored pyrazole‐modified monomers is developed. Simulations for a series of pyrazole‐modified monomers with different numbers of pyrazole groups, different length and polarity of spacers between pyrazole groups and the polymerizable group are first performed. Based on simulations, monomers able to undergo π–π stacking and guide the formation of supramolecular bonds between polymer segments are synthesized and these are used in precipitation polymerization to synthesize anisotropic microgels. This study demonstrates that microgel morphologies can be tuned from spherical, raspberry‐like to dumbbell‐like by the increase of the pyrazole‐modified monomer loading, which is concentrated at periphery of growing microgels. Combining experimental and simulation results, this work provides a quantitative and predictive approach for guiding microgel design that can be further extended to a diversity of colloidal systems and soft materials with superior properties. [ABSTRACT FROM AUTHOR]

In this paper, the aqueous copolymer dispersions of methyl (meth)acrylate-grafted poly(vinyl alcohol) are in situ synthesized and studied as a promising platform for the deposition of thin films with advanced applications. A series of dispersions of the varied copolymer structure and composition are obtained at mild reaction conditions by carrying out a redox polymerization at a different monomer-to-PVA ratio and initiator concentration. The obtained colloidal particles are characterized by Fourier transformed infrared spectroscopy, nuclear magnetic resonance, dynamic light scattering, and transmission electron microscopy. The copolymer dispersions are further used for deposition of thin films on silicon substrates. The films are characterized optically through reflectance measurements and non-linear curve fitting. Their suitability for the optical sensing of acetone vapors is confirmed by reflectance measurements before and during their exposure to analyte vapors. The cross sensitivity, sensing repeatability, and recovery of the sensitive films are discussed. [ABSTRACT FROM AUTHOR]

This work presents a facile strategy for the generation of Fe3O4@poly(4-vinylpyridine)-block-polystyrene (Fe3O4@P4VP-b-PS) magnetic polymer nanocomposites. P4VP-b-PS nanoparticles prepared by dispersion RAFT polymerization of styrene in methanol/water in the presence of macro-P4VP chain transfer agent was employed as templates to grow Fe3O4 on polymeric network templates. With the following addition of FeCl3 into the above polymer colloids, pyridyl moieties in P4VP block of nanoparticles could further react with Fe3+ through a coordination reaction to generate Fe3+@P4VP-b-PS nanoparticles. After the subsequent addition of FeCl2 and NH3⋅H2O, the co-precipitation reaction occurred on the surface of the polymeric nanoparticle to form Fe3O4@P4VP-b-PS magnetic polymer nanocomposites. Herein, FT-IR, XRD, TGA, XPS, TEM and VSM were applied to characterize the morphology, structure and magnetism performance of the synthesized magnetic polymeric nanocomposites. [ABSTRACT FROM AUTHOR]

Anisotropic particles exhibit directional interactions resulting in a rich phase behavior. Considerable efforts have thus been invested in guiding particle synthesis into an anisotropic direction. Dumbbell-shaped polymer particles are one of the most remarkable examples. They result from phase separation during seeded polymerization. The underlying mechanism and thermodynamic principles are understood from its proximal end. Segregation of monomer and seed particle results in a monomer protrusion attached to the seed. Polymerization of the protrusion finally yields particles with two bulb-shaped halves. Little attention has been paid to an investigation of transient states, namely the formation of liquid protrusions grown from monomer-swollen seeds. This study demonstrates that cryogenic transmission electron microscopy is an excellent tool for mapping transient states within colloidal objects. Swelling of polymer particles and formation of liquid protrusions mediated by a surface coating on the seeds is explored for styrene and methyl-methacrylate at different temperatures and monomer-to-seed volume ratios. [ABSTRACT FROM AUTHOR]

In this paper, the atomic structures of sodium aluminosilicate hydrate (N–A–S– H) gels with different Si/Al ratios are studied by molecular dynamics simulation. An N–A–S–H gel model was obtained from the polymerization of Si(OH)4 and Al(OH)3 monomers with the use of a reactive force field (ReaxFF). The simulated atomic structural features, such as the bond length, bond angle, and simulated X-ray diffraction pattern of the gel structure are in good accordance with the experimental results in the literature. Si–O–Al is found to be preferred over Si–O– Si in the N–A–S–H gel structure according to the amount of T–O–T bond angles and distribution of Si4(mAl). Pentacoordinate Al is identified in all simulated N–A–S–H models. It provides strong support to current knowledge that pentacoordinate Al in geopolymer does not only come from raw material. Furthermore, the structural analysis results also show that N–A–S–H gel with lower Si/Al ratios has a more cross-linked and compacted structure. [ABSTRACT FROM AUTHOR]

Initial attempts to perform nearly bulk polymerization of bromoundecyl acrylate unexpectedly produced cross-linked gels, GelCH2Cl2 and GelDMF, exhibiting some interesting chemical features. Monomer concentrations were 50% by weight using methylene chloride (CH2Cl2) and dimethylformamide (DMF) as solvents. Thermal initiation was done with AIBN (azobis[isobutyronitrile]), and analysis of GelCH2Cl2 and GelDMF suggests the isobutyronitrile radical participates in both hydrogen and bromine atomic abstraction reactions. A higher cross-linking density was obtained in DMF, 2 mmol cm−3, than in CH2Cl2, 0.6 mmol cm−3, by measuring swelling in toluene and xylene. Differential scanning calorimetry analysis of these gels reveal melting and freezing transitions over − 30 to − 50 °C, similar to non-cross-linked poly(bromoundecyl acrylate), a room-temperature liquid. Thermally driven apparent evolution of bromine from GelDMF was quantified as corresponding to about 27% of the molar-available bromine by using Ag+ potentiometry. These gel materials represent a new class of telechelic gels that can easily be reacted with diverse reagents to make them interfacially compatible with other phases. [ABSTRACT FROM AUTHOR]

Herein, we reported the synthesis of TiO2 through different non-hydrolytic sol-gel (NHSG) routes in viscous polymer media. For the first time, the influence of the polymer nature (Polystyrene (PS) or Polypropylene (PP)) on the morphology of synthesized inorganic domains was investigated. The non-hydrolytic sol-gel reactions between titanium isopropoxide Ti(OiPr)4 and acetic anhydride in molten polypropylene lead to the formation of microfillers with a mean diameter of about 1 μm, while the same synthesis carried out in viscous polystyrene lead to the formation of nanofillers with diameter lower than 10 nm forming aggregates of approximately 200 nm. We have also investigated the influence of the oxygen donor nature on the morphology of synthesized fillers using aromatic oxygen donors in a polystyrene matrix. The use of benzoic anhydride or acetophenone as oxygen donors with Ti(OiPr)4 in viscous polystyrene lead to respectively platelet-like morphology or aggregated nanofillers. We demonstrated that the affinity between polymer, reactants, and/or by-products had an influence on the morphology and the size of in situ synthesized TiO2 fillers. These results evidenced for the first time the possibility to control and to tune the morphology of in situ grown inorganic objects through the NHSG process by the appropriate choice of solvent, here a viscous polymer medium, and reactants. [ABSTRACT FROM AUTHOR]

Alkene polymerization reactions were studied with three catalyst systems containing complexes of vanadium and titanium with the acetylacetonate ligand (V(acac)3, VO(acac)2, Ti(acac)2Cl2) and a binary activator, a combination of Al(C2H5)2Cl and Mg(C4H9)2 at an [Al]:[Mg] molar ratio of ca 3. All three catalysts are highly active in ethylene homopolymerization reactions. They copolymerize ethylene and 1‐hexene to random, compositionally uniform products with 1‐hexene content of up to 20–25%. The Ti(acac)2Cl2–Al(C2H5)2Cl/Mg(C4H9)2 combination is also an effective catalyst for propylene polymerization to an essentially atactic product. Gel permeation chromatography analysis showed that all the studied M(acac)n–Al(C2H5)2Cl/Mg(C4H9)2 catalysts contain several types of active centers which differ in the average molecular weight of polymer material they produce. © 2021 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

Cross-linked organic-inorganic sulfo-containing membranes of various compositions based on acrylic monomers (acrylonitrile, acrylic acid, 3-sulfopropylacrylate potassium salt, ethylene glycol diacrylate) and sol-gel systems of tetraethoxysilane have been developed. Synthesis of the polymer matrix was carried out by UV-initiated polymerization of the monomer mixture and the inorganic component was formed in situ while conducting the sol-gel process of the precursor. FTIR, SEM, EDS, DMA, impedance spectroscopy were used to characterize the synthesized materials. The influence of inorganic component content on the properties of the membranes was investigated. DMA results show that an increase in silica content leads to a decrease in packing density and an increase in structural heterogeneity in sulfo-containing polyacrylate/silica membranes. The highest values of proton conductivity 1.12 · 10-2 Sm/cm at 60 °C were found in membranes containing 3 wt.%. of the added sol-gel system. Further increase of silica content does not increase the proton conductivity of the membranes. The proton transfer activation energies in the membranes were calculated from the temperature dependence of proton conductivity. The obtained cross-linked sulfo-containing organic-inorganic materials can be used for the development of proton-conducting membranes for fuel cells. [ABSTRACT FROM AUTHOR]

Over the past decade or so, polymerization‐induced self‐assembly (PISA) has become a versatile method for rational preparation of concentrated block copolymer nanoparticles with a diverse set of morphologies. Much of the PISA literature has focused on the preparation of well‐defined linear block copolymers by using linear macromolecular chain transfer agents (macro‐CTAs) with high chain transfer constants. In this review, a recent process is highlighted from an unusual angle that has expanded the scope of PISA including i) synthesis of block copolymers with nonlinear architectures (e.g., star block copolymer, branched block copolymer) by PISA, ii) in situ synthesis of blends of polymers by PISA, and iii) utilization of macro‐CTAs with low chain transfer constants in PISA. By highlighting these important examples, new insights into the research of PISA and future impact these methods will have on polymer and colloid synthesis are provided. [ABSTRACT FROM AUTHOR]

Inspired by porous smart gel materials, we designed pH-responsive polymer-modified silica microspheres as liquid chromatography stationary phase materials by a one-step strategy. The free radicals generated by the oxidation of dopamine are used to initiate the cross-linking polymerization of functional monomers. At the same time, the good adhesion of dopamine enables the polymer to be modified on silica. The hydrophilicity of this new stationary phase can change in response to the pH of the mobile phase and the stationary phase has weaker hydrophilicity under acidic (pH = 3.78) mobile phase conditions and stronger hydrophilicity under neutral mobile phase conditions. The hydrophilicity difference of the stationary phase leads to the selectivity difference in separation. To evaluate the chromatographic performance of this new stationary phase, 10 oligosaccharides and 9 nucleosides/bases were separated on this stationary phase. This paper will provide good guidance for us to achieve more pH-responsive hydrophilic/hydrophobic stationary phases in the future. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: It is of great significance to develop rapid crosslinking strategies to enrich the functions of hydrogels and simplify the preparation process of hydrogels. Herein, we applied the ternary condensation reaction of o‐phthalaldehyde (OPA) with thiol and amino moieties to construct hydrogel networks with fast gelation rate, excellent mechanical strength, and favorable stability. The obtained hydrogels exhibited rapid gelation transition even at a low solid content. The ternary condensation was traced in the gelation process and demonstrated as a pseudo‐first‐order reaction irrespective of the gelation threshold. Interestingly, the crosslinking sites of these hydrogels were constructed with isoindole rings, endowing the materials with fluorescent functions without an extra chemical grafting process. The OPA ternary condensation reaction was a simple and universal strategy towards fabrication of natural or synthetic polymer gels from polysaccharides, proteins, and synthetic polymers, which is expected to have potential biomedical applications. [ABSTRACT FROM AUTHOR]

Background: The contact and frictional response of a hydrogel is dependent on the polymer structure at the gel surface. Recent work has shown that different mold materials in contact with the gel during polymerization will affect the resulting polymer density. Objective: The tribological response of a gel with a 'brushy' less-dense polymer surface has not been thoroughly studied. Our goal was to perform a suite of tribological experiments to better understand the response of the less-dense layer. Methods: In this work, we conducted indentation, creep, and sliding experiments with various loads, speeds, and probe materials to determine the impact of the less-dense layer on the contact and frictional behavior of polyacrylamide hydrogels. We additionally used micro-fluorescent particle exclusion to measure the contact areas throughout each experiment. Results: Indentation revealed a non-Hertzian regime for the first 13–29 µm after first contact that has a weaker force response for a given indentation depth. Creep experiments showed that the surface layer relaxes poroelastically, with water exudation occurring within the gradient layer despite the low contact pressures. Friction was highly speed-dependent, with faster sliding speeds decreasing friction to values as low as 0.01; transient behavior was not seen for most of the experiments, suggesting that the surface layer is capable of quick water re-uptake when out of contact. Conclusions: We have provided a deeper understanding of the contact and frictional response of this gradient-density surface layer, which will prove useful for hydrogel designs requiring ultra-low friction in a dynamic application. [ABSTRACT FROM AUTHOR]

Enzyme entrapment in hydro-ionic liquid gels (HydrIL gels) was explored as an enzyme immobilization strategy. The liquid phase of the gels was a mixture of buffer and tributyl methyl phosphonium alkanesulfonate [P 4441 ][RSO 3 ] ionic liquids. The ionic liquid modifies the liquid phase creating a more "organic" hydrophobic microenvironment around the enzyme. In the esterification of a secondary alcohol by Candida antarctica Lipase B, a 20-fold enhancement in final substrate conversion was achieved using an HydrIL gel compared to a standard poly(acrylamide) hydrogel. Co-polymerization of the poly(acrylamide) matrix with acrylate monomers led to further increases in reaction rate. A CalB HydrIL gel was reused over 10 reaction cycles, achieving a consistent performance from the fifth cycle. IL leaching became undetectable from the third reaction cycle. [Display omitted] • CalB was entrapped with ionic liquid in poly(acrylamide) hydrogels (HydrIL gels). • HydrIL gels are modular, the ionic liquid and co-monomer can be changed. • [P 4441 ][C 8 SO 3 ] facilitated a 20-fold enhancement in conversion c.f. the hydrogel. • Co-monomer acrylate led to higher conversions and minimal product retention. • 10 reaction cycles were performed, CalB stayed active within the gel. [ABSTRACT FROM AUTHOR]

Chiral polymers are often prepared by two ways depending upon chiral monomers, chiral catalysts, and chiral auxiliaries which always come from organics: one is the enantio‐selective polymerization of prochiral or racemic monomers or polymerization of optically active monomers; and the other one is the molecular imprinting technique, which creates chiral recognition sites inside a densely cross‐linked polymer gel. Herein, a unique method for the synthesis of chiroptical cross‐linked polymers via radical polymerization of achiral divinyl monomers in the mediation of the inorganic chiral nanosilica is reported. The monomers that are cross‐linkable such as divinylbenzene (DVB) and N,N′ ‐methylenebisacrylamide (MBA) are physically adsorbed onto chiral silica bundles and then polymerized by dispersion of those monomers/silica bundles in the presence of radical initiators. The products are characterized by SEM, FT‐IR, solid‐state 13C NMR, TGA, and CD. Very interestingly, the cross‐linked polymers themselves obtained via final removal of the chiral silica show remarkable chiroptical activity with mirror relationship and can make achiral guest of porphyrin adsorbed on the polymers become optically active. [ABSTRACT FROM AUTHOR]

3D printing has changed the fabrication of advanced materials as it can provide customized and on‐demand 3D networks. However, 3D printing of polymer materials with the capacity to be transformed after printing remains a great challenge for engineers, material, and polymer scientists. Radical polymerization has been conventionally used in photopolymerization‐based 3D printing, as in the broader context of crosslinked polymer networks. Although this reaction pathway has shown great promise, it offers limited control over chain growth, chain architecture, and thus the final properties of the polymer networks. More fundamentally, radical polymerization produces dead polymer chains incapable of postpolymerization transformations. Alternatively, the application of reversible deactivation radical polymerization (RDRP) to polymer networks allows the tuning of network homogeneity and more importantly, enables the production of advanced materials containing dormant reactivatable species that can be used for subsequent processes in a postsynthetic stage. Consequently, the opportunities that (photoactivated) RDRP‐based networks offer have been leveraged through the novel concepts of structurally tailored and engineered macromolecular gels, living additive manufacturing and photoexpandable/transformable‐polymer networks. Herein, the advantages of RDRP‐based networks over irreversibly formed conventional networks are discussed. [ABSTRACT FROM AUTHOR]

In this work, the spatial uniformity of the polymerization growth of the MAGIC gel in the case of an internal irradiation with iodine-131 was studied. A compartmental mathematical model taking into account the kinetics of polymerization of the MAGIC gel was developed and validated by experimental measurements. In order to check the radioactivity homogeneity distribution in the samples, we performed their scintigraphy, while -- in order to study the rate of polymerization -- we measured the intensity of the MRI signal emitted by each of the samples. The wide dispersion in signal strength observed between different regions of the same sample indicates that the value of the relaxation time T2 varies from one point to another. Scintigraphy and MRI images showed that a homogeneous distribution of 131I activity does not necessarily imply isotropic polymerization. The phenomenon is probably due to the fact that iodine-131 emits beta particles with different energies and the length of polymers does not increase with the same speed for all the polymers in formation. On this basis, we have established a mathematical model which compartmentalizes different species of protons which participate in the modification of the MRI signal. [ABSTRACT FROM AUTHOR]

Based on the introduction of characteristics and advantages of amphiphilic-polymer gels, the influencing mechanism and influencing rules of the components of polymer gel system and the reservoir application environment on the gel performance of amphiphilic-polymer gels have been discussed. Two methods for constructing composite gels based on amphiphilic polymers have been studied, including the methods of "inorganic-particle-reinforced" type and of "host-guest inclusion" type. Then the development trend of amphiphilic-polymer gels has been prospected. This work can provide a theoretical and technical basis for the design and application of amphiphilic-polymer gels. [ABSTRACT FROM AUTHOR]

A novel iodine vapour promoted polymerization method of 2,5-dibromo-3,4-ethylenedioxythiophene, and 2,5-diiodo-3,4-ethylenedioxythiophene and their derivatives at room temperature without using any solvent has been developed. The resulting polymers are conducting and electroactive in nature. After dedoping, the neutral polymers were analyzed in terms of their elemental composition, and the soluble polymers were characterized by 1H NMR and gel permeation chromatography analysis. A systematic study of the cyclic voltammetry, UV-vis absorption and spectroelectrochemistry of these polymers obtained by iodine vapour polymerization has been reported and they have been compared with previously reported solid state polymerization and electrochemically obtained polymers where applicable. [ABSTRACT FROM AUTHOR]

Currently, as a new kind of separator, gel polymer electrolytes (GPEs) not only should play a role to separate cathode and anode, but also should have high ionic conductivity to guarantee the elevated electrochemical performances. As for quasi-solid-state lithium-sulfur batteries (LSBs), it is also very important to confine the shuttle effect and Li dendrite growth. Herein, we synthesize GPEs polymerized under ultraviolet, in which the poly(vinylidene fluoride-hexafluoro propylene) (PVDF-HFP) is one of the polymer matrices to provide high ionic conductivity and toughness, pentaerythritol tetrakis-divinyl adipate (PETT-DA) is another polymer matrix to simultaneously suppress shuttle effect and lithium dendrite. More importantly, Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (LLZTO) provides the Li+ transport sites to facilitate the Li+ transport speed. Meanwhile, it can hinder the crystallization of polymers, reducing crystallinity of GPEs. Prominently, the designed GPEs with 10 wt% LLZTO have elevated ionic conductivity of 8.74 × 10−4 S cm−1 and Li+ transference number of 0.69, accompanied with superb capacity retention of 88.6% after 300 cycles at 1C. Importantly, the excellent mechanical properties and thermal stability give more potentials to the commercialization of LSBs. [ABSTRACT FROM AUTHOR]

In-situ polymerization of gel polymer electrolyte (GPE) is expected to be promising approach to solve the safety and interfacial problems of lithium ion battery, but it is still challenging ways to tradeoff the high electrochemical properties and mechanical toughness. Here, 30 μm thickness of free-standing GPEs with extremely high monomer conversion were obtained by in-situ UV approach on lithium metal anode within only few seconds. The coordination of amide and aliphatic carbonyl groups with lithium ion endows the tough mechanical properties, which tensile strength and elongation at break reach up to ∼1.0 MPa and ∼920 %. Furthermore, the good degree of graphitization on the surface of burned polymer gel contribute to its flame resistance. The ionic conductivity and lithium ion transferance number are up to 1.03 mS/cm and 0.44 at room temperature, respectively. Finally, Li/LiFePO 4 half cells assembled with the optimized GPEs exhibit stable cycle performance at 0.5C rate, delivering 77.44 % of capacity retention after 1000 cycles. • Free-standing GPEs (99 % monomer conversion) was obtained by 15s UV curving. • The interaction of carbonyl groups with Li + endows the tough mechanical properties. • Li/LiFePO 4 half cells show 77.4 % of capacity retention after 1000 cycles at 0.5C. [ABSTRACT FROM AUTHOR]

The Lewis acidic character of borinic‐acid‐functionalized polymers suggests broad potential applications in supramolecular materials, chemo‐ and biosensors, as well as supported catalysts. Two highly electron‐deficient borinic acid copolymers (3 a and 3 b) with variable steric hindrance at the boron center were prepared by reaction of aryldibromoboranes ArBBr2 (2, Ar=2,4‐Cl2Ph, 3,5‐Cl2Ph) with a 10 % stannylated polystyrene random copolymer, followed by conversion to the desired PS‐B(Ar)OH functionalities. The supramolecular assembly of these polymers through Lewis acid–Lewis base interactions and reversible covalent B−O−B bond formation was investigated. Exposure of a polymer solution of 3 a to pyridine triggered spontaneous gelation, whereas 3 b only gelled upon addition of molecular sieves to favor formation of boroxane crosslinks. The crosslinking process was readily reversed by addition of small amounts of water or wet solvent. The dynamic processes were studied in detail by variable‐temperature (VT) NMR by using molecular model compounds. The polymers and their corresponding model compounds were also examined as catalysts in the amide bond formation reaction between phenylacetic acid and benzylamine. The 3,5‐dichlorophenyl borinic acid derivatives proved to be the more effective catalysts. Mechanistic studies suggested that the borane Lewis acid‐catalyzed coupling involves initial acid‐induced protodeboronation to release the dichlorophenyl boronic acid as the active catalyst. [ABSTRACT FROM AUTHOR]

Biological approaches for the removal of heavy metals and radionuclides from contaminated water are reported. The present study was carried out with the objective of identifying bacterial strains for the uptake of cesium that could be used for bioremediation. Polymer carriers prepared by radiation polymerization were used for the immobilization of bacteria and the efficiency of free cells and immobilized cells for the removal of cesium was evaluated. Thirty-five bacterial isolates were screened for resistance to cesium and five bacterial isolates based on resistance to cesium (BR-3, BR-6, BR-21, BR-39, BR-40) were selected for immobilization. Polymer carriers were prepared using 10, 20, 30, 40 and 50% acrylamide at different doses of 1 to 5 kGy gamma radiation. The polymer carriers prepared using 30% and 40% acrylamide at 5 kGy were found to be suitable based on gel fraction and absorption capacity for the immobilization of bacterial cells. Bioremoval of cesium by free and immobilized bacterial cells was evaluated. Significant reductions of 76-81% cesium were observed with bacterial cells immobilized by radiation polymerization. [ABSTRACT FROM AUTHOR]

Since the development of emulsion polymerization techniques, polymer particles have become the epitome of standard colloids due to the exceptional control over size, size distribution, and composition the synthesis methods allow reaching. The exploration of different variations of the synthesis methods has led to the discovery of more advanced techniques, enabling control over their composition and shape. Many early investigations focused on forming particles with protrusions (with one protrusion, called dumbbell particles) and particles with concavities, also called dimpled particles. This paper reviews the literature covering the synthesis, functionalization, and applications of both types of particles. The focus has been on the rationalization of the various approaches used to prepare such particles and on the discussion of the mechanisms of formation not just from the experimental viewpoint but also from the standpoint of thermodynamics. The primary motivation to combine in a single review the preparation of both types of particles has been the observation of similarities among some of the methods developed to prepare dimpled particles, which sometimes include the formation of particles with protrusions and vice versa. The most common applications of these particles have been discussed as well. By looking at the different approaches developed in the literature under one general perspective, we hope to stimulate a more ample use of these particles and promote the development of even more effective synthetic protocols. [Display omitted] • Dumbbells and dimpled particles are the simplest non-spherical polymer colloids. • The preparation of such particles starts from spherical particles and involves swelling. • The role of the crosslinker in the preparation of both types of particles is highlighted. • A proper coating plays an essential role in the formation of new lobes. • A rigid shell is usually necessary to induce the formation of dimples on the surface of spherical particles. [ABSTRACT FROM AUTHOR]

The high theoretical capacity of Li-metal batteries (LMBs) makes them promising alternatives to Li-ion batteries to meet the increasing demand for advanced energy storage devices. However, high-energy-density LMBs with liquid electrolytes (LEs) are affected by dendrites produced during the inhomogeneous electrochemical deposition of Li. Herein, a novel S-containing gel polymer electrolyte (GPE) is synthesized in situ via thiol–ene click chemistry. The prepared S-containing GPE enables uniform Li deposition, and the resulting Li/Li symmetric cell can show cyclic stability for more than 500 h at a current density of 1 mA cm−2. Furthermore, the fabricated GPE-based LiFePO 4 /Li cells exhibit capacity retention of up to 91% after 500 cycles at 0.5C, indicating satisfactory stability compared to LE-based cells. The high electrochemical performance of the cells with GPE can be attributed to the formation of a sulfide and organo (poly)sulfide-reinforced hybrid solid electrolyte interface layer, which effectively stabilizes the interface and inhibits the formation of Li dendrites. [Display omitted] • A novel S-containing GPE was snythesized in situ via thiol-ene click chemistry. • The S element participated in forming inorganic/organo (poly)sulfide SEI layers. • The SEI layer can stabilize interface and inhibit the formation of Li dendrites. • The assembled LMB shows capacity retention of 91% after 500 cycles at 0.5C. [ABSTRACT FROM AUTHOR]

Abstract: The mechanical properties (e.g., stiffness, stretchability) of prefabricated hydrogels are of pivotal importance for diverse applications in tissue engineering, soft robotics, and medicine. This study reports a feasible method to fabricate ultrasoft and highly stretchable structures from stiff and tough hydrogels of low stretchability and the application of these switchable hydrogels in programmable shape‐morphing systems. Stiff and tough hydrogel structures are first fabricated by the mechanical strengthening of Ca2+‐alginate/polyacrylamide tough hydrogels by addition of Fe3+ ions, which introduces Fe3+ ionically cross‐linked centers into the Ca2+ divalent cross‐linked hydrogel, forming an additional and much less flexible trivalent ionically cross‐linked network. The resulting stiff and tough hydrogels are exposed to an L‐ascorbic acid (vitamin C, VC) solution to rapidly reduce Fe3+ to Fe2+. As a result, flexible divalent ionically cross‐linked networks are formed, leading to swift softening of the stiff and tough hydrogels. Moreover, localized stiffness variation of the tough hydrogels can be realized by precise patterning of the VC solution. To validate this concept, sequential steps of VC patterning are carried out for local tuning of the stiffness of the hydrogels. With this strategy, localized softening, unfolding, and sequential folding of the tough hydrogels into complex 3D structures is demonstrated. [ABSTRACT FROM AUTHOR]