Multicomponent Gel Research Articles

3D-Printing Multi-Component Multi-Domain Supramolecular Gels with Differential Conductivity.

We report the use of wet-spinning to 3D-print gels from low-molecular-weight gelators (LMWGs) based on the 1,3 : 2,4-dibenzylidenesorbitol (DBS) scaffold. Gel stripes assembled from DBS-CONHNH2 and DBS-COOH are printed, and their conductivities assessed. Printed gels based on DBS-CONHNH2 can be loaded with Au(III), which is reduced in situ to form embedded gold nanoparticles (AuNPs). The conductivity of these gels increases because of electron transport mediated by the AuNPs, whereas the conductivity of DBS-COOH, which does not promote AuNP formation, remains lower. We then fabricate multi-component gel patterns comprised of spatially well-defined domains of printed DBS-CONHNH2/AuNP (higher conductivity) and DBS-COOH (lower conductivity) resulting in soft multi-domain materials with differential conductivity. Such materials have future prospects in applications such as soft nanoelectronics or tissue engineering.

IMPACT OF A GEL COMPOSITION CONTAINING VARIOUS SUBSTANCES ON INDICES OF IMMUNITY AND TISSUE INFLAMMATION IN PALATINE TONSILS OF PATIENTS WITH CATARRHAL GINGIVITIS DURING CHRONIC TONSILLITIS

The study of pharmacotherapeutic (immunomodulating) action in conditions of in vitro cell cultures is currently considered appropriate and justified for determining the action of drugs at the preclinical level. It is also important to address the pathogenetic nature in using such agents, especially fro local application. This study investigated the efficacy of a multicomponent gel containing decamethoxine and hyaluronic acid in treating chronic catarrhal gingivitis among patients with chronic tonsillitis. The purpose of the work is to assess the efficacy of a gel containing decamethoxine and hyaluronic acid on the tissue of the palatine tonsils in the therapy of chronic catarrhal gingivitis in patients with chronic tonsillitis.
 Materials and methods. To investigate the effects of the main active components in the gel, we followed the recommendations of I.P. Kaidashev et al. for testing pharmacological preparations in in vitro cultures. Tissue samples from the palatine tonsils were obtained from 20 patients with chronic tonsillitis and chronic catarrhal gingivitis undergoing tonsillectomy. All procedures adhered to the guidelines set by the Laboratory of Pathophysiology and Immunology at Prof. O.S. Kolomiichenko Institute of Otolaryngology, National Academy of Sciences of Ukraine. Palatine tonsil tissue was incubated in 199 medium (Serva, Germany) containing gentamicin sulfate (Darnytsa, Ukraine) at a concentration of 120 μg/ml for 20 minutes at 4-8°C. After that, the hemorrhagic parts were removed from the whole tonsil and placed into Eagle's medium (Sigma, USA) and rinsed three to four times. Subsequently, the prepared tissue was placed in sterile vials containing enriched Eagle's medium supplemented with L-glutamine, sodium bicarbonate, 100x vitamin concentrate, 5% fetal calf serum, and 60 μg/mL gentamicin. Tonsil tissue was dissected using scissors and then washed repeatedly (5-7 times) with fresh medium to remove loosely attached cells, then, the resulting cell suspension was filtered. All procedures were conducted within a sterile laminar flow cabinet. Cell viability was assessed using light microscopy (Olympus-23, Japan) and a hemocytometer. A final cell suspension containing 2.5 million lymphocytes per milliliter of medium was prepared. Suspensions with a viability of less than 90% (blue, "dead" cells) were excluded from further experiments.
 Results. Treatment of in vitro palatine tonsil cells from patients with chronic catarrhal gingivitis and recurrent tonsillitis with the main components of the developed gel (decamethoxine and hyaluronic acid) did not induce significant changes in the concentration of α and γ-interferons. Our findings suggest that the gel composition reduces the levels of pro-inflammatory factors: interleukin-1β and immune complexes. Additionally, it appears to stimulate the production of the antimicrobial factor antistreptolysin-O by tonsil cells, potentially leading to increased antibody production against hemolytic streptococcus antigens.
 Conclusion. Based on the in vitro findings, the investigated gel composition containing decamethoxine and hyaluronic acid demonstrates potential anti-inflammatory and antimicrobial properties that stimulate the production of the antimicrobial factor antistreptolysin-O by tonsil cells, which might lead to increased antibody production against hemolytic streptococcus antigens.

Nanoscale assembly of enantiomeric supramolecular gels driven by the nature of solvents.

Understanding the key parameters that control the self-assembly process is critical to predict self-assembly modes in multi-component systems, which will lead to the development of nanofibrous materials with tuneable properties. Enantiomeric amino acid-based low-molecular-weight gelators (LMWGs) were mixed in polar (polar protic) and aromatic apolar (aromatic) solvents and compared to their individual counterparts to probe the effect of solvent polarity on the self-assembly process. Scanning electron microscopy (SEM) reveals that xerogels of individual components display hollow needles in polar protic solvents, while chiral coils are observed in aromatic solvents. In contrast, the multi-component gel displays hollow needle morphologies in both solvents, indicating similar morphologies in polar protic solvents but an entirely different nanostructure for the individual gel networks in aromatic solvents. PXRD experiments performed on the dried gels showed that the nature of the solvents plays a vital role in the co-assembly process of multi-component gels. The self-assembly modes and the gel state structure of the gels are analysed by wide-angle X-ray diffraction (WAXS) and small-angle neutron diffraction (SANS), which reveals that the mixed gel undergoes different co-assembly modes depending on the nature of the solvent systems. This study shows that different co-assembly modes can be achieved for structurally similar components by varying the solvent polarity, demonstrating the importance of solvent choice in the self-assembly process of multi-component gels.

Probing assembly/disassembly of ordered molecular hydrogels.

Supramolecular hydrogels have a wide range of applications in the biomedical field, acting as scaffolds for cell culture, matrices for tissue engineering and vehicles for drug delivery. L-Phenylalanine (Phe) is a natural amino acid that plays a significant role in several physiological and pathophysiological processes (phenylketonuria and assembly of fibrils linked to tissue damage). Since Myerson et al. [Chem. Eng. Commun., 2002, 189(8), 1079-1090] reported that Phe forms a fibrous network in vitro, Phe's self-assembly processes in water have been thoroughly investigated. We have reported structural control over gelation by introduction of a halogen atom in the aromatic ring of Phe, driving changes in the packing motifs, and therefore, dictating gelation functionality. The additional level of control gained over supramolecular gelation via the preparation of multi-component gel systems offers significant advantages in tuning functional properties of such materials. Gaining molecular-level information on the distribution of gelators between the inherent structural and dynamic heterogeneities of these materials remains a considerable challenge. Using multicomponent gels based on Phe and amino-L-phenylalanine (NH2-Phe), we will explore the patterns of ordered/disordered domains in the gel fibres and will attempt to come up with general trends of interactions in the gel fibres and at the fibre/solution interfaces. Phe and NH2-Phe were found to self-assemble in water into crystalline hydrogels. The determined faster dynamics of exchange between the gel and solution states of NH2-Phe in comparison with Phe were correlated with weaker intermolecular interactions, highlighting the role of head groups in dictating the strength of intermolecular interactions. In the mixed Phe/NH2-Phe systems, at a low concentration of NH2-Phe, disruption of the network was promoted by interference of the aliphatics of NH2-Phe with the electrostatic interactions between Phe molecules. At high concentrations of NH2-Phe, multiple-gelator hydrogels were formed with crystal habits different from those of the pure gel fibres. NMR crystallography approaches combining the strengths of solid- and solution-state NMR proved particularly suitable to obtain structural and dynamic insights into the "ordered" fibres, solution phase and fibre/solution interfaces in these gels. These findings are supported by a plethora of experimental (diffraction, rheology, microscopy and thermal analysis) and computational methods.

Intrinsic Design and Modulated Circular Dichroism of Inorganic Nanowire/Hydrogel Composite

AbstractControlling the handedness and absorptive characteristics of chiral materials is essential for exploring new advances in the field of chiral sensors and catalysts. The deliberate architecture of the building blocks and their self‐assembly process are critical factors for fabricating chirally active structures from achiral nanoscale components. Herein, the fabrication of multicomponent gel structures comprising magnetoplasmonic core–shell Au@FexOy nanowires embedded in a macroscopic titania nanocrystal network is demonstrated, which shows broadband absorption covering the ultraviolet–visible light spectrum while maintaining excellent porosity in the aerogel state. The effect of externally applied helical magnetic field is exploited to induce self‐assembly of the magnetoplasmonic nanowires into chirally active superstructures. Furthermore, a second vector of symmetry is observed when the chiral hydrogel unit is rotated up to 45° around the z‐axis perpendicular to the light path, in which the measured circular dichroism intensity is modulated up to ±102% compared to those at 0°. This study serves as a concept of designing optically active chiral 3D superstructures, applicable to optical filters, sensing devices, and chiral photocatalysts.

All-Natural, Robust, and pH-Responsive Glycyrrhizic Acid-Based Double Network Hydrogels for Controlled Nutrient Release.

Supramolecular hydrogels self-assembled from naturally occurring small molecules (e.g., glycyrrhizic acid, GA) are promising materials for controlled bioactive delivery due to their facile fabrication processes, excellent biocompatibility, and versatile stimuli-responsive behaviors. However, most of these natural hydrogels suffer from poor mechanical strength and processability for practical applications. In this work, through adopting a multicomponent gel approach, we developed a novel mechanically robust GA-based hydrogel with an interpenetrating double network (DN) that is composed of a Ca2+-enhanced hydrogen-bond supramolecular GA nanofibril (GN) network and a Ca2+cross-linked natural polysaccharide sodium alginate (ALG) network. Compared to the single GN network (SN) hydrogel, the GN-ALG hybrid hydrogels (GN-ALG-DN) with the hierarchical double-network structure possess excellent mechanical properties and shaping adaptation, encouraging small and large amplitude oscillatory shear (SAOS and LAOS) rheological performances, better thermal stability, higher resistance to large compression deformations, and lower swelling behaviors. Furthermore, the GN-ALG-DN hydrogels exhibit a pH-responsive and sustained release behavior of nutrients (i.e., vitamin B12, VB12), showing a faster VB12 release rate with a higher swelling ratio in an alkaline condition (pH 7.5) than in an acidic condition (pH 2.5). This is ascribed to the fact that the higher dissociation degree of carboxylic groups in GA and ALG molecules in an alkaline environment induces the erosion and looseness of the self-assembled GN network and the ionic-cross-linked ALG network, which can lead to the decomposition of the hybrid hydrogels and thereby increases the release of nutrients. Cytotoxicity tests further demonstrate the excellent biocompatibility of the GN-ALG-DN hydrogels. This study highlights the design of robust shaped and structured supramolecular hydrogels from natural herb small molecules, which can serve as solid, edible, and stimuli-responsive active cargo delivery platforms for food, biomedical, and sustainable applications.

Supramolecular Gel-to-Gel Transition Induced by Nanoscale Structural Perturbation via the Rotary Motion of Feringa's Motor.

Supramolecular rather than covalent molecular engineering on Feringa motors can provide an alternative toolkit for tuning the properties of motorized materials through appropriate supramolecular structural perturbations, which are underexplored. Herein, a multicomponent supramolecular gel system is successfully prepared by employing an ultra-low molecular weight gelator and a modulator-Feringa motor. The electron microscopic, spectroscopic, and rheological data revealed that the morphology and mechanical properties of the gel can be tuned via a crystallographic mismatch branching (CMB) mechanism simply by adding varied amounts of motor modulators. Notably, the rotary motion of the motor is preserved in such a multicomponent gel system, and the morphology and rheology of the gel can be further altered by the motor's rotary motion that promotes the structural perturbation, resulting in seldomly seen gel-to-gel transition events. The work shown here offers prospects to utilize a supramolecular perturbation strategy to deliver responsiveness from molecular motors to the corresponding bulk materials.

АКТУАЛЬНЫЕ ВОПРОСЫ ОЦЕНКИ КАЧЕСТВА ПОЛИКОМПОНЕНТНОГО ГЕЛЯ РЕПАРАТИВНОГО ДЕЙСТВИЯ

The domestic pharmaceutical market still lacks reparative drugs, which determines research on their creation as an urgent theoretical and applied task. In this regard, the expediency of developing the composition and technology for obtaining a polycomponent gel with a predictable positive effect on wound healing processes based on dermal biopolymers and a complex of biologically active substances of corn columns with stigmas is substantiated. The complex of technological studies carried out made it possible to establish the optimal composition and technology for obtaining a polycomponent gel. At the next necessary stage of pharmaceutical development, it was necessary to solve the issues of assessing the quality of the proposed composition of the polycomponent gel. The purpose of this study was to determine the criteria and methods for monitoring the quality indicators of a multicomponent reparative gel. The object of the study was experimental samples of a multicomponent gel obtained by introducing a thick extract of corn columns with stigmas into a collagen base. The quality of the polycomponent gel was assessed in accordance with the requirements of GPM.1.4.1.0008.15 "Ointments" of the State Pharmacopoeia IV edition according to the following criteria: "Description", pH, "Microbiological purity", authenticity and quantitative content of active substances. The indicator "Description" was evaluated organoleptically. The determination of the pH of the gel was carried out potentiometrically using a pH meter (Mettler Toledo, USA) according to GPM.1.2.1.0004.15 "Ionometry" directly in the gel sample. Microbiological purity was studied by the agar plate method in accordance with GPM.1.2.4.0002.15. The presence and quantitative determination of flavonoids in the developed gel was determined spectrophotometrically on a UV-1800 SHIMADZU spectrophotometer, Japan. As a result of the studies carried out, the criteria for the quality of a multicomponent gel of reparative action were studied and proposed. According to the "Description" indicator, the polycomponent gel is a homogeneous mass of light brown color with a pleasant fruity odor without impurities. It has been established that the polycomponent gel is characterized by a slightly alkaline pH value, which creates optimal conditions for the healing phase of the wound process. It is shown that the use of the method of differential spectrophotometry makes it possible to carry out a statistically significant qualitative and quantitative assessment of the content of flavonoids in the composition of a polycomponent gel.

STUDYING THE OSMOTIC ACTIVITY OF A POLYCOMPONENT REPARATIVE GEL

Abstract. Hydrogel-based wound dressings are currently in demand due to their positive effect on reparative processes. The range of such is quite diverse and is represented by gelling agents of both synthetic and natural origin. The latter are most often biopolymers, among which collagen deserves special attention. The most important properties of collagen are its biocompatibility, low level of immunogenicity, ability to biodegrade, which leads to the formation of degradation products that stimulate cell proliferation and the biosynthesis of native collagen. Collagen has optimal physical characteristics, which is important for ensuring the structural and mechanical properties of the compositions. In addition, collagen has been successfully used as a carrier for other pharmacologically active substances. In this regard, the expediency of developing a multicomponent gel with a predictable reparative effect based on collagen and a thick extract of maize columns with stigmas was shown. This medicinal plant raw material has anti-inflammatory, antioxidant, immunotropic effects, which suggests its positive effect on tissue healing processes. One of the important properties of the reparative gel is its osmotic activity, which determines the ability to absorb exudate and cleanse the surface of the wound from purulent secretions, reduce tissue hyperthermia and inflammatory edema. The purpose of this study is to study the osmotic activity of a multicomponent gel of reparative action based on collagen and a thick extract of maize columns with stigmas. The object of the study was experimental samples of a polycomponent gel. Osmotic activity was studied by the method of equilibrium dialysis according to Kruvchinsky. For the purpose of a comparative assessment of the osmotic activity of a multicomponent gel, a control study was carried out in parallel under the same conditions for a 0.9% sodium chloride solution. The results obtained demonstrated the presence of hyperosmolar characteristics in the experimental samples of the polycomponent gel during the first four hours of dialysis, which allows us to predict its positive effect on the processes of cleansing damaged tissues from pathological secretions and their effective repair.

The spontaneous imbibition mechanisms for enhanced oil recovery by gel breaking fluid of clean fracturing fluid

The quick flowback treatment after conventional fracturing construction can waste a lot of energy from fracturing fluid. Meanwhile, spontaneous imbibition has great application potential for enhanced oil recovery (EOR). In this work, based on pre-developed silica nanoparticle-reinforced CO2-sensitive fracturing fluid system, the imbibition factors of the gel breaking fluid were studied. In addition, the HNMR technology, AFM, contact angle test, and interfacial tension (IFT) test were used to explore the mechanism of spontaneous imbibition. The results show that imbibition mainly occurs in the small pores, and the adsorption of components can reduce roughness and flow resistance. Meanwhile, the adsorption layer was formed by surfactants and nanoparticles, changing wettability from oil-wet to water-wet, reducing the IFT between oil and water. The synergistic effect of multi-component improves the imbibition effect. We expect that this study can broaden the application of multi-component gel breaking fluid in low permeability reservoirs.

Superior high-temperature rate performance of LiFePO4 cathode: The stabilizing effect of a multicomponent gel biopolymer binder

A quasi-solid-state polymer gel binder (PGB) has been prepared and investigated for application in high-temperature lithium-ion batteries. The effects of binder on the aging behavior of LiFePO 4 (LFP) cathodes were investigated by electrochemical methods and post mortem analysis. Conventional binder polyvinylidene difluoride (PVDF) was used as a benchmark. At 60 °C, LFP/PGB half cells delivered a capacity of 98 mAh g −1 , which corresponds to 92% of the initial value 140 mA g −1 over 1000 cycles at 10C. These results were far superior to the ones obtained for LFP with PVDF which only exhibited a capacity of 58 mAh g −1 . We showed that a significant degradation of LFP in the LFP/PVDF electrode accompanied by iron dissolution in the electrolyte and deposition on the anodic surface together with a strong swelling of PVDF in the electrolyte as well as some contact loss between the electrode and the current collector represent the main reasons for the capacity fading at 60 °C. In contrast, these effects were much less pronounced in the LFP/PGB electrode. Furthermore, thick LFP/PGB electrodes with 450 μm thickness, corresponding to a 4.5 mg cm −2 mass loading, showed a better cycling performance and more favorable electrochemical kinetics than the electrode incorporating PVDF. • A chitosan-based polymer gel binder for high-temperature Li-batteries is proposed. • The biopolymer gel binder (PGB) is applied to the LiFePO 4 cathode material. • At 60 °C, LiFePO 4 /PGB delivers a capacity of 98 mAh·g −1 over 1000 cycles at 10C. • The dissolving of iron in the electrolyte is much less pronounced with the PGB. • The gel binder is also applied to thick LiFePO 4 electrodes (450 μm thickness).

Building multi-color emitters with tailored lanthanide-based supramolecular metallogels

Multicomponent lanthanide-based metallogel offers unique prospects to access versatile, dynamic supramolecular soft materials with hierarchical stimuli-responsiveness and tunable functions, particularly for applications in the optical display field. In this work, a novel ligand L bearing classical coordinating terpyridine (tpy) and hosting 24-Crown-8 (24C8) moieties was synthesized with a function-oriented design principle, which further allowed the complexation between L and a series of lanthanide ions (Ln). Interestingly, several L-Ln complexes with 1:1 stoichiometry were found to be able to gel the solvent toluene/CH3CN (1:1), and thus lanthanide-based metallogels were successfully prepared. The L-Eu and L-Tb gel was found to be emissive and further utilized to produce a white light emitter through fine adjustment of stoichiometry among Eu, Tb, and L. Importantly, the multicomponent gel strategy was employed, and additional non-coordinating chromophores were introduced into the metallogel system. Thus a broad-spectrum of emission was achieved, and these multicomponent emissive gels were successfully applied as a photo printer. The metallogels also showed multiple stimuli-responsiveness such as pH, guest molecules thanks to the anchoring of predesigned functional moieties such as tpy and 24C8 on the ligand L. It is assumed that our multicomponent metallogel research shown here may open new avenues towards the design and preparation of intelligent and tunable hybrid lanthanide-based optical materials.

Supramolecular hydrogelation via host-guest anion recognition: Lamellar hydrogel materials for the release of cationic cargo

Supramolecular hydrogelation via host-guest anion recognition: Lamellar hydrogel materials for the release of cationic cargo

Experience of applying a multi-component gel based on troxerutin, heparin sodium and dexpanthenol in the rehabilitation of patients after cosmetic procedures

The article reports an up-to-date classification of complications of cosmetic procedures and two clinical cases where multicomponent gel based on troxerutin, heparin sodium and depanthenol was used to rehabilitate patients after cosmetic procedures complicated by ecchymosis, hematomas and edema. In the first case a 30-year-old patient had a procedure to give greater volume to her lips and to correct their asymmetry with hyaluronic acid filler. The procedure was complicated by the formation of hematomas and edema. To minimize the edema and hematomas and to avoid the risk of infection the patient was prescribed 0.05% aqueous solution of chlorhexidine bi-gluconate once per day and taking of multicomponent gel based on troxerutin, heparin sodium and depanthenol two times per day for seven days. By the fifth day there was observed a significant decrease in edema of the lip area and almost complete resorption of hematomas. In the second case a 42-year-old patient had a procedure of a biorevitalization with unstabilized hyaluronic acid complicated by the appearance of ecchymosis up to 12 mm in diameter and edema in the periorbital zone. A 0.05% aqueous solution of chlorhexidine bi-gluconate once per day and a multicomponent gel based on troxerutin, heparin sodium and dexpanthenol twice per day for seven days were prescribed as post-procedural rehabilitation. By the fourth day clinical improvement was noted. The edema disappeared, the color changed, the size of the ecchymosis decreased to 4 mm. The ecchymosis disappeared completely on the sixth day. In addition, the main characteristics of troxerutin, heparin sodium and depanthenol as components of a multicomponent gel were considered. A multicomponent gel based on troxerutin, heparin sodium and depanthenol as supportive aid helped to get complications completely cleaned out and significantly reduced the rehabilitation period for these patients. The authors consider it possible to recommend it as a means of post-procedural rehabilitation.

Spatial Extent of Fluorescence Quenching in Mixed Semiconductor–Metal Nanoparticle Gel Networks

AbstractIn this work, mixing and co‐gelation of Au nanoparticles (NPs) and highly luminescent CdSe/CdS core/shell nanorods (NRs) are used as tools to obtain noble metal particle‐decorated macroscopic semiconductor gel networks. The hybrid nature of the macrostructures facilitates the control over the optical properties: while the holes are trapped in the CdSe cores, the connected CdSe/CdS NRs support the mobility of excited electrons throughout the porous, hyperbranched gel networks. Due to the presence of Au NPs in the mixed gels, electron trapping in the gold NPs leads to a suppressed radiative recombination, namely, quenches the fluorescence in certain fragments of the multicomponent gel. The extent of fluorescence quenching can be influenced by the quantity of the noble metal domains. The optical properties are monitored as a function of the NR:NP ratio of a model system CdSe/CdS:Au. By this correlation, it demonstrates that the spatial extent of quenching initiated by a single Au NP exceeds the dimensions of one NR, which the Au is connected to (with a length of 45.8 nm ± 4.1 nm) and can reach the number of nine NRs per Au NP, which roughly corresponds to 400 nm of total electron travel distance within the network structure.

Exploring the Tunable Optical and Mechanical Properties of Multicomponent Low-Molecular-Weight Gelators.

A class of amino acid-based low-molecular-weight gelators (LMWGs) was used for single and multicomponent gel studies to investigate their tunable optical properties and their self-assembly process. The optical properties of multicomponent gels were found to be easily tuned by changing the proportion of the components, varying from opaque to highly transparent gels as analyzed using ultraviolet-visible spectroscopy. This phenomenon allows tunability without introducing another variable into the system. Scanning electron microscopy, differential scanning calorimetry, and small-angle X-ray scattering (SAXS) were used to investigate the structures of the gels. It was found that because of the structural similarities of the molecules, the gelators favor coassembly packing over self-sorting. The emergence of transparency was ascribed to changes in the fiber diameters. Moreover, analysis of the SAXS data allowed us to compare the molecular order present in the gel phase with single-crystal X-ray diffraction (SCXRD) data. Our analysis suggests that the packing of molecules seen in the crystalline phase is translated into the gel network. This reveals that the structure of the crystalline phase seen through SCXRD is a useful tool to aid in understanding the molecular packing in the gel phase.

Double diffusion for the programmable spatiotemporal patterning of multi-domain supramolecular gels.

To achieve spatial resolution of a multi-component gel, a double diffusion approach is used which enables the precise programming of self-assembled patterned domains with well-defined shapes and sizes. The low-molecular-weight gelators (LMWGs) used in this study are pH-responsive DBS-CO2H and thermally-responsive DBS-CONHNH2 (both based on 1,3:2,4-dibenzylidenesorbitol, DBS). A DBS-CONHNH2 gel was initially assembled in a tray, and then loaded at carefully-selected positions with either basified DBS-CO2H (i.e. DBS-carboxylate) or an acid. These soluble components subsequently diffuse through the pre-formed gel matrix, and in the domains when/where they mix, protonation of the DBS-carboxylate induces self-assembly of the DBS-CO2H network, leading to a patterned gel-in-gel object with well-defined shape and dimensions. Using a strong acid achieves fast gelation kinetics, creating smaller, better-defined macroscale objects but with less nanoscale order. Using a weak acid source with slow kinetics, gives slightly larger objects, but on the nanoscale the DBS-CO2H network formation is better controlled, giving more homogeneous nanoscale structures and stiffer objects. The patterned objects can be further reinforced by the presence of agarose polymer gelator. The shape of the patterning is programmed by both the shape of the central reservoir and the starting geometry in which the reservoirs are organised, with the balance between factors depending on assembly kinetics, as dictated by the choice of acid. This simple methodology therefore enables programming of patterned gels with spatiotemporal control and emergent patterning characteristics.

Highly Efficient Multicomponent Gel Biopolymer Binder Enables Ultrafast Cycling and Applicability in Diverse Battery Formats.

Electrode materials with a high performance and stable cycling have been commercialized, but the utilization of state-of-the-art Li-ion batteries in high-current rate applications is restricted because of limitations in other battery components, in particular, the lack of an efficient binder. Herein, a novel multicomponent polymer gel binder (PGB) is presented, comprising the biopolymer chitosan as the host, embedded with the 1-butyl-1-methylpyrrolidinium dicyanamide (PYR14DCA) ionic liquid and the lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt. The multicomponent approach leads to carbon black arrangement along well-distributed chitosan chains in the electrodes, forming a highly electronic conductive network. Furthermore, the plasticizing effect of the ionic liquid leads to an enhanced ionic conductivity. As a result, shorter charge-transfer paths are enabled, leading to an exceptionally high rate capability in LiFePO4 and Li4Ti5O12 half cells, up to 50C. LiFePO4||Li4Ti5O12 full cells using the PGB for both electrodes also demonstrated stable cycling at 10C, with an impressively high discharge capacity of 173 mA h·g-1 after 1000 cycles. In addition, freestanding electrodes could also be realized and functioning flexible Li-ion cells were successfully demonstrated. Thus, the novel water-processable binder offers multifaceted advantages, making the approach highly promising for industrial implementation.

Research and application of microfoam selective water plugging agent in shallow low-temperature reservoirs

There exists a large interlayer pressure difference in the oil wells of the Fuyu oilfield, and the high-pressure layer has a relatively high liquid production. The low-pressure layer is characterized by a relatively low liquid production, and water shut-off is urgently needed. Selective plugging technology is designed to temporarily block the oil layer before plugging the water layer, which is suitable for low-temperature shallow reservoirs. The foaming comprehensive exponent is considered to optimize the formula of the temporary plugging agent, consisting of 200 mL clean water, 0.25% sodium hexadecyl sulfonate, 0.8% sodium carboxymethyl cellulose, and 0.8% soluble starch. In addition, the formula of the multicomponent gel plugging agent is designed via extremum difference analysis, and the formula is 5% acrylamide (AM), 5% acrylic acid (AA), 0.8% PVA, 0.3% N,N-methylenebisacrylamide, 0.1% ammonium persulfate, and 0.2% sodium hydroxide. The selective plugging performance and permeability recovery characteristics of the system are evaluated. The experimental results show that the microfoam temporary blocking agent is more suitable for a core permeability ranging from 100–200 × 10−3 μm2, and the plugging agent can quickly gel at low temperatures. Field tests in a typical well show that the breakthrough pressure gradient of the temporary plugging layer reaches 3.5 MPa/m, thereby effectively protecting the low-pressure layer, and the fluid production of the high-pressure layer is reduced from 13.7 m3/d to 0.6 m3/d, thus realizing the purpose of plugging the high-pressure layer.

Chirality on dendrimers: “roll booster” of the molecule-level self-sorting assembly in two-component supramolecular gel system

Chirality-induced recognition-promoted molecule-level self-sorting assembly in a two-component supramolecular gel system constructed by two polyhedral oligomeric silsesquioxane (POSS) core-based dendritic gelators with similar geometry and peripheral functionality, which would normally form a homogeneous co-assembled network.