Gel Type Research Articles

Investigation the effects of chlorine doped graphene oxide as an electrolyte additive for gel type valve regulated lead acid batteries

In this study, chlorine-doped graphene oxide (Cl-GOP) was used as an additive in the fumed silica-based gel electrolyte system of Valve Regulated Lead Acid (VRLA) batteries for the first time in the literature, and the performance of the gel electrolyte was increased. In this context, chlorine-doped graphene oxide produced by electrochemical methods was characterized using spectroscopic and microscopic methods, and then it was added to the fumed silica based gel electrolyte as an additive. The amount of Cl-GOP in the gel electrolyte system was optimized using electrochemical methods and 0.6 % by mass was determined as the most suitable. Then, the stirring rate and agitation time, which are the most important parameters affecting the performance of the gel electrolyte system, were optimized and the optimum values were determined as 500 rpm and 30 min, respectively. Finally, the prepared fumed silica-based electrolyte systems and aqueous electrolyte systems were subjected to charge-discharge tests and the highest discharge capacity value was determined as 42 mAh.cm−2 in the fumed silica-based gel electrolyte system containing Cl-GOP with 20 mA.cm−2 charge-discharge current densities. The results showed that Cl-GOP is an important additive in the fumed silica-based gel component of gel type VRLA batteries.

High‐performance Supercapacitors Enabled by Highly‐porous Date Stone‐derived Activated Carbon and Organic Redox Gel Electrolyte

AbstractConstruction of eco‐benign, cost effective, and high‐performance supercapacitors with improved electrolytes and hierarchical porous electrodes is necessary for effective energy storage. In this study, a gel type organic redox electrolyte made of polyvinyl alcohol (PVA)‐H2SO4 and an organic redox molecule, anthraquinone (PVA‐H2SO4‐AQ) was prepared by simple solution casting method, and was used to construct a symmetric supercapacitor (SSC) with a date stone‐derived activated carbon (DSAC) having a high BET surface area (1612 m2/g). The DSAC was synthesized by simple carbonization method followed by activation with potassium hydroxide. The SSC exhibit a high specific capacitance of 126.5 F/g at 0.5 A/g, as well as a high energy density of 17.5 Wh/kg at a power density of 250 W/kg with high capacitance retention (87%) after 1000 GCD cycles. The present research suggests that adding anthraquinone to a PVA‐H2SO4 gel electrolyte improves the performance of the fabricated device significantly as compared to using pristine PVA‐H2SO4 or 1 M H2SO4 electrolytes. The research also presents a promising approach for the development of sustainable and eco‐benign materials for energy storage applications. The use of date stone waste as a precursor material for activated carbon electrodes presents an opportunity for cost‐effective and sustainable energy storage. Overall, the findings of this research have important implications for the future design and fabrication of high‐performance and cost‐effective supercapacitors.

Effects of Abelmoschus manihot gum content, heating temperature and salt ions on the texture and rheology properties of konjac gum/Abelmoschus manihot gum composite gel

To improve the gelling property of konjac gum (KGM) and enhance the application value of Abelmoschus manihot (L.) medic gum (AMG), a novel type of gel was prepared using KGM and AMG in this study. The effects of AMG content, heating temperature and salt ions on the characteristics of KGM/AMG composite gels were studied by Fourier transform infrared spectroscopy (FTIR), zeta potential, texture analysis and dynamic rheological behavior analysis. The results indicated that the AMG content, heating temperature and salt ions could affect the gel strength of KGM/AMG composite gels. Hardness, springiness, resilience, G′, G* and η* of KGM/AMG composite gels increased when AMG content increased from 0 to 2.0 %, but they decreased when AMG increased from 2.0 % to 3.5 %. High-temperature treatment significantly enhanced the texture and rheological properties of KGM/AMG composite gels. The addition of salt ions reduced the zeta potential absolute value and weakened the texture and rheological properties of KGM/AMG composite gels. Furthermore, the KGM/AMG composite gels could be classified as non-covalent gels. The non-covalent linkages included hydrogen bonding and electrostatic interactions. These findings would help understand the properties and formation mechanism of KGM/AMG composite gels and help improve the application value of KGM and AMG.

Construction of different properties single and double cross-linked binary emulsion filled gels based on rice bran oil body emulsion

Rice bran oil bodies (RBOBs) are rich in nutritional value. RBOBs are a by-product of rice processing. In this study RBOBs with different fractions (0–10%) were filled in binary networks formed by soy protein isolate (SPI) and flaxseed gum (FG). Two types of emulsion-filled gel (EFG) were constructed via Ca2+ crosslinking or double-crosslinking with transglutaminase (TG) and Ca2+. Microstructure and fluorescence spectra revealed that RBOBs were integrated into the structural matrix, resulting in altered gel network structure. Ca2+ crosslinking induced droplet aggregation and led to the formation of a segregated network structure, increasing surface roughness. TG and Ca2+ double cross-linking yielded a homogeneous gel network. Meanwhile, double-crosslinking and filling of RBOB emulsion resulted in a denser structure with higher water-holding capacity. Rheology and tribological tests demonstrated that RBOBs acted as active fillers in EFGs constructed via two crosslinking methods, improving the colloidal strength by forming different structures. Thixotropy of double- crosslinked EFG is obvious better than Ca2+-crosslinked EFG, which has higher creep recovery rate. During friction sliding, Ca2+ crosslinking and double-crosslinking resulted in different friction behavior. Filling with 10% RBOBs fraction leads to better friction behavior. This study provides a new idea for the potential application of oil bodies as fat substitutes.

Release of aroma components from agarose gels during human chewing: Effects of agarose molecular weight and chewing cycles

Experiments were conducted using a method of collecting aroma compounds in the mouth through one nostril. Three types of agarose gels with different molecular weights and nine types of aroma compounds were used as samples. After the agarose gel was chewed 0–30 times while holding breath, aroma compounds were collected by blowing intraoral air into the sampling bag through the nostril. The effects of the number of chewing cycles and the type of agarose gel on the release rate of aroma compounds were investigated using relative release values, Qc/Q0 (where Qc is the amount of aroma compounds collected after chewing and Q0 is the amount collected without chewing). The relative release value increased with increasing number of chewing cycles, and the degree of increase in the relative value depended on the molecular weight of agarose. The relative release values for low chewing cycles were similar for all types of gels. At higher chewing cycles, the relative release value increased in gels with lower network densities than in other types of gels. It was suggested that the molecular weight of agarose and the number of chewing cycles changed the mechanism of flavor release.

Dielectric Properties Characterization and Evaluation of Commercial Silicone Gels for High-Voltage High-Power Power Electronics Module Packaging

The lack of a method to select the suitable silicone gel from various commercial silicone gels for encapsulation in next-generation high-voltage high-power electronics modules has become a challenge. In this article, a comprehensive evaluation approach of three commercial silicone gels is carried out via multiple characterizations in terms of surface microstructure, main internal components, dc volume resistivity, dielectric properties, breakdown strengths under dc and ac voltages, thermogravimetric properties, and glass transition temperature. This study shows that the analytical tools set proposed in this article can be used as an efficient guideline for comparing different types of silicone gels and selecting suitable silicone gels for different applications. For example, the drawn radar chart intuitively shows that Gel 3 has the best all-around performance in both electrical and thermal properties, and Gel 1 has the highest thermal stability. The surface microstructure and internal functional groups of the three silicone gels are almost the same. The glass transition temperatures of the three silicone gels were also measured, and the thermo gravimetric analysis (TGA) showed that the three silicone gels had high thermal stability. According to the test results and analytical tools established in this article, we were able to identify silicone gels suitable for different applications. In this regard, Gel 3 is suitable for applications with higher voltage levels (10–20 kV), while Gel 1 and Gel 2 are suitable for lower voltage levels.

Effect of self-assembly gel crosslinking property and the wetting characteristics of coal under different acid solution

In view of the serious dust pollution in coal mines, the self-assembly gels that can uniformly distribute acid are investigated. The effect of acid type and concentration of the self-assembly gel on the viscosification and wettability in coal, as well as the internal mechanism for the changes are revealed. The results show that the formed micelles of the inorganic acid self-assembly gels are compact and thick, and the high potential enhances the interaction force inside the micelles. In the organic acid environment, it is not conducive to assemble the surfactant molecules, to be specific, the wormlike micelles are sparse and short, but has a better wettability and the minimum surface tension of 12.50 mN/M. In the inorganic acid environment, the wettability is poor, however, it shows a strong adsorption on the coal, and imposes the greatest influence on -OH group in coals. • The viscosification behavior of self-assembly gel in different acid solutions were found. • The wettability of self-assembly gel in different acid solutions were found. • The internal mechanism in viscosification and wetting were obtained.

Clarification of the Effects of Oxygen Containing Functional Groups on the Pore Filling Behavior of Discharge Deposits in Lithium–Air Battery Cathodes Using Surface-Modified Carbon Gels

In lithium–air batteries (LABs), controlling the characteristics of the Li2O2 deposited during discharging can lead to the reduction of the large overpotential required for charging. The large overpotential is one of the most significant problems that needs to be solved to improve the cycle performance of LABs. Here, we focused on the effects of functional groups in the cathode carbon on the characteristics of the Li2O2 deposited during discharging and the cathode performance of LABs. In this study, 4 types of carbon gels (CGs) were prepared using different treatment methods to modify their surface properties. The types and amounts of oxygen-containing functional groups (OCFGs) existing within the CGs were clarified along with the number of edge H’s by a high-sensitivity temperature-programmed desorption (TPD) technique. The results of N2 adsorption analysis of discharged CGs suggested that, by increasing the number of OCFGs from 0.40 to 1.80 mmol g–1 through acid treatment, the ratio of Li2O2 deposited within the mesopores of the porous carbon particles can be increased from 1% to 60%. This significant change in the manner of Li2O2 deposition led to the reduction of the charging overpotential. Side reactions that are thought to deteriorate cycle performance tended to proceed in CGs having a large number of OCFGs. This negative effect could be reduced by removing carboxyl groups in the CGs through simple heat treatment at 300 °C in an inert atmosphere. Our study clarified the critical roles of OCFGs in the cathode during the discharging and charging of LABs. The obtained knowledge can be utilized for the development of a high-performance cathode for LABs.

Laboratory Testing of Nanosilica-Reinforced Silicate and Polyacrylamide Gels

Summary One of the most common methods used to reduce excessive water production is water shutoff operations. These types of operations include injection of gel for flow profile modification. The most widely used gels are polyacrylamide- and silicate-based gels. As a way to improve and optimize gel characteristics, nanosilica can be added to the gelant solution. In this paper, laboratory testing of nanosilica-reinforced silicate and polyacrylamide gels is presented. Bulk gelation and capillary tubing tests were used for determination of gelation time, and core flooding tests on low permeability carbonate core samples were conducted as a way to assess gel-plugging ability. Tests showed that gelation time for both types of gels was faster when nanosilica was added. The strength of the polyacrylamide-based gel was enhanced. Silicate gel samples with nanosilica led to a 17% higher reduction in permeability compared to pure silicate gel, and polyacrylamide gel with the addition of nanosilica has almost 43% higher permeability reduction compared to pure polyacrylamide gel.

A new type of highly efficient fir sawdust-based super adsorbent: Remove cationic dyes from wastewater

It is still a challenge to prepare dye adsorbents with a favorable separation capacity, a remarkable adsorption capacity, a high removal rate and certain reusability. In this study, a new type of gel (i.e., AA-DWF-PAM) was prepared with treated fir sawdust and verified to be an effective adsorbent for removing cationic dyes in water. The adsorption properties of AA-DWF-PAM were systematically explored by taking methylene blue (MB) and methyl violet (MV) as representative cationic dyes and methyl orange (MO) and carmine (CM) as representative anionic dyes. Through experiments, it is concluded that the most ideal adsorption effect will be achieved under the following parameters: the particle size of AA-DWF-PAM: 60–100 meshes, content: 5 g/L, pH of the solution: 4, temperature: 35 ℃. Furthermore, the adsorption process shows good correlations with the Langmuir isotherm and the pseudo-second-order kinetic model. The maximum adsorption capacities of AA-DWF-PAM for MB and MV are 499.27 mg/g and 481.71 mg/g, respectively, and it is easy to desorb in 0.05 mol/L HCl solution. In addition, through the molecular dynamics simulation technology, it is verified that the adsorption mechanisms behind the adsorption of AA-DWF-PAM include both physical and chemical adsorption represented by electrostatic interaction, hydrogen bonds and van der Waals force. Due to its sustainability, low cost and excellent adsorption performance, AA-DWF-PAM is expected to serve as an adsorbent applied to water treatment.

Supramolecular polymer network gels constructed by a pillararene-containing polymer and their applications in adhesion between semihard materials

Two types of supramolecular gels based on one kind of pillararene-containing polymer with multiple-stimuli-responsiveness were fabricated and showed strong adhesive strength in the semihard state.

A Review on Bigel- A Newer Base for Topical Drug Delivery System

Bigel are two-phase semisolid formulations that contain oleogel and hydrogel that can deliver both hydrophilic and hydrophobic drugs. The formulation has a number of advantages over conventional semisolid dosage forms, including good spread ability, water washability, better permeability, improved stratum corneum hydration, dose adjustment, patient compliance, and controlled drug delivery. Because both phases are combined, these systems can overcome the drawbacks of both types of gels and have a wide range of applications in the pharmaceutical, cosmetics, and food industries. The main objective of this review article is to provide information on bigels, including types, methods of preparation, and characterizations. A special emphasis is focused on the use of bigels as a drug delivery vehicle for topical administration.

Effects of L-lysine and L-arginine on the structure and gel properties of konjac glucomannan

To explore greener modifier of konjac glucomannan, a new type of thermal irreversible gel using konjac glucomannan (KGM) and basic amino acids (l-lysine, and l-arginine) was prepared in the present study. The effects of different concentrations (1%, 2%, 3%, 4%, and 5%) of these two basic amino acids on the structure and properties of KGM hydrogels were mainly studied. The results showed that there was a better texture characteristic of composite gel as the concentration of amino acids was above 4%. Besides, with the increase in amino acid concentrations, the pore size of composite gel was denser and the syneresis of composite gel was more obvious, respectively. The rheological results indicated that the storage modulus (G′) was influenced by the concentration of amino acids and temperature. It was found that the two basic amino acids removed the acetyl group of KGM molecule and changed the original crystalline domain of KGM as evidenced by FT-IR and X-ray diffraction (XRD) analysis. Furthermore, compared to l-lysine, l-arginine could exert a greater effect on the KGM gel. In conclusion, the two basic amino acids (l-lysine, and l-arginine) could remarkedly improve the structure and properties of natural KGM and could be used as modifiers of the KGM hydrosol.

Visualization of supramolecular assembly by aggregation‐induced emission

AbstractSupramolecular architectures are constructed by the self‐assembly of small building blocks via the use of metal‐ligand coordination, π–π stacking interactions, hydrogen bonding, host‐guest interactions, and other noncovalent driving forces, which confer unique dynamic reversibility and stimulus responsiveness to the supramolecular materials and also lead to the demand of expensive and complex equipment for the characterization of supramolecular assembly processes. Fortunately, the self‐assembly processes bring the monomeric chromophores together, offering possibilities to establish ties between the supramolecular assembly and aggregation‐induced emission (AIE) techniques. Compared to conventional luminescent molecules, AIE luminogens (AIEgens) exhibit significant fluorescence enhancement upon the restriction of molecular motions, thus displaying the advantages of signal amplification and low background noises. Given the above, the real‐time, sensitive, and in situ visualization of the formation of self‐assemblies and their stimuli responsiveness based on AIE becomes accessible. Here, we review recent works that encompass the visualization of supramolecular assembly‐related behaviors by means of AIE characteristics of chromophores. The organization of this review will be by different types of supramolecular architectures, including metallacycles/cages, micelles/vesicles, supramolecular polymers, and supramolecular gels. An overview of future opportunities and challenges for the real‐time monitoring of supramolecular assembly by AIE is also provided.

Characteristics of pork emulsion gel manufactured with hot-boned pork and winter mushroom powder without phosphate

This study investigated the physicochemical characteristics of pork emulsion gels manufactured from hot-boned (HB) pork and winter mushroom powder in the absence of phosphate. It was found that compared to cold-boned (CB) pork, HB pork had a higher pH and exhibited a higher myofibrillar protein solubility with a lower actomyosin content (P < 0.05). Four types of pork gels were prepared, namely CB pork without phosphate, CB pork with phosphate (CBP), HB pork without phosphate, and HB pork with winter mushroom powder but without phosphate (HBW). The total exuded fluid was comparable for the CBP and HBW gels on all storage days. In addition, the HB and HBW gels had similar springiness and cohesiveness properties to the CBP gel (P > 0.05). These results indicate that the quality of pork gels manufactured in the absence of phosphate can be improved by the use of HB pork and with the incorporation of winter mushroom powder.

Insights on Some Polysaccharide Gel Type Materials and Their Structural Peculiarities.

Global resources have to be used in responsible ways to ensure the world's future need for advanced materials. Ecologically friendly functional materials based on biopolymers can be successfully obtained from renewable resources, and the most prominent example is cellulose, the well-known most abundant polysaccharide which is usually isolated from highly available biomass (wood and wooden waste, annual plants, cotton, etc.). Many other polysaccharides originating from various natural resources (plants, insects, algae, bacteria) proved to be valuable and versatile starting biopolymers for a wide array of materials with tunable properties, able to respond to different societal demands. Polysaccharides properties vary depending on various factors (origin, harvesting, storage and transportation, strategy of further modification), but they can be processed into materials with high added value, as in the case of gels. Modern approaches have been employed to prepare (e.g., the use of ionic liquids as "green solvents") and characterize (NMR and FTIR spectroscopy, X ray diffraction spectrometry, DSC, electronic and atomic force microscopy, optical rotation, circular dichroism, rheological investigations, computer modelling and optimization) polysaccharide gels. In the present paper, some of the most widely used polysaccharide gels will be briefly reviewed with emphasis on their structural peculiarities under various conditions.

Construction of 3D printable Pickering emulsion gels using complexes of fiber polysaccharide-protein extracted from Haematococcus pluvialis residues and gelatin for fat replacer

Structural fat replacers that can meet the requirements of various forms of reduced-fat foods are essential for the application of fat replacement, and emulsion gels emerge as a potential alternative for fat replacers. In this study, fiber polysaccharide-protein extracted from Haematococcus pluvialis residues (FPHRs) formed FPHRs-Gelatin complexes with gelatin. Fourier transformed infrared spectroscopy confirmed the formation of hydrogen bonds between FPHRs and gelatin, the secondary structure order of the protein was enhanced. Three-phase contact angle determination showed that the contact angle of FPHRs-Gelatin complexes was 104°–114°. By exploring the effect of FPHRs concentration, gelatin concentration, and oil-water ratio on the emulsion gels, the Pickering emulsion gels were formed when the FPHRs and gelatin concentration were 2 wt% and 3 wt%, respectively. What's more, these emulsion gels had shear thinning phenomenon, low frequency dependence as well as excellent thixotropy when the oil-water ratio was 0.6, which indicated that they had strong structural support and great recovery capacity to be used as 3D printed materials. The 3D objects printed by the FPHRs-Gelatin complexes emulsion gels had superior print resolution and shape fidelity. This study provides a new type of emulsion gel with structure that can be used as an ideal fat replacer in food processing, the construction of a new 3D emulsion gel material is of great significance for broadening the applications of gelatin-based gels and microalgal food.

Alkali -silica reaction and its dynamic relationship with cement pore solution in highly reactive systems

Despite extensive research, the relationship between the progression of alkali-silica reaction (ASR) and the cement hydration mechanism, particularly the influence of the pore solution composition on the nature of reaction products is not thoroughly understood. A multi-analytical approach was applied to study ASR mechanism under accelerated conditions using a mortar system comprising of fused silica aggregates. For the first time, large field SEM mapping was used to correlate physical expansion with the composition, distribution and amount of ASR reaction products produced over time. A three-stage behavioral model was proposed to explain the dynamic relationship between ASR progression and pore solution composition. The results confirmed the co-existence of two phases within the ASR products: a CSH- type gel and an ASR-type gel. The relative abundance of one gel type over the other was dictated by their accessibility to the pore solution, which in turn influences how ASR propagates through the microstructure.

New Zwitterionic Polymer as a Highly Effective Salt- and Calcium-Resistant Fluid Loss Reducer in Water-Based Drilling Fluids.

To control the filtration loss of drilling fluids in salt-gypsum formations, a novel type of zwitterionic polymer gel (DNDAP) was synthesized by free radical polymerization, which was used as a salt- and calcium-resistant fluid loss reducer for water-based drilling fluids (WBDF). DNDAP was prepared with N, N-dimethylacrylamide (DMAA), N-vinylpyrrolidone (NVP), Diallyl dimethyl ammonium chloride (DMDAAC), 2-acrylamide-2-methylpropaneonic acid (AMPS), and isopentenol polyether (TPEG) as raw materials. Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance (1H-NMR) were used to characterize the composition and structure of the DNDAP copolymer. The thermal stability of DNDAP was evaluated by the use of thermogravimetric analysis (TGA). WBDF with DNDAP was analyzed for zeta potential and particle size and the corresponding filter cake underwent energy dispersive spectrum (EDS) analysis and scanning electron microscope (SEM) analysis. The results showed that the thermal decomposition of DNDAP mainly occurred above 303 °C. DNDAP exhibits excellent rheological and filtration properties in water-based drilling fluids, even under high-temperature aging (up to 200 °C) and high salinity (20 wt% NaCl or 5 wt% CaCl2) environments. The strong adsorption effect of DNDAP makes the particle size of bentonite reasonably distributed to form a dense mud cake that reduces filtration losses.

Deterioration of Omeprazole Suspension Due to Inappropriate Storage Practice

Dental complications are the main health problems worldwide and can cause harmful and irreversible loss to general human health. Therefore, there is a need to treat these problems. Most of the techniques for the prevention of these oral diseases are costly and lengthy; therefore, there is a need to introduce some effective, low-cost, and easy methods or medicine to deal with oral health issues. The combined mixture of extracts from T. chebula and A. nilotica proven to treat sore throat and ulcers of the mouth. Eucalyptol is one of the main compounds in the essential oil used for the preparation of an endodontic solvent and mouthwash. The important components present in the rhizome of the turmeric plant which can be used for the treatment of oral complications are essential oils (turmerones) and curcuminoids. Plant-based extracts can be used to prepare several types of mouthwash, toothpaste, and gel due to the presence of anti-microbial activities and a large number of beneficial compounds. This review paper aims to find the role of medicinal plants and their properties for the effective treatment of oral diseases in dentistry.