Gel System Research Articles

Insighting the effect of lard-based diacylglycerol on the thermal gelation and rheological properties of myofibrillar protein influenced by soy protein isolate

The objective of this study was to investigate the role of the replacing animal fat in the meat gel system with lard-based diacylglycerol (DG), which has health benefits and similar characteristics (such as taste, smell, and usability) to lard triacylglycerol (TG, the major component of pork fat). The impact of lard-based DG on the thermal gelation and rheological properties of myofibrillar protein (MP) as influenced by the incorporation of soy protein isolate (SPI, 0–0.75% protein) was investigated, and the interaction mechanism was also explored. The gel structure became more continuous and compact with the incorporation of DG or purified DG (PDG) and the decrease of SPI content, as reflected by the change of secondary structures, which was beneficial to restrict the mobility of immobilized water. With the incorporation of DG or PDG and the decrease in the amount of SPI, the gel strength, G′, and G″ were increased. Molecular docking results further revealed that the DG interacted with SPI mainly through van der Waals forces and hydrogen bonds, and interacted with MP mainly through van der Waals forces, hydrogen bonds, and hydrophobic interactions. More importantly, the negative binding energies of the DG-protein complexes were lower than those of the TG-protein complexes, indicating that the interaction was spontaneous and that DG is more likely to interact with proteins than TG. In conclusion, this study provides a vital theoretical basis at the molecular level for the development of desired quality meat products containing DG with health benefits.

The Use of an Advanced Intelligent-Responsive Polymer for the Study of Dynamic Water-Carbon Dioxide Alternating Displacement.

Addressing the issue of inadequate temperature tolerance in traditional polymers, in this study, we successfully executed a one-step synthesis of intelligent-responsive polymers which have excellent adaptability in water-gas alternating displacement scenarios. Utilizing the fatty acid method, we produced OANND from oleic acid (OA) and N,N-dimethyl-1,3-propanediamine (NND). Upon testing the average particle size in the aqueous solution both prior and subsequent to CO2 passage, it became evident that OANND assumes the form of a small-molecule particle in the aqueous phase, minimizing damage during formation. Notably, upon CO2 exposure, it promptly organizes into stable micelles with an average size of 88 nm and a relatively uniform particle distribution. This unique characteristic endows it with a rapid CO2 response mechanism and the ability to form a highly resilient gel. In the exploration of viscoelastic fluids, we observed the remarkable behavior of the AONND aqueous solution when CO2/N2 was introduced. This system displayed repeatable transitions between aqueous and gel states, with the highest viscosity peaking at approximately 3895 mPa·s, highlighting its viscosity reversibility and reusability properties. The rheological property results that we obtained indicate that an elongated micellar structure is present in the solution system, with the optimal concentration ratio for its formation determined as 0.8, which is the molar ratio of the OANND-NaOA system. In the sealing performance tests, a 1.0 wt% concentration of the gel system exhibited excellent injectability properties. At 80 °C, this gel effectively reduced the permeability of a sand-filled model to 94.5% of its initial value, effectively sealing potential leakage paths or gas fluxes. This remarkable ability to block leakage paths and reduce seepage capacity highlights the material's superior blocking effect and erosion resistance properties. Furthermore, even at a temperature of 90 °C and an injection pore volume (PV) of 3, this plugging system could reduce the permeability of a high-permeability sand-filled model to over 90% of its initial value.

Lignocellulosic hydrogel for profile control and water plugging in high salt reservoirs

Profile control is an effective method for enhancing oil recovery. In-situ crosslinked gels offer advantages such as easy pumping and controllable gel formation time when used as agents for profile control. However, conventional in-situ crosslinked gels suffer from the drawback of shrinkage under high salinity, and the crosslinking agent is typically organometrics, leading to permanent damage to the reservoir. Therefore, it is very important to develop a plugging agent that is resistant to high salinity and causes minimal damage. In this study, sodium lignosulfonate, known for its excellent thermal stability and biocompatibility, was crosslinked with carboxymethyl cellulose and β-cyclodextrin to create a hydrogel gf. The structures of the hydrogel were characterized using FTIR, XRD, viscosimeter and SEM. The temperature resistance, salt resistance, shear resistance, long-term stability and plugging ability of the gel gf-5 were evaluated. The results showed that, compared with the traditional underground crosslinked gel pg-1, gf-5 showed better application performance. Even at a high salinity level of 200,000 mg/L in the aqueous solution, the viscosity of gf-5 was 96830 mPa·s. Additionally, the Ca2+ present in the mineralized water formed calcium hydroxide particles with hydroxide, acting as rigid support points. This phenomenon enhanced the strength and toughness of the gel. Furthermore, the gel system maintained a stable structure at 60–90 ℃ for 120 days. In sand-packed tubes with varying permeability, the sealing rate exceeded 96 %, and the breakthrough pressure reached 8.593 MPa. SEM images demonstrated that the gel effectively enveloped the sand and adhere to the porous medium.

Effect of MoS2 on Simple and Novel PEG/κ-Carrageenan Hydrogels for TNBC Cancer Drug Delivery

Molybdenum disulfide (MoS2), a two-dimensional inorganic molecule, has lately been studied in medical research with regard to carrying pharmaceuticals due to its distinctive characteristics. A biodegradable polymer system applicable in cancer drug delivery can be created with the addition of MoS2. In our research described in this paper, we investigated the influence of the amount of MoS2 on the characteristics and performance of our novel gel blend. It was aimed to prepare a new gel blend, which we thought would have the potential to be used as a stimulus-sensitive, polymeric hydrogel as a carrier in the triple negative breast cancer (TNBC) drug delivery system, with the MoS2 added to the polyethylene glycol (PEG)/κ-carrageenan combination. This 2D material (MoS2) impacted the hydrogel by improving the transmittance, swelling, and elasticity performance compared to the normal no MoS2 structure of the polymeric gel. The polymer blend characteristics were mainly tested using UV-VIS spectrophotometry and gravimetric analysis. The varied properties of these gel mixtures were investigated using five different mass ratios of MoS2. The 5 mg MoS2/(PEG)/κ-carrageenan gel was the best sample investigated in terms of the elasticity. The results of the study demonstrated that our gel system can be utilized for precisely targeted and regulated delivery of cancer drugs. To create preliminary data for this near future goal, the release mechanism of the Doxorubicin drug loaded into the produced gel were examined.

Dietary fibre from seeds of Australia native Plantago species as modulators of quality and glycaemic response in starch gels

Dietary fibre (DF) is a non-digestible nutrient which has important roles in the digestive system including mantaining regularity, and reducing the risk of certain cancers and non-communicable diseases, such as metabolic syndrome. Even though the positive health effects of DF have long been established, it has been shown that DF intake for children and adults in Australia is below the recommended range – less than 20% of adults met the suggested intake for reducing risk of chronic diseases(1). Plantago ovata, also known as psyllium, is widely used as DF supplement with evidence showing positive effects on weight control, hyperglycaemic response, cholesterol levels, and irritable bowel syndrome(2). P. ovata seed husk produces a highly viscous gel called mucilage when seeds are exposed to moisture. This mucilage is nearly pure DF and has an intricately layered structure which can be further fractionated and studied as a proxy for different gelling systems. Interestingly, Australia is home to many mucilage-producing Plantago species, most of which are underexplored and underutilised, but show remarkable gelling properties and hypoglycaemic potential(3). In this work, we compare structural and functional properties of fractionated DF from P. ovata, and two promising Australian native relatives, P. turrifera and P. drummondii, and their effect on enzymatic hydrolysis in potato starch gels. Using a 3-step fractionation method, we have separated distinct fractions and explored their individual properties(4). P. turrifera and P. drummondii have higher water absorbing capacity, DF yield, and viscosity compared to P. ovata. Monosaccharide composition of all three species is similar – they are highly substituted heteroxylans with minor pectic component. Notably, arabinose to xylose ratio in all species increases with further extraction steps, which is different from cereal arabinoxylans. In an attempt to explore impact of DF in starch-rich systems, we have fabricated DF-potato starch gels and measured enzymatic hydrolysis (with porcine pancreatic α-amylase), freeze-thaw stability, and colour change. Addition of DF reduced syneresis (water separation) during 15 day freeze-thaw cycle measurement, which can lead to prolonged storage stability and has positive implications for shelf life. Colour change was most noticeable when P. drumondii DF were added, while colour of P. ovata and P. turiferra DF gels was similar to control potato starch gel. Effects on α-amylase starch hydrolysis were significant as well, and depended on species and fractions. Certain DFs had impacts on constant k (speed of hydrolysis), while effects on the extent of hydrolysis are still being explored. In conclusion, utility of Australia native P. turrifera and P. drumondii DFs are evident when applied to starch gels, and should be further explored in food products such as bread to increase DF intake and possibly lower glycaemic index.

Intelligent responsive self-assembled micro-nanocapsules: Used to delay gel gelation time

In the application of polymer gels to profile control and water shutoff, the gelation time will directly determine whether the gel can “go further” in the formation, but the most of the methods for delaying gel gelation time are complicated or have low responsiveness. There is an urgent need for an effective method for delaying gel gelation time with intelligent response. Inspired by the slow-release effect of drug capsules, this paper uses the self-assembly effect of gas-phase hydrophobic SiO2 in aqueous solution as a capsule to prepare an intelligent responsive self-assembled micro-nanocapsules. The capsule slowly releases the cross-linking agent under the stimulation of external conditions such as temperature and pH value, thus delaying gel gelation time. When the pH value is 2 and the concentration of gas-phase hydrophobic SiO2 particles is 10%, the gelation time of the capsule gel system at 30, 60, 90, and 120 °C is 12.5, 13.2, 15.2, and 21.1 times longer than that of the gel system without containing capsule, respectively. Compared with other methods, the yield stress of the gel without containing capsules was 78 Pa, and the yield stress after the addition of capsules was 322 Pa. The intelligent responsive self-assembled micro-nanocapsules prepared by gas-phase hydrophobic silica nanoparticles can not only delay the gel gelation time, but also increase the gel strength. The slow release of cross-linking agent from capsule provides an effective method for prolongating the gelation time of polymer gels.

Application of Thermoresponsive Smart Polymers based in situ Gel as a Novel Carrier for Tumor Targeting.

The temperature-triggered in situ gelling system has been revolutionized by introducing an intelligent polymeric system. Temperature-triggered polymer solutions are initially in a sol state and then undergo a phase transition to form a gel at body temperature due to various parameters like pH, temperature, and so on. These smart polymers offer a number of advantages, including ease of administration, long duration of release of the drug, low administration frequency with good patient compliance, and targeted drug delivery with fewer adverse effects. Polymers such as poly(N-isopropylacrylamide) (PNIPAAm), polyethylene glycol (PEG), poly (N, N'-diethyl acrylamide), and polyoxypropylene (PPO) have been briefly discussed. In addition to various novel Drug Delivery Systems (DDS), the smart temperature-triggered polymeric system has various applications in cancer therapy and many other disease conditions. This review focuses on the principals involved in situ gelling systems using various temperature-triggered polymers for chemotherapeutic purposes, using smart DDS, and their advanced application in cancer therapy, as well as available marketed formulations and recent advances in these thermoresponsive sol-gel transforming systems.

Unleashing the electrochemical performance of zirconia nanoparticles on valve-regulated lead acid battery

The electrochemical act of valve-regulated lead acid batteries can be enhanced by conductive materials like metal oxides. This work aims to examine the preparation and influence of zirconia on poly(vinyl alcohol) based gel valve-regulated lead acid battery. Characterizations like Fourier transform infrared spectroscopy, ionic conductivity, water retention study, cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge-discharge techniques were done. The optimized gel system exhibited a discharge capacity of 198.45 μAh cm−2 at the current density of 0.6 mA cm−2. The battery cell with an optimized gel matrix displayed a maximum discharge capacity of 22.5 μAh at a current of 20 μA. After 500 continuous cycles, the battery attained a discharge capacity retention of 91 %. The presence of zirconia will increase the electrochemical performance of gel valve-regulated lead acid batteries.

Exploring the Transformative Potential of In Situ Gels: An Overview of Thermosensitive and pH‐Sensitive Gel Systems for Biomedical Applications

AbstractIn situ gel systems have emerged as promising drug delivery platforms due to their numerous benefits, including increased patient compliance and decreased administration frequency. The potential of in situ gel extends beyond its formulation benefits, with the ability to transform medical treatment by enhancing drug delivery, offering personalized therapies, and introducing innovative approaches. Ongoing research and the efforts of pharmaceutical companies are dedicated to exploring the vast opportunities presented by in situ gel, pushing the limits of innovation in the field of drug delivery. The selection of suitable polymers is critical for the development of in situ gel formulations. Additionally, consideration of drug‐polymer compatibility ensures the stability and efficacy of the drug within the gel matrix. Formulation considerations play a pivotal role in the development of effective in situ gel systems. They have shown great potential in drug delivery systems, tissue engineering, and regenerative medicine. The ability to prolong gastric retention time, targeted delivery, and localized drug release are among the advantages offered by in situ gels. Although in situ gel technology has shown significant advancements, challenges remain, including stability and shelf‐life issues, biocompatibility and safety concerns, and the need for further research and development. Future directions focus on overcoming these challenges and exploring new applications and advancements in the field. In conclusion, in situ gel systems provide a versatile and promising drug delivery and tissue engineering platform. However, further research and development are essential to address the challenges and fully harness the potential of this innovative technology.

Effect of quinoa protein concentration and oil volume fraction on the physicochemical and mechanical properties of alginate‐based emulsion gels

AbstractBackgroundThis work studies emulsion gel (EG) formulation with quinoa proteins (QP), high‐oleic sunflower oil and alginate, and the effect of QP concentration (0.5–1–2%) and the oil volume fraction (10–30–50%) on the physicochemical and mechanical properties of EG systems. EGs were tested for their microstructural and textural attributes, color, and water holding capacity as well as for their thermal, physical, and oxidative stability.ResultsThe microstructure of EG showed that with increasing QP concentrations, the gel structure tended to be much denser, with oil droplets entrapped within the network. A significant decrease in droplet diameter with increasing QP concentration (p = 0.015) and oil volume fraction (p < 0.000) was observed. Hardness mean value was 2.8 N ± 0.5, reaching the highest value with 1 and 2% QP and 30% oil (p < 0.000). Cohesiveness shows a similar trend to that observed for hardness, while springiness showed the opposite behavior. As for adhesiveness, there were no significant differences between samples. EG have high lightness with slight yellow and green contributions. The mean water holding capacity was 88 ± 4%, and after heat treatment all samples exhibited a good fluid retention, significantly lower for the lower oil volume fraction (p = 0.001). EG, also proved to be highly stable against creaming and oxidative damage.ConclusionResults suggest that EG could be useful to create a new generation of healthier and innovative products that could substitute animal fat and deliver nutrients and biological compounds, thus improving food quality.

Formulation determination and performance study of high-volume fly ash-based grouting fire extinguishing materials

Considering the continued advancement of China's industrial sector, a substantial quantity of circulating fluidized bed fly ash (CFBFA) and calcium carbide slag (CS) is generated throughout the production process. Considering the rich calcium content inherent in CFBFA (circulating fluidized bed fly ash) and the inherently alkaline nature of CS(carbide slag), the amalgamation of these two constituents leads to a multitude of hydration reactions, culminating in the synthesis of polymeric grouting materials. This study undertaked a comprehensive examination and regulation of three factors within the binary system: water-cement ratio, CS content, and CS particle size. Through the utilization of scanning electron microscopy (SEM), X-ray diffraction (XRD), and (TG) thermogravimetric analysis, the investigation aims to elucidate the influence mechanism of the composite gelling system comprising fly ash and calcium carbide slag on the compressive strength, setting time, and other pertinent indicators of grouting materials. The data reveals that when the water-cement ratio is set at 0.85, CS content at 30%, and CS ball milling time at 1 h, the resulting grouting material exhibits a fluidity of 279 mm, a water separation ratio of 3.13%, and achieves a strength of 15.6 MPa at 28 days. It boasts a stable and easily transportable slurry, which possesses a certain degree of cementitious performance, effectively sealing off any air leakage channels. Moreover, by subjecting CS to appropriate pre-treatment measures, a suitable quantity of active silicon and aluminum elements can be thoroughly dissolved within the CFBFA (circulating fluidized bed fly ash) slurry system, giving rise to a staggered distribution and dense hydration product structure. Considering the requirements for gangue mountain fire extinguishing slurry, a CFBFA-CS based grouting material formula has been carefully selected. Additionally, simulation grouting fire extinguishing experiments have demonstrated that the injection of the slurry is highly effective in reducing the temperature of the combustion test block, isolating oxygen, and lowering the temperature within the combustion zone. After 5 h, the temperature drops to below 100 °C, and no re-ignition phenomena are observed. The outcomes of this research can provide valuable scientific guidance for the development of high-performance fire extinguishing grouting materials utilizing fly ash and carbide slag.

Enhancement of emulsion pH stability by Ca2+ modulation: A novel approach for preparing egg white protein fibril cold emulsion gels

Egg white, a crucial ingredient in bulk food production with limited emulsifying properties, can be significantly improved by fibrillation modification. However, resulting emulsions may exhibit instability at critical food processing pH values. In this study, the egg white protein fibril (EWPF) emulsion gel was constructed by Ca2+, and the stability enhancement mechanism under different EWPF and Ca2+ concentrations was investigated. The results showed that higher EWPF concentrations led to improved stabilization of the oil-water interface. At 60 mg/mL EWPF concentration, water loss decreased by 13.86% and oil loss by 35.79%, while the firmness and viscosity of the emulsion gel system were enhanced. The ζ-potential was reduced by 67.98% and the ionic bond content was increased by 22 times with the addition of Ca2+, the droplets showed a uniform cross-linked structure, and the stability and plasticity of the system were improved. By adjusting EWPF concentration to 40 mg/mL and Ca2+ concentration to 30 mM, pH stability of the system was also enhanced. This study provided a reference for the high-value utilization of egg white and a possibility for the application of EWPF in food processing, such as low-fat foods.

Sodium Alginate–Soy Protein Isolate–Chitosan–Capsaicin–Nanosilver Multifunctional Antibacterial Composite Gel

We constructed a sodium alginate/soy protein isolate/chitosan gel system and incorporated silver nanoparticles reduced by capsaicin into the system, forming a sodium alginate–soy protein isolate–chitosan–capsaicin–silver nanoparticle composite gel (SA/SPI/CTS/CAP/Ag). In tests, the SA/SPI/CTS/CAP/Ag gel exhibited excellent antimicrobial properties. Using the agar diffusion method, the inhibition zone diameter for Staphylococcus aureus was determined to be 29.5 mm. Soy protein isolate (SPI), containing a large number of hydrophobic amino acid residues, effectively enhanced the moisture retention capability of the gel and improved its stability to a certain extent at an appropriate addition concentration. In a milk preservation experiment, the SA/SPI/CTS/CAP/Ag gel significantly extended the shelf-life of the milk. In dye adsorption experiments, the adsorption curve of the SA/SPI/CTS/CAP/Ag gel well fitted a pseudo-second-order kinetic model. It showed a degree of adsorption capacity for methylene blue, malachite green, methyl orange, and Congo red, with the most significant adsorption effect for malachite green being 42.48 mg/g. Considering its outstanding antimicrobial performance, preservation ability, and adsorption capacity, the SA/SPI/CTS/CAP/Ag gel holds significant potential in wastewater treatment and as an antimicrobial gel in the exploration of food preservation.

A Review of Recent Developments in Nanomaterial Agents for Water Shutoff in Hydrocarbon Wells.

Reducing water production from hydrocarbon wells is one of the major requirements to prolong the life span of production wells. Gel treatment is commonly regarded as one of the traditional cost-effective methods for water shut-off applications. Different gel systems have been developed to overcome the challenges of performing a successful water shut-off treatment. Each gel system has its advantages and disadvantages. A new proposed technology is to enhance the gel performance by utilizing nanomaterials in its composition. Nanomaterials such as nanosilica, nanoclay, and graphene can significantly modify gel properties to improve plugging efficiency. This paper provides a brief review of the added value of using nanomaterials in the structure of polymer in situ gel, preformed particle-gel, and nanosilica-based fluid. Nanomaterials such as nanoclay, nanosilica, and nanographene are capable of adjusting the properties of in situ gel, such as control of gelation time (9-10) hours and enhancing gel strength up to 4.5 times. Nanomaterials also improved the swelling ratio of the preformed particle-gel by up to 400%, accompanied by increased gel strength. Notably, nanosilica-based gels exhibit an exceptional plugging efficiency (100%). Additionally, the paper discusses how modeling can be used to overcome operational challenges in terms of placement and plugging performance.

Use of Self-Generating Foam Gel Composition with Subsequent Injection of Hydrogel to Limit Gas Inflow in Horizontal Wells of Vostochno-Messoyakhskoye Field.

Gas inflow control in oil wells is one of the most challenging types of repair and sealing operations, the success rate of which does not exceed, as a rule, 30%. Conventional shutoff methods are often ineffective for this purpose. For instance, cement solutions cannot be injected into wells in the required volumes, while gel screens can only temporarily block the breakthrough zones, as gas easily seeps through the gel, forming new channels for gas inflow. Technology for the two-stage injection of gas-insulating gel systems for gas control in horizontal wells was developed. At the first stage, a self-generating foam gel composition (FGC), consisting of gel-forming and gas-forming compositions, was used. A foam gel structure with enhanced rheological and flow characteristics was formed over a controlled time as a result of the interaction between the gel-forming and gas-forming compounds. A PAM-based hydrogel crosslinked with an organic crosslinker was added to the FGC at the second stage of treatment. The laboratory experiments substantiated the technology of well gas and water shutoff by the sequential injection of self-generating foam gel composition and hydrogel. Field tests confirmed the correctness of the chosen concept. It is very important to clearly identify the sources of gas inflow for the success of this well intervention and take into account the well design, as well as the reservoir geological structure and characteristics. The gas shutoff operation can be properly designed for each well only by comparing all these factors. The validity of the selected technology was tested through a series of laboratory experiments. Successful laboratory tests allowed for the application of the studied technology in a field setting, where the gas shutoff agent was injected into three horizontal wells. As a result of the field application, the gas inflow was successfully isolated in two wells. However, the application of the technology failed in the third well which gave an opportunity to revisit the technology's design and to review the sources of gas inflow. Overall, the achieved success rate of 66% demonstrated the high efficiency of the studied technology and supported its wider application in the field.

Potential functional oleogels based on phytosterol and diacylglycerol corn oil: Development and physicochemical characterization

This study aims to create oleogels by combining beeswax (BW) and plant sterols with diacylglycerol corn oil (DGCO). The findings demonstrate that gel formation occurred with 6:4 (w/w) blends of BW with sitosterol (Sit) and β-sitosterol (PS) oils at a 20% (w/w) concentration, while BW-plant sterol ester (PE) gelled at a 15% (w/w). Texture analysis reveals that the maximum hardness of the BW-PE oleogel (582.62 N) was approximately five times higher than other oleogels and DGCO-based oleogel displayed greater hardness (52.39 N∼140.89 N) and lower viscosity (−57.06 N∼−25.94 N). The melting point of the DGCO-based oleogel increased from 48.35 °C to 57.64 °C as the BW content increased and microstructure from polarized light microscope displayed that he BW-PE oleogel presented itself as bundle-shaped crystals and with an augmentation in concentration, the dimensions of these crystals diminished while their abundance escalated. Notably, the BW-PE oleogel based on DGCO exhibited the most condensed structure. X-ray diffraction analysis revealed oleogel based on DGCO corresponding to characteristic peaks of β′and β-type crystals while the infrared spectroscopy demonstrated no new peaks formation whether for hydrogen bonds or covalent interactions in DGCO-based oleogel. These stable physical DGCO-based gel system provide a choice for the preparation of functional oleogels with lipid-lowering ingredients.

Multifunctional Polyoxometalates-Based Ionohydrogels toward Flexible Electronics.

Multifunctional flexible electronics present tremendous opportunities in the rapidly evolving digital age. One potential avenue to realize this goal is the integration of polyoxometalates (POMs) and ionic liquid-based gels (ILGs), but the challenge of macrophase separation due to poor compatibility, especially caused by repulsion between like-charged units, poses a significant hurdle. Herein, the possibilities of producing diverse and homogenous POMs-containing ionohydrogels by nanoconfining POMs and ionic liquids (ILs) within an elastomer-like polyzwitterionic hydrogel using a simple one-step random copolymerization method, are expanded vastly. The incorporation of polyzwitterions provides a nanoconfined microenvironment and effectively modulates excessive electrostatic interactions in POMs/ILs/H2O blending system, facilitating a phase transition from macrophase separation to a submillimeter scale worm-like microphase-separation system. Moreover, combining POMs-reinforced ionohydrogels with a developed integrated self-powered sensing system utilizing strain sensors and Zn-ion hybrid supercapacitors has enabled efficient energy storage and detection of external strain changes with high precision. This work not only provides guidelines for manipulating morphology within phase-separation gelation systems, but also paves the way for developing versatile POMs-based ionohydrogels for state-of-the-art smart flexible electronics.

REMOVAL OF PRESSURE SENSITIVE TAPES FROM VINTAGE SILVER GELATIN PRINTS USING SELECTED GEL-BASED SYSTEMS: AN EXPERIMENTAL STUDY

Historical photographs play a significant role as records, documenting the various stages of the history of Egypt and reflecting our identity and social, cultural, and religious values. Silver gelatin prints were the dominant positive printing processes in the 20th century. One of the most common forms of damage found among photographic collections is tears, which may result from improper handling and misuse, inappropriate storage, disasters, and other factors. In the past, tears were mended using pressure-sensitive tapes by amateurs and conservators. Over time, these tapes caused damage to the photographic surfaces since they oxidised, forming stains that are difficult and sometimes impossible to remove. Recently, many gel-based systems have been developed for use in the conservation of different cultural and historical materials, particularly paper artifacts. The aim of this research is to evaluate the efficacy of Klucel G and agar, as gel systems that are favoured by conservation specialists, in removing pressure-sensitive tapes from the surfaces of silver gelatin prints, as well as to study their effect on the photographs themselves. Organic solvents were added to the gel systems, and invaluable old photographs were used for this study. After treatment, samples were subjected to artificial ageing at a temperature of 80°C and 65% RH. Evaluation of the selected treatments was carried out through visual inspection, microscopic examination, colorimetric measurements, and attenuated total reflectance Fourier transform infrared spectroscopy. Results showed that both gel-based systems with mixed organic solvents gave great results compared to the conventional methods in terms of tape removal. However, colour change was detected in the case of agar gel-treated samples. Agarose gel may be a more proper option.

Effect of protein-polysaccharide hybrid gelator system on the material properties and 3D extrusion printability of mashed potatoes.

Mashed potatoes (MP) are famous as ready-to-eat products due to their excellent taste and texture. Problems such as complex injection occur when MP is used as a 3D printing material. To improve the smoothness of MP loading into a 3D syringe barrel and its 3D extrusion printability, the effects of the protein-polysaccharide hybrid gelator developed with different gelatin-B (GB, 2%, 4%, 6%) and κ-carrageenan (KG, 1%) on the rheology and 3D extrusion printability of MP were studied. The rheological results showed that the MP developed a glass transition temperature by adding the hybrid gelator. Adding 1% KG+6% GB (w/w, dry base) to the hybrid gelator has good shear thinning and self-supporting properties and showed the best geometric accuracy. In the extrusion stage, the yield stress, the consistency index (K), and the flow behavior index (n) of MP were 470.69Pa, 313.48Pa·sn, and 0.159, respectively. In the recovery stage, the shear recovery time is 30 s. In the self-supporting stage, the storage modulus and loss modulus are significantly higher than those of other groups and have the strongest mechanical properties. Moreover, water distribution, Fourier transform infrared spectroscopy, X-ray diffraction analysis, and microstructure of printed MP with different hybrid gelators were observed. The addition of hybrid gelators reduced the content of free water in MP. Hybrid gelators did not produce new functional groups in the printed materials and did not change the structure of starch. These results provide new insights for applying protein and polysaccharide hybrid gelators in 3D printing.

Nontoxic Initiator Alternatives to TEMED for Redox Hydrogel Polymerization.

Polymeric hydrogels are versatile biomaterials, offering unique advantages in tunability and biocompatibility that make them well-suited to a range of applications. Cross-linking, a fundamental step in hydrogel fabrication, is often initiated using a toxic redox system, ammonium persulfate (APS), and tetramethylethylenediamine (TEMED), which hinders hydrogel utility in direct contact with cells (e.g., wound dressings). To overcome this limitation, we developed alternative redox gelation systems that serve as nontoxic replacements for TEMED. The alternate initiators were either synthetic or bioinspired amine-containing polymers, Glycofect and polyethylenimine (PEI). Used with APS, these initiator candidates produced hydrogels with short gelation time and comparable moduli to TEMED-based gels and underwent further mechanical testing and biocompatibility characterization. While achieving mechanical properties similar to those of the control, the gels based on Glycofect and PEI outperformed TEMED-based gels in two cell viability studies, with Glycofect-initiated gels displaying significantly higher cytocompatibility. Taken together, these results indicate that Glycofect may serve as a drop-in replacement for TEMED to fabricate hydrogels with improved biocompatibility.