Sol-gel Transition Temperature Research Articles

Development of a natural ingredient based on phenolic compounds from propolis extract and bentonite and its application in carrageenan hydrogels

Nowadays, there is an increasing consumer demand for more natural and environmentally friendly food additives. The current research aimed to produce and characterize a new additive based on bentonite and the phenolic compounds from green propolis extract, as well as to characterize the effect of this additive on the rheological properties of carrageenan hydrogels. The new additive (biohybrid) was obtained after the adsorption of phenolic compounds on the clay platelets. The adsorption mechanism was explained by Langmuir and Freundlich models, which suggested that adsorbed phenolic compounds form a monolayer and multilayers on the clay surface. Despite phenolic adsorption, the physico-chemical attributes of the bentonite remained unchanged. The incorporation of the biohybrid (BH) increased the sol-gel transition temperature of carrageenan hydrogels. This research reports for the first time the development and application of a new natural ingredient with potential food applications.

Sol-Gel Transition of a Thermo-Responsive Polymer at the Closest Solid Interface.

Thermo-responsive polymers are applied as surface modifications for the temperature switching of hydrophilic and hydrophobic properties through adsorption and grafting on solid substrates. The current understanding of the influence of polymer chains bound to the solid surface on the transition behavior of thermo-responsive polymers is rather restricted. In this study, we aim to elucidate the effect of the bound polymer chains at the interface on the thermo-responsive sol-gel transition behavior of aqueous methylcellulose (MC) solutions by employing a quartz crystal microbalance (QCM) to evaluate the shear modulus near the solid interface. When the sample thickness was thinner on the order of the millimeter scale, the sol-gel transition temperature evaluated by the cloud point decreased because the condensation of MC near the solid interface promoted the sol-gel transition. On the other hand, focusing on the closest solid interface on the nanometer scale by QCM, the sol-gel transition temperature increased when approaching the solid interface. Adsorption and interfacial interactions reduced the chain mobility and restrained the sol-gel transition by preventing MC chain aggregation. We demonstrated the physical properties evaluation at the closest interface between the thermo-responsive polymer and solid substrate by combining a simple analytical model of QCM and controlling the analytical depth of the QCM sensors. In conclusion, the mobility change of the bound polymer chains at the solid interface caused by adsorption and interfacial interactions must be considered when a thermo-responsive polymer is applied as in adsorbed or thin films on solid substrates for the functionalization of biomaterials.

Hemostatic Gelatin-Alginate Hydrogels Modified with Humic Acids and Impregnated with Aminocaproic Acid

The work is devoted to the development of safe and biocompatible multicomponent gelatin-alginate hydrogels modified with humic acids (HA) and impregnated with the antifibrinolytic agent aminocaproic acid (АА).These hydrogels are designed to be effective hemostatic materials with anti-inflammatory properties and the ability to deliver in less than 30 seconds to deep and hidden areas of hemorrhages. Studies of the crystal structure by X-ray diffraction analysis and non-covalent interactions of molecules by Fourier transform infrared spectroscopy of the developed hemostatic gelatin-alginate hydrogels modified with bactericidal and anti-inflammatory humic acids made it possible to identify the optimal concentrations of HA from 2.5 wt.%. up to 5 wt.%. At such concentrations of HA, gelatin-alginate hydrogels have a semicrystalline structure. Due to non-covalent bonds between polymer chains, they are thermo-responsive with a gel-sol transition temperature of about 37 °C. Impregnation of these hydrogels with aminocaproic acid led to an almost threefold increase in their swelling, which facilitated the dissolution of AA in the hydrogels and its subsequent delivery to the wound. Experiments simulating the transmembrane transport of aminocaproic acid from the developed gelatin-alginate hydrogels confirmed their ability to rapidly deliver up to 494± 3 mg of AA from 5 ml of hydrogel to the wound.

Synthesis and characterization of injectable thermosensitive hydrogel based on Pluronic-grafted silk fibroin copolymer containing hydroxyapatite nanoparticles as potential for bone tissue engineering

Injectable hydrogels are promising for bone tissue engineering due to their minimally invasive application and adaptability to irregular defects. This study presents the development of pluronic grafted silk fibroin (PF-127-g-SF), a temperature-sensitive graft copolymer synthesized from SF and modified PF-127 via a carbodiimide coupling reaction. The PF-127-g-SF copolymer exhibited a higher sol-gel transition temperature (34 °C at 16 % w/v) compared to PF-127 (23 °C), making it suitable for injectable applications. It also showed improved flexibility and strength, with a yielding point increase from <10 % to nearly 30 %. Unlike PF-127 gel, which degrades within 72 h in aqueous media, the PF-127-g-SF copolymer maintained a stable gel structure for over two weeks due to its robust crosslinked hydrogel network. Incorporating hydroxyapatite nanoparticles (n-HA) into the hydrogel reduced pore size and decreased swelling and degradation rates, extending structural stability to four weeks. Increasing n-HA concentration from 0 % to 20 % reduced porosity from 80 % to 66 %. Rheological studies indicated that n-HA enhanced the scaffold's strength and mechanical properties without altering gelation temperature. Cellular studies with MG-63 cells showed that n-HA concentration influenced cell viability and mineralization, highlighting the scaffold's potential in bone tissue engineering.

Polyurea-urethane Temperature-responsive Hydrogels for Sustained Delivery of Anti-VEGF Therapeutics.

Temperature-responsive hydrogels, or thermogels, have emerged as a leading platform for sustained delivery of both small molecule drugs and macromolecular biologic therapeutics. Although thermogel properties can be modulated by varying the polymer's hydrophilic-hydrophobic balance, molecular weight and degree of branching, varying the supramolecular donor-acceptor interactions on the polymer remains surprisingly overlooked. Herein, to study the influence of enhanced hydrogen bonding on thermogelation, we synthesized a family of amphiphilic polymers containing urea and urethane linkages using quinuclidine as an organocatalyst. Our findings showed that the presence of strongly hydrogen bonding urea linkages significantly enhanced polymer hydration in water, in turn affecting hierarchical polymer self-assembly and macroscopic gel properties such as sol-gel phase transition temperature and gel stiffness. Additionally, analysis of the sustained release profiles of Aflibercept, an FDA-approved protein biologic for anti-angiogenic treatment, showed that urea bonds on the thermogel were able to significantly alter the drug release mechanism and kinetics compared to usage of polyurethane gels of similar composition and molecular weight. Our findings demonstrate the unrealized possibility of modulating gel properties and outcomes of sustained drug delivery through judicious variation of hydrogen bonding motifs on the polymer structure.

Modulating the Thermoresponsive Characteristics of PLGA-PEG-PLGA Hydrogels via Manipulation of PLGA Monomer Sequences.

Hydrogels are promising materials for biomedical applications, particularly in drug delivery and tissue engineering. This study highlights thermoresponsive hydrogels, specifically poly(lactic-co-glycolic acid) (PLGA)-poly(ethylene glycol) (PEG)-PLGA triblock copolymers, and introduces a feed rate-controlled polymerization (FRCP) method. By utilizing an organic catalyst and regulating the monomer feed rate, the sequence distribution of PLGA within the triblock copolymer is controlled. Various analyses, including 13C NMR and rheological measurements, were conducted to investigate the impact of sequence distribution. Results show that altering sequence distribution significantly influences the sol-gel transition, hydrophobicity-hydrophilicity balance, and drug release profile. Increased sequence uniformity lowers the glass transition temperature, raises the sol-gel transition temperature due to enhanced hydrophilicity, and promotes a more uniform drug (curcumin) distribution within the PLGA domain, resulting in a slower release rate. This study emphasizes the importance of PLGA sequence distribution in biomedical applications and the potential of FRCP to tailor thermoresponsive hydrogels for biomedical advancements.

Effect of Acetaminophen on Poloxamer 407 Micelles and Hydrogels: The Relationship between Structural and Physical Properties.

Poloxamer hydrogel possesses thermosensitive sol-gel transition characteristics and is widely used as a drug-controlled-release carrier for topical or injectable formulations. In this study, the effect of loading of a drug, acetaminophen (ACE), on the physical and structural properties of poloxamer 407 (P407) micelles and hydrogels was investigated. Differential scanning calorimetry measurements revealed that ACE reduced the critical micelle temperature and enthalpy of micellization of P407 solutions. The P407 micellization was promoted by ACE incorporation. Rheometry showed that ACE increased the sol-gel transition temperature and reduced the gel strength of P407. In situ small-angle X-ray scattering (SAXS) using synchrotron radiation revealed that ACE altered the structure of P407 micelles and their packing in the P407 gels. As ACE concentration increased, the P407 micelle packing changed from a face-centered cubic phase to a body-centered cubic phase. Furthermore, ACE disordered the micelle packing structure and induced the formation of an amorphous phase. Structural analysis of the P407 micelle packing indicated that ACE reduced the aggregation number (Nagg) of P407 micelles in the gels. The SAXS study for diluted P407 solutions revealed that ACE reduced the P407 micelle size and its uniformity. The structural changes in P407 micelles by ACE loading (e.g., the reduction of Nagg, size, and size uniformity) would alter the micelle packing structure. It was found that these structural changes of micelle packing, especially the formation of an amorphous phase, could destabilize the P407 gel. As a result, the physical properties of P407 gels, such as gelation temperature and gel strength, were changed. This relationship between the structure and physical property of drug-loaded P407 gels was well-explained by correlating the micelle and gel structures. The mechanistic understanding of the change in the physical properties of P407 gels by drug loading is essential for the effective development of poloxamer gel formulations.

Gelation of gellan induced by trivalent cations and coexisting trivalent with monovalent cations studied by rheological and DSC measurements

The effect of trivalent cation Fe3+ on the gelation process of a sodium salt form of gellan (DG, deacylated gellan gum) was investigated by rheology and DSC studies. On addition of a fairly low concentration of Fe3+ (1 mM), both the complex modulus (G*) of a 1.0 % DG solution in gel state and the sol-gel transition temperature (Tgel) slightly decreased. At higher Fe3+ concentrations (2 and 3 mM), however, a slight increase in the G* and Tgel was observed. In the coexisting monovalent cation (K+) solutions, addition of Fe3+ always improved the G* in gel state and the Tgel in a concentration-dependent manner. Moreover, for all Fe3+ DG solutions, the ordered structure formation temperature (Torder) was always lower than Tgel and increased with increasing Fe3+ concentration. This finding indicates that the network formation in the DG solutions should occur in advance of the ordered structure formation of the DG chains and that the presence of Fe3+ unfavorably affected the conformational transition of DG. In coexisting cation solution, the presence of K+ ion made a favorable contribution to the binding of Fe3+ to the disordered DG chains and to the subsequent ordered structure formation of the DG chains.

Formulation and Evaluation of Bilastine Thermosensitive Mucoadhesive Ophthalmic in situ Gel

Background: Bilastine is a non-sedating, second-generation antihistamine used to treat urticaria and allergic conjunctivitis. Objective: to formulate and test bilastine as a mucoadhesive ophthalmic in situ gel in order to extend its presence at site for longer time and help treat conjunctivitis and allergic rhinitis. Methods: We prepared formulations using different concentrations of poloxamers (Poloxamer 407 (P407) and Poloxamer 188 (P188)) in combination with hydroxypropyl methyl cellulose (HPMC). The prepared formulas were evaluated for their physicochemical properties, sol-gel transition temperature, viscosity, mucoadhesive strength, drug release, and kinetic modeling. Results: The prepared in situ gels were clear and transparent, having a pH ranging from 7.4 to 7.5 and a gelation temperature between 29.5 and 34.7 °C. Increasing the concentrations of P-407 and HPMC increased viscosity, gel strength, and mucoadhesion force, but caused a decrease in gelation temperature and drug release. Formula (F 14) containing P 407/P 188/HPMC as 19/4/0.75% w/v, respectively, exhibited favorable characteristics, including optimal gelation temperature (33°C), drug content (93%), gel strength (40 sec), mucoadhesive force (6125 dyne/cm2), and 91.4% in vitro drug release over 5 hours. Conclusions: The bilastine mucoadhesive in situ gel formulation is presented as a promising ophthalmic formulation for the treatment of allergic conjunctivitis.

Modeling, the Optimization of the Composition of Emulgels with Ciclopirox Olamine, and Quality Assessment.

The design and development of pharmaceutical products require specific knowledge, time, and investment. Response surface methodology (RSM) is a widely used technique in the design of experiments (DoE) to optimize various processes and products. The aim of this study was to model and produce experimental emulgels containing 1% ciclopirox olamine and to evaluate their physical, rheological, and mechanical properties and their ability to release ciclopirox olamine. The objective was to optimize the composition of the experimental emulgel containing 1% ciclopirox olamine by applying a central composite design based on selected criteria. The surfactant (polysorbate 80) had the greatest influence on the physical, rheological, and mechanical properties of the emulgels, as well as on the release of ciclopirox olamine from these systems. During the optimization process, an emulgel of optimal composition was generated containing 38.27% mineral oil, 6.56% polysorbate 80, and 55.17% hydrogel containing 1% ciclopirox olamine, meeting specified criteria (dependent variables) including the maximum flux of ciclopirox olamine, the minimum sol-gel transition temperature (Tsol/gel), and the minimum particle size of the oil phase. The oil phase particle size (D50) of this emulgel was determined to be 0.337 µm, the system Tsol/gel was 9.1 °C, and the flux of ciclopirox olamine from this gel matrix was calculated to be 1.44 mg/cm2. This emulgel of optimal composition could be used to treat fungal skin diseases.

In-situ gel injection of poloxamer-based metamizole provides long-acting antipyretic effects.

Metamizole easily decomposes in the body and has a short action time and low bioavailability. Hence, frequent injection administrations are needed to maintain its plasma concentration. This study aimed to design and develop an in-situ gel based on poloxamer 407 and 188 to assess its long-acting antipyretic effects. The in-situ gel-forming systep00m with optimum sol-gel transition temperature of 35.9°C to 36.3°C could be formed using a combination of P407 at a ratio of 21-23% (w/v) and P188 at a ratio of 2-4% (w/v). In vitro erosion test showed that the in-situ gel's erosion curve and the metamizole release rate both reached about 90% at 6h, revealing a good linear relationship between the in-situ gel erosion and the drug release. In vitro release test with dialysis tube showed that the release of metamizole from the in-situ gel was remarkably slower than that from the metamizole solution. Approximately 85% of metamizole was released in the dialysis tube within 7h, implying a good sustained release effect. Pharmacodynamic study showed that the in-situ gel injection extended the action time of metamizole relative to that when using the metamizole solution. Pharmacokinetic study revealed that the in-situ gel significantly increased the blood serum half-life and area under the curve), contributing to a sustained release and improved bioavailability. This study demonstrated that in-situ gel injection could prolong the action of metamizole in the body to reduce the number of administration times and has good clinical application.

Recombinant scFv-Fc Anti-kallikrein 7 Antibody-Loaded Thermosensitive Hydrogels Against Skin Desquamation Disorders.

Human tissue kallikrein-related peptidase 7 (KLK7) is a serine protease implicated in the physiology of skin desquamation, and its uncontrolled activity can lead to chronic diseases such as psoriasis, atopic dermatitis, and Netherton syndrome. For this reason, kallikrein 7 has been identified as a potential therapeutic target. This work aimed to evaluate Pluronic (PL) hydrogels as topical carriers of four specific scFv-Fc antibodies to inhibit KLK7. The hydrogels comprised PL F127 (30% w/v) alone and a binary F127/P123 (28-2% w/v) system. Each formulation was loaded with 1 μg/mL of each antibody and characterized by physicochemical and pharmaceutical techniques, considering antibody-micelle interactions and hydrogel behavior as smart delivery systems. Results showed that the antibodies were successfully loaded into the PL-based systems, and the sol-gel transition temperature was shifted to high values after the P123 addition. The antibodies released from the gels preserved their rheological properties (G' > G'', 35- to 41-fold) and inhibitory activity against KLK7, even after 24 h. This work presented potential agents targeting KLK7 that may provide strategies for treating skin abnormalities.

Gel‐forming properties of Bambara groundnut globulin and protein subfractions: structural and rheological characterisation

SummaryThe gel‐forming ability of the pulse proteins influences the formation of food products with desirable texture, structure, and stability. In this study, Bambara globulin was fractionated into legumin and vicilin for structural and physicochemical analyses, and heat‐induced gel rheological characterisation. Bambara globulin showed major vicilin (7S, Mw: 120 kDa) and minor legumin (11S, Mw: 410 kDa) components by size exclusion chromatography and gel electrophoresis analyses. Legumin had the lowest amount of all the charged amino acids. One basic subunit (22 kDa) was identified in the legumin fraction with predominant helical structures. The sol–gel transition temperatures increased in the order of globulin (40 °C) &lt; legumin (50 °C) &lt; vicilin (80 °C). The G′ and G″ of globulin showed relatively low dependency on heating time beyond the gel point compared to legumin and vicilin subfractions, suggesting a more rapid establishment of its gel network during gelation. Vicilin gel consisted of a microporous structure with a small lath sheet‐like structure compared to others. Bambara vicilin could be a prospective ingredient in the development of new products with defined textural characteristics.

Nanoarchitectonics and Biological Properties of Nanocomposite Thermosensitive Chitosan Hydrogels Obtained with the Use of Uridine 5'-Monophosphate Disodium Salt.

Currently, an important group of biomaterials used in the research in the field of tissue engineering is thermosensitive chitosan hydrogels. Their main advantage is the possibility of introducing their precursors (sols) into the implantation site using a minimally invasive method-by injection. In this publication, the results of studies on the new chitosan structures in the form of thermosensitive hydrogels containing graphene oxide as a nanofiller are presented. These systems were prepared from chitosan lactate and chitosan chloride solutions with the use of a salt of pyrimidine nucleotide-uridine 5'-monophosphate disodium salt-as the cross-linking agent. In order to perform the characterization of the developed hydrogels, the sol-gel transition temperature of the colloidal systems was first determined based on rheological measurements. The hydrogels were also analyzed using FTIR spectroscopy and SEM. Biological studies assessed the cytotoxicity (resazurin assay) and genotoxicity (alkaline version of the comet assay) of the nanocomposite chitosan hydrogels against normal human BJ fibroblasts. The conducted research allowed us to conclude that the developed hydrogels containing graphene oxide are an attractive material for potential use as scaffolds for the regeneration of damaged tissues.

Two-dimensional polydopamine nanosheet-based thermosensitive supramolecular hydrogels for photothermal-chemo synergistic treatment of melanoma

The development of injectable thermosensitive hydrogels with photothermal elimination of tumors and precisely controllable drug release properties is critical for tumor eradication. Herein, a novel injectable thermosensitive supramolecular hydrogel PDAns@CPT-peg/α-CD was developed, which was formed by using two-dimensional polydopamine nanosheets (PDAns) as the photothermal backbone, loaded with the PEGylated camptothecin prodrug (CPT-peg) through π-π stacking and hydrophobic binding, and then crosslinked by the introduction of α-cyclodextrin (α-CD) host–guest self-assembly. PDAns as hydrogel skeleton endowed the hydrogel with excellent photothermal conversion effect, and the large specific surface area of PDAns enables efficient loading of hydrophobic anticancer drugs and avoids undesired leakage. Moreover, the dynamic host–guest cross-linking endows the hydrogel with reversible gel-sol transition and injectability, the gel-sol transition temperature can be easily tunable by the CD concentration, under 808 nm laser irradiation, the PDAns@CPT-peg/α-CD hydrogel can be rapidly heated to the temperature required for photothermal therapy, simultaneously triggering the thermosensitive gel-sol transition followed by the on-demand release of CPT-peg. In vivo evaluation demonstrated that the synergistic photothermal-chemotherapeutic effect mediated by PDAns@CPT-peg/α-CD hydrogel almost eradicated melanoma under low-dose NIR laser (0.15 W cm−2) irradiation. This work provides an effective and convenient strategy for constructing a multifunctional hydrogel platform for the photothermal-chemo synergistic treatment of tumors.

Surfactant-mediated gelation by 12-hydroxyoctadecanoic acid in a nonionic surfactant system

In this study, we present a hydrogel fabrication utilizing a water-insoluble, low-molecular-weight organogelator by the surfactant-mediated gelation (SMG). Specifically, we employed a nonionic surfactant (poly(oxyethylene) sorbitan monooleate, Tween 80) and an organogelator (12-hydroxyoctadecanoic acid, 12-HOA) to produce hydrogels. Gelation experiments conducted at varying concentrations of surfactant and gelator demonstrated successful hydrogel formation in the water/Tween 80/12-HOA system. Moreover, we observed a significant dependence of surfactant concentration on gelation ability. The sol-gel transition temperature was found to be influenced by both the gelator and surfactant concentrations. Optical and electron microscopy analyses revealed that the SMG hydrogels comprised an entangled network of fibers with micrometer-scale widths, formed as bundles of submicron-wide fibers, and further composed of fine fibers measuring several tens of nanometers in width. These fine fibers exhibited a left-handed helical structure. Small- and wide-angle X-ray scattering corroborated the presence of a lamellar structure within the fine fibers, displaying a triclinic subcell morphology. The coexistence of micelles with the fiber network was confirmed through small-angle neutron scattering and UV–vis spectroscopy. Furthermore, dynamic viscoelasticity tests demonstrated that the SMG hydrogels exhibited typical solid-like properties indicative of gel behavior.

Reverse mode LCPG films with self-assembly support of gel networks

ABSTRACT Liquid crystal physical gels (LCPG) with a 3D network structure show considerable promise as novel functional materials with a great impact on scientific and practical applications. LCPGs are not characterised by high hardness and high strength, but this mild nature is capable of forming dynamic supramolecular structures with the self-assembly ability of various non-covalent bonds such as hydrogen bonding, π-π stacking, and van der Waals forces. In addition to anisotropic changes under optical and electrical stimulation, it enables to be one of the candidates for display devices. When the isotropic-anisotropic transition temperature of LCPG solution (TIA) is higher than the sol-gel transition temperature of gel molecules (TSG), the gelation can anchor the orientation of liquid crystal molecules to achieve the alteration of transparency and scattering of the film. In this paper, reverse mode LCPG films with high contrast, low driving voltage, and excellent cycle life were prepared using oriented liquid crystal cassettes and LCPG solutions, it also focused on the effects of chiral compounds (S)-octan-2-yl 4-((4-(hexyloxy)benzoyl)oxy)benzoate (S811) and gel 1,3:2,4-bis-0-(3,4-dimethylbenzylidene)sorbitol (DMDBS) content on electro-optical properties of LCPG films as well as the different functions of TIA and TSG on film orientation.

Injectable Thermo-Responsive Peptide Hydrogels and Its Enzyme Triggered Dynamic Self-Assembly.

Endogenous stimuli-responsive injectable hydrogels hold significant promise for practical applications due to their spatio-temporal controllable drug delivery. Herein, we report a facile strategy to construct a series of in situ formation polypeptide hydrogels with thermal responsiveness and enzyme-triggered dynamic self-assembly. The thermo-responsive hydrogels are from the diblock random copolymer mPEG-b-P(Glu-co-Tyr). The L-glutamic acid (Glu) segments with different γ-alkyl groups, including methyl, ethyl, and n-butyl, offer specific secondary structure, facilitating the formation of hydrogel. The L-tyrosine (Tyr) residues not only provide hydrogen-bond interactions and thus adjust the sol-gel transition temperatures, but also endow polypeptide enzyme-responsive properties. The PTyr segments could be phosphorylated, and the phosphotyrosine copolymers were amphiphilies, which could readily self-assemble into spherical aggregates and transform into sheet-like structures upon dephosphorylation by alkaline phosphatase (ALP). P(MGlu-co-Tyr/P) and P(MGlu-co-Tyr) copolymers showed good compatibility with both MC3T3-E1 and Hela cells, with cell viability above 80% at concentrations up to 1000 μg/mL. The prepared injectable polypeptide hydrogel and its enzyme-triggered self-assemblies show particular potential for biomedical applications.

Effect of zein-pectin composite particles on the stability and rheological properties of gelatin/hydroxypropyl methylcellulose water-water systems

To improve the compatibility of gelatin (GA) and hydroxypropyl methylcellulose (HPMC), we investigated the effects of zein-pectin composite particles (ZCPs) with various zein/pectin ratios (1:0, 1:0.5, 1:1, 1:1.5, and 1:2) on the physical stability, microstructure, and rheological properties of the GA/HPMC water-water systems. With increasing pectin ratio, the particle size of the composite particles increased from 234.53 ± 1.48 nm to 1111.00 ± 26.91 nm, and their zeta potential decreased from 20.60 mV to below −34.77 mV. Macroscopic and microstructure observations indicated that pectin-modified ZCPs could effectively inhibit phase separation behavior between GA and HPMC. Compared to pure HPMC, the GA/HPMC water-water systems possessed a higher viscosity and dynamic modulus at room temperatures but lower gel temperatures (reduction of about 11 %). The viscosity and modulus of the water-water systems increased with increasing pectin ratio in ZCPs. However, the ratio had no impact on the gel-sol (sol-gel) transition temperatures (not statistically significant (P < 0.05)). This study may serve as a reference for advancing the processability of HPMC.

Combining Carbon Materials and Ionic Liquid Gels to Boost Simultaneous Removal of Emerging Pollutants from Wastewaters

AbstractWater bodies contamination is a pressing issue of modern society, exacerbated by the large structural variety of contaminants. This explains the interest toward developing systems able to remove from wastewater different contaminants, with different susceptibility to removal methods. Consequently, herein hybrid ionic liquid gels, based on 1,3:2,4‐dibenzylidene‐D‐sorbitol (DBS), doped with graphite, carbon nanotubes, graphene, and graphene oxide, are described. First, the gel–sol transition temperatures (Tgel), rheological and self‐healing properties are determined. These gels are then used as sorbent materials and, for the first time, for removing mixtures of pollutants of different classes, namely the dyes rhodamine B and methyl orange, the drugs diclofenac and carbamazepine, or the endocrine disruptor bisphenol A, to simulate real wastewaters. Interestingly, hybrid gels prove efficient in removing single and mixed pollutants. The best performing gel is reusable for at least 12 consecutive cycles, without any intermediate washing. It can also be embedded in adsorption columns or dialysis membranes, to treat larger volumes of wastewater. Here, this gel achieves an adsorption capacity of 117 and 66 mg g−1 for rhodamine B and bisphenol A in mixture, with a distinct preference toward cationic contaminants, exhibiting competitive performance with most systems previously reported.