Dynamic Rheology Research Articles

Effect of solvents and supercritical‐CO2 extraction of lipids on physico‐chemical, functional, pasting and rheological properties of hard, medium hard and soft wheat varieties

SummaryThis study was conducted to compare the effect of lipids removal using supercrital‐CO2 extraction and organic solvents (hexane and isopropanol) from hard and soft wheat flour varieties. Flours were evaluated for physicochemical properties (protein, ash, hunter colour), sodium dodecyl sulphate‐polyacrylamide gel electrophoresis, foaming properties, water and oil absorption capacity, pasting, farinographic and dynamic rheology. Protein content of flours increased after defatting and supercritical fluid extracted (SCE) wheat flours showed the highest increase. SCE flours showed higher peak viscosity than native and hexane extracted (HE) and isopropyl alcohol extracted (IPAE) flours. Functional properties improved upon defatting and the highest increase in functional properties was observed for SCE flours. Empirical and fundamental rheological measurements were affected by defatting and SCE flours showed the highest change in visco‐elasticity. SC‐CO2 was proved better alternative technique over conventional organic solvent methods to remove lipids from flours that brought desirable changes in some functional properties.

Establishment of a Quantitative Time Conversion Relationship Between Laboratory Accelerated Weathering Aging and Outdoor Natural Aging of the High-Content Polymer Modified Asphalt Applied in Porous Asphalt Pavement: From Theory to Experiment

The purpose of this study was to determine the quantitative time conversion relationship between indoor accelerated weathering aging (AWA) and outdoor natural aging of the high-content polymer modified asphalt (HCPMA) applied in porous asphalt pavement from both theoretical and experimental aspects. Firstly, the calculated aging acceleration rate of the AWA test was determined based on orthogonal analysis and chemical reaction kinetics. The indoor AWA test (0–12 days) and outdoor natural aging (0–12 months) were then performed on HCPMA, and the dynamic shear rheology test and multiple stress creep recovery test were conducted to investigate the rheological properties of HCPMA. Furthermore, the measured aging acceleration rate of the AWA test was determined according to rheological index comparison and then compared with the calculated aging acceleration rate to obtain the ultimate time conversion relationship between indoor and outdoor aging. Results show that it is practical to simulate the natural aging by using the AWA test. HCPMA exhibits similar changes in macroscopic rheological properties in indoor AWA and outdoor natural aging. According to the comparison of rheological indexes, the measured aging acceleration rate of HCPMA under the harshest aging condition is 57.5–120, which is basically consistent with the calculated aging acceleration rate (66) by the chemical reaction kinetics. This further demonstrates the feasibility of this study for determining the indoor-outdoor aging time conversion relationship from theoretical and experimental aspects.

Rheological behaviour and antibacterial activities of MWCNTs/ lyotropic liquid crystals based nanocolloids

ABSTRACT Nanocolloids are prepared via doping of 0.015 mg and 0.030 mg multiwalled carbon nanotubes (MWCNTs) in the lyotropic phases of cetylpyridinium chloride (CPC)/glycerol (2:98, 5:95, 10:90 and 20:80 wt%/wt%). Nanocolloids are characterised by polarising optical microscopy (POM) for structural confirmations. No phase change has been observed in any sample with MWCNTs doping concentrations. Non-doped lyotropic phases and nanocolloids are studied for static and dynamic rheology, frequency sweep and thixotropic behaviour. Shear rheology infers about the shear thinning to Newtonian till 10:90 CPC/glycerol concentration and shear thickening to Newtonian for 20:80 wt%:wt% system. The studied systems follow the nematodynamic concept. The frequency sweep test infers that lyotropic mesophases and nanocolloids exhibit viscoelastic behaviour. Further, the thixotropic measurements infer the weak gel nature of mesophases and nanocolloids. Lyotropic phases and nanocolloids show strong inhibition properties against the gram-negative Escherichia Coli (E. Coli.) bacteria. Lyotropic phases and nanocolloids can be used in microbial and lubrication applications. The unique antibacterial properties of these systems make them suitable for use in medical and pharmaceutical devices to prevent the spread of infection.

Effects of molecular characteristics and microstructure of amaranth particle sizes on dough rheology and wheat bread characteristics

The aim of this research is to investigate the molecular features and microstructure of amaranth flour (AF) fractions and their partial replacement effect of wheat flour (WF) on the chemical composition, dough dynamic rheology, technological and sensory characteristics of bread. The microstructure and molecular characteristics of AF were depending on their particle size (PS). When WF replacement increased and PS decreased the composite flour was richest in protein, lipids, and ash, while the moisture and carbohydrates of these flours decreased. Dynamic rheological behavior revealed significant variations depending on PS and replacement level. Bread volume and firmness increased when more than 15% AF from large PS replaced WF, while medium and small PS at 5–15% replacements was increased the loaf porosity. Chroma values decreased and samples became darker when the replacement level increased. Moreover, replacement of WF with various AF fractions impacted bread sensory characteristics, obtaining better acceptance for large and medium PS up to 10%.

A sustainable high-viscosity modified asphalt modified with multiple anti-aging agents: Micro-chemical analysis and macro-rheological characterization

This study aimed to use aging inhibition technology to actively improve the environmental aging resistance, thus achieving the sustainable and long-life application of high-viscosity modified asphalt (HVMA). The sustainable HVMAs with different anti-aging agents was prepared, and the long-term environmental aging effect, including solar radiation, heat, and moisture, was simulated using the accelerated environmental aging tester. Then, the chemical and molecular composition of sustainable HVMAs were investigated using Fourier transform infrared spectroscopy test, X-ray photoelectron spectroscopy test, and gel permeation chromatography test. Afterwards, the nano-indentation test was used to study the nanomechanical property of sustainable HVMAs. Finally, the dynamic shear rheology test and linear amplitude sweep test were applied to evaluate the aging resistance, crack resistance, and fatigue resistance of sustainable HVMAs. The results show that environmental aging leads to the rapid oxidation of asphalt molecules and substantial degradation of polymer molecules in HVMA, as evidenced by the transformation of carbon elements from CC/CH bonds to CO/CO bonds and sulfur elements from CSC bonds to SO/OSO bonds. A single anti-aging agent has a little aging inhibition effect, while the compounding of multiple anti-aging agents has a synergistic anti-aging enhancement effect. The combination of UV absorbers and UV blocking agents can absorb/reflect some of the UV rays and delay the UV aging process. However, they cannot effectively prevent the binding of UV-excited reactive radicals with oxygen. In contrast, incorporating antioxidants can allow hydrogen atoms to combine with UV-excited reactive radicals and prevent further oxidation of asphalt molecules. The compound incorporation of UV absorbers, UV blocking agents, and antioxidants can improve the rheology property, crack resistance, and fatigue resistance of aged HVMA, thus effectively promoting the sustainable and long-life application of HVMA.

Biological activity of pectic polysaccharides investigated through biomembrane models formed at the air-water interface

Pectin, a polysaccharide with potential bioactivity, was inserted in the aqueous subphase of monolayers of the selected lipids DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) and DPPE (1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine), representing mammalian and bacterial membranes, respectively. Pectin condensed both monolayers but made the DPPC monolayer more fluid, while for DPPE, it made its monolayer more rigid, as detected with dynamic interfacial rheology. Complementary data using surface potential, infrared spectroscopy, and Brewster angle microscopy also showed distinctive effects of pectin on DPPE and DPPC. We believe these data can be correlated with the action of this polysaccharide with biological lipidic surfaces with different polar heads, which may be relevant, generally speaking, to understanding the molecular mechanism of this bioactive compound for pharmaceutical purposes.

Ultrasonic pretreatment improves the gelation properties of low-salt Penaeus vannamei (Litopenaeus vannamei) surimi

The effects of different ultrasonic pretreatments (120–600 W, 20 min; 360 W, 10–30 min) on the gel properties of shrimp surimi were investigated. Gel properties and protein functional properties were analysed to clarify the mechanism of action of ultrasound. The gel strength, water holding capacity and surface hydrophobicity of shrimp surimi gel increased initially and then decreased with the increase in ultrasound power or time, but the change in total sulfhydryl content showed the opposite trend, which indicated that proper ultrasound pretreatment could improve the gel properties of shrimp surimi, expand the protein to a greater extent and expose more SH groups and hydrophobic groups. According to scanning electron microscopy observation, ultrasound made shrimp surimi gel form a denser gel network. Fourier transform infrared analysis indicated that the α-helix content in shrimp surimi gel decreased initially and then increased with the increase of in ultrasound power or time, whereas the change in β-sheet content showed the opposite trend. And the protein was the most stable in 360 W/20 min pretreatment. SDS-PAGE patterns showed that proper ultrasound inhibited the degradation of actin and troponin C. In addition, dynamic rheology illustrated that the G′ values of the ultrasonic pretreatment group were higher than that of the control group, indicating that ultrasound could improve the elasticity and stability of shrimp surimi gel. The results suggested that the shrimp surimi gel pretreated by 360 W/20 min ultrasound showed the best gel properties. Furthermore, the correlation between the indexes affecting the properties of the gel was analyzed. This study provides a new technical means to improve the gel properties of shrimp surimi.

Composition and Evaluation on Road Performance of SBS/PTW High-Viscosity-Modified Asphalt and Its Mixtures for Ultrathin Overlays

As a highway pavement maintenance technology, the road performance of the ultra-thin overlay depends heavily on the performance of asphalt cement. For the preparation of high-performance-modified asphalt suitable for ultrathin overlay, the reactive blending technology was used based on SBS modified asphalt and combined with a penetration test, softening point test, ductility test, dynamic viscosity test, and viscous toughness test to study the optimal blending ratio of high-viscosity modified asphalt. Further, the rolling thin-film oven test (RTFOT), dynamic shear rheological (DSR) test, and Brookfield viscosity test are used to evaluate the technical properties of SBS/PTW modified asphalt under the best mixing ratio. Finally, the SMA-13 asphalt mixture was prepared with SBS/PTW high-viscosity modified asphalt and evaluated through a rutting test, low-temperature bending test, immersion Marshall test, freeze-thaw splitting test, structural depth test (TD), and British pendulum number (BPN) test. These results showed that the best blending mass ratio of high-viscosity modified asphalt is 6% SBS + 4% solubilizer + 0.2% PTW + 0.2% nano-ZnO. All technical property indexes of the prepared SBS/PTW high-viscosity modified asphalt meet the requirements of an ultra-thin overlay binder. The dynamic viscosity at 60°C reaches 64204 Pa·s, and the viscosity and toughness are 25.4 N·m and 20.9 N·m, respectively. SBS/PTW high-viscosity modified asphalt under dynamic shear rheology (DSR) test is classified as PG88 at high temperature. The rutting factor changes the smallest before and after aging, and it has excellent anti-aging performance. Furthermore, the asphalt mixture prepared by SBS/PTW high-viscosity modified asphalt has excellent high and low-temperature performance, water stability, and skid resistance performance. All properties meet the requirements of the ultra-thin overlay. This study demonstrated that the SBS/PTW high-viscosity modified asphalt possessed high viscosity properties, which can be used in the ultra-thin overlay and other highly demanding working environments.

Development and Preclinical Investigation of Physically Cross-Linked and pH-Sensitive Polymeric Gels as Potential Vaginal Contraceptives.

This study explored the development of cross-linked gels to potentially provide a physical barrier to vaginal sperm transport for contraception. Two types of gels were formulated, a physically cross-linked iota-carrageenan (Ci) phenylboronic acid functionalized hydroxylpropylmethyacrylate copolymer (PBA)-based (Ci-PBA) gel, designed to block vaginal sperm transport. The second gel was pH-shifting cross-linked Ci-polyvinyl alcohol-boric acid (Ci-PVA-BA) gel, designed to modulate its properties in forming a viscoelastic, weakly cross-linked transient network (due to Ci gelling properties) on vaginal application (at acidic pH of ~3.5–4.5) to a more elastic, densely cross-linked (due to borate-diol cross-linking) gel network at basic pH of 7–8 of seminal fluid, thereby acting as a physical barrier to motile sperm. The gels were characterized for dynamic rheology, physicochemical properties, and impact on sperm functionality (motility, viability, penetration). The rheology data confirmed that the Ci-PBA gel was formed by ionic interactions whereas Ci-PVA-BA gel was chemically cross-linked and became more elastic at basic pH. Based on the screening data, lead gels were selected for in vitro sperm functionality testing. The in vitro results confirmed that the Ci-PBA and Ci-PVA-BA gels created a barrier at the sperm-gel interface, providing sperm blocking properties. For preclinical proof-of-concept, the Ci-PBA gels were applied vaginally and tested for contraceptive efficacy in rabbits, demonstrating only partial efficacy (40–60%). Overall, the in vitro and in vivo results support the development and further optimization of cross-linked gels using commercially available materials as vaginal contraceptives.

Investigation of DSC curing kinetic model fitting and rheological behavior of urushiol/IPDI system

The curing behavior of urushiol/IPDI system was monitored by differential scanning calorimetry (DSC) and dynamic rheology. The change of activation energy during curing process was calculated by KAS, OFW and Friedman isoconversional methods. The relationship between curing reaction rate and temperature and curing degree was described by the piecewise fitting method. The results of model fitting and model-free fitting showed that the kinetic mechanism of the reaction changed from autocatalytic mechanism a<0.86 to n-order reaction mechanism a>0.86. The curing process of urushiol/IPDI was fitted by piecewise model, which was in good agreement with the experimental results. The piecewise model can accurately describe the curing process. The isothermal rheological test of urushiol/IPDI system was carried out. The results showed that the gelation time shortened with increasing temperature.

Characterization of Tuna Gelatin-Based Hydrogels as a Matrix for Drug Delivery.

The skin of yellowfin tuna is one of the fishery industry solid residues with the greatest potential to add extra value to its circular economy that remains yet unexploited. Particularly, the high collagen content of fish skin allows generating gelatin by hydrolysis, which is ideal for forming hydrogels due to its biocompatibility and gelling capability. Hydrogels have been used as drug carriers for local administration due to their mechanical properties and drug loading capacity. Herein, novel tuna gelatin hydrogels were designed as drug vehicles with two structurally different antitumoral model compounds such as Doxorubicin and Crocin to be administrated locally in tissues with complex human anatomies after surgical resection. The characterization by gel permeation chromatography (GPC) of purified gelatin confirmed their heterogeneity composition, exhibiting three major bands that correspond to the β and α chains along with high molecular weight species. In addition, the Fourier Transform Infrared (FT-IR) spectra of gelatin probed the secondary structure of the gelatin showing the simultaneous existence of α helix, β sheet, and random coil structures. Morphological studies at different length scales were performed by a multi-technique approach using SAXS/WAXS, AFM and cryo-SEM that revealed the porous network formed by the interaction of gelatin planar aggregates. In addition, the sol-gel transition, as well as the gelation point and the hydrogel strength, were studied using dynamic rheology and differential scanning calorimetry. Likewise, the loading and release profiles followed by UV-visible spectroscopy indicated that the novel gelatin hydrogels improve the drug release of Doxorubicin and Crocin in a sustained fashion, indicating the structure-function importance in the material composition.

Rheological and Thermal Study about the Gelatinization of Different Starches (Potato, Wheat and Waxy) in Blend with Cellulose Nanocrystals

The goal of this work was to analyze the effect of CNCs on the gelatinization of different starches (potato, wheat and waxy maize) through the characterization of the rheological and thermal properties of starch–CNC blends. CNCs were blended with different starches, adding CNCs at concentrations of 0, 2, 6 and 10% w/w. Starch–CNC blends were processed by rapid visco-analysis (RVA) and cooled to 70 °C. Pasting parameters such as pasting temperature, peak, hold and breakdown viscosity were assessed. After RVA testing, starch–CNC blends were immediately analyzed by rotational and dynamic rheology at 70 °C. Gelatinization temperature and enthalpy were assessed by differential scanning calorimetry. Our results suggest that CNCs modify the starch gelatinization but that this behavior depends on the starch origin. In potato starch, CNCs promoted a less organized structure after gelatinization which would allow a higher interaction amylose–CNC. However, this behavior was not observed in wheat and waxy maize starch. Insights focusing on the role of CNC on gelatinization yielded relevant information for better understanding the structural changes that take place on starch during storage, which are closely related with starch retrogradation. This insight can be used as an input for the tailored design of novel materials oriented towards different technological applications.

Formation of Salts and Molecular Ionic Cocrystals of Fluoroquinolones and α,ω-Dicarboxylic Acids.

The cocrystallization of the fluoroquinolones ciprofloxacin (cip), norfloxacin (nor), and enrofloxacin (enro) with the α,ω-dicarboxylic acids glutaric acid (glu), adipic acid (adi), pimelic acid (pim), suberic acid (sub), azeliac acid (az), and sebacic acid (seb) resulted in 27 new molecular salts and ternary molecular ionic cocrystals of compositions A+B–, A2+B2–, A2+B2–B, and A+B–A. Depending on the solvent, different stoichiomorphs, solvates, or polymorphs were obtained. All salts and cocrystals contain the robust R2NH2+...–OOC or R3NH+...–OOC synthon but have different supramolecular ring motifs. Moderate solubility enhancements over the parent fluoroquinolones were observed. Salts in the ratio of 1:1 and 2:1 were also prepared by ball-milling. The milled sample nor/az (1:1) was shown to gel the GRAS (generally recognized as safe) solvent propylene glycol, and enro/sub (1:1) was shown to gel both propylene glycol and water. Dynamic rheology measurements confirmed that nor/az and enro/sub behave like viscoelastic materials and supramolecular gels.

Oscillatory motion of viscoelastic drops on slippery lubricated surfaces

The introduction of slippery lubricated surfaces allows for the investigation of the flow of highly viscous fluids, which otherwise will hardly move on standard solid surfaces. Here we present the study of the gravity induced motion of small drops of polymeric fluids deposited on inclined lubricated surfaces. The viscosity of these fluids decreases with increasing shear rate (shear thinning) and, more importantly, they exert normal forces on planes perpendicular to shear directions (elasticity). Despite the homogeneity of the surface and of the fluids, drops of sufficiently elastic fluids move downward with an oscillating instantaneous speed whose frequency is found to be directly proportional to the average speed and inversely to the drop volume. The oscillatory motion is caused by the formation of a bulge at the rear of the drop, which will be dragged along the drop free contour by the rolling motion undergone by the drop. This finding can be considered as a kind of new Weissenberg effect applied to moving drops that combines dynamic wetting and polymer rheology.

Glass-like Signatures in the Dynamic Rheology of Particle-Filled Polymers

Glass-like Signatures in the Dynamic Rheology of Particle-Filled Polymers

Effect of amaranth addition on texture of maize tortilla produced from extruded composite flours

AbstractBackground and ObjectivesNutritional benefits of amaranth addition to maize products have been documented. However, studies of the effect on the final product's rheological and textural properties are scarce. The objective was to study the effect of amaranth addition on masa's rheological properties and the tortilla texture of maize nixtamalized flours obtained by extrusion technology.FindingsComposite flours of maize with 0%, 15%, 30%, or 45% amaranth were extruded, and masa and tortillas were obtained. Masa properties were evaluated with dynamic rheology and tortilla firmness with the texture profile analysis. The amaranth addition effect was not linear. Fifteen percent addition increased frequency sweep values for G′ and G″, while 30% and 45% addition decreased them. Tortilla firmness decreased at 2 storage hours for 15% addition compared with maize‐only samples (5440 and 7190 (g‐f)/mm). The effects can be partially explained by differences in starch characteristics.ConclusionsAmaranth (15% addition) improved masa viscoelastic behavior and reduced firmness during storage. Besides the nutritional effects, amaranth use at the tested level will be helpful in improving the texture of maize tortillas produced with extruded flour.Significance and NoveltyThe texture of tortillas obtained by extruded flours has not been reported to be completely satisfactory; therefore, the use of amaranth has the potential to improve the final product quality.

Immobilization of acetate based ionic liquids on silica gel to fabricate a prospective desulfurizing adsorbent

ABSTRACT Ionic liquids have the potential to play a significant role in mitigating the critical challenge of refractory sulfur removal from diesel. In the present investigation, a mixture of imidazolium, pyrazolium and triazolium acetate -based ionic liquids has been immobilized on silica gel using sol-gel technology at ambient temperature (25°C), yielding a novel adsorbent. The sol-gel processing route has been elucidated by Dynamic Light Scattering (DLS) and rheology study. The fabricated adsorbent has been characterized by Fourier Transfer Infra-red (FTIR) spectroscopy, X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The results reveal that the ionic liquids have been immobilized in the silica gel support. This adsorbent has been successfully applied to remove heterocyclic sulfur compounds from model diesel containing thiophene and dibenzothiophene. The highest desulfurization efficiencies achieved for thiophene and dibenzothiophene removal are 98.31 and 99.29% respectively, using an adsorbent with 15% ionic liquid loading, model diesel: adsorbent ratio of 1:0.075, an adsorption time of 60 minutes at 25°C. The system under investigation followed the Langmuir isotherm model and the adsorption performance best fitted with the Ho’s pseudo second-order kinetics.

Impact of L-cysteine addition on nixtamalized corn dough: proteins and viscoelasticity

&#x0D; The effect of L-cysteine on the solubility, protein structure, rheological and textural characteristics of corn masas were investigated. Masa was prepared with L-cysteine at two levels (0.25, 0.50 %). Size exclusion chromatography and Fourier transform infrared spectroscopy were utilized for protein characterization. Dynamic rheology and textural profile analysis were carried out on masas. There was a significant difference in relative solubility between the control and masas containing L-cysteine. Treatments with L-cysteine increased the relative solubility of proteins. Determination of FT-IR revealed that addition of L-cysteine did not affects secondary structure of protein. Data also showed significant differences in textural properties. Masas con L-cysteine improved the springiness, adhesiveness and cohesiveness. This investigation reveal that L-cysteine, may improve the elasticity or storage moduli, important characteristics of masas.&#x0D;

Modification of asphalt using polyurethanes synthesized with different isocyanates

To study the effect of isocyanates on the properties of polyurethane (PU) modified asphalt, three kinds of polyurethane with different hard segments were synthesized, by the reaction of polyethylene adipate (PEA) with diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI) and polyaryl polymethylene isocyanate (PAPI), respectively. These three kinds of polyurethane were used to modify the asphalt and study the effects of isocyanate on the performance of polyurethane modified asphalt by experiments. The Fourier transform infrared spectrometer (FTIR), and the gel permeation chromatography (GPC) were used to analyse PU samples. The dynamic shear rheology (DSR), bending beam rheology (BBR), multiple stress creep test (MSCR), Fourier transform infrared spectroscopy (FTIR), atomic force microscope (AFM), and differential scanning calorimetry (DSC) were used to research rheological properties, modification mechanism and microstructure of the asphalts, respectively. The results show that isocyanates influence the structure of polyurethane molecules, the distribution of soft and hard segments and the content of hard segments, and affect the distribution of asphaltenes in asphalt, resulting in different modification effects on asphalt. Of the three isocyanates, the PU synthesized by TDI provides the best improvement to the asphalt in terms of resistance against permanent deformations, low-temperature property and storage stability. Improvement effects of PU synthesized by PAPI on resistance against the permanent deformations and storage stability are better than that of MDI, but the effects on low-temperature property are worse with that of MDI.

Supramolecular Hydrogels Developed from Mafenide and Indomethacin as a Plausible Multidrug Self-Delivery System as Antibacterial and Anti-inflammatory Topical Gels.

Following a structural rationale, a series of simple organic salts derived from mafenide (a drug for treating burn wounds) and n-alkyl carboxylic acids (Me-(CH2)n-COOH; n = 1-3, 10-15) and various nonsteroidal anti-inflammatory drugs (NSAIDs), namely, indomethacin (IND), diclofenac (DIC), meclofenamic acid (MEC), tolfenamic acid (TOL), and flufenamic acid (FLU) (designated as salts 1-14, respectively) were synthesized as potential hydrogelators. Gelation studies revealed that mafenide n-alkyl carboxylates with n = 11-14, i.e., salts 5-8, and the indomethacin salt of mafenide, i.e., salt 10, were hydrogelators. The corresponding hydrogels, namely, 5(HG)-8(HG) and 10(HG), were characterized by table-top and dynamic rheology and high-resolution transmission electron microscopy (HR-TEM). Single-crystal structures of the nongelator salts 1-3 and the gelator salt 10 were determined by X-ray diffraction. The results obtained from various studies, which included the solubility, biostability, biocompatibility (MTT assay), and anti-inflammatory (PGE2 assay) response of salt 10, the antibacterial response (zone inhibition assay) of salt 10, its components, and 10(HG), and the release of salt 10in vitro from the corresponding hydrogel bed to the bulk solvent at 37 °C in 24 h, suggested their plausible use in developing multidrug-derived topical hydrogels for self-delivery applications.