Differential Scanning Calorimetry Research Articles

DESIGN, OPTIMIZATION AND EVALUATION OF RANOLAZINE FAST-DISSOLVING FILMS EMPLOYING MANGO KERNEL STARCH AS A NEW NATURAL SUPERDISINTEGRANT

Objective: The BCS class II cardiovascular medication, Ranolazine (RZN), is characterized by limited solubility and inadequate oral absorption. The objective of the current research is to develop a natural superdisintegrant in the formulation of Fast-Dissolving Films (FDFs) of Cardio Vascular Drug (CVD) RZN to enhance its dissolution rate, solubility, absorption, and therapeutic action. Methods: Mango Kernel Starch (MKS) is isolated by grinding the kernels, forming a slurry with water, filtering, and using repeated centrifugation and washing to purify the starch, which is then dried. The obtained starch is collected. Along with obtained natural superdisintegrant MKS, Maltodextrin (MDX) and Sodium Starch Glycolate (SSG) were also utilized in the fabrication of FDFs containing RZN via the solvent casting technique. A total of eight formulations (RF1 to RF8) were developed employing a 23 factorial design, using the natural superdisintegrant alone at a concentration of 5% and in combination with other superdisintegrants. Results: The prepared MKS was found to be free-flowing, fine, amorphous, insoluble in organic solvents, and exhibiting 0.17% solubility in water with a swelling index of 89.95%, indicating superdisintegrant properties. Fourier-transform infrared spectroscopy (FTIR) studies and Differential scanning calorimetry (DSC) analysis indicated that there was no drug-excipient interaction. The films prepared with a 5% concentration of the MKS showed good physical properties and resulted in an increased drug dissolution rate, with 99.78 % of the drug dissolved within 10 min, along with the lowest disintegration time of 13.45 sec. Conclusion: The research successfully isolated a new superdisintegrant, MKS and formulated FDFs of the poorly water-soluble drug RZN. The MKS was found to be an effective superdisintegrant with no drug interactions, producing films with good physical and mechanical properties, increasing the drug dissolution rate, and providing rapid disintegration with improved relative bioavailability.

Sustainable barrier coatings for paperboard packaging: Effect of VeoVa-10 on 2-EHA and MMA containing water-based emulsions

Developing environmentally benign barrier coatings may provide a sustainable alternative to the packaging sector and facilitate minimizing the consumption of single-use plastics in packaging. The synthesis of seven different water-based (W/B) emulsions was achieved via seeded emulsion polymerization using 2-Ethylhexylacrylate (2-EHA), methyl methacrylate (MMA), and a varying amount of vinyl ester of Versatic™ acid 10 (VeoVa-10) to impart the hydrophobic properties. Potassium persulfate (K2S2O8) was used as an initiator. Antifoaming agent and biocide were also added to improve the application and shelf-life of these coatings. The coatings were evaluated by conducting various analytical tests, including pH measurement, viscosity assessment, determination of solid content, measurement of drying time, evaluation of gloss, water absorption testing using Cobb's Test, and assessment of oil and grease resistance via the Kit Test. The coatings were also analyzed using advanced characterization techniques, including Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Zetasizer Nano ZS, and contact angle analysis. The results indicated that as the amount of VeoVa-10 increases in barrier coatings, the coated paperboard demonstrated improved moisture and oil/grease resistance compared to the control paperboard (uncoated). Furthermore, the coatings were also applied on paperboard trays and stored at 0 °C and 90 °C to confirm their practical usefulness, a careful examination after an hour showed no leakage/seepage of hot and cold water through the coated trays, unlike the uncoated ones. Barrier coatings offer sustainable and eco-friendly options that could positively impact the packaging industry, helping reduce environmental footprints while enhancing packaging performance.

Novel highly performing tandem selective solar absorber for industrial heat applications

The needed decarbonisation of the industrial sector for an efficient transition to a Net Zero future, alongside the lack of commercially competitive solar absorbers for industrial heat applications using small non-evacuated receiver tubes, has motivated the design of a new highly stable material suitable for the open-air conditions. This work demonstrates that the potential candidate is the CuCoMnOx/SiO2 tandem selective absorber, designed to coat line-focussed receiver tubes to supply thermal energy up to 450 °C for industrial process heat applications. Remarkably, with only two layers deposited on stainless-steel (SS) under optimised conditions, the material exhibits excellent optical performance, achieving a αs > 0.95 and a ε350°C = 0.16. The absorber design prioritises cost-effective industrialisation by optimising thermal treatment to lower both temperature and duration time, while fine-tuning layer thicknesses to locate optical interferences at the required wavelengths. This approach ensures outstanding reproducibility, uniformity, and efficiency, marking the first successful deposition of coatings on tubular forms. The coatings composing the absorber are characterised optically, by X-ray diffraction, scanning electron microscope, and thermogravimetric and differential scanning calorimeter techniques. In terms of durability, the absorber shows extraordinary resilience, maintaining thermal stability for 27 months at 400–450 °C in open air, and exhibiting good resistance to condensation (PC = 0.03 in the most drastic situation). Therefore, the SS-substrate/CuCoMnOx/SiO2 absorber emerges as a promising commercial material for both evacuated and non-evacuated receiver tubes, promoting the integration of concentrating solar power (CSP) technology with solar heat for industrial processes (SHIP).

Paper‐based sensors for real‐time cure monitoring in the production of glass fiber‐reinforced phenol‐formaldehyde composites for aerospace interiors

AbstractThe aerospace industries demand for advanced materials necessitates stringent quality control measures, particularly for composite structures to ensure optimal curing and structural integrity. Traditional methods like differential scanning calorimetry (DSC) and dynamic mechanical analysis, while useful, are limited to laboratory settings. This study explores the use of a printed paper‐based sensor for real‐time cure monitoring of glass fiber‐reinforced phenol‐formaldehyde (PF/GF) prepregs. The sensor, composed of a cellulose paper substrate with screen‐printed electrodes, offers flexibility, ease of integration, and cost‐effectiveness compared to commercial polymer‐based dielectric sensors. Real‐time monitoring with the printed paper‐based sensor was conducted at temperatures ranging from 130 to 180°C, both with and without pressure, and validated against DSC and Fourier‐transform infrared (FTIR) spectroscopy. The results showed a strong correlation between real‐time monitoring and the DSC prediction model, as well as FTIR spectroscopy. Notably, the real‐time monitoring revealed a shorter curing cycle on the production line than the predicted cure kinetic model, which is crucial for large‐scale production, such as fabricating honeycomb panels for aircraft interiors. This research underscores the importance of innovative sensor technologies in improving quality control and manufacturing efficiency in aerospace composites.Highlights Cure Monitoring of PF‐based prepregs was carried out using paper‐based sensor. Sensor offered reproducibility and seamless integration in composites. Sensor data showed a strong correlation with DSC and FTIR spectroscopy results. Paper sensors enable online monitoring of composite in aerospace manufacturing.

Strength Retention of Carbon Fiber/Epoxy Vitrimer Composite Material for Primary Structures: Towards Recyclable and Reusable Carbon Fiber Composites

Recently, the growth of the recyclability of carbon fiber reinforced polymer (CFRP) composites has been driven by environmental and circular economic aspects. The main aim of this research work is to investigate the strength retention of a bio-based vitrimer composite reinforced with carbon fibers, which offers both recyclability and material reusability. The composite formulation consisted of an epoxy resin composed of diglycidyl ether of bioshpenol A (DGEBA) combined with tricarboxylic acid (citric acid, CA) and cardanol, which was then reinforced with carbon fibers to enhance its performance. Differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy were performed to analyze the chemical composition and curing behavior of the vitrimer. Mechanical testing under tensile loading at room temperature was carried out on epoxy, vitrimer, and associated carbon fiber reinforced composite materials. The results demonstrated that the DGEBA/CA/cardanol vitrimer exhibited thermomechanical properties comparable to those of an epoxy cured with petroleum-based curing agents. It was observed that the maximum tensile strength of vitrimer is about 50 MPa, which is very close to the range of epoxy resins cured with petroleum-based curing agents. Notably, the ability of the vitrimer composite to be effectively dissolved in a dimethylformamide (DMF) solvent is a significant advantage, as it enables the recovery of the fibers. The recovered carbon fiber retained comparable tensile strength to that of the fresh carbon composites. More than 95% strength was retained after the first recovery, which confirms the use of fibers for primary and secondary applications. These research results open up new avenues for efficient recycling and contribute to the overall sustainability of the composite material at an economic level.

Synthesis and Characterization of Caladium bicolor-Stabilized Iron Nanoparticle

Caladium bicolor samples were collected, thoroughly washed, shade dried, cut into small pieces, oven-dried and ground. Distilled water was added to the ground C. bicolor samples and heated. It was then filtered after heating, and the filtrate stored. To 0.05M solution of FeCl3 was added the extract and stirred. The solution was then filtered and the residue oven dried. This synthesized NP was characterized with Differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), Braunauer-Emmett-Teller (BET) analysis, Scanning Electron Microscope (SEM) and X-ray diffraction (XRD) technique. The results from these analyses were characterised by attributes that indicated a successful synthesis of Caladium bicolor-incorporated Iron nanoparticles. Fourier transform infrared (FTIR) analysis was also carried out on the Caladium bicolor extract and synthesized NPs. Some of the results include O-H stretching (3291.50 cm-1) which is characteristic of alcohol functional group. Alkane is suspected due to C-H stretching at 2919.20 cm-1 and alkene due to C=C stretching at 1628.11 cm-1. Iron (III) chloride vibrations are suspected at 639.22 cm-1 (Fe-Cl stretching). DSC shows exothermic peaks at 323.6°C and 335.5°C and endothermic peaks at 105.7°C and 251.3°C. These results confirmed the presence of iron NPs. The use of plant extracts to synthesize nanoparticles (NP) has become increasingly desirable due to its low cost and non-toxic nature. Caladium bicolor fits this role because of its cheapness and not a food source for man or animals. Iron nanoparticles were synthesized using iron (III) chloride and Caladium bicolor extract.

Fabrication and application of a dual drug-loaded nanoniosomes encapsulating rutin and berberine: optimization, in vitro and ex vivo evaluation

Rutin and berberine are naturally occurring polyphenols but their usefulness is restricted by their low bioavailability and poor solubility. Thus, by delivering rutin–berberine in the form of niosomes simultaneously and hoped to enhance the permeability through nasal route for the treatment of depression. Thin-film hydration approach was used to generate dual drug-loaded niosomes (rutin–berberine) encapsulating rutin and berberine. Various analytical techniques were used to characterize the morphology, size, compatibility, and leakage of the particles. These techniques included transmission electron microscopy, dynamic light scattering, UV spectrophotometry, and differential scanning calorimetry. The optimized formulation (rutin–berberine optimized niosomal formulation) was subjected to additional characterization for drug release, ex-vivo penetration investigation, confocal laser scanning microscopy, and 2,2-diphenyl-1-picrylhydrazyl assay. The rutin–berberine optimized niosomal formulation analysis showed that the drug release was 76.66 ± 1.24% at 24 hours, the entrapment efficiency was 74.8 ± 2.13% (rutin), and 79.0 ± 3.47% (berberine) and the vesicle size was 72.6 nm with a polydispersion index of 0.208. The antioxidant activity showed 73.67 ± 2.5% which is close to regular ascorbic acid. Studies on permeation ex-vivo revealed that rutin–berberine optimized niosomal formulation had considerably higher permeation (84.89 ± 3.15%) compared to rutin–berberine suspension (37.28 ± 2.33%). Furthermore, rhodamine B-loaded rutin–berberine optimized niosomal formulation appeared to have higher penetration than the control (rhodamine B-solution) according to the confocal laser scanning microscope results of the nasal mucosa. Based on all the experimental data, rutin–berberine optimized niosomal formulations were determined to be a viable and successful intranasal delivery formulation.

Non-standard adhesives for wood-based composites: powder adhesives and bicomponent fibers

Powder adhesives and bicomponent fibres are widely used for composite manufacturing; mainly, they are used for glueing fibres during non-woven production. However, in the woodworking industry, they are rarely used. This study aims to investigate the possibility of powder adhesive and bicomponent fibres utilisation for gluing wood. For this purpose, epoxy-polyester powder adhesive and polyester (PES) bicomponent fibres were selected, and one-component moisture-curing polyurethane adhesive was used as a reference. The selected wood species were spruce, beech, oak and wenge. The differences between powder adhesive- and bicomponent fibre-glued wood joints were observed using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX). Mechanical properties of glued wood joints were characterised by tensile shear strength and modelled using finite element modelling (FEM). The adhesives were further characterised using Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The wood joints produced by all combinations of selected wood species and adhesives were comprehensively characterised. The highest values of tensile shear strength were reached by powder epoxy-polyester adhesive (14.85 MPa), whereas joints bonded by bicomponent fibres (5.19 MPa) reached lower values than reference samples.

Interphase mechanics vs chemical compatibility: Generating a deformable PA6-carbon fiber interphase

Good interfacial adhesion is typically correlated to obtaining the best tensile/flexural performance for carbon fibre-reinforced composites. The nature or even presence of the interphase, a localized region around the fibre-matrix junction, is often discussed but notoriously difficult to visualize and characterise. Here, a surface-initiated electro-polymerization approach to covalently graft either polyacrylamide or polygylcidyl methacrylate to the carbon fibres was used. This was followed by continuous melt compounding into the polyamide-6 matrix prior to injection moulding. Analysis via X-ray photoelectron spectroscopy (XPS) coupled with topological/visual study through scanning electron microscopy (SEM), showed distinct surface changes after modification and at the composite fracture surface. Additionally, mechanical (tensile, flexural, and tribological characteristics) and thermal (differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA)) investigations were performed. The results showed that the unmodified CF samples exhibit higher tensile and flexural modulus than the modified CF samples. However, the wear rate has been significantly decreased for modified CF samples. SEM of fractured composite surfaces showcased a clear interphase region surrounding the fibre, highlighting the importance of interphase/interphase mechanics in the design of optimal composite interfaces.

Synthesis and mesomorphic characterisation of coumarin-Schiff base and carboxylate molecules

ABSTRACT Three novel sets of coumarin-based derivatives viz. Schiff’s bases from 2-oxo-2 h-chromene-3-carboxylic acid with terminal alkyl benzene and alkyl biphenyl cores, methyl- or ethyl-group-derived coumarin esters from 7-hydroxy-4-methyl-2 h-chromen-2-one, and ethyl-7-hydroxy-2-oxo-2 h-chromene-3-carboxylate were synthesised and characterised for mesomorphic properties. The structures of the newly prepared compounds were confirmed by FT-IR, 1H-NMR, 13C-NMR, and elemental analysis. The mesophase textures of all coumarin derivatives were observed under a polarising optical microscope, and the transition temperature and enthalpy change data were measured and recorded using differential scanning calorimetry. Most of the compounds exhibit smectic and nematic mesomorphism monotropically and enantiotropically. Thermal stability was investigated by thermal gravimetric analysis (TGA).

Tunable green-blue luminescence of Dy2O3 doped borosilicate glasses for optoelectronic devices

The optical-structural correlated properties of the 40B2O3−40SiO2−10V2O5−(10−x)Fe2O3−xDy2O3 system, where 2, 4, and 6 mol%, were studied. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) confirmed the glassy and amorphous nature of the samples. Adding Dy2O3 promoted the formation of bridging oxygens (upto 4 mol%) by converting BO3 into BO4 units, however, above 4 mol% Dy2O3 act as a modifier. The optical band gap increased from 3.70 to 4.01 eV, while the refractive index decreased from 2.23 to 2.16. The CIE coordinates indicated that the emission spectra fall within the green-blue region. The as-prepared sample exhibited the highest correlated colour temperature value above 5000 K, suggesting its suitability for cool light-emitting diodes sensitive to human vision. These glasses have potential applications in light-emitting diodes and optoelectronic devices.

Thermal analysis of mortar based on crushed dune sand

This study investigates the thermal decomposition behavior of mortars formulated using crushed dune sand and thixotropic polyester resin. Thermal analysis techniques, including Differential Scanning Calorimetry (DSC), Differential Thermal Analysis (DTA), and Gravimetric Thermal Analysis (GTA), were employed to characterize the thermal transitions, decomposition stages, and stability of these mortars. Results indicate that crushed dune sand maintains consistent glass transition (Tg) and crystallization temperatures (Tc) when integrated into the mortar matrix, highlighting its thermal stability. However, the melting point (Tm) varies due to the presence of the resin, which significantly influences the composite’s thermal behavior. Decomposition analysis reveals two major weight loss stages: water evaporation between 200°C to 400°C and organic decomposition of the resin between 700°C to 800°C, with minimal weight change beyond 800°C, indicating thermal stability. The DTA results exhibit distinct endothermic reactions related to dehydration and dehydroxylation, along with a pronounced exothermic peak around 400°C, signifying resin decomposition. Elemental analysis confirms that the crushed dune sand is predominantly silica with minimal impurities, making it suitable for construction applications. This research contributes to a deeper understanding of the thermal behavior of polymer-modified mortars, with implications for enhancing thermal and mechanical properties in construction materials.

Durability of non-woven geotextiles produced from recycled polyethylene terephthalate (PET)

Achieving the goals of sustainable development and circular economy requires recycling and reusing plastic materials. In this research, the durability of five needle-punched non-woven geotextiles were experimentally studied. The geotextiles were made of recycled PET (rPET), virgin PET (vPET), and combinations of rPET and vPET fibers. The samples were hydrolyzed for a period of 14, 28, and 56 days and the retained tensile strength and puncture resistance of the samples were determined at the end of each interval. Moreover, this study took the benefits from the capability of differential scanning calorimetry (DSC), Fourier transforms in infrared spectroscopy (FTIR) analysis, and scanning electron microscopy (SEM) images to interpret the results acquired. Testing on as-received products, it was understood that recycling process could increase crystallinity of the fibers, increasing the fibers fragility, reducing the tensile strength and elongation capacity of rPET fibers. Moreover, considering the borderline value of 50% retained strength, a shorter service life (up to 30%) of rPET products in comparison with vPET products, due to higher degradation rates, was observed.

A different approach to identifying thermal parameters for invasive species.

The brown marmorated stinkbug, Halyomorpha halys Stål (Hemiptera: Pentatomidae), is a polyphagous invasive insect found in the eastern United States in 1998 but became a major agricultural pest in 2010. Environmental temperatures regulate the location of invasive species establishment in new locations. To determine those areas where an invasive species might establish it is essential to understand the metabolic response of all life stages to temperature. Differential scanning calorimetry is a useful tool to monitor living organisms' metabolism at different temperatures, providing vital information related to the ability of the species to survive in new environments. The information obtained from isothermal and scanning calorimetric experiments on all the life stages of H. halys indicates that the third instar is the most thermoresponsive stage and eggs and fifth instar are the least thermoresponsive, whereas the third instars exhibit a broad range of thermoresponsiveness as compared to all other developmental stages. The recorded values for lower, optimal, and upper developmental temperatures in this study were similar to those reported by other researchers using laboratory and field data to develop degree-day models. This method can help in the rapid development of degree day models to improve and synchronize control efforts for newly invasive species.

Stabilizer Effects on the Gelation of Modified Recycled PET for 3D Printing Filament Application

This research identification gel types of the modified-recycled poly (ethylene terephthalate) (modified-rPET) filament, with and without the addition of heat stabilizer Pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (Irganox®1010). This research also identifies the gel types and studies thermal behavior of the modified-rPET filaments above, by using a hot-stage microscopy, and a differential scanning calorimetry, respectively. rPET flakes were dried to deplete the moisture. Then, they were mixed with additives and heat stabilizer (Irganox®1010) at 0 and 0.5 pph, Then, they were extruded to be compound using twin screw extruder. The compounds were extruded into filament by using filament extruder. The two temperature profiles were used. The first and the second temperature profiles from the feed zone to the die zone were 275-275-275 oC and 290-290-290 oC, respectively. The extrudate of modified-rPET with and without heat stabilizer, were investigated the type of gel and the thermal behavior of the modified-rPET filament. From this preliminary experiment, it was found that the “unmelt-gel” defect was found from the modified-rPET filament, without the addition of Irganox®1010. On the other hand, the “crosslinked gel” defect was found from the modified-rPET filament, with the addition of Irganox®1010. Therefore, the addition of heat stabilizer (Irganox®1010) may cause the “crosslinked gel” significantly. Our future work, we will investigate the effect of another stabilizer and chain extenders on the gelation behavior, to complete this clarification systematically.

Temperature and Pressure Effects on Phase Transitions and Structural Stability in CsPb2Br5 and CsPb2Br4I Perovskite-Derived Halides.

All-inorganic perovskites exhibit outstanding light absorption properties in the visible range suitable for solar energy applications. We focus on the synthesis of CsPb2(Br,I)5 using mechanochemical procedures. Synchrotron X-ray diffraction (SXRD) data are essential for determining the crystallographic evolution in the 295-753 K temperature range. From room temperature to 573 K, the crystal structure is refined in a two-dimensional (2D) tetragonal framework (space group: I4/mcm) consisting of layers of face sharing [Pb(Br,I)8] polyhedra. Above a transition temperature of Tt = 630 and 621 K, identified from differential scanning calorimetry (DSC) curves for CsPb2Br5 and CsPb2Br4I, respectively, a cubic three-dimensional (3D) corner-sharing perovskite structure is identified, showing substantial Cs and (Br,I) deficiency. A more ionic character for Cs-halide versus Pb-halide is derived from the evolution of the anisotropic atomic displacements. An ultralow thermal conductivity of 0.35-0.18 W m-1 K-1 is related to the low Debye temperatures. From high-pressure SXRD studies, the change in B0 can be attributed to a basic expansion of the unit-cell volume caused by the chemical pressure from iodine within the CsPb2Br5 framework. UV-vis-NIR spectroscopy revealed optical gaps of approximately 2.93 and 2.50 eV, respectively, which agrees with ab initio calculations.

Screening and inclusion of luteolin for β-cyclodextrin: molecular simulations and experiments

In this study, we first established a guest small molecule screening mechanism by molecular simulation, and then screened lignans from 10 polyphenolic compounds to identify the most suitable guest molecule for encapsulation with β-cyclodextrin (β-CD). Subsequently, the subject-guest interactions and encapsulation mechanisms of lignans with β-CD, 2-hydroxypropyl-cyclodextrin (HP-β-CD) and 2,6-dimethyl-cyclodextrin (DM-β-CD) were investigated using a combination of molecular simulation and experimental methods, respectively. Molecular simulations were performed to calculate the microstructural parameters, including solubility parameters, binding energies, and mean square displacements. The simulation results demonstrated that DM-β-CD exhibited the strongest interaction with luteolin and formed the most stable inclusion complex. The inclusion complexes of luteolin with the three cyclodextrins were prepared by freeze-drying method, and the formation of the inclusion complexes was demonstrated using infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and ultraviolet-visible spectroscopy (UV). Phase solubility studies confirmed the formation of 1:1 stoichiometric inclusion complexes of lignans with cyclodextrins. Furthermore, 2,2-diphenyl-1-pyridine hydrazine (DPPH) free radical scavenging experiments demonstrated that the inclusion complexes exhibited enhanced antioxidant capacity. In light of these findings, it can be concluded that among the three cyclodextrins, DM-β-CD was optimally encapsulated with luteolin.

Synergistic effects of tertiary amine and imidazole accelerators on epoxy resin curing

AbstarctIn order to improve the curing rate, this study investigated the influence of various accelerators and their combinations on the curing behavior of epoxy resins. differential scanning calorimetry (DSC) was used to analyze the curing behavior of various accelerators in diglycidyl ether of the bisphenol A epoxy resin and the methyl hexahydrophthalic anhydride curing system, and activation energies were calculated using the Kissinger and Ozawa models. The results indicated a self‐catalytic characteristic in the curing process and showed that the activation energies for tris(dimethylaminomethyl)phenol (DMP‐30) and 1‐cyano‐2‐ethyl‐4‐methylimidazole (2E4MZ‐CN) were significantly lower compared to N,N‐dimethylbenzylamine, demonstrating higher curing reactivity. Furthermore, a novel strategy combining tertiary amine accelerator (DMP‐30) and imidazole accelerator (2E4MZ‐CN) was proposed and the activation energy variations with the degree of cure were analyzed employing the KAS method. When the mass ratio of DMP‐30 to 2E4MZ‐CN was 1:3, the activation energy was 59.08 kJ/mol, approximately 12% lower than using a single accelerator, which indicated the synergistic effects of the accelerators. Finally, the mechanism of synergistic effect of tertiary amine and imidazole accelerators on epoxy resin curing were proposed.

Hydronium-Crosslinked Inorganic Hydrogel Comprised of 1D Lepidocrocite Titanate Nanofilaments.

When a few drops of acid (hydrochloric, acrylic, propionic, acetic, or formic) are added to a colloid comprised of 1D lepidocrocite titanate nanofilaments (1DLs)-2 × 2 TiO6 octahedra in cross-section-a hydrogel forms, in many cases, within seconds. The 1DL synthesis process requires the reaction between titanium diboride with tetramethylammonium (TMA+), hydroxide. Using quantitative nuclear magnetic resonance (qNMR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC), the mass percent of TMA+ after synthesis is determined to be ≈ 13.1±0.1%. The TMA+ is completely removed from the gels after 2 water soak cycles, resulting in the first completely inorganic, TiO2-based hydrogels. Ion exchanging the TMA+ with hydronium results in gels with relatively strong hydrogen bonds. The hydrogels' compression strengths increased linearly with 1DL colloid concentration. At a 1DL concentration of 45gL-1, the compressive strength, at 80% deformation when acrylic acid is used, is ≈325kPa. The strengths are ≈ 50% greater after the TMA+ is removed. The removal of all residual organic components in the hydrogels, including TMA+, is confirmed by qNMR, Fourier-transformed infrared spectroscopy (FTIR), and TGA/DSC. The 1DL phase is retained after gelation, TMA+ removal, and 80% compression.

Impact of green techniques on intricate cell wall structure of bee pollen to enhance functional characteristics and improve its in vitro digestibility.

Bee pollen is a nutrient-rich super food, but its rigid dual-layered structure limits nutrient release and absorption. The outer exine, composed of stress-resistant sporopollenin, and the inner intine, consisting of cellulose and pectin, form a barrier to digestive breakdown. This study investigates the potential of green techniques, specifically supercritical fluid extraction and ultrasonication, to disaggregate pollen cell walls, enhancing its bioavailability and maximizing nutrient utilization. Ultrasonication treated pollen (USTP) and supercritical fluid extraction-treated pollen (STP) demonstrated disruption, as evidenced by scanning electron microscopy imaging. In relation to scanning electron microscopy, techno-functional, antioxidant, and compositional analysis displayed a positive outcome, with crude lipid, protein, antioxidant activity (2,2-diphenyl-1-picrylhydrazyl activity and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid assay) and total phenolic content increased by 34.80%, 32.58%, 10.80%, 11.37%, and 83.94%, respectively. Based on the above properties, USTP for 4 h and STP at 400 bar for 40 min were identified as the optimal conditions for disintegration. Furthermore, optimized samples analyzed for amino acid and mineral release revealed a notable increase in composition of essential amino acid and minerals (Ca, Cu, Fe, etc.) by ∼1.5 and 1.2 times, respectively. Along with significant changes in composition, fractured pollen exhibited 1.4 folds increase in protein digestibility with minor differences in thermal stability, and crystallinity as established by differential scanning calorimetry, and X-ray diffraction analysis. The study confirms that nutrient release and absorption remain restricted without pre-treatment, highlighting the necessity of specific treatment to disintegrate bee pollen before its use as a functional food ingredient. PRACTICAL APPLICATION: Bee pollen is a rich source of all the essential nutrients required by the humans and recognised as a complete food. However, its tough cellular structure restricts its utilisation in numerous food applications. Therefore, to disintegrate bee pollen and release its nutrients, ultrasonication and super critical fluid extraction processes were employed to improve its utilization for human purposes. Both the treatment techniques, enhanced bee pollen's bioavailability and functional properties, making it more suitable for use in nutraceuticals and functional foods.These treatments proved to increase the antioxidant capacity, digestibility, and create high-value ingredient for supplements, beverages, and fortified foods.