In this study, we have developed functionalized mono- and dicationic 1,4-diazabicyclo[2.2.2]octane (DABCO) based ionic liquid salts ([C(n)DABCO(+)][Br-] or ([Bz C(n)DABCO(2+)] [2Br(-)]. For the dicationic salts, the nitrogen atoms of DABCO were conjugated to a benzyl group at one end and various long-chain alkyl groups - where n ranged from 10 to 18-at the other end. The interactions of the DABCO salts with ionic liquids such as 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide [Bmim] [Ntf2] and 1-butyl-3- methylimidazolium dicyanamide [Bmim] [DCA] were examined computationally. As proof of concept, the most optimal DABCO salts were synthesized and their gelation ability with ionic liquids [Bmim] [Ntf2] and [Bmim] [DCA] was examined. Our results indicate that the length of alkyl chains of the DABCO salts as well as the anionic component of the ionic liquids played a key role in the gelation process. The DABCO salts with n > 12 formed gels more efficiently in the presence of [Bmim] [Ntf2], while [Bmim] [DCA] gels were formed when n > 14. Furthermore, the dicationic DABCO salt gels were found to form nanofibers or nanowires in the presence of [Bmim] [Ntf2] while the [Bmim] [DCA] gels exhibited gelatinous structures. The monocationic DABCO salts formed dense nanorods or nanofibrillar structures regardless of the ionic liquid components. The thermal properties of the gels indicated that overall the gels formed with [Bmim] [Ntf2] showed higher stability. Additionally, we explored the ability of the gels to extract the environmental pollutant dye methyl orange. Our results indicated that the gels were able to extract the dye efficiently and thus may be potentially developed for trapping environmental pollutants from industrial waste. This study provides a better understanding of the interactions occurring between the DABCO salts and the ILs [Bmim] [DCA] and [Bmim] [Ntf2] and may open new doors for developing nanoscale gelatinous structures for applications in environmental remediation.
Poly(vinyl alcohol) (PVA) is constrained by its low thermal resistance, high water solubility, and moderate mechanical strength, limiting its use in advanced applications. To overcome these issues, a novel, one-step bio-based modification of PVA was developed using starch, malic acid, and phthalic anhydride. The resulting biocomposite film (PVA+) is transparent, flexible, and exhibits significantly enhanced properties. Thermogravimetric analysis showed a 60 degrees C improvement in decomposition temperature to 297.8 degrees C. Mechanical testing revealed percent of extension increase from 262.00 +/- 3.92% to 371.00 +/- 6.65%, while force of strain increase from 42.000 +/- 1.829 N to 54.00 +/- 1.398 N. Furthermore, the film demonstrated complete insolubility in common organic solvents while maintaining 30% biodegradability over 90 days. This sustainable approach effectively enhances the performance of PVA without the use of toxic cross-linkers.
Clobetasol propionate, a topical glucocorticoid, is commonly used to treat inflammatory skin conditions, including atopic dermatitis and psoriasis. However, prolonged use offers risks to patients. This study evaluated the influence of diverse gel-forming polymers (hydroxypropyl methylcellulose, xanthan gum, and chitosan, at 2%) for clobetasol cutaneous delivery (0.05% drug). The formulations were characterized in terms of their appearance, pH, spreadability, rheology, and in vitro drug release. Cutaneous performance, including ex vivo skin permeation and retention (intact and injured skin), in vitro skin adhesion and cytotoxicity, was evaluated. All hydrogels demonstrated favorable characteristics, with a pH of approximately 4. Viscosity did not significantly affect the release rate, which was sustained for 24 h across formulations. Xanthan gum was considered the most promising gel, with higher viscosity and shear-thinning properties, as well as enhanced skin adhesion, without increasing permeation into deeper skin layers, which has been observed for chitosan in intact and injured skin. Hydroxypropyl methylcellulose was also capable of retaining the drug in the upper skin layers; however, its low degree of skin adhesion and low viscosity might reduce its clinical applicability. Importantly, all formulations exhibited superior cytocompatibility compared with the drug solution. Overall, the cutaneous performance of xanthan gum hydrogel is expected to reduce systemic exposure and minimize potential adverse effects.
5-fluorouracil (5-FU) is widely used in clinical chemotherapy, but its non-targeted delivery causes severe systemic toxicity, and uncontrolled burst release limits therapeutic efficacy. Existing pH/temperature-responsive hydrogels for 5-FU delivery suffer from low drug loading capacity and unbalanced sustained release performance, failing to meet clinical demands. To develop highly efficient and safe drug delivery carriers, this study employed a green aqueous solution radical polymerization method. Using DEA and AMPS as functional monomers and EGDMA as a crosslinking agent, a dual-response hydrogel PDAE responsive to both temperature and pH was synthesized. Performance testing demonstrated that this hydrogel exhibits excellent mechanical and swelling properties, along with good temperature/pH sensitivity. At a DEA/AMPS molar ratio of 121:9, the gel achieved maximum 5-FU loading capacity (326.84 mg & centerdot;g(-1)) and encapsulation efficiency (16.72%). Under physiological conditions (37 degrees C, pH 7.4), it exhibited a cumulative release rate of 26.34%, consistent with a first-order release model. Hemolysis rate <1.9% and cell viability >87.6% indicate favorable biosafety. The optimized hydrogel addresses the limitations of current 5-FU delivery systems, providing a promising smart carrier for clinical chemotherapy with improved targeting and reduced side effects.
Zwitterionic polymer films have been fabricated for combating bacterial fouling on PDMS surface. However, zwitterionic polymers-based non-fouling surfaces are liable to be destroyed due to strong hydration. Herein, dimethacryloylated poloxamer 407 antifouling film was photografted onto the PDMS surface. Surface characterization demonstrated that grafted PM exhibited outstanding stretching resistance when pulled to 50% strain, and dynamic resistance to saline solution at 37 degrees C for 10 days compared to the grafted zwitterionic film. Bacterial adhesion assays revealed that both zwitterionic and PM-modified surfaces exhibited superior antibacterial efficacy compared to pristine PDMS film. We believe that the poloxamer grafted films will be great potential for antifouling applications.
Perillyl alcohol (POH) is a monoterpene found in the essential oils of several plants and citrus fruits, with well-documented anticancer potential. However, its poor aqueous solubility and low oral bioavailability significantly limit its therapeutic efficacy. This study describes the development of mucoadhesive chitosan/tripolyphosphate (CS/TPP) nanoparticles for the encapsulation and controlled delivery of POH. The nanoparticles, prepared by ionic gelation, exhibited a mean diameter of similar to 300 nm, a positive zeta potential (+9 +/- 3 mV), low polydispersity (0.09 +/- 0.04), spherical morphology, and an encapsulation efficiency of 35 +/- 3%. XRD and DSC analyses indicated partial amorphization and enhanced thermal stability of the encapsulated compound, whereas FTIR confirmed nanoparticle formation and suggested physical entrapment of POH within the chitosan matrix. The formulation provided sustained POH release for up to 144 h, with approximately 38% released over the first 72 h. Cytotoxicity assays in HT-29 and LNCaP cells demonstrated concentration-dependent reductions in viability for both free and encapsulated POH, with higher IC50 values for the nanoparticle formulation, consistent with its prolonged release profile. Mucoadhesion studies revealed significant mucin adsorption, physicochemical alterations upon contact with mucin, and clear evidence of surface interactions by SEM, supporting strong mucoadhesive properties. Collectively, these findings highlight CS/TPP/POH nanoparticles as a promising platform to improve the oral delivery, absorption, and therapeutic potential of POH for cancer treatment.
This study presents fabrication and analysis of carbon nanotube (CNT)/Ecoflex composites with characteristics of balanced conductivity, flexibility and mechanical robustness. We developed uniform composites using a low-viscosity CNT/Ecoflex suspension combined with a solvent evaporation technique. The electrical resistance and strain characteristics of the composites were analyzed, followed by further examination of their stress-strain behaviors. The 8.5 wt.% and 9.1 wt.% composites demonstrated higher elastic properties without compromising their conductivity. Furthermore, our exploration into tactile sensing characteristics revealed that the 2 wt.% CNT/Ecoflex composites responded optimally at a voltage of 20 V. Finally, the 1.5 wt.% CNT/Ecoflex composites were implemented in a hand motion sensor, showcasing its ability to accurately track and differentiate complex hand gestures. This work provides crucial insights into the potential of CNT/Ecoflex composites in fields requiring mechanical strength, flexibility, and consistent conductivity.
This study investigates the complexation of long-chain carboxymethylcellulose sodium salt (NaCMC) with short-chain quaternized poly(4-vinylpyridine) (QP4VP). The novelty of this work lies in how the pH-dependent behavior of the polysaccharide derivative influences its conformation, which, in turn, impacts the polyelectrolyte complexes (PECs) formed. The study uses the polyanion NaCMC below its critical overlap concentration (C * = 0.2 wt%), ensuring the dominance of NaCMC - QP4VP interactions over NaCMC self-associations to yield soluble complexes. Complexation occurs through electrostatic interactions between carboxylate groups (COO) and pyridinium sites (4VPH+), along with hydrogen bonding, as validated by UV-visible spectroscopy, conductivity, and pH measurements. The manuscript also discusses the possibilities of interactions between the functional groups of both polyions. These interactions govern the appearance of insoluble zones of complexed segments and soluble zones of non-complexed segments within the material. Transmittance at 500 nm and zeta potential measurements confirm these zones. Those possibilities change based on the pH of NaCMC, which controls the ratio of COOH/COO groups along the NaCMC chains. SEM imaging reveals a 3D porous network with features ranging from 175 nm to 23 mu m, and TGA quantifies the contributions of each polyelectrolyte in the PEC.
Hydrogel materials have a variety of applications, ranging from biomedical materials and drug delivery systems, to their employment as immobilization matrices in bioprocessing applications. Polyvinyl alcohol (PVA) is a synthetic, water-soluble, and biocompatible polymer. Due to its physical properties when gelled, this polymer has been highlighted as a suitable candidate for application in the bioprocessing industry as an immobilization matrix for microorganisms. This study investigates the effects of using various polyols as co-solvent on the gelation of PVA-based hydrogels formed at ambient conditions, and their resulting properties. In addition to glycerol, previously known for its capabilities to improve gelation when used as co-solvent, polyols including erythritol (C4H10O4), xylitol (C5H12O5), and sorbitol (C6H14O6) were investigated. Key physical properties of the resulting PVA-based hydrogels were investigated, including: transparency; tensile and compressive strengths; diffusion coefficients; rates of gelation; and method of gelation. It was determined that the hydrogels are formed through physical crosslinking rather than chemical crosslinking. The glycerol-PVA hydrogels tended to exhibit more suitable properties for application in the immobilization of photosynthetic organisms, although the differences in properties between the glycerol-PVA, xylitol-PVA, and sorbitol-PVA hydrogels were comparable and often not significantly different after rehydration. This investigation showed that through the addition of simple polyols, solid PVA-based hydrogels could be formed at ambient conditions without the requirement of cytotoxic chemicals, harsh gelation conditions, or unfavorable intermediate chemicals.
Ultraviolet curing (UV) water-based ink has the advantages of low viscosity, high gloss, and wide application range. However, there are some defects such as slow curing speed and low cross-linking degree. In this paper, the copolymer p(GMA-r-AA) was prepared via traditional radical polymerization using glycidyl methacrylate (GMA) and acrylic acid (AA) as monomers, and then p(GMA-r-AA) was modified by 2-hydroxyethyl methacrylate (HEMA) to obtain acrylic prepolymer P(GMA-r-AA)-g-HEMA with double bonds. Triethylenetetramine reacted with GMA to obtain a multifunctional reactive diluent triethylenetetramine hexamethacrylate glycidyl amide (TGMA). Fourier transform infrared (FTIR) spectroscopy combined with hydrogen nuclear magnetic resonance spectroscopy (1H NMR) was used to characterize the structures of the prepolymer P(GMA-r-AA)-g-HEMA and the reactive diluent TGMA. Three ingredients were needed to prepare UV curable ink: photoinitiator, multifunctional reactive diluent (TGMA), and acrylic prepolymer P(GMA-r-AA)-g-HEMA. The effects of the mass fraction and relative molecular weight of P(GMA-r-AA)-g-HEMA, the type and mass fraction of the photoinitiator, the number of functional groups, and the mass fraction of TGMA on the UV ink curing speed and wear resistance of the ink film were discussed. At a mass fraction of 1% for the photoinitiator TPO, the mass fraction of the reactive diluent was 55% with 4 functional groups, and the prepolymer had an average relative molecular mass of 5.63 x 104 g/mol. The UV water-based ink completed curing in 0.1 s, and the mass loss abrasion was 2-5% after 50 times. Finally, the UV ink was used to prepare UV conductive magnetic ink. The UV conductive and magnetic ink can be cured into a film in 0.1 s, no peeling phenomenon, with good magnetic properties.
The introduction of graphene quantum dots (GQDs) in a pentacene field effect transistor (FET) device structure notably improved the on/off ratio, demonstrating a significant memory window. This indicates that GQDs are effective in enhancing carrier retention properties. However, the subsequent introduction of Ag nanoparticles (NPs) between the pentacene layer and GQDs led to a significant decrease in the memory window and a far smaller on/off ratio. This decrease is primarily attributed to an increase in the "off" current, suggesting a detrimental impact of Ag NPs on the device performance. The formation of an interface dipole at the Ag NPs-GQDs interface appears to be the main factor behind this effect, influencing the energy band bending and altering the flat band energy. The integration of Ag NPs into the device not only modifies the threshold voltage and elevates the "off" current through interface dipole effects, but also considerably diminishes the "on" current. This reduction is attributed to the dual influences of reduced carrier concentration resulting from screening phenomena and the obstruction of charge movement caused by interfacial scattering. This twofold effect on both the "on" and "off" currents underscores the complex influence of Ag NPs in regulating the electronic behavior of the FET device.
In the present work, we report the effect of solvent content on the beta-phase fraction in PVDF (poly(vinylidene fluoride)) films synthesized by the facile wet chemical route using DMF (N,N-Dimethylformamide) as the solvent. The amount of PVDF powder was kept fixed while the amount of DMF was varied. X-ray diffraction (XRD) revealed the transformation of the alpha-phase in the PVDF powder to beta-phase in the synthesized PVDF films, which was further confirmed by Fourier Transform Infrared Spectroscopy (FTIR). Deconvolution of the XRD profiles of the films showed the increase of the beta-phase content (viz. ${\beta \over \alpha }$beta alpha ratio) with initial increase in the DMF volume. However, a surprising and previously unreported result emerged, i.e. the saturation of the beta-phase beyond a certain volume of the solvent. The plausible mechanism for the formation and further saturation of the beta-phase in the PVDF films is discussed.
The kinetics of the curing reactions of two epoxy resin types, aliphatic epoxy resin (ALER) and aromatic epoxy resin (ARER), were evaluated by FTIR, TGA, DSC, SEM, and XRD characterization techniques. Increased curing times improved the mechanical properties of cured ALER epoxy and improved durability compared to that of cured ARER epoxy resin. Flexural stress and modulus of cured ARER epoxy resin were significantly improved after an increase in the curing time. The flexural strength of ARER epoxy increased by 27.2%, while the ALER epoxy flexural strength increased by 10.1% after 840 h curing time. The glass transition temperature at maximum curing was higher for ARER epoxy (76 degrees C) than for ALER epoxy (65 degrees C). The XRD results of epoxy resins showed that crystallinity increased as curing times were increased. The kinetic parameters calculated from the maximum rate of TGA mass losses for both ARER and ALER cured for 840 h were equivalent with rate coefficients, ${10<^>{11 \pm 2}}{{\rm{s}}<^>{ - 1 }}\exp \left({ - 164 \pm 2 {\rm{kJ\ mo}}{{\rm{l}}<^>{{\rm{ - 1}}}}/RT} \right)$1011 +/- 2s-1exp-164 +/- 2kJ mol-1/RT. This indicated that first-order decomposition is rate-determining. Afte curing for 168 h the kinetic parameters were significantly smaller indicating that the epoxy resins are more volatile and the maximum mass-loss rate is both reaction and diffusion rate limiting.
Selenium complexes modifying their chemical structure through the variation of amino acids such as L-phenylalanine, L-histidine, and L-tryptophan were dispersed in collagen-starch hydrogels (1 wt.%), generating the (Se-F), (Se-H), and (Se-T) biomatrices, respectively. SEM/EDS analysis confirmed a uniform selenium distribution, with (Se-H) biomatrix displaying the largest aggregates, influencing the formation and size of aggregates within the biopolymer matrix. All matrices exhibited a semicrystalline nature; notably (Se-T) decreased fibrillar structure crystallinity of collagen. Physicochemical assessments revealed (Se-H) with the shortest gelation time (10 +/- 1 minutes), highest swelling (4500 +/- 230%) and superior resistance to proteolytic degradation. (Se-T) demonstrated the highest crosslinking index (52 +/- 4%), while (Se-F) was characterized by having the highest storage modulus (840 Pa at 1 hz), enabling the sustained release of methylene blue for up to 7 days. Upon contact with commercial plant substrate, all matrices showed negligible mass variation. Biological findings showcased (Se-F) stimulating monocyte metabolism and proliferation, while (Se-H) fostered fibroblast metabolism, proliferation, and interleukin-10 (IL-10) secretion in monocytes, alongside reduced tumor necrosis factor-alpha (TNF-alpha) secretion. All matrices decreased TNF-alpha secretion in monocytes, signifying potential as advanced wound healing dressings. For plant tissue, all matrices enhanced tomato cell metabolism and proliferation. Seeds grown on commercial plant substrate revealed (Se-F) yielding plants with larger stem sizes, while (Se-T) resulted in higher leaf counts within 30 days, indicating their potential agricultural applications.
A quaternary polymer paraffin inhibitor and pour point depressant (PIaPPD) with hyperbranched structure was prepared by free radical solution polymerization using docosyl methacrylate (DM), maleic anhydride (MA), methyl methacrylate (MMA) and diethylene glycol dimethacrylate (DEGDMA) as raw materials. The experimental results show that when the dosage of PIaPPD is 250 ppm, the paraffin inhibiting rate of SY1 for high waxy crude oil can reach 83.3%, and the pour point can be reduced by 16 degrees C. At the same time, it has good universality for the crude oil of the remaining 12 different blocks of oil wells. The paraffin inhibiting rate is up to 83.3%, and the crude oil pour point can be reduced by up to 19 degrees C. Through DSC, FTIR, fluorescent inverted microscope, polarizing microscope, XRD, SEM and carbon number distribution analysis, it can be seen that: PIaPPD achieves the purpose of paraffin inhibition and pour point depression by cocrystal-adsorption and dispersion of wax crystals. It mainly achieves the effect of paraffin inhibition and pour point depression by reducing the wax appearance temperature, inhibiting the amount of wax precipitation, destroying the normal growth structure of wax crystals, reducing the strength of wax crystals, reducing paraffin isoparaffins, and inhibiting the precipitation of most medium and low carbon paraffins and a small number of high carbon paraffins. Finally, the wax crystals exist in the crude oil in a less, small and non-aggregated, irregular state in a more dispersed form.
In this research, the hydrogel nanocomposites based on acryl amide containing penicillin 800, 1200, Ag, and ZnO nanoparticles as wound dressing applications have been studied. In this work, the preparation was done via a reaction of optimal values to produce an antibacterial hydrogel nanocomposite. The hydrogel was obtained in an aqueous medium by using reagents such as acrylamide, potassium persulfate, and methylene bisacrylamide crosslinker, Ag, ZnO nanoparticles, and penicillins and then, the products were dried as white powders. The properties such as swelling rate, pH sensitivity, and high water swelling capacity of the swelling rate study of the hydrogel showed a high absorption rate of water in pH about 3-4. The effect of temperature on the percentage of hydrogel swelling was shown to swell with increasing temperature and the absorption capacity of polyacrylamide hydrogels decreased with increasing NaCl concentration. The chemical structure of hydrogel was confirmed by FTIR spectrum, and the morphology of synthesized hydrogel surfaces was studied via SEM. The antibacterial studies were done in blood, agar, chocolate, and M & uuml;ller medium via three methods, first on gram-negative bacteria E. coli and Klebsiella, second in urine medium, and third in drug medium. This polymeric blend can be used as a new wound dressing compound.
The preparation of polymer nanocomposites (PNCs) by employing green, efficient, and cost effective approach rather than the traditional ways of preparation is considered as a key challenge. In this work, an eco-friendly and cost-effective approach represented by dipping of Acrylonitrile Butadiene Styrene (ABS) pellets in Graphene Oxide (GO) suspensions of different concentrations was adopted to prepare the nanocomposites and improve their thermal performance. GO powder was prepared by Improved Hummers' method, and four different concentrations of GO (0.1, 0.2, 0.3 and 1.0) mg/ml suspended stably via ultrasonication in distilled water. 2.0 g of ABS was dipped in each GO concentration for 20 minutes and then, hot-pressed in order to obtain disc-like samples. The findings showed a successful preparation and adherence of GO to ABS that was confirmed by optical microscopy (OM) and Raman spectroscopy. An improvement in thermal properties of glass transition temperature (Tg) and endothermic temperature was achieved for the ABS pellets dipped in GO suspensions compared to the undipped neat polymer.
In this work, five new peptides derived from natural resources and two peptide bolaamphiphiles were designed. The self-assembling ability of the peptides and the bolaamphiphiles, as well as their predicted antioxidant activity was examined computationally. In particular, replica modeling molecular dynamics studies were carried out at three different temperatures. Results showed that the bolaamphiphiles as well as three of the peptides efficiently formed spherical or fibrous assemblies, particularly at physiological temperatures. In addition, stacking interactions and hydrogen bonds played a critical role in assembly formation. Furthermore, molecular docking studies with extracellular matrix proteins such as the triple helix motif of collagen and the fibronectin (III) motif of tenascin-X displayed binding interactions with the peptides and the bolaamphiphiles. The most optimal peptide bolaamphiphile WMYGGGWMY-CO-NH-(CH2)4-YMWGGGYMW was then synthesized in the laboratory and its ability to form functional scaffolds upon binding to collagen and tenascin-X was examined. The scaffolds were bioprinted with co-cultures of fibroblasts and keratinocytes. The cells not only proliferated over time but also showed strong adherence and spreading within the matrix. Thus, the peptides and the bolaamphiphiles studied in this work, may be potentially developed as scaffold components for tissue regeneration applications.
A thermodynamic model developed by our group has been employed to explore the electro-optical properties of the chiral antiferroelectric smectic C (Sm $C_A<^>*$CA & lowast;) phase. In the present study, the temperature dependence of tilt angle and spontaneous polarization of binary ferroelectric mixtures represented as W-330-3 and W-331-3 exhibiting ferroelectric Sm C* and antiferroelectric Sm $C_A<^>*$CA & lowast; phase has been investigated. Within the framework of this model, the free-energy density characterizing the system featuring the Sm $C_A<^>*$CA & lowast; phase is expressed as a series expansion that incorporates all pertinent degrees of freedom: tensor orientational order ${{\bf{Q}}_{{\bf{ij}}}}$Qij, scalar smectic order psi, polarization vector P, wave vector q of the helix and the resulting coupling terms between these order parameters. The values of Landau coefficients featured in the expansion series are derived from experimental data (tilt angle and spontaneous polarization) of W-330-3 and W-331-3. A substantial agreement between the theoretical predictions and experimental observations has been found.
This article describes the preparation of structural acrylic adhesives (SAA) with low odor and high strength. Isobornyl methacrylate and methacrylic acid were used as the main monomers. Cumene hydroperoxide was used as a radical polymerization initiator. The effects of tougheners, coupling agents, elastomers, monomers, and peroxide on the performance of acrylic adhesives were studied sequentially. The toughness of acrylic structural adhesives was discovered to be enhanced by the addition of carboxyl-terminated butadiene-acrylonitrile liquid rubber (CTBN) to the acrylic matrix. Coupling agents were added to improve SAA's ability to adhere to steel. The results demonstrated that the SAA performs best when the methacrylic acid's content is 7 wt%, cumene hydroperoxide's content is about 1.5 wt%, CTBN's content is 3 wt%, and the coupling agent's content is 1 wt%. Adhesive modified using 2-hydroxyethylmethacrylate phosphate and CTBN as the toughener provided excellent adhesion to the steel substrate. Its lap shear strength was found to be above 24 MPa, its T-peel strength was up to 8.29 N/mm, and its impact strength was up to 12 kJ/m2. The resulting SAA is capable of meeting structural adhesive bonding strength criteria for steel-to-steel joints.
