Hydroxypropyl Research Articles

A novel mucoadhesive film containing probiotic extract for oral candidiasis treatment: Formulation and antifungal evaluation

Probiotic strains offer a novel and potentially effective approach to treat oral candidiasis. Buccal mucoadhesive films have attracted considerable attention in recent years due to their unique ability to adhere and persist on the oral mucosa, while gradually releasing their encapsulated drug content. Therefore, the aim of the study was to develop mucoadhesive films containing probiotic extract for treatment of oral candidiasis. Mucoadhesive films were fabricated with hydrophilic polymers, such as polyvinyl alcohol (PVA) and hydroxy propyl methyl cellulose (HPMC). Then, films were evaluated regarding their thickness, pH, tensile strength and elongation, swelling, in vitro release and antifungal activity. The type of polymer used had an impact on the mechanical properties, swelling and release of the films. Films prepared using PVA showed significantly higher tensile strength and elongation at break values compared to those prepared using HPMC. However, swelling index increased with enhancing HPMC concentration in the films. The release of probiotic extract from the film prepared with HPMC occurred slowly. Based on these results, films containing 54 % HPMC and 26 % PVA were selected as optimal formulation. Moreover, it was found that optimal film containing probiotic extract could inhibit the growth of Candida albicans. Regarding to the obtained results, probiotic oral adhesive mucoadhesive films can be considered as a promising alternative to traditional methods in the treatment of candidiasis.

Heteroatom‐Containing Zeolites as Solid Lewis Acid Catalysts for the Cycloaddition of CO2 to Epoxides

AbstractThe catalytic cycloaddition of CO2 to epoxides to produce valuable cyclic carbonates represents a simple and promising strategy for CO2 utilization, circumventing the ineffective CO2 reduction process. Despite current progresses, there remains an impending demand for highly‐active, cost‐effective and stable catalysts especially the ideal heterogeneous catalytic systems. Herein, we report the preparation of heteroatom‐containing zeolites through a two‐step process comprising of framework dealumination and subsequent heteroatom incorporation, and their catalytic applications in CO2 cycloaddition to epoxides. Characterization results reveal the successful incorporation of heteroatoms into framework to derive Lewis acidic M‐Beta zeolites (M = Ti, Zr or Hf). The as‐prepared M‐Beta Lewis acids show remarkable performance in the model reaction of CO2 cycloaddition to propylene oxide with the assistance of potassium iodide under solvent‐free conditions. The reaction parameters have been optimized employing Ti‐Beta catalyst and the substrate scope has been investigated. Finally, the impact of Lewis acidity on the cycloaddition reaction is discussed and the actual bifunctional Ti‐Beta/KI catalyst system is proposed, which is of important significance for the understanding of CO2 catalytic cycloaddition to epoxides.

Mild condition lignin modification enabled high-performance anticorrosive polyurethane coating

The diverse active hydroxyl groups of lignin pose challenges in the preparation of lignin-based polyurethane coatings with exceptional long-term anticorrosive properties. Here, the dense and defect-free lignin-based polyurethane coating with a thickness of 25 ± 5 μm was successfully synthesized using a mild hydroxypropyl lignin modification approach, exhibiting outstanding barrier properties (|Z| > 109 Ω cm2) and long-term anti-corrosion performance exceeding 120 d. Under ambient conditions (i.e., 25 °C and atmospheric pressure), propylene oxide was directly blended with the alkali solution of lignin to effectively convert phenolic hydroxyl groups into more reactive aliphatic hydroxyl groups, while also minimizing the significant increase in molecular weight caused by lignin condensation. As a result, the high crosslinking density of lignin polyurethane coatings effectively prevented the penetration of corrosive media and enhanced the long-term corrosion resistance of the coatings. Overall, the results demonstrate that a mild hydroxypropyl modification process is an effective and facile strategy to prepare highly reactive lignin-based polyols, which is crucial for the development of high-performance bio-based polyurethane anticorrosive coatings.

Plant Design for the Production of Propylene Oxide by Isopropylbenzene 2-phenylpropane, or (1-Methylethyl) Benzene (Cumene)

Cumene is a colorless, volatile liquid with a gasoline-like odor. It’s also known as isopropylbenzene, 2-phenylpropane, or (1-methylethyl) benzene. It’s a natural component of coal tar and crude oil, and it can also be employed in gasoline as a blending component. Cumene hydroperoxide is produced by oxidizing cumene with benzene and propylene in the presence of air. As a result, the cumene hydroperoxide is changed to cumyl alcohol, which is then transformed to propylene without the use of oxygen. Propylene oxide is an organic compound produced through various methods such as the cumene process and the hydroperoxide process. The cumene method is preferred due to its low by-product production and high market value of co-products. The reactive distillation process is a feasible method for producing propylene oxide with high purity and reduced costs. Future work includes optimizing processes, developing new catalysts, and improving efficiency. Propylene oxide has practical applications in the production of polyurethane foams, coatings, adhesives, polyether polyols, and propylene glycols.

Different Mo-Bi Phase Coupled with Fe-Co for Propylene Oxidation to Acrolein

Different Mo-Bi Phase Coupled with Fe-Co for Propylene Oxidation to Acrolein

Ce(III) formate-derived hierarchical cerium oxide particles with icosahedral symmetry-based architectures: Effect of third level of structural hierarchy in soot and propane oxidation

The article investigates the role of architecture of complex hierarchically structured ceria and gadolinium doped ceria particles in soot combustion (solid-solid reaction) and propane oxidation (gas-solid reaction). Synthesis of hierarchical ceria mesostructures showing icosahedral symmetry-based architecture has been presented for the first time. Carefully choosing synthetic conditions allows to obtain particles with intended morphology of dodecahedron, rhombic hexecontahedron, great stellated dodecahedron, fractal-like branched great stellated dodecahedron and great dodecahemicosacron polyhedra. Twinning-based multiple branching of Ce(III) formate crystals by {101} twin orientation relation was proposed as a driving mechanism for the formation of macroparticles architecture that has been confirmed by the construction of macroparticle models using the identified twinning law. In the catalytic studies, the third level of the material organizational structure referring to shape of hierarchical macroparticles was chosen as a tested variable, while other architecture-related properties were controlled to be alike. In result, the shape of hierarchical particles plays a vital role in the catalytic soot oxidation, and architecture modulation allows the catalytic properties of the material to be enhanced through increasing the geometrical fit between ceria and soot particles. The best sample lowers temperature of half oxidation by 143 °C as compared to non-hierarchically organized ceria nanocrystals. The shape of hierarchical particles does not play leading role in gas-solid propane oxidation, but introduction of Gd dopant diversifies catalytic activity. The architecture of the particles may serve as a modifier of the catalytic activity through grain boundary engineering of gadolinium doped ceria.

Highly Efficient Carbonylation of Propylene Oxide into β‐Butyrolactone Catalyzed over Co‐Al Bimetallic Species†

AbstractRational designation of the catalyst for efficient atom‐economic conversion of propylene oxide (PO) and carbon monoxide (CO) into β‐butyrolactone is of current significance. By employing the O,N,O‐tridentate ligands R1,R2LH2 (1–4), the aluminium compounds (R1,R2LAlCl)2 (R1,R2=H,H (5), tBu,tBu (6), Cl,Cl (7), Br,Br (8)) and the derived anion‐cation pairs [H,HLAl(THF)3]+[Co(CO)4]− (9) and [(R1,R2LAl)2Cl(THF)2]+[Co(CO)4]− (R1,R2=tBu,tBu (10), Cl,Cl (11), Br,Br (12)) as well as the aluminium‐cobalt bimetallic cluster compounds [(R1,R2LAl)2Cl(THF)][Co3(CO)10] (R1,R2=tBu,tBu (13), Cl,Cl (14), Br,Br (15)) were prepared. Compounds 9–12 efficiently catalyzed the PO carbonylation into β‐butyrolactone to achieve up 93.4–98.9 % yields while 13–15 gained 95.2–99.0 % yields all at 25 °C and 0.1 MPa CO pressure. The Lewis acidic property of the aluminium compounds 5–8 was investigated. The kinetic of the catalytic reaction using compound 10 was studied. The cooperatively catalytic reaction mechanism by the Co−Al bimetallic species is proposed.

Mechanism Insights into Allylic Hydroxylation versus Epoxidation of Propene Catalyzed by Model Catalyst Iron Phthalocyanine in the Presence of Hydrogen Peroxide.

High-valent metal-oxo species are key reactive intermediates in many biological and biological oxidation reactions. Herein, allylic hydroxylation (C-H) versus epoxidation (C═C) reactions of propene with a model catalyst iron phthalocyanine (FePc) in the presence of hydrogen peroxide were investigated contrastively, aiming to probe the active intermediates, structure-activity relationship, and reaction pathways. Our results showed that H2O2 as an oxygen-donor reagent can be easily decomposed on FePc to produce key active intermediates O═FePc and O═FePc═O with the energy barriers of 19.57 and 23.89 kcal/mol, respectively. In the selective oxidation of propene, O═FePc has a small preference for C═C epoxidation over C-H hydroxylation while O═FePc═O has a small preference for C-H hydroxylation. Since the electron-withdrawing O axial ligand in O═FePc═O further increases the radical character (Fe-O·) and Fe-O bond length of the iron-oxo moiety, O═FePc═O has better catalytic performance in both C═C epoxidation and C-H hydroxylation than O═FePc. Furthermore, in the whole reaction processes, the dual-hydrogen bonds between the two terminal H atoms of the alkene and allylic groups of propene and oxygen atom of the iron-oxo moiety would lead to the reaction toward C═C epoxidation while the single-hydrogen bond between the terminal H atom of the allylic group and the oxygen atom of the iron-oxo moiety would lead to the reaction toward C-H hydroxylation, implying that the weakly interacting hydrogen bonds affecting oxidation pathways also play a very important role in the regioselectivity of C═C epoxidation and C-H hydroxylation.

Asymmetric oxygen vacancies of self-supporting Co3O4/CuOx on Cu foam boosts propane total oxidation

As a low-cost and environmentally friendly transition metal oxides material, the Co3O4 has good catalytic activity for volatile organic compounds (VOCs) oxidation. However, the active components of powder cobalt-based catalysts may present uneven distribution and aggregation, thus affecting the catalytic efficiency. Herein, the Co/Cu-CF monolithic catalyst with asymmetric oxygen vacancies was developed through in-situ growth of Cu(OH)2 nanoarrays on Cu foam, which exhibits excellent performance for propane oxidation (T90 at 215 ℃). It is impressive that the catalyst shows satisfactory stability in terms of long-term, cyclic and water resistance. The results indicate that the existence of nanoarrays can provide a rich load surface and better disperse the active components, which effectively facilitates the interface interaction between cobalt and copper, inducing the generation of asymmetric oxygen vacancies. And, the activity of catalyst was significantly improved owing to the double activation effect of asymmetric oxygen vacancy on molecular oxygen and lattice oxygen. Therefore, this research offers a novel approach for designing efficient nanoarray monolithic catalysts for VOCs oxidation and other environmental applications.

Revamping anti-cGAS-STING therapy via an injectable thermo-responsive supramolecular hydrogel for pathological retinal angiogenesis

Retinal neovascularization is a leading cause of blindness. While current anti-VEGF drugs effectively inhibit pathological angiogenesis, some patients develop resistance or reduced responsiveness to treatments over time, leading to diminished effectiveness. In this study, we identified high activation of the cGAS-STING signaling pathway, which exacerbated pathological neovascularization and vessel leakage. We developed an injectable thermo-responsive supramolecular hydrogel loaded with an anti-STING drug. The hydrogel, made of Pluronic F127 (PF·127) consisting of poly(ethylene oxide) and poly(propylene oxide) units, demonstrated excellent transparency and biocompatibility. Importantly, the thermo-sensitive property allowed for precise spatial release of the drug, extending the effective treatment duration of C-176, which suppressed STING activation in the retina, reduced inflammation, and protected retinal tissue. HydroC-176 effectively inhibited microglial cell infiltration and the release of inflammatory angiogenic factors, highlighting its enhanced efficacy. While demonstrating slightly lower effectiveness compared to traditional anti-VEGF therapy, HydroC-176 exhibited more robust capabilities in regulating ocular microenvironmental inflammation. This approach may assist in enhancing the sensitivity and effectiveness of anti-VEGF therapy for reducing ocular inflammation, potentially improving patients’ response to traditional treatment. These results have suggested innovative and comprehensive strategies for the management of retinal neovascularization.

Hydrophobic modification of biomass chitosan for treatment of oily wastewater and its demulsification mechanism

Traditional demulsifiers are commonly produced using raw materials like ethylene oxide and propylene oxide, which deplete significant petroleum resources and involve hazardous and complex manufacturing processes. In this investigation, a hydrophobically modified chitosan (HMC) was synthesized by grafting dodecyl diethanolamine onto natural chitosan to facilitate the separation of O/W emulsions. Characterization of HMC was conducted using Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance hydrogen spectroscopy (1H NMR) and scanning electron microscopy (SEM). The demulsification efficacy of HMC was assessed through a bottle test in an O/W emulsion containing 0.2 % crude oil. Results showed that at a HMC dosage of 40 mg/L, the light transmission (WT) and oil removal efficiency (WR) of the resulted water phase were 93.4 ± 0.8 % and 99.8 ± 0.1 %, respectively. Furthermore, the competitive adsorption between natural surfactants and HMC at the interface was investigated using interfacial tension (IFT), three-phase contact angle (CA), droplet coalescence time (CTA), and interfacial film substitution. A potential demulsifying mechanism was also proposed, emphasizing HMC’s hydrophilic core and dispersed hydrophobic alkyl chains that enable rapid diffusion to the oil–water interface, replacing interfacial active components to induce demulsification by destabilizing the composite film. The advantages of HMC demulsifier over commercial demulsifiers lie in its superior environmental benefits, diverse range of sources, higher efficiency, and outstanding demulsification performance.

Selective adsorption of aldehyde impurities from propylene oxide using perethylated pillar[5]arene enabled by spatial size matching effect

Effective removal of acetaldehyde and propionaldehyde from propylene oxide is important for polyether industry but remains a significant challenge due to their similar molecular sizes and relatively close volatilities. Herein, we studied flexible molecular materials, perethylated pillar[n]arene crystals (n = 5, 6), which can be used to separate acetaldehyde and propionaldehyde in propylene oxide. Through a space size matching effect, perethylated pillar[5]arene demonstrates excellent adsorption selectivity of 95 % and 100 % for aldehydes in ternary mixture and binary mixture of propylene oxide, acetaldehyde and propionaldehyde, respectively. These impressive selective adsorption is achieved based on their differential host–guest interactions. Density functional theory calculations provide a comprehensive explanation of the adsorption process, revealing that the adsorption mechanisms of perethylated pillar[5]arene for acetaldehyde and propionaldehyde primarily involve C-H···O hydrogen bonding and C-H···π interactions. This study also provides a novel method for achieving one-step purification of propylene oxide in industrial applications.

Physicochemical influence of graphite agent for fabrication of MoVTeNbO catalyst for direct oxidation of propene to acrylic acid

Physicochemical influence of graphite agent for fabrication of MoVTeNbO catalyst for direct oxidation of propene to acrylic acid

Mn/CeO2 contains enriched surface lewis acid sites and pore structures accelerated catalytic oxidation of propane at low temperature

The development of highly efficient non-precious metal catalysts for the low-temperature catalytic oxidation of volatile organic compounds (VOCs) is a critical imperative in VOCs control. In this study, a series of highly active CeMnOx catalysts with Mn-doped CeO2 were investigated. The catalysts (WHSV=30,000 mL g−1 h−1) exhibited the highest catalytic propane oxidation activity (T90 = 230 °C) and excellent stability over 600 h, When the Mn:Ce ratio was 2.5. The introduction of Mn doping resulted in modifications to the pore structure of CeO2, leading to an increase in specific surface area and enhanced gas transfer kinetics. Additionally, it induced surface electronic defects and elevated the concentration of acidic sites, thereby facilitating the adsorption and activation of propane. Consequently, these improvements contributed to an enhanced catalytic performance of the catalyst. The in-situ DRIFTS infrared spectra revealed that Mn doping reduced the activation energy of the reaction and facilitated the conversion of acetone groups as well as decomposition of carboxylic acid groups.

Air-Stable Boranes and Borinanes Encapsulated in Organogels for Anionic Ring-Opening (Co)Polymerization.

Organoborane reagents play a pivotal role as Lewis acids in acid-base pairs used in anionic polymerization and in other reactions; yet their high sensitivity to oxygen and moisture necessitates effective stabilization to prevent their oxidation and thus maintain their catalytic activity. In this study, we present novel encapsulation methods employing a cost-effective hexatriacontane (C36H74, C36) organogel to stabilize sensitive organoborane reagents, including triethyl borane (TEB) and a borinane-based ammonium salt (B3NBr). These organoboranes encapsulated in stable, self-standing organogel blocks enable their safe handling in open laboratory environments without the need for a glovebox. Upon heating such borane-containing organogel blocks organoboranes could be freed from the organogel and used to mediate both the homopolymerization of propylene oxide (PO) and the copolymerization of PO with CO2. Furthermore, efficient recovery of the C36 gelator from polymerization mixtures is achieved, with mass recovery ranging from 70 % to 90 %. This encapsulation method offers a practical and efficient solution for stabilizing, storing, and handling highly reactive organoborane reagents, thereby broadening their applicability and utilization in various chemical transformations.

Direct propylene epoxidation with molecular oxygen over titanosilicate zeolites.

The direct epoxidation of propylene with molecular oxygen represents a desired route for propylene oxide (PO) production with 100% theoretical atomic economy. However, this aerobic epoxidation reaction suffers from the apparent trade-off between propylene conversion and PO selectivity, and remains a key challenge in catalysis. We report that Ti-Beta zeolites containing isolated framework Ti species can efficiently catalyze the aerobic epoxidation of propylene. Stable propylene conversion of 25% and PO selectivity of up to 90% are achieved at the same time, matching the levels of industrial ethylene aerobic epoxidation processes. H-terminated pentacoordinated Ti species in Beta zeolite frameworks are identified as the preferred active sites for propylene aerobic epoxidation and the reaction is initiated by the participation of lattice oxygen in Ti-OH. These results are expected to spark new technology for the industrial production of PO toward more sustainable chemistry and chemical engineering.

Chemical reactions as a means of installing adlayers on electron transport layers

Adlayers are often placed at metal-on-organic interfaces as a common strategy to alleviate damage during metal deposition by thermal evaporation. Methods of chemically installing adlayers have been recently demonstrated on organic semiconductors that address these interfacial issues while providing many secondary benefits. Chemical installation has yet to be attempted at the cathode-electron transport layer (ETL) interface within organic light-emitting devices (OLEDs), offering a powerful option to optimize electron injection, improve surface wetting, and reduce metal penetration. Here, a reaction between TPBi (2,2′,2′’-(1,2,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) and propylene oxide results in a controllable 1–3 nm thick layer of propylene oxide as shown by high-resolution X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDX). The reactive addition of the adlayer at temperatures below 40℃ does not affect the morphology of the thin film and reaches a high degree of coverage within 3 h. Integration of this layer into a phosphorescent OLED does not introduce any significant negative impact on device function. This result opens up the possibility of introducing further specific functionality into the adlayer to engineer OLED performance.

Single B-doped palladium electrocatalyst Enabling direct cathodic coupling of carbon dioxide with methanol into dimethyl carbonate

Dimethyl carbonate (DMC) is a green chemical of large market demand with widespread applications. Direct cathodic coupling of carbon dioxide (CO2) with methanol (CH3OH) into DMC represents a green and sustainable electrochemical route yet remains a great challenge. Reported electrochemical syntheses of DMC from CO2 and CH3OH necessitate the use of toxic methyl iodine or carcinogenic propene oxide. Herein, we for the first time employ a nanosized B-doped palladium catalyst (Pd-B) to realize the direct electrosynthesis of DMC through cathodic coupling of CO2 and CH3OH, which no longer requires any hazardous reagent. Under the optimal condition, the DMC Faradaic efficiency reaches to 47.5 % at 30 mA/cm2, and the yield of DMC is up to 257.3 umol.h−1. A thorough mechanistic investigation has proven that the DMC electrochemical synthesis in our work involves three cascade reactions including CO2-to-CO reduction, methanol-to-methoxide (CH3O–) activation and coupling of CO with CH3O–, simultaneously occurring on the surface of Pd-B catalyst assisted by bromine (Br2) generated at the anode. Two key intermediates in the decisive coupling step, CH3OCO* and CH3O*, are detected on the surface of Pd-B catalyst by In situ ATR-SEIRAS. This work provides a first example of direct cathodic coupling of CO2 and CH3OH into DMC, and the mechanistic investigations in this work will benefit the future design of advanced Pd-based catalysts toward DMC electrosynthesis.

An experimental and modeling study of propane oxidation kinetics in low temperature supercritical water

Propane oxidation in supercritical water was investigated at iso-thermal iso-baric conditions using a batch reactor facility. Mixtures were comprised of 0.014 % propane by volume with an equivalence ratio of 0.8 and a total density of 222 mg/mL or 610 mg/mL. Reaction times ranged from 8 to 30 min for a temperature of 375ºC at 220 or 400 bar, or 400ºC at 220 bar. Major reaction products were CO and CO2 and minor products were propene, acetone, ethene, ethanol, methane, methanol and hydrogen. New detailed chemical kinetic models were developed by combining and refining existing models using genetic optimization. Model predictions exhibited excellent agreement with experimental observations, and indicated that rates of H-abstraction and OH addition reactions involving alkanes and alkenes are affected by the supercritical water environment. Model accuracy was highly sensitive to the rates of CH3O2H = CH3O + OH and CH3 + H2O2 = CH4 + HO2.

Development and In vivo Evaluation of Nanogel Drug Delivery System for Promoting Wound Healing in Diabetic Induced Rats

Recently, researchers have looked at the use of nanotechnology as a drug-delivery system for topical and transdermal applications. The transport of medications and active ingredients to the skin via formulations, including nanoparticles, is a subject of substantial contemporary interest. The present work is proposed to prepare the atorvastatin nanogels to promote wound healing in a diabetic animalmodel.Atorvastatin nanogels were prepared by precipitation polymerization technique using hydroxy propyl methacrylate as polymer. The drug and polymer were selected in ratios of 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7 and 1:8. Additionally, the produced nanogel was evaluated in vivo and examined for its particle size, trapping effectiveness, and drug release in vitro. The particle size of the prepared various formulations (F1-F8) showed a size range of 68 to 80nm, and entrapment efficiency was seen to be in the range of 58.36-86.75%. The cumulative percentage of drug release was reported to be 61.96 to 73.76 percent over a period of 12hours during the in vitro drug release investigation, which was conducted using phosphate buffer at pH 7.4.The drug release followeda non-fiction mechanism of release kinetics. On the other hand, in vivo comparative study showed a complete wound healing effect for nanogels on the 11th day, whereas for conventional gel on the 15th day.This study indicates that nanogels formulation heals the diabetic wound completely at a faster rate, and also the drug atorvastatin also can be used for diabetic wound healing.