Explore the vast range of titles available.

Silica aerogel, a kind of nanoporous material, is regarded as a desired drug carrier for its low toxicity, high specific surface area, and excellent biocompatibility. Using silica aerogel in a drug carrier may be an appropriate method to improve the performance of pure resveratrol. In this study, resveratrol-loaded silica aerogel (RSA) as a drug delivery system was prepared by the sol-gel method. Before gelling, resveratrol was added into the hydrolyzed tetraethyl orthosilicate (TEOS) ethanol solution then dispersed by stir and ultrasound. The results showed that RSA has a high loading rate of 19% with low cost and excellent biocompatibility. The SEM images showed that silica aerogel wraps up outside the resveratrol. Sustained releasing effect could be observed in RSA after 1 h, while pure resveratrol did not display this. The release of RSA lasted for over 6 h, and the release amount reached over 90% and 80% in either simulated gastric fluid (pH = 2.0) or phosphate-buffered saline (pH = 7.4) at 37 °C. Preliminary in vitro toxicity test revealed RSA to be biocompatible and stable; and when coupled with the anti-inflammatory effects of resveratrol, showed good potential for osteoarthritis treatment.

In the context of energy and the environment and considering the increasing energy demand in industrial processes and for thermal comfort, enhancing system performance and optimizing operations are essential. This paper presents a comprehensive analysis of the adsorption -desorption isotherms of silica gels, which are widely used desiccant materials. Accurate characterization of the adsorption and desorption behaviors is pivotal for assessing their performance across various applications. In this study, we examined multiple isothermal equations describing the interaction between silica gel and water vapor. Our findings highlight the critical importance of the adsorption capacity at low temperatures, as confirmed by experimental results from a climatic wind tunnel. The experimental results indicate that the isosteric heat of adsorption (ΔH ads ) decreases with increasing moisture content, suggesting a progressive reduction in the energy required for water uptake as adsorption progresses. Furthermore, we demonstrate that the adsorption and desorption isotherms follow distinct paths, highlighting a divergence from hypothetical models. Two empirical correlations linking water content to temperature and relative humidity for both adsorption and desorption processes were developed, showing good agreement with experimental results compared to existing correlations in the literature and illustrating the gap between theoretical and experimental findings. This research enhances our understanding of the adsorption properties of silica gel and provides the groundwork for its effective application in areas such as atmospheric water generation and air conditioning systems, among others.

Hydroxyl-α-sanshool is the main alkylamide produced by Zanthoxylum armatum DC., and it is responsible for numbness after consuming Z. armatum-flavored dishes or food products. The present study deals with the isolation, enrichment, and purification of hydroxyl-α-sanshool. The results indicated that the powder of Z. armatum was extracted with 70% ethanol and then filtrated; the supernatant was concentrated to get pasty residue. Petroleum ether (60–90 °C) and ethyl acetate at a 3:2 ratio, with an Rf value of 0.23, were chosen as the eluent. Petroleum ether extract (PEE) and ethyl acetate–petroleum ether extract (E-PEE) were used as the suitable enriched method. Afterward, the PEE and E-PEE were loaded onto silica gel for silica gel column chromatography. Preliminary identification was carried out by TLC and UV. The fractions containing mainly hydroxyl-α-sanshool were pooled and dried by rotary evaporation. Lastly, all of the samples were determined by HPLC. The yield and recovery rates of hydroxyl-α-sanshool in the p-E-PEE were 12.42% and 121.65%, respectively, and the purity was 98.34%. Additionally, compared with E-PEE, the purity of hydroxyl-α-sanshool in the purification of E-PEE (p-E-PEE) increased by 88.30%. In summary, this study provides a simple, rapid, economical, and effective approach to the separation of high-purity hydroxyl-α-sanshool.

Conventional approaches of making a flexible circuit are generally complex, environment unfriendly, time and energy consuming, and thus expensive. Here, we describe for the first time the method of using high-performance GaIn(10)-based electrical ink, a significantly neglected room temperature liquid metal, as both electrical conductors and interconnects, for directly writing flexible electronics via a rather easy going and cost effective way. The new generation electric ink was made and its wettability with various materials was modified to be easily written on a group of either soft or rigid substrates such as epoxy resin board, glass, plastic, silica gel, paper, cotton, textiles, cloth and fiber etc. Conceptual experiments were performed to demonstrate and evaluate the capability of directly writing the electrical circuits via the invented metal ink. Mechanisms involved were interpreted through a series of fundamental measurements. The electrical resistivity of the fluid like GaIn(10)-based material was measured as 34.5 µΩ·cm at 297 K by four point probe method and increased with addition of the oxygen quantity, which indicates it as an excellent metal ink. The conductive line can be written with features that are approximately 10 µm thick. Several functional devices such as a light emitting diode (LED) array showing designed lighting patterns and electrical fan were made to work by directly writing the liquid metal on the specific flexible substrates. And satisfactory performances were obtained. The present method opens the way to directly and quickly writing flexible electronics which can be as simple as signing a name or drawing a picture on the paper. The unique merit of the GaIn(10)-based liquid metal ink lies in its low melting temperature, well controlled wettability, high electrical conductivity and good biocompability. The new electronics writing strategy and basic principle has generalized purpose and can be extended to more industrial areas, even daily life.

Silica aerogels or xerogels are renowned dried gels with low density, high surface area, higher porosity, and better thermal stability which makes it suitable for aerospace, light weight structures, thermal insulation, and hydrophobic coatings. But brittle behaviour, low mechanical strength, and high manufacturing cost restrict its usage. Recently, the addition of various fibres like glass or carbon fiber is one of the best reinforcement methods to minimize the brittle behaviour. Supercritical drying technique usually used to develop aerogel that is expensive and difficult to produce in bulk quantities. Higher cost obstacle can be tackled by applying ambient pressure drying technique to develop xerogel. But researcher observed cracks in samples prepared through the ambient pressure drying technique is still a major shortcoming. The aim of this study is to systematically analyze the influence of silica gel fiber reinforcement on silica xerogels, encompassing morphology, mechanics, thermal behaviour, compression test, and thermogravimetric characteristics. The research used a low-cost precursor named Tetraethyl orthosilicate to synthesize low-cost composite Silica xerogel and glass and carbon fiber added to provide strength and flexibility to the overall composite. Silica gel works as binder in strengthening the xerogel network. The investigation employs scanning electron microscopy (SEM) to examine the morphology of the composites, Fourier Transform Infrared (FTIR) analysis to affirm hydrophobic characteristics, compression tests to assess mechanical strength, and thermogravimetric tests to study weight loss under different conditions. SEM results reveals that glass fibers exhibit lower adhesion to the xerogel network compared to carbon fibers. FTIR analysis confirms the hydrophobicity of the composite silica xerogel. Compression tests showed that, under a 48% strain rate, the carbon fiber composite demonstrates superior compressive stress endurance. Thermogravimetric tests revealed a 1% lower weight loss for the carbon fiber composite compared to the glass fiber composite. This work concludes that glass and carbon fiber together with silica gel particles successfully facilitated in developing flexible, less costly, hydrophobic, and crack-free silica xerogel composites by APD. These advancements have the potential to drive innovations in material science and technology across diverse industries.

Monod, Wyman, and Changeux (MWC) explained allostery in multisubunit proteins with a widely applied theoretical model in which binding of small molecules, so-called allosteric effectors, affects reactivity by altering the equilibrium between more reactive (R) and less reactive (T) quaternary structures. In their model, each quaternary structure has a single reactivity. Here, we use silica gels to trap protein conformations and a new kind of laser photolysis experiment to show that hemoglobin, the paradigm of allostery, exhibits two ligand binding phases with the same fast and slow rates in both R and T quaternary structures. Allosteric effectors change the fraction of each phase but not the rates. These surprising results are readily explained by the simplest possible extension of the MWC model to include a preequilibrium between two tertiary conformations that have the same functional properties within each quaternary structure. They also have important implications for the long-standing question of a structural explanation for the difference in hemoglobin oxygen affinity of the two quaternary structures.

Molybdenum coordination compounds, [MoO 2 L 1 (CH 3 OH)] ( 1 ) and [MoO 2 L 2 (CH 3 OH)]0.5(CH 3 OH) ( 2 ), were obtained by the reaction of molybdenum trioxide with ONO-donor ligands [H 2 L 1  = ( E )-4-amino- N' -(5-bromo-2-hydroxybenzylidene)benzohydrazide and H 2 L 2  = ( E )-4-amino- N' -(2-hydroxynaphthalen-1-yl)methylene)benzohydrazide]. The structures of 1 and 2 were determined by single crystal X-ray analysis and they further characterized by elemental analysis (carbon, hydrogen and nitrogen) and spectroscopic methods such as FT-IR, UV–Vis and NMR analyses. According to the structural analyses, a free amine functionality (Ph-NH 2 ) was present in the structure of compounds 1 and 2 . Therefore, compounds 1 and 2 were supported on the surface of functionalized silica gel by amidification reaction. The obtained supported catalysts ( Si-Mo-1 and Si-Mo-2 ) were characterized by XPS, XRD, EDX, DRS, TGA and FT-IR analyses. The obtained supported catalysts ( Si-Mo-1 and Si-Mo-2 ) were tested in the epoxidation of olefins using aqueous TBHP oxidant. Some effective parameters on the selectivity and activity of Si-Mo-1 and Si-Mo-2 like the effect of the concentration of catalyst and oxidant, temperature and solvent were studied. The supported catalysts were easily recovered from the mixture of the reaction by filtration and the recovered catalysts were also characterized by various analyses. The results indicated that the supported catalysts ( Si-Mo-1 and Si-Mo-2 ) are selective and effective catalysts for epoxidation of olefins. Graphical Abstract

Several cottonseed varieties are cultivated in different countries. Each variety produces a different amount of gossypol as a natural toxic compound. The rising interest in cottonseed products (oil and feed) increases the demand for establishing simple methods for gossypol detection. Silica gel-based methods are ideal for its isolation, purification, and characterization. Silica gel-based methods are variants and can be used as simple methods for tracking plants’ compounds. In this study, gossypol was isolated, characterized, and purified as gossypol acetic acid in the form of yellow crystals. Methods used for its characterization were TLC, preparative TLC, silica gel column, UV/IR spectrophotometer, and HPLC (robust spherical silica gel). A comparative study between its amount in both the Egyptian and Chinese varieties was performed. Under the experimental conditions, the Egyptian’s cottonseed contains 8.705 gm/kg, while the Chinese’s cottonseed contains 5.395 gm/kg. The TLC used in this study proved to be fast, accurate, and inexpensive. It can be used for gossypol acetic acid evaluation and quantification. Additionally, using TLC as a pre-purification step will give a pre-judgment for the sample’s purity and quality. This step will protect the expensive HPLC silica gel-based column from any unexpected impurities. During each step, the silica gel itself could be simply removed by paper filtration. Collectively, the different silica gel-based methods as well as the other used methods are recommended for better Gossypol acetic acid isolation, purification, and characterization, as well as for maintaining HPLC columns.

This study explores a solar-driven hybrid desalination approach developed for Saudi Arabian climatic conditions, combining adsorption desalination (AD) based on a silica gel/CaCl2 composite with an ejector (EJ) and a HDH system. The proposed integration aims to enhance vapor utilization and reuse condenser heat to generate additional distillate. Two operating modes are examined, including a productivity-focused strategy that activates evaporator/condenser heat recovery (HR) when cooling is not required. Compared to raw silica gel (SG), the composite adsorbent improves adsorption cycle performance, raising the COP from about 0.38–0.43 to 0.55–0.63, and increasing SCP from roughly 130–240 W/kg to 320–675 W/kg. Without HR, the full AD–EJ–HDH system achieves SDWP of 52–100 m3/ton·day with GOR of 2.40–2.75 over the year. In HR-enabled operation, SDWP increases to 81–140 m3/ton·day and GOR rises to 2.7–2.95, reflecting stronger internal heat reuse and improved vapor management. Techno-economic results show that the solar-driven unit cost for AD–EJ–HDH decreases from winter values (2.7–2.9$/m3) to a minimum around June (1.53 $ /m3), while waste heat operation reduces the cost further to 0.49$/m3 in June (rising to ~0.76–0.80 $ /m3 in winter). With HR, the full AD–HR–EJ–HDH reaches around 1.44$/m3 (solar, June) and 0.38–0.40 $ /m3 (waste heat, summer), confirming the advantage of desalination-focused HR operation when cooling is not required. Finally, compared with SWRO, the AD–HR–EJ–HDH configuration delivers an approximately 90% lower carbon footprint on the same environmental assessment basis. The study highlights the environmental benefit of the intensified SG/CaCl2 hybrid configuration.

Over the past two decades, microfluidic-based separations have been used for the purification, isolation, and separation of biomolecules to overcome difficulties encountered by conventional chromatography-based methods including high cost, long processing times, sample volumes, and low separation efficiency. Cyclotides, or cyclic peptides used by some plant families as defense agents, have attracted the interest of scientists because of their biological activities varying from antimicrobial to anticancer properties. The separation process has a critical impact in terms of obtaining pure cyclotides for drug development strategies. Here, for the first time, a mimic of the high-performance liquid chromatography (HPLC) on microfluidic chip strategy was used to separate the cyclotides. In this regard, silica gel-C18 was synthesized and characterized by Fourier-transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance ( 1 H-NMR) and then filled inside the microchannel to prepare an HPLC C18 column-like structure inside the microchannel. Cyclotide extract was obtained from Viola ignobilis by a low voltage electric field extraction method and characterized by HPLC and matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF). The extract that contained vigno 1, 2, 3, 4, 5, and varv A cyclotides was added to the microchannel where distilled water was used as a mobile phase with 1 µL/min flow rate and then samples were collected in 2-min intervals until 10 min. Results show that cyclotides can be successfully separated from each other and collected from the microchannel at different periods of time. These findings demonstrate that the use of microfluidic channels has a high impact on the separation of cyclotides as a rapid, cost-effective, and simple method and the device can find widespread applications in drug discovery research. Graphical Abstract