Site Of Absorption Research Articles

N-Type boron β-diketone-containing conjugated polymers for high-performance room temperature ammonia sensors.

Organic semiconductor (OSC) gas sensors with good mechanical flexibility have received considerable attention as commercial and wearable devices. However, due to poor resistance to moisture and low conductivity, the improvement in the sensing capability of individual OSCs is limited. Reported here is a promising pathway to construct a series of conjugated organic polymers (COPs) with well-defined pyrimidine (Py-COP) or boron β-diketone (BF-COP) units. Unlike traditional metal- or carbon-based hybrid materials, the developed COPs can provide abundant absorption sites for gaseous analytes. As a result, the as-prepared BF-COP results in an excellent sensing response of over 1500 (Ra/Rg) toward 40 ppm of NH3 at room temperature, which is the highest value among those of pristine COPs as n-type sensing materials. Notably, they can maintain their initial sensing responses for two months and 90% relative humidity resistance. Combining the results of in situ Fourier transform infrared spectroscopy and theoretical calculations, the β-diketone skeleton is found to activate the surface electronic environment, verifying that the electron-deficient B ← O groups are adsorption centers. The B/N-heterocyclic decoration effectively modulates the redox properties and electronic interactions, as well as perturbs charge transfer in typical π-conjugated COPs. These results offer insight into developing highly efficient OSC gas sensors, which potentially have broadened sensing applications in the areas of organoboron chemistry.

The desorption of n-hexadecane in calcareous soils from a karst area: Insight into endogenous Cd/Pb

To comprehensively reveal the effects of endogenous heavy metals on the desorption and release of n-hexadecane in calcareous soils from a karst area, the present work conducted desorption kinetic experiments and column experiments. This study also focused on the relationship between heavy metals and n-hexadecane desorption under various environmental factors including pH, ionic strength (IS), and rhamnolipid (RL). Results of desorption kinetic experiments demonstrated that the higher desorption content of Pb in the solution with a lower pH level created additional absorption sites for n-hexadecane, thereby inhibiting the desorption of n-hexadecane in soil samples. The co-desorption of Pb and n-hexadecane was observed in the presence of IS/RL. Particularly, a significant positive coefficient between n-hexadecane desorption and IS was observed (r = 0.904, p < 0.01), and Pb desorption positively correlated to RL (r = 0.810, p < 0.01). In contrast, results of column experiments showed that neither Cd nor Pb were released from the soil column. The limited interaction between soil and solution in the column led to the negligible influence of Cd and Pb on the release of n-hexadecane. The increased release efficiency of n-hexadecane with lower pH, reduced IS, or higher RL concentration can be attributed to the soil properties such as ion enrichment, higher soil pH, and weaker mineral compositions. The findings provide valuable insights into petroleum hydrocarbons mobility in karst areas.

In-vitro Evaluation and Optimization of Sacubitril and Valsartan Floating Tablet using Natural Polymer

Oral systems have become gradually extensive for human consumption because of their numerous advantages, such as formulation efficiency, cost-effectiveness, and patient safety compliance. These systems offer a versatile platform for controlled drug release, allowing precise targeting of absorption site in the gastrointestinal tract. Accomplishing ideal therapeutic results for certain medications often requires precise control of drug release at specific locations within the gastrointestinal tract. In this study, our goal was to create a floating drug delivery system for two vital cardiovascular medications, sacubitril and valsartan. Our specific objectives were to extend floating time, prolong stomach residency, and reduce floating lag time. The strategy involved harnessing the synergistic potential of natural polymers in optimal proportions to enhance drug activity. Following the principles of quality by design (QbD), we systematically explored various formulation factors to optimize the drug delivery system. Analysis of tablet characteristics revealed significant variations in key parameters, such as swelling index, floating lag time (FLT), total floating time (TFT), and drug content for both sacubitril and valsartan. The enhanced formulation (F12) stood out with a remarkable swelling index of 93.4%, a floating lag time of 6.7 seconds, and an impressive total floating time of 12 hours. Furthermore, high drug content percentages were achieved, with sacubitril at 98.70% and valsartan at 94.65%. The successful development and optimization of the floating tablet formulation carry substantial clinical implications. The extended gastric retention, controlled drug release, and high drug content of the optimized formulation suggest enhanced bioavailability and therapeutic efficacy for both sacubitril and valsartan. The prolonged total floating time offers convenience to patients, potentially improving medication adherence in managing cardiovascular diseases. In conclusion, this study highlights the formulation and optimization of floating tablets as a noteworthy advancement in drug delivery technology, promising improved therapeutic outcomes and enhanced patient convenience.

Design, Development and Evaluation of Tetracycline Controlled Release Microspheres

Microsphere drug delivery methods have been used to boost efficacy, reduce toxicity, and improve patient compliance. Additional benefits of using microspheres to deliver medications include controlled drug release, improved bioavailability, and targeted drug delivery to the desired location. In order to achieve the required therapeutic effect, hydroxypropyl methyl cellulose K4M and sodium alginate are used as a polymer in microsphere delivery system and different concentration of aluminium chloride is used as cross linking agent. The advantage of microsphere formulations over traditional tablet or capsule formulations is that they increase the surface area exposed to the absorption site, boosting medication absorption and reducing drug dose frequency. Tetracycline is a broad-spectrum antibiotic that is frequently used to treat illnesses like pneumonia and respiratory tract infections. The encapsulation effectiveness, particle size, in -vitro release analysis and release kinetics of the microsphere formulations was assessed.

An Overview of Biosynthetic Pathway and Therapeutic Potential of Naringin

Abstract: Naringin is a naturally obtained chemical from plants that is formed as a secondary metabolite in them. It possesses significant properties that are useful to humans. The primary sources of naringin extract include fruits of the citrus family which are Citrus reticulata, Citrus bergamia, Citrus aurantium, and Citrus paradisi. It belongs to a class of alcohols primarily consisting of a fused ring system which is responsible for its different medicinal properties, as a consequence, it is widely used in the nutraceutical market nowadays. Nutraceuticals are a part of food that provides health benefits by giving supplements to the body; their final extract form is white in color having crystalline properties with a melting point of 83oC and solubility of 1 mg/ml at 40oC. The absorption of nutraceuticals occurs inside the stomach as it requires a specific pH range between 3.5-4.2. After absorption, it gets converted into naringenin in the liver via a cascade of reactions like dehydrogenation, acetylation, and hydrolysis. Several enzymes are responsible for its conversion into an active form which includes cytochrome P-450, and chalcone isomerase. Its bioavailability depends on a variety of factors including disease condition, gastric moiety, pH of absorption site, the presence of other drugs, and many more. It gets metabolized in the liver itself and finally excreted in the urine. It can be tolerated by the body at high doses, but other conditions can cause its toxicity inside the human body. Its primary properties include anti-inflammatory actions, anti-aging properties, antibacterial properties, anti-cancer properties, and obesity issues.

Recent Advancements in the Development of Nanocarriers for Mucosal Drug Delivery Systems to Control Oral Absorption.

Oral administration of active pharmaceutical ingredients is desirable because it is easy, safe, painless, and can be performed by patients, resulting in good medication adherence. The mucus layer in the gastrointestinal (GI) tract generally acts as a barrier to protect the epithelial membrane from foreign substances; however, in the absorption process after oral administration, it can also disturb effective drug absorption by trapping it in the biological sieve structured by mucin, a major component of mucus, and eliminating it by mucus turnover. Recently, functional nanocarriers (NCs) have attracted much attention due to their immense potential and effectiveness in the field of oral drug delivery. Among them, NCs with mucopenetrating and mucoadhesive properties are promising dosage options for controlling drug absorption from the GI tracts. Mucopenetrating and mucoadhesive NCs can rapidly deliver encapsulated drugs to the absorption site and/or prolong the residence time of NCs close to the absorption membrane, providing better medications than conventional approaches. The surface characteristics of NCs are important factors that determine their functionality, owing to the formation of various kinds of interactions between the particle surface and mucosal components. Thus, a deeper understanding of surface modifications on the biopharmaceutical characteristics of NCs is necessary to develop the appropriate mucosal drug delivery systems (mDDS) for the treatment of target diseases. This review summarizes the basic information and functions of the mucosal layer, highlights the recent progress in designing functional NCs for mDDS, and discusses their performance in the GI tract.

Constructing green superhydrophilic and superoleophobic COFs-MOFs hybrid-based membrane for efficiently emulsion separation and synchronous removal of microplastics, dyes, and pesticides

Oil spills and micropollutants have become thorny environmental issues, posing serious threat to ecosystem and human health. To settle such dilemma, this study successfully constructed a robust and environmentally-friendly MOFs-COFs hybrid-based membrane (FS-50/COF(MATPA)-MOF(Zr)/PDA@PVDF) for the first time through solution synthesis and solvothermal method, combined with surface modification of FS-50 molecule. Importantly, we employed a simple two-step strategy to obtain the high-aspect-ratio MOFs fibers: (1) solvent regulation to generate smaller needle-like whiskers during the in-situ growth of MOFs on COFs; (2) high pressure induced directional crystallization in filtration process. The introduction of polydopamine (PDA) greatly improved the adhesion between coating and PVDF membrane. The in-situ growth of high length-diameter ratio MOFs fibers on blocky COFs greatly enhanced the specific surface area of MOFs-COFs hybrid, thus provided sufficient absorption sites. The functional groups of FS-50 endowed the hybrid membrane with superhydrophilicity and superoleophobicity, which facilitated to selectively penetrate water molecules and repel non-polar pollutants. The separation efficiency and decontamination mechanism of hybrid membrane to the simulated oily wastewater (containing various MPs, dyes, and pesticides) were investigated through experiments and theoretical calculations. The hybrid membrane could selectively and synchronously adsorb various dyes (20 mg/L–120 mg/L, almost 100% removal) and pesticides (10 mg/L for DIF and TET, adsorption rates 93.2% and 90.9%, respectively) from oil-water emulsion (50 mL). The large-scale coated sponge (6 cm × 4.5 cm × 3 cm) could quickly achieve separation of oil-water mixture (almost 100%) with a water permeability of more than 162 L m−2·h−1·bar−1, and simultaneously remove various MPs (PP-2000, PP-100, PE-2000, PS-100, 0.2 g/300 mL for each), Sudan Ⅲ (C0 = 200 mg/L), and DIF (C0 = 10 mg/L) from a simulant oily wastewater (300 mL), with the removal rates of almost 100% for MPs, 99.7% for Sudan Ⅲ, and 95.8% for DIF. Furthermore, we elucidated the removal mechanism of pesticide and dyes through simulating the theoretical adsorption energy and potential adsorption sites. The hybrid membrane not only provides a promising candidate for the removal of multiple pollutants from oil-water emulsion, but also opens a new strategy for achieving efficient and clean aquatic environment restoration.

A Review on Nasal Self-Emulsifying Drug Delivery Systems: An Alternative Approach to Improve Brain Bioavailability of Poorly Water-Soluble Drugs

Neurotherapeutic drugs fail to reach the site of action due to poor bioavailability, poor water solubility, limited permeability, hepatic first-pass metabolism, and the blood-brain barrier. The nasal cavity allows drugs to be delivered directly to the brain, bypassing the blood-brain barrier. The nasal cavity also avoids hepatic first-pass metabolism, enhancing the systemic bioavailability of highly metabolized substances. As a result, most neurotherapeutics have physicochemical properties that necessitate their formulation in lipidic nanosystems as self-emulsifying drug delivery systems (SEDDS). These are isotropic mixes of oils, surfactants, and co-surfactants that, when diluted in water, produce micro or nanoemulsions containing high quantities of lipophilic medicines. SEDDS should prevent drug precipitation at absorption sites, boost permeability through absorptive membranes, and improve labile drug stability against enzymatic activity. When the benefits of SEDDS and the intranasal route for brain delivery are combined, an increase in medication brain targeting and bioavailability might be expected.

Efficient visible-light photocatalysis of chloramphenicol using novel engineered biochar-based Ti-doped Bi2WO6 composite: Mechanisms, degradation pathways, and applications

A novel engineered biochar (ACB)-based Ti-doped Bi2WO6 composite (Ti-Bi2WO6@ACB) was synthesized via a one-step hydrothermal reaction for the efficient degradation of chloramphenicol (CAP) and extensive environmental applications. Multiple characterization techniques, CAP degradation effects, total organic carbon (TOC) removal, effects of environmental factors, recycling tests, actual wastewater treatment, enhancement strategies, and disinfection effects were systematically evaluated. It was found that Ti-Bi2WO6@ACB is a Ti3+ self-doped TiO2/Bi2WO6/ACB ternary heterogeneous photocatalyst. The introduction of ACB and Ti doping enhanced the elemental composition, oxygen-containing functional groups, defect structure (oxygen vacancies), visible-light absorption, and active sites. Moreover, Ti-Bi2WO6@ACB effectively inhibited the recombination of photogenerated carriers. The removal efficiency of Ti-Bi2WO6@ACB for 50 mg⋅L−1 CAP was 92.44 % at 120 min of irradiation, and the TOC removal rate was 67.72 %, which was significantly higher than that of the control treatment. Ti-Bi2WO6@ACB is reusable and photostable, with approximately 99 % sterilization of Staphylococcus aureus and Escherichia coli within 10 min of light irradiation and 48 h of cultivation. The addition of H2O2, ultrasonication, heating, and blowing air in the system improved the photocatalytic efficiency. The ultrasound enhancement mechanisms are related to the effects of cavitation, microjets, and photocatalysis coupled with sonocatalysis. CAP degradation was dominated by OH, O2−, and h+. The doping of Ti3+/TiO2 generated more defects and O2−, and the ACB acted as a carrier to prevent the agglomeration of TiO2 and Bi2WO6. Further, the degradation process of CAP was documented and the degradation pathways may include hydroxylation addition, methanol denaturation, substitution, C–N bond breaking, oxidation, hydrolysis, and decarboxylation reactions. The research presents fresh insights into the development of high-performance engineered biochar-based composite for environmental detoxification.

What to consider for successful administration of oral liquids via enteral feeding tubes? a case study with paediatric ibuprofen suspensions

Administration of medications via enteral feeding tubes (EFTs) is a common practice for children who cannot swallow properly. Although liquid formulations are the preferred dosage forms for this route of administration, little attention has been paid to the amount of drug that reaches the site of absorption after administration via an EFT. This systematic in vitro study aimed to identify formulation parameters and administration approaches that are critical for successful dose delivery via EFTs. For this purpose, drug recovery after administration of three different paediatric ibuprofen suspensions via different types of EFTs was studied using derivative UV spectrophotometry for quantification. Study results indicate that in addition to formulation parameters, feeding tube characteristics and the administration process can have a significant impact on the administered dose. The ratio between the total administered fluid volume (TAV), represented by the sum of dose- and flushing volume, and the feeding tube volume (FTV) proved to be a valuable indicator for assessing successful administration. Incorrect dosing and complications could be avoided if the TAV/FTV ratio was greater than 4. This and other knowledge gained in the study will help to make the administration of liquid paediatric medicines via EFTs both more effective and safer.

Effects of microstructure and morphological distribution on hydrogen-embrittlement sensitivity of Ti–6Al–4V alloy welded joint

The effects of the organizational characteristics and morphological distribution of Ti–6Al–4V alloy welded joint on their resistance to hydrogen embrittlement were investigated. The β-phase continuity of the base material (BM) was poor, and the large volume of the striped α-phase hindered hydrogen diffusion. Consequently, the BM has low hydrogen embrittlement sensitivity. The basket-like phase distribution of the weld material (WM) had better β-phase continuity and higher phase boundary density compared with the BM, providing a more convenient channel for hydrogen diffusion and more hydrogen absorption sites. Therefore, the WM had a high hydrogen embrittlement sensitivity.

The synergistic effect of Ni and C14 Laves phase on the hydrogen storage properties of TiVZrNbNi high entropy hydrogen storage alloy

As a hydrogen storage alloy, the body-centered cubic (BCC) structure has been well studied due to its large hydrogen storage capacity. On this basis, the introduction of catalytic elements and an appropriate amount of C14 Laves phase can further improve the comprehensive hydrogen storage properties of hydrogen storage alloys. Based on this theory, (Ti32.5V27.5Zr7.5Nb32.5) 1-xNix (x = 0.03, 0.06, 0.09) high entropy hydrogen storage alloys with an appropriate amount of catalytic element Ni are prepared in this study. The raise in Ni content is accompanied by grain refinement of the dendritic structure, an increase in the number of grains and grain boundaries, and a gradual increase in the proportion of C14 Laves phase. The introduction of catalytic element Ni reduces the dissociation energy of hydrogen molecules. The increasing grain and grain boundaries increase more hydrogen absorption sites with lower activation energy. The diffusion channel provided by the appropriate amount of C14 Laves phase makes it easier for hydrogen atoms to diffuse into the main phase BCC phase with strong hydrogen absorption capacity, and the hydrogen atoms are trapped by vacancy defects with large hydrogen binding energy. The synergistic effect of the three factors ensures the improvement of hydrogen absorption performance of high entropy hydrogen storage alloys. (Ti32.5V27.5Zr7.5Nb32.5) 0.94Ni0.09 high entropy hydrogen storage alloy achieves excellent saturated hydrogen storage capacity of 2.78 wt % and 2.99 wt % at room temperature and 150 °C under 3 MPa hydrogen pressure, respectively. In addition, the introduction of Ni element reduces the thermal stability of metal hydrides, thereby improving the dehydrogenation performance of high entropy hydrogen storage alloys. The reversible phase transition occurs during the whole hydrogen absorption and desorption cycle.

Aminoalkyl organosilicon with dual chemical sites for SO2 absorption and analysis of site-specific absorption entropy and enthalpy

Wet flue gas desulfurization is widely used for its high efficiency, however, the low absorption capacity, high viscosity and poor thermal stability of absorbents remains an open question. Herein, a low viscosity and high thermal stability SO2 absorbent with dual interacting sites was synthesized by introducing phenyl into organic silicon. The thermal stability of 1,5-bis (diethylamino)− 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane (BADPS) is comparable to ILs, while its viscosity is much lower than that of ILs. For the first time, we use a variant of the pseudo-first-order reaction rate equation obtained the reaction rate constant and the saturation absorption capacity. In addition, the optimal absorption and desorption temperatures were obtained based on an objective function. Mostly importantly, the absorption enthalpy change (ΔH) and entropy change (ΔS) of BADPS absorption reaction show the highest absolute values of SO2 absorbents reported so far. These results indicated that the prepared amine alkyl organosilicon could serve as a promising desulfurizing agent with low-energy consumption.

Study on the characteristic of asphaltene-wax co-precipitation during gas injection of unconventional gas condensate reservoirs

The intensification of energy shortage has accelerated the development of unconventional oil and gas resources, during which complex problems of organic solid precipitation often occur. The precipitation behavior of organic solid such as asphaltene and wax play an important role in the optimization of reservoir production. However, there is still a lack of comprehensive understanding of the precipitation mechanism and interaction between asphaltene and wax, especially under high temperature and pressure. A self-designed precipitation apparatus based on backscattered light was utilized to achieve this objective. The effects of temperature range 30–120 ℃, pressure range 5–85 MPa, gas-oil ratio of 150，300 and 500 sm3/sm3 and injection gas of CH4, CO2 and N2 on organic solid precipitation in condensate oil-gas system were studied by physical simulation. The results revealed that asphaltene precipitated separately at high temperature, and asphaltene and wax co-precipitated at low temperature. Based on the observed precipitation behavior, a co-precipitation mechanism of asphaltene and wax under high-pressure conditions was proposed: Asphaltene particles precipitated first, providing nucleation sites for wax absorption, growth, and cross-linking as the pressure decreased. Moreover, the depressurization induced phase separation during oil and gas production resulted in the extraction of light components, reducing the solubility of wax and exacerbating reservoir damage caused by the precipitation of organic solid. Increasing the gas-oil ratio led to higher amounts of organic solid precipitation and shifted the pressure at which precipitation occurred. Furthermore, the miscibility of injection medium and condensate oil will also significantly affect organic matter precipitation, and the potential damage to the reservoir can be shown as follows: N2＞CO2＞CH4.

Self-Nano Emulsifying Drug Delivery System: A Potential Solution to the Challenges of Oral Delivery of Poorly Water-Soluble Drugs

Lipid-based drug delivery systems (LBDDS) are the most promising technique to formulate the poorly water soluble drugs. Nanotechnology strongly influences the therapeutic performance of hydrophobic drugs and has become an essential approach in drug delivery research. Self-Nanoemulsifying drug delivery systems (SNEDDS) are a vital strategy that combines benefits of LBDDS and nanotechnology. SNEDDS are now preferred to improve the formulation of drugs with poor aqueous solubility. SNEDDS are isotropic mixtures composed of oils, surfactants, and occasionally cosolvents. The ability of these formulations and methods to produce nanoemulsions or fine oil-in-water (o/w) emulsions after moderate stirring and dilution by water phase along the GI tract. SNEDDS has garnered attention during recent years as it improves oral bioavailability, reduces drug dose, and increases drug protection from unsuitable environment in the gastrointestinal tract. It can solve the problems related to the dissolution and bioavailability of the Biopharmaceutics Classifcation System Class II and IV drugs. This review shortly describes the ambiguity between nanoemulsions and microemulsions, mechanism of self-emulsifications, composition and function of various excipients of SNEDDS. This review discusses characterization of SNEDDS, advantage of SNEEDS over other emulsion, biopharmaceutical aspects, and limitation as well as future views. The SNEDDS is a potential formulation for drug delivery. Owing to its small particle size, large surface area, high encapsulation efficiency, and high drug loading, the SNEDDS can improve the rate and extent of oral absorption by maximizing drug solubility in the intestinal absorption site. Moreover, because of the lipid-based formulation of SNEDDS, it can stimulate and enhance lymphatic transport of drugs to avoid hepatic first-pass metabolism, and thus improve their bioavailability.

Aminosiloxane having double absorption sites with low viscosity for efficient SO2 capture

The viscosity and absorption capacity are important factors in evaluate the performance of SO2 absorbent, but it is not an easy task to balance the contradiction between them. Herein, we designed and synthesized a novel aminosiloxane (3-diethylaminomethyl-1,1,3,3-tetramethyl-disiloxyalkyl methyl)-diethylamine (DTDA) with double absorption sites. This absorbent has low viscosity before and after absorption, with 3.41 mPa·s and 180.00 mPa·s at 303.15 K, respectively. The absorption capacities of DTDA can reach 3.42 mol/mol (303.15 K, 1.00 atm) and 1.71 mol/mol (303.15 K, 0.02 atm). The desorption of SO2 can be realized at 363.15 K with good cyclic absorption performance. Moreover, with the introduction of dimethyl silicone oil (DSO), a mixed absorption system (DTDA-DSO) with liquid-liquid phase-change behaviors was obtained. The mixed absorption system not only shows better thermal stability but also needs lower thermal desorption energy consumption. The excellent absorption performance of DTDA-DSO system makes them have great potential in the field of SO2 capture and could provide strong support for their industrial application.

Direct determination of paraquat herbicide by square-wave voltammetry by two-step transfer mechanism at heterogeneous boron-doped carbon nanowall electrodes

Boron-doped carbon nanowalls (B:CNW) versus boron-doped diamond (BDD) materials were investigated for the effective electrochemical detection of highly toxic herbicide paraquat (PQ). Depending on the surface morphology and functional groups of BDD and B:CNWs, the electrochemical absorption and detection of the target analyte PQ revealed different detection mechanisms. The surface absorption mechanism was mainly observed for BDD, while for B:CNWs, both surficial and edge absorption were observed due to the sharp edges of carbon nanowalls. This effectually drives the high heterogenous electron transfer kinetics at absorption sites. Detection of PQ was carried out in phosphate buffer solution with an optimized pH of 10 and parameters of the square-wave voltammetry. Comparative studies show higher voltammetric current peak heights for B:CNWs (∼90.5 μA) than BDD (∼7.5 μA) at a much lower PQ concentration of 4 μM. B:CNWs show a higher sensitivity of 11 μA/μM/cm2 than BDD of 2.23 μA/μM/cm2, hence BDD shows a LOD of 1.8 μM, whereas B:CNWs have a much lower LOD of 0.47 μM. Density functional theory calculations (DFT) show a higher propensity of the B:CNW models toward electrocatalytic reduction of the PQ. Moreover, the proposed two-step detection mechanism is strongly supported by the distribution of the PQ electrostatic potential in different oxidation states in conjunction with the slab surfaces. The higher the sensitivity, the lower the LOD, and the excellent performance of B:CNWs in the detection of PQ in real water samples also suggests its potential for use in the environmental monitoring and assessment of emerging pollutants.

Computationally design aspects of superbasic amidine-arsinine 1-oxide binary frameworks

Novel Brønsted superbases (1–10) were designed on the basis of arsinine 1-oxide core by changing the species of proton absorption site, type and situation of electron-donating substituents in the gas phase and CH3CN medium. The conjugate acids of the designed structures are stabilized through positive charge distribution and/or formation of an intramolecular hydrogen bond. To explore the various structural aspects of the designed molecules for reaching the higher basicity values in gas phase and solution phase in CH3CN solvent, proton affinity (PA), gas phase basicity (GB), pKa, and Nucleus-IndependentChemicalShifts 1 Å above the arsinine 1-oxide ring center along with zz axis (NICS(1)zz) parameters as well as natural bond orbital (NBO) charges calculated and obtained for each structure. The basicity strength of proposed structures was evaluated using B3LYP/6–311 + G(d,p) level of theory. The protonation of all designed structures was studied from both possible sites in gas and CH3CN phase and PA, GB, pKa, and NICS(1)zz values were calculated for each case. It was found that most designed compounds demonstrate superbasicity characteristics and especially amidine-arsinine 1-oxide core structure including two phosphazene electron donating groups (10) shows highest superbasicity properties. The most important finding of the study was the considerable synergistic effect between amidine and arsinine 1-oxide moieties for creating remarkable basicity strength. Aromaticity alterations of the arsinine 1-oxide ring also was monitored during protonation process.

Halogen-free deep eutectic solvents with multiple active sites for efficient absorption of ammonia

The use of reversible absorbents such as ionic liquids (ILs) and deep eutectic solvents (DESs) has recently garnered significant attention for NH3 absorption. Nonetheless, absorbents containing halogen ions, which are often presented in ILs or DESs, impose limitations on their practical applications due to increased corrosiveness. Consequently, there is a strong demand for the development of halogen-free and sustainable absorbents. In this study, a series of halogen-free DESs were synthesized using amino-2-propanol nitrate ([APH]NO3) as a hydrogen bond acceptor, and resorcinol (Res), phenol (PhOH), glycerol (Gly), and ethylene glycol (EG) as hydrogen bond donors. Remarkably, [APH]NO3-Res(2:1) exhibited outstanding NH3 absorption performance of 0.253 g·g−1 at 293 K and 1 bar, which is comparable to, or even exceeds, the absorption capacities of previously reported absorbents. Furthermore, it also showed the ability to be recycled multiple times without a significant decreased in NH3 adsorption performance. Further insight into the NH3 absorption mechanism was gained through quantum chemical calculations and spectral studies, suggesting that the high solubility of NH3 in DESs is facilitated by the multi-site hydrogen bond interaction. The DESs developed in this study have the potential to be viable options for halogen-free and environmentally friendly NH3 capture.

High-performance fractal microsupercapacitors based on Ti3C2Tx MXene for kHz alternating current line-filtering applications

Microsupercapacitors (MSCs) are attracting attention as vital filter capacitors for microscale power conversion in alternating current (AC) line-filtering circuits due to their rapid frequency response characteristics. This study demonstrates the wafer-scale fabrication of Ti3C2Tx MXene-based MSCs with a high-potential device structure incorporating fractal microelectrodes. The experimental and simulation results show that the new structure enables increased ion-transport rates through increased absorption sites and a strong electric field, resulting in improved energy storage and frequency response performance. Therefore, by optimizing the size of the microelectrodes, the fractal MSCs (FMSCs) achieve a high specific capacitance of 615.3 μF cm−2 at 1 V s−1 and their highest frequency characteristic (f0) can reach kHz. Notably, the FMSCs exhibit excellent filtering performance in AC line-filtering circuits by successfully filtering different AC waveforms at a high frequency of 20 kHz into direct current.