In-silico study on viability of MXenes in suppressing the coronavirus infection and distribution.

Herein, based on the paramount importance of combating emerging diseases, through employing a detailed in-silico study, the possibility of using MXenes in suppressing the coronavirus infection was elucidated. To this end, first, interactions of MXene nanosheets (Mn2C, Ti2C, and Mo2C) and spike protein (SP), the main infecting portion of the COVID-19, were investigated. It was found that the modeled MXenes were effective in attracting the SP, so that they can be exploited in filtering the coronavirus. In addition, the effect of the MXenes on the SP structure was assessed which demonstrated that the secondary structure of the SP could be changed. Therefore, the post-interactions of the SP/ACE2 (receptor of coronavirus in the body) could be interrupted, declaring the lower chance of coronavirus infecting. The in-silico studies revealed that the MXenes not only can be used to adsorb and hinder the distribution of the coronavirus but also affect the SP structure and the SP/ACE2 interactions to interrupt the COVID-19 threat. Therefore, MXenes can be exploited with simultaneous roles in physical inhibition and reactive weakening of the COVID-19. In this regard, the Mn2C nanosheet was well suited, which is suggested as a promising candidate to combat the coronavirus.

In-silico study on perovskites application in capturing and distorting coronavirus.

The COVID-19 pandemic, known as coronavirus pandemic, a global pandemic, emerged from the beginning of 2020 and became dominant in many countries. As COVID-19 is one of the deadliest pandemics in history and has a high rate of distribution, a fast and extensive reaction was needed. Considering its composition, revealing the infection mechanism is beneficial for effective decisions against the spread and attack of COVID-19. Investigating data from numerous studies confirms that the penetration of SARS-CoV-2 occurs along with bonding spike protein (S protein) and through ACE2; Therefore, these two parts were the focus of research on the suppression and control of the infection. Performing lab research on all promising candidates requires years of experimental study, which is time-consuming and not an acceptable solution. Molecular dynamic simulation can decipher the performance of nano-structures in preventing the spread of coronavirus in a shorter time. This study surveyed the effect of three nano-perovskite structures (SrTiO3, CaTiO3, and BaTiO3), a cutting-edge group of perovskite materials with outstanding properties on coronavirus. Various computational parameters evaluate the effectiveness of these structures. Results of the simulation indicated that SrTiO3 performs better in SARS-CoV-2 suppression.

Experimental and Computational Study on the Microfluidic Control of Micellar Nanocarrier Properties.

Microfluidic-based synthesis is a powerful technique to prepare well-defined homogenous nanoparticles (NPs). However, the mechanisms defining NP properties, especially size evolution in a microchannel, are not fully understood. Herein, microfluidic and bulk syntheses of riboflavin (RF)-targeted poly(lactic-co-glycolic acid)-poly(ethylene glycol) (PLGA-PEG-RF) micelles were evaluated experimentally and computationally. Using molecular dynamics (MD), a conventional "random" model for bulk self-assembly of PLGA-PEG-RF was simulated and a conceptual "interface" mechanism was proposed for the microfluidic self-assembly at an atomic scale. The simulation results were in agreement with the observed experimental outcomes. NPs produced by microfluidics were smaller than those prepared by the bulk method. The computational approach suggested that the size-determining factor in microfluidics is the boundary of solvents in the entrance region of the microchannel, explaining the size difference between the two experimental methods. Therefore, this computational approach can be a powerful tool to gain a deeper understanding and optimize NP synthesis.

Defect engineering-induced porosity in graphene quantum dots embedded metal-organic frameworks for enhanced benzene and toluene adsorption.

The emerging environmental issues necessitate the engineering of novel and well-designed nanoadsorbents for advanced separation and purification applications. Despite recent advances, the facile synthesis of hierarchical micro-mesoporous metal-organic frameworks (MOFs) with tuned structures has remained a challenge. Herein, we report a simple defect engineering approach to manipulate the framework, induce mesoporosity, and crease large pore volumes in MIL-101(Cr) by embedding graphene quantum dots (GQDs) during its self-assembly process. For instance, MIL-101@GQD-3 (Vmeso: 0.68 and Vtot: 1.87 cm3/g) exhibited 300.0% and 53.3% more meso and total pore volume compared to those of the conventional MIL-101 (Vmeso: 0.17 and Vtot: 1.22 cm3/g), respectively, resulting in 1.7 and 2.8 times greater benzene and toluene loading at 1 bar and 25 °C. In addition, we found that MIL-101@GQD-3 retained its superiority over a wide range of VOC concentrations and operating temperature (25-55 °C) with great cyclic capacity and energy-efficient regeneration. Considering the simplicity of the adopted technique to induce mesoporosity and tune the nanoporous structure of MOFs, the presented GQD incorporation technique is expected to provide a new pathway for the facile synthesis of advanced materials for environmental applications.

Molecular insight into optimizing the N- and P-doped fullerenes for urea removal in wearable artificial kidneys.

Urea is the result of the breakdown of proteins in the liver, the excess of which circulates in the blood and is adsorbed by the kidneys. However, in the case of kidney diseases, some products, specifically urea, cannot be removed from the blood by the kidneys and causes serious health problems. The end-stage renal disease (ESRD) patients are not able to purify their blood, which endangers their life. ESRD patients require dialysis, a costly and difficult method of urea removal from the blood. Wearable artificial kidneys (WAKs) are consequently designed to remove the waste from blood. Regarding the great amount of daily urea production in the body, WAKs should contain strong and selective urea adsorbents. Fullerenes-which possess fascinating chemical properties-have been considered herein to develop novel urea removal adsorbents. Molecular dynamics (MD) has enabled researchers to study the interaction of different materials and can pave the way toward facilitating the development of wearable devices. In this study, urea adsorption by N-doped fullerenes and P-doped fullerenes were assessed through MD simulations. The urea adsorption was simulated by five samples of fullerenes, with phosphorous and different nitrogen dopant contents. For comparing the urea adsorption capacity in the performed simulations, detailed characteristics-including the energy analysis, radius of gyration, radial distribution function (RDF), root-mean-square fluctuation (RMSD), and H-bond analyses were investigated. It had been determined that the fullerene containing 8% nitrogen-with the highest reduction in the radius of gyration, the maximum RDF, a high adsorption energy, and a high number of hydrogen bonds-adsorbs urea more efficiently.

Shedding Light on Miniaturized Dialysis Using MXene 2D Materials: A Computational Chemistry Approach.

Materials science can pave the way toward developing novel devices at the service of human life. In recent years, computational materials engineering has been promising in predicting material performance prior to the experiments. Herein, this capability has been carefully employed to tackle severe problems associated with kidney diseases through proposing novel nanolayers to adsorb urea and accordingly causing the wearable artificial kidney (WAK) to be viable. The two-dimensional metal carbide and nitride (MXene) nanosheets can leverage the performance of various devices since they are highly tunable along with fascinating surface chemistry properties. In this study, molecular dynamics (MD) simulations were exploited to investigate the interactions between urea and different MXene nanosheets. To this end, detailed analyses were performed that clarify the suitability of these nanostructures in urea adsorption. The atomistic simulations were carried out on Mn2C, Cd2C, Cu2C, Ti2C, W2C, Ta2C, and urea to determine the most appropriate urea-removing adsorbent. It was found that Cd2C was more efficient followed by Mn2C, which can be effectively exploited in WAK devices at the service of human health.

Engineering the pH-Sensitivity of the Graphene and Carbon Nanotube Based Nanomedicines in Smart Cancer Therapy by Grafting Trimetyl Chitosan.

PURPOSE: The aim of this study was to introduce a smart and responsive drug carrier for Doxorubicin (DOX) and Paclitaxel (PAX) for desirable therapeutic application. METHOD: Loading and releasing of DOX and PAX from smart and pH-sensitive functionalized single-walled carbon nanotube (SWCNTs) and graphene carriers have been simulated by molecular dynamics. The influences of chitosan polymer on proposed carriers have been studied, and both carriers were functionalized with carboxyl groups to improve the loading and releasing properties of the drugs. RESULTS: The results showed that DOX could be well adsorbed on both functionalized SWCNTs and graphene. In contrast, there was a weak electrostatic and Van der Waals interaction between both these drugs and carriers at cancerous tissues, which is highly favorable for cancer therapy. Adding trimethyl chitosan (TMC) polymer to carriers facilitated DOX release at acidic tissues. Furthermore, at blood pH, the PAX loaded on the functionalized SWCNTs carrier represented the highest dispersion of the drug while the DOX-graphene showed the highest concentration of the drug at a point. In addition, the mean-square displacement (MSD) results of PAX-graphene indicated that the PAX could be adsorbed quickly and be released slowly. Finally, functionalized graphene-TMC-PAX is a smart drug system with responsive behavior and controllable drug release, which are essential in cancer therapy. CONCLUSION: Simultaneous application of the carboxyl group and TMC can optimize the pH sensitivity of the SWCNTs and graphene to prepare a novel and smart drug carrier for cancer therapy.

Molecular insight into the smart functionalized TMC-Fullerene nanocarrier in the pH-responsive adsorption and release of anti-cancer drugs.

The Doxorubicin (DOX) and Paclitaxel (PAX) are widely used for cancer-therapy. Herein, in the efforts devoted to developing smart drug carriers, the loading and releasing of the DOX and PAX on the pH sensitive functionalized Fullerene carrier was investigated by molecular dynamics (MD) simulations. The effects of chitosan polymer as a functionalizing agent of the Fullerene carrier was also studied. In addition, the Fullerene carrier was functionalized with carboxyl groups in order to improve the loading and releasing properties of the DOX and PAX. The results showed the DOX is well adsorbed on Fullerene which was functionalized with carboxyl group and it was released controllably in cancerous tissues. According to the results of the electrostatic and Van der Waals interactions, it was found that the functionalized Fullerene can be a proper carrier for DOX in comparison with PAX. Adding the trimethyl chitosan (TMC) polymer to the carrier could improve the Van der Waals attractions of the PAX and Fullerene which indicates that by passing the time at acidic pH, the Van der Waals energy reaches zero that leads to promote the release of the PAX in cancerous tissues. The carboxyl group which was employed as a functionalizing agent could also increase the number of hydrogen bonds for the PAX and DOX at acidic and neutral pH, respectively. Moreover, a significant rise in the number of hydrogen bonds between the PAX and Fullerene at neutral pH was achieved by adding the TMC to the carrier. A more decrease of gyration radius was obtained for the DOX at acidic pH which confirms that the DOX with TMC-Fullerene is a more stable carrier. So, this smart nanomedicine system is introduced as an promising composition for smart cancer therapy.

Highly uniform molybdenum oxide loaded N-CNT as a remarkably active and selective nanocatalyst for H2S selective oxidation.

Selective oxidation of H2S to elemental sulfur is a low cost and highly efficient process for sulfur removal from H2S-containing hydrocarbon streams in medium scale (i.e. 0.2-10 ton sulfur/day) for environmental protection and prevention of emitting toxic gases to the atmosphere. In this research, in order to prepare a highly active and selective nanocatalyst for selective oxidation of hydrogen sulfide, for the first time, molybdenum oxides were loaded uniformly over nitrogen- doped carbon nanotubes through incipient wetness impregnation. Different metal loadings including 5, 10, and 15 wt% Mo were considered in the synthesis procedure to achieve the optimized performance and provide complete environmental protection. The Mox/N-CNT nanocatalysts were thoroughly characterized via TEM, FE-SEM, XPS, N2 adsorption/desorption, and XRD techniques. The characterization methods confirmed that the Mo oxides nanoparticles were successfully distributed over the N-CNT support uniformly in nanoscale in which there was no sign of agglomeration. The catalytic experiments on Mox/N-CNT were performed in temperature range of 190-230 °C in which the feed gas was composed of 3000 ppm H2S and 1500 ppm O2. The results showed that the Mox/N-CNT samples were highly active at all considered temperatures providing the H2S conversion of almost 100% from which almost no H2S was emitted. Furthermore, by loading the Mo oxide over the N-CNT support, selectivity toward elemental sulfur was increased significantly at high temperatures (i.e. above 190 °C) suggesting that the progress of side reactions on the nanocatalyst has been minimized. The best result was obtained with the sample containing 15 wt% Mo at 230 °C providing the H2S conversion of 100% and selectivity of 89.7%. According to these results, Mo oxide/N-CNT is introduced as a potential candidate for catalytic H2S removal processes toward environmental protection in industrial plants.

A novel highly sensitive and selective H2S gas sensor at low temperatures based on SnO2 quantum dots-C60 nanohybrid: Experimental and theory study.

In this study, SnO2 quantum dots-fullerene (SnO2 QDs-C60) nanohybrid as novel sensing material was synthesized by a simple hydrothermal method. The structure and morphology of the synthesized sample were studied by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The prepared hybrid was used as gas sensors for detection of different gasses including 70 ppm H2S, 1% methane, and 1% propane at low temperatures of 100-200 °C. The results indicated that the SnO2 QDs-C60 nanohybrid has high response and high selectivity to 70 ppm H2S, 1% methane, and 1% propane gasses at low temperatures. The highest response (Rair/Rgas) of 66.0 and 5.4-70 ppm H2S and 1% methane gasses at 150 °C and the response of 2.7-1% propane at 200 °C were observed for the prepared nanohybrid gas sensor. Moreover, the prepared sensor showed a good selectivity toward H2S gas. Also, DFT calculations were used for studying the interaction of these gases with SnO2-C60. DFT results showed that H2S has the strongest interaction and the highest effect on band-gap variation which is in a good agreement with experimental results.