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Unfortunately, malaria still remains a major problem in tropical areas, and it takes thousands of lives each year and causes millions of infected cases. Besides, on December 2019, a new virus known as coronavirus appeared, that its rapid prevalence caused the World Health Organization (WHO) to consider it a pandemic. As a potential drug for controlling or treating these two undesired diseases at the cellular level, chloroquine and its derivatives are being investigated, although they possess side effects, which must be reduced for effective and safe treatments. With respect to the importance of this medicine, the current research aimed to calculate the solubility of chloroquine in supercritical carbon dioxide, and evaluated effect of pressure and temperature on the solubility. The pressure varied between 120 and 400 bar, and temperatures between 308 and 338 K were set for the measurements. The experimental results revealed that the solubility of chloroquine lies between 1.64 × 10−5 to 8.92 × 10−4 (mole fraction) with different functionality to temperature and pressure. Although the solubility was indicated to be strong function of pressure and temperature, the effect of temperature was more profound and complicated. A crossover pressure point was found in the solubility measurements, which indicated similar behaviour to an inflection point. For the pressures higher than the crossover point, the temperature indicated direct effect on the solubility of chloroquine. On the other hand, for pressures less than the crossover point, temperature enhancement led to a reduction in the solubility of chloroquine. Moreover, the obtained solubility results were correlated via semi-empirical density-based thermodynamic correlations. Five correlations were studied including: Kumar & Johnston, Mendez-Santiago-Teja, Chrastil, Bartle et al., and Garlapati & Madras. The best performance was obtained for Mendez-Santiago-Teja's correlation in terms of average absolute relative deviation percent (12.0%), while the other examined models showed almost the same performance for prediction of chloroquine solubility., Highlights • Measuring solubility of chloroquine in supercritical CO2 • Thermodynamic modeling of chloroquine solubility at different conditions • Solubility of chloroquine lies between 1.64 × 10−5 to 8.92 × 10−4 (mole fraction).

Present study focused on the adsorption behavior of two cationic dyes (Neutral Red (NR) and Rhodamine B (RB)) on mesoporous silica (MPS) and amino-functionalized MPS with N1-(3-Trimethoxysilylpropyl) diethylenetriamine linker (TAF/MPS). In order to provide more details about adsorption mechanism of dyes on the adsorbents surface, the molecular dynamics (MD) simulations were employed. A very promising simulation approach for adsorption of NR and RB dyes by functionalized and bare MPS adsorbents were obtained by MD results. The obtained results of quantum chemical calculations confirmed the highest adsorption energy for TAF/MPS-water-RB configurations, while the MPS-water-NR had the lowest adsorption energy. According to the results, functionalization of MPS with amino groups led to improvement in adsorption affinity of both dyes. The Sigma profiles demonstrated higher RB adsorption on both adsorbent while lower HOMO–LUMO energy gap was observed for RB dye compared to NR dye. Based on the energies of the HOMO and LUMO, other quantum chemical descriptors were calculated for different dyes, water and adsorbent configurations. These descriptors include: hardness (η), softness (σ), chemical potential (μ), nucleophilicity (ɛ) and electrophilicity index (ω). It was observed that the chemical reactivity, softness, and polarizability of RB dye were more than that of NR dye. The results of this study provide deeper atomic/molecular understanding into the adsorption mechanism of dye molecules on adsorbent surface which could help to get new insights about interactions of molecules. Moreover, MD simulation can be a very useful approach in term of cost-efficient and time saving for predicting the adsorption behavior of structures.

The structure, electronic properties, and the slippage of cyclopentadienyl and indenyl ligands in the (η5-C5H5) (η3-C5H5)W(CO)2 and (η5-C9H7)(η3-C9H7)W(CO)2 were illustrated by applying the mPW1PW91 functional. The solvent impacts were surveyed by the self-consistent reaction field theory (SCRF) based on conductor-like polarizable continuum model (CPCM).The behavior of these compounds was investigated by studying the dipole moment and carbonyl stretching frequencies in solvents of different polarities such as tetrahydrofuran (THF), dichloromethane (DCM), cyclohexanone (CH), ortho-nitrotoluene (NT), Propanonitrile (PN), Acetonitrile (AN), Dimethylsulfoxide (DMSO). The correlations of dipole moment values with Lippert–Mataga polarity function, Bakhshiev polarity function and Bilot and Kawski were illustrated. Also, correlations of the calculated carbonyl stretching frequencies (ν(CO)) with the Kirkwood–Bauer–Magat equation (KBM) were explored. Natural bond orbital analysis (NBO) was utilized for illustration of the W–C bonds in the studied complexes.

Curing cancer has drastically improved in recent decades, but it is essential to find more effective and specific treatments. Radiotherapy and chemotherapy can cause serious side effects and tumor resection surgery may not always be possible. In order to prevail these problems, it is required to find novel therapies to reduce side effects. Application of drug delivery nanovehicles is a promising strategy. Mesoporous silica nanoparticles (MSNPs), amongst various vehicles, have gained tremendous attentions owing to their excellent characteristics including ease of surface modification, improved biocompatibility, chemical and thermal stability, tunable pore diameters and great surface areas. MSNPs possess ordered structure which is very appropriate for packing high amount of drug moieties. Moreover, MSNPs can be tailored by several stimuli sensitive gatekeepers for releasing their cargos. Drug delivery from MSNPs can be controlled by passive targeting of cancer tissues through enhanced permeability and retention (EPR) effect or by active targeting with surface modification of MSNPs using various ligands. This review article outlines the MSNPs synthesis, focuses on the recent progression on the use of MSNPs for stimuli responsive and targeted drug delivery for cancer treatment, and discusses the endosomal escape of MSNPs. Although MSNPs are known for being versatile tools for safer and more efficient cancer treatment, more translational research is needed to study their multifunctional ability in clinical trials.

Low solubility of some drugs in water is a challenging issue in pharmaceutical area which should be properly addressed to achieve drugs with high efficacy. The solubility of an active pharmaceutical ingredient (API) namely lornoxicam in carbon dioxide at supercritical conditions is measured in this work. The experimental measurements were carried out utilizing gravimetric technique, at the pressure and temperature intervals of 120–400 bar and 308–338 K, respectively. The determined mole fraction of solubility revealed that the solubility of this drug is between 3.08 × 10−5 to 3.54 × 10−4. It was perceived that pressure has strong and direct effect on the solubility in which the solubility increases with rising system's pressure. Unlike pressure, the effect of temperature depends on the cross-over point which is between 160 and 200 bar for lornoxicam. Above the cross-over point, the solubility indicated direct relationship with temperature due to improvement of sublimation pressure which is the dominant mechanism. In addition to the experimental measurements, the solubility data are correlated using five semi-empirical correlations namely Mendez-Santiago-Teja (MST), Bartle et al., Chrastil, Kumar and Johnston (KJ) and Garlapati & Madras with minimum average absolute relative deviation (AARD %) 6.2% for Bartle et al. model.

In this study, membrane based solvent extraction of vanillin as one of the most popular flavour was investigated theoretically using computational fluid dynamic technique. A mass transfer model and simulation was developed based on continuity and transport phenomena equations. The effect of operating parameters such as pH, type of solvent and feed flow rate as well as membrane specifications including fibres number, fibre length and porosity-to tortuosity ratio was investigated. There was good agreement between experimental data and modelling value in terms of vanillin extraction percentage. The results showed that butyl acetate is the best solvent and it had the highest vanillin extraction at pH of 7. It was found that increasing feed flow rate can decrease vanillin extraction due to reduction of residence time in the contactor. Change in the membrane specifications had positive impact on the vanillin extraction. Increase in all fibres length, number of fibre, and porosity-to tortuosity ratio because of improving residence time, mass transfer area, and increase in effective diffusivity, respectively led to the enhancement of vanillin extraction. The extraction was reached 44% when the fibre length became 5 times longer. Moreover, it was concluded that the membrane system showed better performance when the feed flows in the tube side of contactor.

One of the effective medications for Glioblastoma Multiforme is Temozolomide (TMZ) which is taken as a treatment for some brain cancers. With respect to the importance of this drug in cancer therapy, the solubility of this medicine was analyzed under various ranges of pressure and temperature in supercritical carbon dioxide (SC-CO2) to evaluate the possibility of drug micronization for reducing its undesired side effects. The measurements were conducted using gravimetric method and revealed that the solubility of the drug is between 4.30 × 10−4 to 5.28 × 10−3 based on mole fraction. The results demonstrated the strong dependency of the TMZ solubility to pressure and temperature, while the effect of pressure is more profound at higher temperatures. Besides, the calculated solubility data was correlated employing five popular semi-empirical density-based correlations including Bartle et al., Chrastil, Kumar and Johnston, Mendez-Santiago-Teja, and Garlapati & Madras models. The obtained outcomes illustrated that among the tested models, KJ led to the best correlative ability with average absolute relative deviation percent (AARD %) of 8.39%, while Garlapati and Madras led to the worst modeling results with AARD % of 15.20%.

We studied the facile synthesis, design, simulation, and modeling of novel diamino-functionalized hollow mesosilica spheres (DAF-HMSS) structures to remove Neutral Red (NR) and Crystal Violet (CV) from aqueous media. The synthesized sample was characterized by FESEM, TEM, LXRD, BET-BJH, and FTIR techniques. The adsorption and removal mechanism of these hazardous dyes on DAF-HMSS in the presence of water molecules was studied using molecular dynamics simulation. The equilibrium adsorption capacities of DAF-HMSS were computed via the conductor-like screening models with segmented activity coefficients known as COSMO-SAC. Simulation results of optimization by DMol3 showed that adsorption of CV dye by diamino groups of DAF-HMSS is more active in comparison with NR dye. Reactivity of molecules, chemical hardness (η), global softness, and electrophilicity index (ω) of compounds were assessed using the HOMO–LUMO gap. The Sigma profiles of DAF-HMSS with dyes showed that mesoporous adsorption of CV was more than NR while HOMO–LUMO energy gap of CV dye was less than NR. So, the chemical reactivity, chemical softness, and polarizability of CV dye were more than that of water and NR. Meanwhile, the kinetic stability of NR was more than CV dye. Besides, results of electrophilicity index (ω) exhibited high electrophilicity index of CV dye which indicates high toxicity of this dye.

One of the authentic separation methods to purification of bioproducts is expanded bed adsorption (EBA). The magnetic field expanded bed adsorption (MFEBA) can be used to improve the efficiency of the EBA process. New type adsorbent beads composed as κ-Carrageenan-Fe2O3 (KC-Fe2O3) and superporous κ-Carrageenan- Fe2O3 (SP-KC-Fe2O3) have been prepared and well-studied by w/o emulsification method followed by morphological, physical and hydrodynamic investigations. The optical microscopy (OM) and field emission scanning electron microscopy (FESEM) were applied to the morphology study of the adsorbent particles. A suitable spherical morphology and porosity have been detected for the fabricated composite beads. A suitable wet density between 1.278 and 1.895 g/mL has been detected for the composite adsorbent. The beads porosity and egg (EA) albumin effective porosity were measured for SP-KC-Fe2O3-3 with the values of about 97.83% and 75.62% respectively. In order to study the hydrodynamic behavior of KC-Fe2O3 and SP-KC-Fe2O3 composite adsorbents in expanded bed adsorption process, the residence time distribution (RTD) measurements were carried out. The results indicated that suitable physical and hydrodynamic properties of the fabricated matrices in proof the potential of their application in high flow rate magnetic field expanded bed adsorption.

This paper reports development and validation of a thermokinetic model capable of tracking time-dependent water penetration and the corresponding swelling in polymeric membranes, polybenzimidazoles as case study here. This attempt is highly important as the effect of water in separation performance and properties of membrane is a hot topic to understand the separation mechanism. Specially as humidity in feed gas is common in most of industrial gas separation processes noting that water penetration can cause swelling which may result in variation in mass transport and mechanical deformation in form of thickness change. We compared model calculation to relevant reported data showing robustness of developed thermokinetic model.

Nitrogen dioxide (NO2) is known as a detrimental acidic contaminant, which its emission into the atmosphere can significantly endanger the human well-being. Therefore, the necessity of mitigating and controlling the NO2 molecules emission needs substantial attention. This research aims to addresses molecular sequestration of NO2 from a gaseous flow applying NaOH absorbent in a hydrophobic porous membrane contactor (HPMC). A mechanistic two dimensional (2D) model is developed based on mass transfer and fluid flow, while computational fluid dynamics (CFD) approach is used for numerical solution of the model's equations. The governing mathematical equations with their corresponding boundary conditions are solved via finite element (FE) approach. The comparison of the model's findings with the experimental data corroborated an excellent agreement with average absolute relative error (AARE) of approximately 2%. The results also demonstrated that the NaOH liquid absorbent can sequester 90% of the NO2 molecules at the inlet feed gas stream, which implies NaOH adequacy for NO2 molecular sequestration. Additionally, the results demonstrated the improvement of NO2 molecular sequestration by increasing some functional/operational parameters such as inner tube radius, module length, absorbent concentration and gas flow velocity inside the HPMC.

This research paper is aimed to deal with evaluating the separation efficiency of SO2 molecules applying novel 1-ethyl-3-methylimidazolium ethyl sulfate (EMISE) ionic liquid and dimethylaniline (DMA) aromatic amine solution inside a microporous membrane contactor (MMC). For this aim, a CFD-based mechanistic modeling and its associated simulation are developed. Simultaneously, the existed momentum and mass transfer equations are analyzed using the finite element procedure (FEP). The results demonstrated that the developed model's results are in acceptable agreement with the achieved literature data (experimental results) with average relative deviation (ARD) of lower than 5%. It is well understood that both EMISE and DMA solutions are significantly promising to separate SO2 molecules from an inlet SO2/Air gaseous mixture. A comparison of the results showed that EMISE ionic liquid has been able to separate 100% of inlet SO2 molecules while DMA possesses the ability to sequester about 98.8% of inlet SO2.

Nowadays, various types of liquid solutions have been applied to remove acidic contaminants such as CO2 with the aim of mitigating their pernicious emission to atmosphere. Ionic liquids are recently of tremendous attention as promising solutions for CO2 molecular removal from disparate gaseous mixtures due to their superior characteristics such as regeneration simplicity, low volatility and negligible environmental toxicity. The main objective of this paper is to mathematically implement a model based on finite element approach (FEA) to analyze the governing mass and momentum partial differential equations inside the domains of polytetrafluoroethylene-co-perfluorinated alkyl vinyl ether membrane contactor (PFAMC). Also, a computational fluid dynamics (CFD) simulation is carried out to analyze the CO2 molecular removal percentage using MEA absorbent and a mixed solution containing 30% 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) ionic liquid and 70% MEA amine solution. The results show that although MEA has been able to remove only 18% of CO2 from the inlet gas, the addition of 30% [Bmim][BF4] ionic liquid to MEA significantly improved the CO2 mass transfer performance and consequently its removal efficiency to 79%. Study on the effect of some operational parameters such as inlet feed gas flow rate, packing density and number of hollow fibers on removing the CO2 molecules is another objective of this paper.