Solvent Impregnation Research Articles

Selective Extraction of Terbium Using Functionalized Metal–Organic Framework-Based Solvent-Impregnated Mixed-Matrix Membranes

Advancements in membrane separation techniques will expand the applications and requirements for highly specialized, inventive, efficient, and resistant separation materials. The selective separation of rare earth elements (REEs) is one of the expanding applications of membrane-based techniques, as their use is becoming more widespread. Membrane techniques are becoming increasingly desired as environmentally friendly, straightforward methods for treating wastewater and separating metals. For the separation of REEs, an innovative impregnated mixed-matrix membrane (IMMM) technique was developed in this study. It provides a selective, efficient, and reusable method that is suitable for industrial applications. Terbium was selectively adsorbed from other REEs using organophosphorus IMMM with a loading capacity of 113.2 mg/g in 3 h and was reused three times without destroying the initial membrane. Solvent impregnation is thought to offer specific chelation sites that are selective for terbium separation.

Functionalization of chitosan films using essential oils by supercritical CO2 impregnation method for various applications

Herein, chitosan films obtained by different approaches were functionalized with essential oils, i.e. mentha, clove, and cinnamon, by Supercritical Solvent Impregnation method to impart antioxidant and antimicrobial activity. The films were prepared from solutions with two different polymer concentrations (1 and 2.5 wt%) following three methodologies: casting and then drying at air (25 °C, 39 % relative humidity), casting and drying at 60 °C in humid conditions (82 % relativity humidity) and casting and water elimination by a freeze-drying process. The films were, then, characterized by scanning electron microscopy and X-ray diffraction, proving that the thickness, porosity, and crystallinity of the films are highly dependent on the preparation method. These structural variations affected the impregnation of essential oils by supercritical fluids, in terms of the amount and composition of the active compounds. Subsequently, yellowness, antioxidant and antimicrobial properties of the impregnated films were evaluated. The results demonstrated that the impregnated films retained high concentration of essential oils, especially the films impregnated with clove and produced by the freeze-drying process due to their higher porosity and lower crystallinity. These films also exhibited superior antimicrobial activity against Gram-positive and Gram-negative bacteria in comparison with the other two analyzed preparation methods.

Drug-impregnated contact lenses via supercritical carbon dioxide: A viable solution for the treatment of bacterial and fungal keratitis

Keratitis is a corneal infection caused by various bacteria and fungi. Eye drop treatment of keratitis involves significant challenges due to difficulties in administration, inefficiencies in therapeutic dosage, and frequency of drug applications. All these are troublesome and result in unsuccessful treatment, high cost, time loss, development of drug resistance by microorganisms, and a massive burden on human health and the healthcare system. Most of the antibacterial and antifungal medications are non-water-soluble and/or include toxic drug formulations. Here, the aim was to develop drug-loaded contact lenses with therapeutic dosage formulations and extended drug release capability as an alternative to eye drops, by employing supercritical carbon dioxide (ScCO2) as a drug impregnation solvent to overcome inefficient ophthalmic drug use. ScCO2, known as a green solvent, has very low viscosity which provides high mass transfer power and could enhance drug penetration into contact lenses much better with respect to drug loading using other solvents. Here, moxifloxacin (MOX) antibiotic and amphotericin B (AMB) antifungal medicines were separately loaded into commercially available silicone hydrogel contact lenses through 1) drug adsorption from the aqueous solutions and 2) impregnation techniques via ScCO2 and their efficacies were compared. Drug impregnation parameters, i.e., 8–25 MPa pressure, 310–320 K temperature, 2–16-hour impregnation times, and the presence of ethanol as polar co-solvent were investigated for the optimization of the ScCO2 drug impregnation process. The highest drug loading and long-term release kinetic from the contact lenses were obtained at 25 MPa and 313 K with 2.5 h impregnation time by using 1 % ethanol (by volume). Furthermore, antibacterial/antifungal activities of the MOX- and AMB-impregnated contact lenses were effective against in vitro Pseudomonas aeruginosa (ATCC 10145) bacteria and Fusarium solani (ATCC 36031) fungus for up to one week. Consequently, the ScCO2 method can be effectively used to impregnate commercial contact lenses with drugs, and these can then be safely used for the treatment of keratitis. This offers a sustainable delivery system at effective dosage formulations with complete bacterial/fungal inhibition and termination, making it viable for real animal/human applications.

Адсорбционное извлечение аминов из водных растворов

Aquatic biological resources are an important part of the ecosystems of our planet, since they are involved in economic turnover as a source of food. The composition of water, including waste water from enterprises, has a direct impact on the state of aquatic biological resources. To extract and concentrate metals from solutions, hydrometallurgical processes are used – extraction and sorption. Their implementation is possible with the use of special substances – extractants and in a number of processes – sorption materials (Solvent Impregnated Resins (SIR’s) and Levextrel’s) with a mobile phase of the extractant, combining the properties of sorbents and extractants. Despite the advantages of the latter, such as high kinetic parameters, lack of swelling and high values of mechanical strength, they are characterized by the disadvantages of extraction methods – the entrainment of the extractant into the aqueous phase in dissolved and emulsion forms. Under static conditions, the possibility of purification of aqueous solutions containing primary or tertiary amine by adsorption on carbon materials (activated carbon NWC, carbon NWC-T modified with carbon nanotubes, CS-PTFE modified with polytetrafluoroethylene), as well as on styrene-divinylbenzene nonionic copolymer Porolas-T and a natural shell rock adsorbent was studied. The kinetics of adsorption of аmines Primene-JMT and TOA from aqueous solutions by these adsorbents has been studied by the method of a limited volume of solution. Of the known pseudo-first order, pseudo-second order and Elovich models, the pseudo-second order model describes kinetic data more adequately (R2>0.99). The values of the distribution coefficients and the rate constants of adsorption of Primene-JMT and TOA are determined. A block diagram of adsorption purification of aqueous solutions from amines is proposed, the implementation of which will reduce the toxicity of waste solutions and return some of the expensive extractant to circulation.

Greenhouse gases capture applying impregnated silica with ionic liquids, deep eutectic solvents, and natural deep eutectic solvents.

The development of technologies to capture greenhouse gases (GHGs) like carbon dioxide (CO2) and nitrous oxide (N2O) is vital for climate change mitigation. Ionic liquids (ILs), deep eutectic solvents (DES), and natural deep eutectic solvents (NADES) are promising absorbents to abate GHGs emissions. However, their high viscosity limits the gas-liquid contact, as consequence of the mass transfer. To overcome this, their impregnation onto porous silica gel has been carried out, increasing the gas-liquid contact area. The present study analyzes the effect of size particle of silica gel impregnated with ILs, DES, and NADES over the CO2 and N2O capture at atmospheric conditions. The degree of impregnation of silica particles was determined by thermogravimetric analysis (TGA). The identification of functional groups present on the surface of silica, ILs, DES, and NADES was performed using Fourier-transform infrared spectroscopy (FTIR), and their crystalline structure was determined by X-ray diffraction (XRD). The partition coefficient of CO2 and N2O between gas and ILs, DES, and NADES was determined by a static headspace method. Results show that the degree of solvent impregnation on silica gel ranged from 36.8 to 43.0% w/w, the partition coefficient of CO2 in the impregnated silica varied from 0.005 to 0.067, and for N2O, from 0.005 to 0.032. This suggests that impregnated particles have a greater affinity for N2O compared to CO2. Using impregnated particles requires only 40% of the bulk solvent to achieve a similar GHG capture capacity compared to using bulk solvents.

Nanocellulose membrane with double-salt deep eutectic solvent for efficient carbon capture

Membrane-based gas separation technology is becoming increasingly attractive as a feasible alternative for carbon capture to alleviate global warming. Here, a double-salt deep eutectic solvent (DES) composed of organic salt (choline chloride) and inorganic salt (ZnCl2) is designed. The as-prepared DES exhibits a superb affinity and compatibility with nanocellulose because of the interactions between salt ions and cellulose carboxyl/hydroxyl groups. Through a solvent impregnation process, the DES was integrated into the nanocellulose gel precursor and used as a facilitated transport agent to form the functionalized nanocellulose membrane. The DES is tightly attached to the cellulose fibers with a high uniformity in the membrane matrix. Gas separation tests demonstrated that the DES@nanocellulose membranes presented a maximum CO2 permeability of 155.8 Barrer, with CO2/N2 and CO2/CH4 ideal selectivities of 43.6 and 48.4, respectively. Mixed gas separation tests were performed and the optimal membrane exhibited separation factors of 48.1 and 52.3 for CO2/N2 and CO2/CH4, respectively. The membranes provide a high solubility for CO2 due to the presence of abundant zinc ions, choline cations and carboxyl groups in the network, which can establish reversible coordination with CO2 and promote CO2 transport.

Super-stable modified wood for enhanced autonomous indoor humidity regulation

The crucial development of materials that automatically adjust indoor humidity, a significant factor in human health and daily life, has gained importance due to the emphasis on energy conservation. Wood, with its natural hygroscopic properties, is effective in this regard but faces challenges of deformation and cracking due to moisture content changes. Herein, we introduced an innovative in-situ wood modification strategy, which integrated deep eutectic solvent (DES) impregnation with heat treatment, producing dimensionally super-stable modified wood for enhanced autonomous indoor humidity regulation. This modification process focused on creating more robust cross-linking structures within the amorphous regions of the wood cell wall. As a result, water-induced deformation of natural wood was significantly reduced, as evidenced by an anti-swelling efficiency exceeding 80%, ensuring the long-term reliability of DES-modified wood in varying humidity environments. Additionally, the introduction of additional pores and hygroscopic sites in the cell wall enhanced the natural wood’s moisture buffering value by 2.5 times, showcasing the superior ability of DES-modified wood to control indoor humidity effectively. Moreover, the DES-modified wood also exhibited commendable flame retardancy and antibacterial properties. Consequently, this novel modified wood emerges as a reliable material for indoor humidity regulation, promoting healthier indoor conditions and offering a sustainable alternative for energy-efficient construction practices.

Supercritical fluid and cocrystallization technologies for designing antimicrobial food packaging PLA nanocomposite foams loaded with eugenol cocrystals with prolonged release

Searching for effective strategies to modify the release rate of essential oil derivatives is one of the main challenges in designing prolonged-release antimicrobial food packaging materials. Herein, supercritical fluid technology and cocrystallization engineering were used to develop novel eugenol (EU) prolonged-release poly (lactic acid) (PLA) nanocomposite foams. Eugenol-phenazine (EU-PHE) cocrystals, produced by a solvent-free mechanochemical method, were incorporated by supercritical solvent impregnation (SSI) inside PLA nanocomposite foams with different contents of Cloisite30B® (C30B). The effect of the cocrystallization process and C30B content on the EU release kinetics and its relation with their antimicrobial activity by direct contact (anti-attachment) and release in broth culture were studied. The deposition of isolated spherical-shaped micrometric EU-PHE cocrystal particles with 0.8 µm average diameter inside the pores of PLA foams was evidenced by XRD, SEM, DSC, and TGA analyses. The release mechanism of EU and its cocrystal was defined as a quasi-Fickian diffusion process successfully described by the Korsmeyer-Peppas model with release rate constants up to 3.6-fold lower than the release rate constant of pure EU. The impregnated foam samples completely inhibited the attachment of Listeria monocytogenes and Salmonella Enteritidis and provided prolonged antimicrobial activity in broth culture against both food-borne pathogens. This study suggests a new, environmentally friendly method for designing prolonged-release antimicrobial food packaging materials.

Selection of processing parameters for the integrated supercritical CO2 extraction from green tea leaves and extract impregnation onto starch-chitosan based films

The study aimed toward the development of biocompatible and biodegradable polymeric films (starch-chitosan and starch-chitosan-cyclodextrin) with biologically valuable green tea leaf extract using an environmentally friendly integrated process of supercritical fluid extraction (SFE) and supercritical solvent impregnation (SSI). The SFE-SSI process parameters were selected through the initial estimation of the SFE parameters effect (temperatures 35 and 70 °C and the addition of co-solvents ethanol, ethanol/water, and water). The present early-stage work showed that an increase in temperature increased extraction yield (from 0.9 to 4.2%) and caffeine content while it decreased polyphenolic and pigment content as well as antioxidant activity and extract loading onto films (from 7.1 to 0.1%). The addition of co-solvents to sc-CO2 had an adverse effect on extract yield, composition, and loading. The highest recorded total phenolic, flavonoid, chlorophyll A, and caffeine content in extracts were 136.5 mg GE/g, 22.7 mg RE/g, 8.1 mg/g, and 460.0 mg/g, respectively.

Effect of pressure on the supercritical solvent impregnation of pomegranate peel extract into low-density polyethylene films

Effect of pressure on the supercritical solvent impregnation of pomegranate peel extract into low-density polyethylene films

Synergistic Combination of Antimicrobial Peptides and Cationic Polyitaconates in Multifunctional PLA Fibers.

Combining different antimicrobial agents has emerged as a promising strategy to enhance efficacy and address resistance evolution. In this study, we investigated the synergistic antimicrobial effect of a cationic biobased polymer and the antimicrobial peptide (AMP) temporin L, with the goal of developing multifunctional electrospun fibers for potential biomedical applications, particularly in wound dressing. A clickable polymer with pendent alkyne groups was synthesized by using a biobased itaconic acid building block. Subsequently, the polymer was functionalized through click chemistry with thiazolium groups derived from vitamin B1 (PTTIQ), as well as a combination of thiazolium and AMP temporin L, resulting in a conjugate polymer-peptide (PTTIQ-AMP). The individual and combined effects of the cationic PTTIQ, Temporin L, and PTTIQ-AMP were evaluated against Gram-positive and Gram-negative bacteria as well as Candida species. The results demonstrated that most combinations exhibited an indifferent effect, whereas the covalently conjugated PTTIQ-AMP displayed an antagonistic effect, potentially attributed to the aggregation process. Both antimicrobial compounds, PTTIQ and temporin L, were incorporated into poly(lactic acid) electrospun fibers using the supercritical solvent impregnation method. This approach yielded fibers with improved antibacterial performance, as a result of the potent activity exerted by the AMP and the nonleaching nature of the cationic polymer, thereby enhancing long-term effectiveness.

Direct Extraction of Sodium Hydroxide by Calix[4]pyrrole-Based Ion-Pair Receptors.

Described in this work are calix[4]pyrrole-based ion-pair receptors, cis/trans-1 and cis/trans-2, designed for the extraction of sodium hydroxide. An X-ray diffraction analysis of a single crystal of the cis-1·NaOH isomer isolated from a mixture of cis/trans-1 revealed a unique dimeric supramolecular structure. An average dimer in toluene-d8 solution was inferred on the basis of diffusion-ordered spectroscopy (DOSY). Support for the proposed stoichiometry came from density functional theory (DFT) calculations. The structural stability of the dimeric cis-1·NaOH complex in toluene solution was further confirmed by ab initio molecular dynamics (AIMD) simulation with explicit representation of solvent. Under conditions of liquid-liquid extraction (LLE), purified receptors cis- and trans-2 were both found to remove NaOH from a pH 11.01 aqueous source phase into toluene with extraction efficiencies (E%) of 50-60% when used equimolar to NaOH. However, in all cases, precipitation was observed. Complexities associated with precipitation could be avoided by immobilization of the receptors onto a chemically inert poly(styrene) resin by means of solvent impregnation. The use of solvent-impregnated resins (SIRs) eliminated precipitation in solution while retaining the extraction efficiency toward NaOH. This allowed both the pH and salinity of the alkaline source phase to be lowered.

Generation of high-porosity cerium oxide nanoparticles and their functionalization with caryophyllene oxide using supercritical carbon dioxide

Oral diseases affect to millions people worldwide. Metallic nanoparticles are used as novel treatment due to its antimicrobial, antifungal, anti-inflammatory properties. Supercritical anti-solvent process and supercritical solvent impregnation process have been used to create cerium oxide nanoparticles and impregnate them with caryophyllene oxide, an antifungical and anti-microbial compound. High porosity nanoparticles, between 70 and 450 times higher than the raw cerium material were precipitated and impregnated successfully. The antimicrobial activity of impregnated nanoparticles investigated in vitro showed promising results against Staphylococcus aureus.

An ultra-high disulfiram-loaded delivery system achieved by supercritical carbon dioxide technology for copper-enhanced chemotherapy

Disulfiram (DSF) is a conventional alcohol-aversion drug that has recently been explored as a chemotherapeutic agent and has shown excellent anticancer activity in cooperation with Cu2+ ions. However, the existing DSF delivery system has multiple shortcomings, including low drug loading and Cu2+ delivery efficiency, hindering its clinical applicability. Here, we demonstrated a simple but efficient strategy for realizing the controllable loading of hydrophobic DSF into Cu2+-doped mesoporous silica nanoparticles (Cu-MSN) by using supercritical CO2 technology with ultra-high drug loading efficiency. Benefiting from the unique environment of high pressure and solubility, DSF was well dispersed in supercritical CO2 and immersed into the carriers with controllable drug loading. Factorial experiments indicated an optimal condition (55 °C, 250 bar, and 6 h) for the DSF loading up to 30.8 %. In vitro and in vivo experiments demonstrated high Cu2+-enhanced chemotherapeutic efficacy of DSF. In particular, in cooperation with Cu2+ ions in MSN, the formation of complex (CuET) greatly enhanced and prolonged the antitumor effect. Together, our findings indicated that DSF-loaded Cu-MSN prepared using supercritical solvent impregnation (SSI) enhanced the antitumor effect and had potential in anticancer therapy.

Effect of CeO2 nanoparticle sizes on catalytic performances of sulfated CeO2/Al2O3 catalyst in NH3-SCR reaction

The sulfated CeO2/Al2O3 catalysts with different sizes of CeO2 nanoparticles were prepared by using pure H2O or acetic acid solution as impregnation solvent, and the influence of sizes of CeO2 nanoparticles on the catalytic performances of the sulfated CeO2/Al2O3 catalyst was studied. The catalytic performance tests show that the sulfated CeO2/Al2O3 catalyst using acetic acid solution as impregnation solvent has better catalytic activity and the resistance to K+ poisoning than the sulfated CeO2/Al2O3 catalyst using pure H2O as impregnation solvent. The excellent catalytic performances can be ascribed to the smaller sizes of CeO2 nanoparticles in CeO2/Al2O3 catalyst using acetic acid solution, which results in larger amount of adsorbed sulfate species, surface acid sites, surface active oxygen species and excellent redox property. These features are helpful for improving the catalytic performances of sulfated CeO2/Al2O3 catalyst using smaller amount of CeO2 to cut the costs.

Novel nanowire self-assembled hierarchical CeO2 microspheres loaded with nickel-based catalysts for hydrogen production from steam reforming of glycerol

The nickel-based catalysts with shape-specific CeO2 nanocrystals (hierarchical and spheres) and adjustable impregnation solvents were successfully synthesized. The synthesized Ni-CeO2 catalysts were used as the model catalyst to study the structure-dependent catalytic behavior and catalytic reaction mechanism for hydrogen production from glycerol steam reforming (GSR). Ni/CeO2-HE with the hierarchical structure and ethanol impregnation solvent obtained the strongest metal-support interaction. Electron effects because of the strong interaction between nickel and cerium dioxide promoted the formation of reducible nickel species. High nickel reduction and nickel dispersion contributed to the maximum active nickel exposure surface area, thus Ni/CeO2-HE exhibited superior glycerol conversion than other catalysts. The abundant oxygen vacancies generated due to strong Ni-CeO2 interaction facilitated the dissociation of water, thereby achieving a high yield of H2 for Ni/CeO2-HE. As a comparison, Ni/CeO2 and Ni/CeO2-E showed relatively poor catalytic activity due to lower exposed specific surface area and oxygen vacancy concentration. Moreover, the strong oxygen storage-release ability (CO-OSCC) promoted the oxidation of carbon deposition on Ni/CeO2-HE. As a result, Ni/CeO2-HE obtained good catalytic stability with no inactivation within 25 h. The study of the modulation role of Ni-CeO2 interaction on catalytic behavior can provide valuable guidelines for designing efficient catalysts for GSR.

Preparation of cellulose tri-acetate membranes for high-alcohol beverages via genetic algorithms and high throughput experimentation

In fermented beverages, volatile esters are trace compounds with a significant effect on the flavour profile. Some of the most important esters in beer are ethyl acetate (solvent-like aroma) and isoamyl acetate (banana aroma). These esters have a defined threshold which, when exceeded, will be experienced as unpleasant upon tasting. Therefore, the industry needs to selectively remove and fractionate esters by means of adsorption and tune the level of esters in the different process streams.Nanofiltration (NF) and Reverse Osmosis (RO) membranes are known to have a high potential towards removal of low molecular weight components from liquid streams. However, membrane preparation depends on several parameters with complex interactions to obtain the targeted membrane performance. Multi-parameter optimization strategies are thus very useful to reduce material consumption, minimize time and labour during the development of a ‘bottom-up’ preparation method. High throughput (HT) filtration techniques in combination with genetic algorithms (GAs) are known to be very powerful to direct such membrane preparation.This optimization strategy is used to obtain cellulose tri-acetate (CTA) membranes for filtration of high-alcoholic beverages towards ethyl acetate and isoamyl acetate depletion. Before the implementation of the proposed strategy, a successful optimization of the HT operating conditions was setup together with a selection of benchmark membranes by screening the performance of various commercially available nanofiltration (NF) and reverse osmosis (RO) membranes.Next, the non-compositional (solvent impregnation, membrane thickness, solvent evaporation time, annealing time and temperature) and compositional parameters (polymer concentration, solvents and additives selection) used during non-solvent induced phase separation (NIPS) preparation of CTA membranes were determined. Finally, CTA membranes were optimized using GAs.

Recovery of Naringin-Rich Flavonoid Extracts from Agroresidues with Anxiolytic- and Antidepressant-like Effects in Mice

Citrus paradisi species belong to the Rutaceae family, and it is commonly known as grapefruit. Grapefruit consumption involves a large amount of waste that goes to landfills and produces significant pollution affecting the human health. To examine this phenomenon, we designed an efficient chemical method that recovers naringin-rich flavonoid extracts from the fresh waste of grapefruits, by using the solvent impregnation resin method (SIR) with XAD-4 amberlite and either methanol or water as elution systems. Additionally, we focused on evaluating these extracts' anxiolytic- and antidepressant-like effects in behavioral predictive paradigms in mice. According to direct Principal Component Analysis (PCA) by NMR, and Direct Injection Electrospray Ionization-Mass Spectrometry (DIESI-MS), methanol extracts obtained after resin treatment were free of coumarin compounds and evinced had a high content of naringin. Poncirin, phenylalanine, chrysin 5,7-dimethyl ether, 5,7-dimethoxy-4'-hydroxyflavanone, 2,3-dihydro-2-(4-hydroxyphenyl)-5,6,7,8-tetramethoxy-4H-1-benzopyran-4-one, tetrahydrocurcumin, corchoionoside C, 6'-coumaroyl-1'-O-[2-(3,4-dihydroxyphenyl) ethyl]-β-D-glucopyranoside were also detected. Naringin-rich methanol extract caused a clear anxiolytic-like effect in the Elevated Plus Maze (EPM) and the Hole-Board (HBT) Tests, increasing oral doses of this extract did not produce a sedative effect. A single oral dose caused an antidepressant-like effect in the Tail Suspension Test (TST), while repeated administrations of the methanol extract elicited a robust antidepressant effect in the Forced Swimming Test (FST) in mice. Our evidence highlights the importance of bioprospecting studies of organic waste with therapeutic potentials, such as anxiety and depression disorders.

Towards a modern approach to traditional use of Helichrysum italicum in dermatological conditions: In vivo testing supercritical extract on artificially irritated skin

Ethnopharmacological relevanceHelichrysum italicum has been widely used in traditional medicine to treat allergies, colds, cough, skin, liver and gallbladder disorders, inflammation, infections, and sleeplessness. Furthermore, it possesses considerable wound healing and skin protective properties, documented by several in vivo studies performed on animals. However, there is a lack of experimental evidence supporting its potential as a topical agent tested by human clinical trials. Aim of the studyThe study aimed to investigate the skin protective activity of cotton gauze and polypropylene non-woven fabric, impregnated with H. italicum extract by the integrated supercritical CO2 extraction-supercritical solvent impregnation process. Materials and methodsThe integrated process of supercritical CO2 extraction of H. italicum and the impregnation of cotton gauze and polypropylene non-woven fabric was performed under 350 bar and 40 °C with and without the addition of ethanol as a cosolvent. Impregnated textile materials were tested in vivo for their bioactivity on irritated human skin. Randomized in vivo studies performed involved assays of both safety and efficacy of the impregnated textiles. The effects were evaluated using the in vivo non-invasive biophysical measurements of the following skin parameters: electrical capacitance, transepidermal water loss, melanin index, erythema index, and skin pH. ResultsBoth cotton gauze and polypropylene non-woven fabric were impregnated with H. italicum extracts under supercritical conditions with considerable values of the impregnation yield (1.97%–4.25%). The addition of ethanol as a cosolvent during the process caused significant changes in the incorporated extracts’ impregnation yield and chemical profile. Both impregnated textile materials were safe, evaluated by their testing on the human skin with no cause of any irritation and redness. However, efficacy studies revealed that polypropylene non-woven fabric impregnated with H. italicum extract with ethanol as a cosolvent, possessed significantly greater potential for skin protection than the other investigated samples. ConclusionsThe present study demonstrated the feasibility of the combined supercritical extraction and impregnation process in developing materials for topical application based on H. italicum extract. The results of in vivo studies performed on human volunteers confirmed the suitability of H. italicum active components to be a part of human skin protective preparations because of their ability to maintain the skin unimpaired. Traditionally claimed applications as a medicinal plant capable of regenerating skin have been scientifically proven, in addition to employing green technology in obtaining the impregnated materials with a broad spectrum of utilization.

Nanoconfinement of lithium alanate for hydrogen storage

LiAlH4 is considered as a promising material for solid state hydrogen storage. However, the lack of reversibility along with sluggish kinetics hinders its practical application. In this paper, hollow carbon nanospheres (HCNs) were used as a porous scaffold to confine LiAlH4 via solvent impregnation method. Nanoconfined LiAlH4 (LiAlH4@HCNs) exhibited significant improvements in hydrogen sorption compared to its bulk counterpart. LiAlH4@HCNs releases hydrogen sharply at 146 °C with full conversion to LiH within 1.5 h. The desorbed material can also be regenerated back to some extent into LiAlH4 under 8 MPa H2 at 150 °C. Measurement of the pressure-composition isotherm suggests an alteration in the equilibrium state upon confinement of LiAlH4 in voids of a few nanometres and thus altered hydrogen thermodynamic paths.