Character Of Adsorption Research Articles

Investigation of Kinetic, Equilibrium, and Thermodynamic Modeling of Perfluorooctanoic Acid (PFOA) Adsorption in the Presence of Natural Organic Matter (NOM) by Dielectric Barrier Discharge Plasma-Modified Granular Activated Carbon (GAC)

Perfluorooctanoic acid (PFOA) contamination in water sources poses significant environmental and health concerns. The kinetic, equilibrium, and thermodynamic features of PFOA adsorption in the existence of natural organic matter (NOM) were thoroughly investigated in this work using granular activated carbon (GAC) modified by dielectric barrier discharge (DBD) plasma. The impacts of DBD plasma parameters on the adsorption process were systematically examined. The results demonstrated that GAC modified by DBD plasma exhibited enhanced adsorption performance for PFOA, even in the presence of NOM. The optimal condition for plasma-treated GAC was achieved with 20 min of plasma treatment time and 100 W of plasma power, resulting in 92% PFOA removal efficiency in deionized water (DIW) and 97% removal efficiency in Chao Phraya River water (CPRW). A kinetic investigation using the pseudo-first-order model (PFOM), the pseudo-second-order model (PSOM), and the Elovich model (EM) indicated that plasma treatment time and NOM presence influenced the adsorption capacity and rate constants of PFOA with the PSOM having emerged as the most fitting kinetic model. The Langmuir isotherm model indicates monolayer adsorption of PFOA on plasma-treated GAC, with higher maximum adsorption capacity while NOM is present. The Redlich–Peterson and Sips isotherm models indicated varying adsorption capacity and heterogeneity in the adsorption system. The Sips model was determined as the most fitting isotherm model. Furthermore, the favorable and spontaneous character of PFOA adsorption onto plasma-treated GAC was validated by thermodynamic analysis, with endothermic heat absorption during the process. Overall, this comprehensive investigation provides valuable insights into the adsorption characteristics of PFOA in the existence of NOM using GAC modified by DBD plasma.

Evaluation of the inhibitory action of essential oil from Eucalyptus globulus leaves on the corrosion of mild carbon steel in 1M HCl medium

Abstract The present work aims to valorize an aromatic and medicinal plant of Eucalyptus globulus found in the region of Dakar, Senegal. To do so, we first extracted the essential oil contained in the leaves of the plant harvested in October 2020. We obtained the essential oil by hydrodistillation using a Clevenger type extractor with a yield of 1.70% of the dry plant mass. This value is quite appreciable compared to the different values in the literature. The essential oil extracted from the leaves of Eucalyptus globulus was tested as a green inhibitor on carbon steel type XC38 in 1M HCl acid medium by the mass loss method. The results obtained led to a maximum inhibitory efficiency of 89.03% for a concentration of 1.6 g/L of essential oil at room temperature of 298 K. The effect of temperature on the inhibitory behavior of the essential oil was also studied over a range of 298 K to 338 K. In this temperature range, a loss of efficiency was observed with increasing temperature, reaching a value of 15.33% at 338 K. Thermodynamic quantities were then determined. The plot of the different isotherms showed that the adsorption of the essential oil obeys the Langmuir isotherm. The results obtained showed a physical character of adsorption of this essential oil.

Amine-Modified Carbon Xerogels as Effective Carbon-Based Adsorbents of Anionic Dye from Aqueous Solutions.

Carbon xerogels were obtained by polycondensation of resorcinol and formaldehyde in a water medium. Their surface was oxidized by ammonium persulfate and then modified with amine groups. Four amines were used: methylamine, ethylamine, propylamine, and ethylenediamine, differing in carbon chain length and number of amine groups. The materials were characterized by low-temperature nitrogen sorption, elemental analysis, thermal analysis, X-ray diffraction, infrared spectroscopy, and determination of the surface oxygen group content with the use of the Boehm method. The final carbon adsorbents had surface areas ranging from 172–663 m2/g and acid–base nature. They were applied for adsorption of thymol blue from water solution. The sorption capacities of the studied adsorbents ranged from 83 to 140 mg/g. The presence of amine groups on the xerogel surface was found to increase its sorption capacity towards the dye studied. The dye adsorption process is endothermic and spontaneous, as indicated by the positive values of ΔH and the negative values of ΔG, respectively. The kinetics of adsorption of thymol blue was established to be described by the pseudo-second-order model. The equilibrium data were analyzed by the Langmuir and Freundlich models. The character of thymol blue adsorption is much better described by the Langmuir isotherm.

From agricultural wastes to a resource: Kiwi Peels, as long-lasting, recyclable adsorbent, to remove emerging pollutants from water. The case of Ciprofloxacin removal

This work accounts for the first example of dry Kiwi Peels to remove emerging pollutants from water. Both the inner and outer sides of Kiwi Peels were characterized by using in synergy FTIR-ATR, TG, and SEM analyses before and after its use and re-use, proposing it as long-lasting, recyclable adsorbent material. Among the tested 14 emerging pollutants, 6 of them were successfully removed by Kiwi Peels, also if present in mixtures, calculating the Kiwi Peels maximum adsorption capacities, occurring in the range of 1–4 mg/g. To infer information about the behavior of Kiwi Peels during water treatments, Ciprofloxacin, a well-known and largely used antibiotic, was selected as a dangerous model contaminant. The roles of ionic strength, pH values, adsorbent/pollutant amounts, and temperature values during the adsorption process were assessed, giving physical and chemical information about the whole adsorption process. The thermodynamics, the adsorption isotherms, and kinetics were studied. The Freundlich model, with a good correlation, well described the obtained results, indicating the heterogenous character of the Ciprofloxacin adsorption with the formation of a multilayer of pollutant molecules onto the adsorbent surface. If, on the one hand, in the range of temperatures 283–303 K, the Ciprofloxacin adsorption was favored by increasing the temperature, on the other hand, the adsorption was hindered by further incrementing of temperature due to the pollutant desorption. Until the occurrence of desorption, the process occurred with ΔH° and ΔS° > 0 with a ΔG° < 0. Both the pseudo-first and pseudo-second-order kinetic equations seemed to describe the process with the applicability of the Weber-Morris model. The results suggested the main presence of electrostatic interaction between the pollutant and adsorbent by changing the pH values and ionic strength of Ciprofloxacin solutions. As a whole, from the obtained results, the best condition to remove Ciprofloxacin is neutral pH in the absence of salt at 303 K. The Kiwi Peels and Ciprofloxacin recycling was also investigated by performing desorption experiments using 0.1 M MgCl2 solution, increasing the Kiwi Peels maximum adsorption capacity at least from 4 to 40 mg/g for Ciprofloxacin. At least 10 cycles of adsorption/desorption were performed, desorbing almost 75% of adsorbed pollutants during each run. Preliminary information about the possibility of inducing the solid-state pollutant photodegradation by using Advanced Oxidation Processes was also explored, giving a possible alternative for pollutant desorption and adsorbent recycling.

Oxidized jute as a valuable adsorbent for Congo Red from an aqueous solution

The raw jute fabric was oxidized with 0.2% or 0.4% NaIO4 for 60 or 120 min to obtain valuable adsorbents for the textile dye Congo Red (CR). Batch adsorption experiments were carried out as a function of solution pH, contact time, initial CR concentration, and temperature. At an initial CR concentration of 25 mg/L, the raw jute possessed the lowest adsorption due to the lowest availability and content of carboxyl and aldehyde groups capable of binding dye. The fabrics oxidized for 60 min with 0.2% NaIO4 and 120 min with 0.4% NaIO4 reached equilibrium adsorption after 240 and 330 min, respectively. The adsorption of CR onto studied fabrics followed the pseudo-second-order model indicating that the chemisorption process is primarily represented. Within the studied range of CR concentrations (25–100 mg/L), its adsorption onto fabric oxidized for 120 min with 0.4% NaIO4 obeys the Langmuir isotherm model (i.e. adsorption occurs at specific, energetically equivalent adsorbent sites with monolayer coverage of CR over a homogeneous surface), wherein the calculated maximal adsorption capacity is 12.863 mg/g. A thermodynamic study revealed the spontaneous and endothermic character of CR adsorption onto jute fabric. Based on the recorded ATR-FTIR spectra before and after CR adsorption, it is suggested that repulsion, hydrogen bonds, and π-π stacking interactions are involved in the binding of CR onto jute fabrics.

Kinetic and Thermodynamic Characteristics of Fluoride Ions Adsorption from Solution onto the Aluminum Oxide Nanolayer of a Bacterial Cellulose-Based Composite Material.

The described research examined the adsorption of fluoride ions from solution immobilized onto an aluminum oxide-coated bacterial cellulose-based composite material in which aluminum oxide had been deposited using ALD technology. The kinetic regularities of the adsorption of fluoride ions from the solution as well as the mechanism of the processes were analyzed. The established equations show that the dynamics of adsorption correspond to first-order kinetics. Based on the Langmuir adsorption isotherms, we defined the adsorption equilibrium constants, parameter maximum adsorption, and change in Gibbs free energy. It is shown that, with increasing temperature, an increase in the reaction rate is constant, both forward and reverse. This testifies to the activated character of adsorption of the first fluoride on the surface of the sorbent based on bacterial cellulose modified with an alumina nanolayer. The activation energy of the desorption process is higher than the activation energy of the adsorption process, which characterizes the adsorption as ionic. The negative value of entropy indicates that in the course of sorption, an adsorption complex “aluminum-fluorine” is formed, where the system is more ordered than the initial system in which fluorine ions are in solution. The limiting stages of the process are revealed. The high sorption capacity of the resulting bacterial cellulose-based composite material obtained by means of biosynthesis through cultivation of the bacterium Komagataeibacter sucrofermentans B-11267 was demonstrated.

Removal of Cu(Ⅱ) ions from aqueous solution by a magnetic multi-wall carbon nanotube adsorbent

Copper (Cu(Ⅱ)) pollution has a hazardous effect on human health. However, designing new adsorbents with prominent properties is a tremendous challenge in effectively removing Cu(Ⅱ) ions from the environment. In this study, new adsorbent—MnFe2O4/multi-wall carbon nanotubes (MMWCNTs), with excellent magnetic properties were synthesized and then systematically characterized. Introducing MnFe2O4 addressed the challenge of separating the nano-adsorbent from the liquid medium. Batch adsorption experiment results indicated that effective adsorption occurred in a relatively neutral range (pH=6–8). The adsorption behaviors were consistent with the pseudo-second-order model and the Freundlich model. The maximum adsorption capacity reached 46.41 mg/g at 308 K. The adsorption thermodynamics revealed the endothermic character of adsorption by MMWCNTs, and increasing the temperature benefitted the adsorption process. Furthermore, many surface functional groups of MMWCNTs facilitated adsorption performance. Compared with the MWCNTs before modified, the adsorbent had a nearly tenfold improvement from 3.4% to 34.8% in the removal efficiency of Cu(Ⅱ) ions. These results demonstrated that MMWCNTs are a suitable, efficient adsorbent that can be used in natural water bodies for adsorbing Cu(Ⅱ) ions.

Simultaneous Removal of Cu2+, Zn2+ and Cd2+ from Aqueous Solutions by Alkali Activated Slag

Electric Arc Furnace (EAF) slag containing larnite, gehlenite, wuestite, montcellite and calcite as the main crystal phases was alkali activated using the alkali activator prepared by the mixing of two solutions, sodium silicate and NaOH. Alkali Activated (AA) slag based on EAF slag is used as an adsorbent for Cu2+,Cd2+ and Zn2+ from aquatic solutions performing the batch adsorption test at the range temperature between 20 and 45 °C. AA slag sample is characterized by XRPD, FTIR and SEM/EDS analysis and the results indicate crystalline-amorphous structure of AA slag that contains Calcium Aluminate Silicate Hydrate (C-A-S-H) phase. Concentration of Cu2+, Cd2+ and Zn2+ in aqueous solution was determined using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The results obtained indicate that, in a multicomponent system of three dissolved ions, AA slag shows highest affinity towards the Cu2+. The order of the metal ion adsorption onto AA slag was: Cu2+, Cd2+ and Zn2+. The highest adsorption of Cu2+ is attributed to the highest electronegativity and lowest hydrated ionic radii of cation in comparison to Cd2+ and Zn2+. Pseudo-first-order and pseudo-second-order kinetics models, Langmuir and Freundlich isotherm models were applied in order to investigate the adsorption process. The results have shown that data better fitted the pseudo-second kinetic and Langmuir isotherm models The investigation of mechanism of adsorption indicate that both film diffusion and intra-particle diffusion have occurred during the adsorption process. The thermodynamics parameters of adsorption process indicate the spontaneous and endothermic character of heavy metals adsorption on the AA slag.

Synergetic Effect between Phenolic Extracts of Ammi visnaga and Zea mays Formulation on the Corrosion of Mild Steel in 1 M HCl Solution

The synergetic effects between hydroethanolic extracts of A. visnaga HE (AV) and Z. mays hairs HE (ZM) on corrosion of mild steel in 1 M HCl solution was investigated at 298 K by two techniques: potentiodynamic polarization (PP) methods (Tafel and Stern &amp; Geary) and electrochemical impedance spectroscopy (EIS). The mixture of HE (AV)/HE (ZM) acted as an efficient corrosion inhibitor and its inhibition efficiency increased with concentration up to 96.55% at 0.01 gL−1 HE (AV)/0.2 gL−1 HE (ZM). The polarization curves revealed that the mixture acted as a mixed-type inhibitor, with anodic predominant action. The EIS studies were fitted by the (Rs + CPEdl)/(Rct + CPEf/Rf) equivalent circuit model. The kinetic parameters were in favor of a physisorption character of adsorption of HE (AV)/HE (ZM) components onto the mild steel surface. The influence of exposure time on the efficiency of mixture extract was investigated. Scanning electron microscopy (SEM/EDX) analyses confirmed the formation of a protective adsorbed film upon the mild steel surface.

A Strategy to Revalue a Wood Waste for Simultaneous Cadmium Removal and Wastewater Disinfection

In this investigation, the possibility of wood waste (hardwoods such as oaks’ and alternatives’ staves from Balkan cooperage) revalorization for simultaneous cadmium removal and wastewater disinfection was examined. All samples were characterized in terms of their crystallinity index and crystallite size, amount of functional groups, and surface chemistry (determined by ATR-FTIR) as well as antibacterial activity. Mulberry is characterized by the lowest crystallinity index which can be ascribed to the highest crystallite size disabling crystallite denser packaging, while myrobalan plum has about 23% lower crystallite size that enables crystallite better packaging, thus resulting in a 42.4% higher crystallinity index compared to the mulberry. All oaks have a significantly higher amount of carboxyl groups compared to the alternatives (0.23-0.28 vs. 0.12-0.19 mmol/g). The adsorption experiments revealed that with increasing the initial cadmium concentration from 15 up to 55 mg/g, samples’ adsorption capacity increases by 89-220%. The equilibrium data fit well with the Langmuir isotherm model implying monolayer coverage of cadmium ions over a homogeneous wood surface. The relationship between the samples’ maximum adsorption capacities (ranged from 5.726 to 12.618 mg/g), their crystallinity index, and crystallite size was established. According to ATR-FTIR spectra, aldehyde, carboxyl, hydroxyl, and phenyl groups present on the wood waste surface are involved in Cd2+ adsorption which proceeds via the interplay of the complexation, cation- π interactions, and ion-exchange mechanisms. Mulberry and myrobalan plum showed about 89% and 80% of the total uptake capacity of cadmium within 60 min, while the equilibrium was attained after 240 min of contact time. Good compliance with pseudo-second kinetic order indicated that cadmium adsorption was mediated by chemical forces. Thermodynamic parameters revealed the spontaneous and exothermic character of cadmium ion adsorption onto mulberry and myrobalan plum. All studied samples provide maximum bacterial reduction (&gt;99%) for E. coli and S. aureus. Wood waste from Balkan cooperage can be successfully used for simultaneous cadmium removal and wastewater disinfection.

Elimination of paracetamol from water by a spent coffee grounds biomaterial

The aim of this work is the preparation of activated carbon from coffee grounds waste in order to use it as adsorbent in the removal of Paracetamol (PCM) largely existing in wastewaters rejected by pharmaceutical industries.The coffee ground was used in three forms: natural state (NAC), thermally activated at 450 °C (TAC) and chemically activated in the presence of phosphoric acid (CAC). The three biomaterials were analyzed by XRD, FTIR, SEM and BET in order to identify eventual structural and adsorptive characteristics. The specific area has significantly increased from 102.2 m2/g for NAC to 648.6 and 888.1 m2/g for TAC and CAC, respectively.The adsorption tests showed a very remarkable solid-liquid affinity with the following efficiency sequence: CAC < TAC < NAC with the elimination rates of 98, 35, 34 % and 20 %, respectively. The isotherm adsorption is in accordance with the Freundlich model, indicating heterogeneity of the biomaterial and the multi cover layers character of PCM adsorption.

Xenon adsorption isotherms on chabazite. Statistical physics modeling investigation: Adsorption energy and pore size distributions computation

In order to investigate the toxic Xenon removal by an adsorption process on chabazite, the grand canonical formalism of statistical physics has been used. This conducted statistical physics treatment enabled us to draw information about the interactions between Xenon atoms and chabazite surface through the determined physico-chemical parameters. The adsorption energy and pore size distributions have been derived by using an integral expression based on a monolayer model as local isotherm. The fitted values of the steric coefficient showed that one chabazite active site can trap only one Xenon atom. The evaluated densities of receptor sites played an important role in the assess of the adsorption capacity. Ca−CHA sample showed the maximum adsorption capacity (2.36 mmol.g−1). By using the adsorption energy distributions (GD), the physisorbed character of the Xenon adsorption on chabazite samples was brought out. The diversification of the active sites is noticed for all chabazite samples. The highest adsorption energies are observed in the case of the Xenon adsorption on CA−CHA sample. Furthermore, by using the pore size distribution (PSD), the microporous character of all samples (Ca−CHA, Cs−CHA, Li−CHA, K−CHA and Rb−CHA) has been showed. The maximum surface area was found to be 187.23 m2. g−1 for Ca−CHA. The calculated surface tensions are in the range [10.07E-5 N.m−1-13.46E-5 N.m−1]. Finally, by combining the thermodynamical and statistical physics treatments, the chemical potential describing the Xenon adsorption, is calculated at different pressures.

Drop Size Dependence of the Apparent Surface Tension of Aqueous Solutions in Hexane Vapor as Studied by Drop Profile Analysis Tensiometry

Surface tension experiments were performed using the drop profile analysis tensiometry method. The hexane was injected into the measuring cell at certain times before the formation of the solution drop. The influence of the capillary diameter and solution drop size on the measured apparent dynamic surface tension was studied. The amount of hexane transferred from the vapor phase to the drop was estimated. For large pure water drops, it was shown that the ageing of the drop in the hexane vapor during a long time resulted in the formation of a liquid hexane phase covering the drop, but the volume of this phase did not exceed 0.5 mm3. On the contrary, for surfactant solution drops the volume of the hexane phase covering the drop was essentially larger. Experiments with solution drops were performed to measure the surface tension within a wide range of surfactant concentration. It was found that the dependencies of dynamic surface tension on the C13DMPO and C14EO8 solutions concentration exhibit maxima at concentrations of about 1–2 μmol/L for C14EO8 and 2–5 μmol/L for C13DMPO at ageing times of 100 to 1000 s; these maxima were shown to exist also at equilibrium. This phenomenon is presumably ascribed to the competitive character of simultaneous adsorption of hexane and surfactant.

Influence of Manganese on the Catalytic Properties and Structure of the Active Surface of a Cobalt Fischer–Tropsch Catalyst

It is shown that the Fischer–Tropsch synthesis in the presence of Co–xMn/SiO2 cobalt catalysts with a manganese content of 0.5–2 wt % is characterized by high activity and C5+ hydrocarbon selectivity. The optimum concentration of manganese as a promoter is 1 wt %. The influence of manganese on the state of the surface of the catalysts in oxide and reduced forms is studied by a number of physicochemical methods. The formation of solid solutions of cobalt and manganese oxides of the xCo3O4–(1−x)Mn3O4 type is confirmed. The relationship between the promoting effect of manganese and the structure of active sites and the character of adsorption of H2 and CO on the surface of the catalysts is ascertained.

A facile approach for elimination of ibuprofen from wastewater: an experimental and theoretical study

AbstractHerein, we developed the waste‐derived adsorbent, mesoporous Schumannianthus dichotomus (MSD) and used for the exploitation of Ibuprofen (IBP) in an economic and reliable way. The developed adsorbent was characterized by various physicochemical and spectroscopic analyses. Relatively higher surface area of 1058 m2/g, pore volume of 0.9909 cm3/g and average article size of 39.09 µm justified the utilization of the developed material for the removal of IBP from aqueous phase. The effect of ionic strength ( , Cl–, and ), divalent ions (Ca2+ and Mg2+) and surfactant on the removal of IBP onto MSD was investigated. Adsorption equilibrium is attained in 60 min with adsorbent load of 1.8 g/L. The removal efficiency of MSD is around 98% with sequestering capacity of 243.90 mg/g. Thermodynamic investigation revealed the adsorption process to be exothermic, (ΔH = −8.729 kJ/mol) and spontaneous in nature (ΔG = −7.06 kJ/mol) with a decrease in the randomness (ΔS = −5.57 JK/mol) at the solid/liquid interface. The energy recovered from the adsorbent‐loaded IBP in terms of higher heating value (17.15 mJ/kg) further enhanced its utilization. The low cost of MSD (USD 14.39 per kg) also justified its utilization for wastewater treatment in an economic perspective. Density Function Theory studies showed that a weak interaction occurs between IBP and the developed activated carbon, MSD. The exothermic character of IBP adsorption onto MSD was confirmed by experimental investigation.

Adsorption of recombinant human erythropoietin and protein impurities on a multimodal chromatography membrane

Multimodal chromatography adsorbents are novel materials with promising properties for downstream processing of therapeutic glycoproteins. This work analyzes the properties of a salt-tolerant membrane, Sartobind STIC, for the purification of recombinant human erythropoietin (rhEPO) produced by human embryonic kidney cells. Batch adsorption experiments were carried out to determine equilibrium properties of the membrane as a function of pH and NaCl concentration. It was found that the membrane adsorbs strongly both rhEPO and impurity proteins but the selectivity of binding is low independent of process conditions. Since the membrane demonstrated strong salt tolerance, flow experiments were designed to elucidate the effect of elution conditions on the bound proteins desorption. These experiments have revealed irreversible character of protein adsorption on the multimodal adsorbent probably caused by protein unfolding on the hydrophobic groups of the adsorbent. The recovery degree was especially low in case of rhEPO with the maximum at about 45% even when solutions of kosmotropic agents were used as desorbents.

Oscillating Character of Adsorption of Iron(III) Ion by Carbon Sorbents

The kinetics of sorption of iron ions from solutions with concentrations of 10 and 250 mg/l by various types of carbon materials was investigated. It was shown that the adsorption curve for an iron ion concentration of 10 mg/l in the solution has an anomalous form. However, if the concentration of the ions in the solutions is increased the oscillations on the curve for the dependence of the sorption capacity on time disappear.

Kinetic, isotherm and thermodynamic investigations of the adsorption of Ag+ and Cu2+ on vermiculite

Vermiculite was used as a low-cost adsorbent for the removal of silver and copper ions from aqueous solutions. The raw material and acid- or base-treated adsorbents were characterised by SEM, BET, XRD and FTIR analysis. The effect of the pH and temperature of the solution, dose and average size of adsorbent particles, contact time, stirring rate and initial of metal ions concentration on the adsorption efficiency was studied systematically. The maximum adsorption capacity of vermiculite was determined (for Ag(I) as about 73mg/g and for Cu(II) 117mg/g). In this study, the four isotherm models (Langmuir, Freundlich, Temkin and Sips) were employed to correlate experimental adsorption isotherm data, which were obtained by batch tests. The linear and non-linear isotherm models were compared. The pseudo-first-order, pseudo-second-order, and Elovich models were used to describe the kinetic data. The kinetics of adsorption indicates that the process followed pseudo-second order kinetics well, which suggests the chemical character of adsorption. Finally, the thermodynamic parameters (ΔG°, ΔH° and ΔS°) were determined. The parameters indicated that, in the studied temperature range, the adsorption of Ag(I) and Cu(II) by vermiculite had a spontaneous and endothermic nature. Based on all of the results, vermiculite can be evaluated as a potentially cost-effective sorbent for the removal of Ag(I) and Cu(II) from aqueous solutions.

Adsorption of dyes on the surface of polymer nanocomposites modified with methylamine and copper(II) chloride

Polymer nanocomposite was prepared by the conventional sol-gel method using formaldehyde and resorcinol. The surface of the nanocomposite was functionalized with methylamine. Some of the samples were additionally impregnated with copper(II) chloride. All the materials obtained were characterized by FT-IR spectroscopy, low-temperature nitrogen sorption, thermal and elemental analysis. The samples modified with amine groups had lower surface areas and smaller pore volumes than the pure nanocomposite. The modification with methylamine and copper(II) chloride led to increased content of both acidic and basic oxygen functional groups.All materials were tested for the removal of rhodamine B and sunset yellow FCF from the liquid phase. The sorption capacities of the samples studied towards rhodamine B (140–208mg/g) were higher than their maximum capacities towards sunset yellow FCF (58–105mg/g). The most effective adsorbent of the dyes was the material modified with amine groups and copper(II) chloride. Thermodynamic study showed that the adsorption of the dyes was a spontaneous and endothermic process. The character of adsorption of sunset yellow FCF and rhodamine B on the composite materials studied could be described by the Langmuir type isotherm.

On the possibility of soft matter nanostructure formation based on mesoporous aluminum hydroxide. Prospects for biomedical applications

The effect of the nonequilibrium structure of 2D aluminum hydroxide-based objects on the macroscopic response (adsorption properties) is studied in the physical mesomechanics framework. Molecular dynamics simulation is performed to examine the nature of selective adsorption of the considered low-dimensional structures. The role of defects and structural elements, such as polar functional groups, is analyzed. Model ions and endotoxin are used to illustrate the selective character of adsorption. Prospects for biomedical applications of the obtained results are discussed.