Cs Solution Research Articles

Analysis of Cs solution by nano-silica particles-enhanced laser-induced breakdown spectroscopy

Analysis of Cs solution by nano-silica particles-enhanced laser-induced breakdown spectroscopy

Innovative potassium hexacyanoferrate intercalated into layered double hydroxide adsorbent for efficient cesium removal from seawater

Effective radioactive wastewater treatment technology is essential to ensure the sustainable development of nuclear energy. Here, the potassium ferrocyanide (HCF) intercalating with layered double hydroxide (LDH) (HCF@LDH) was successfully synthesized by coprecipitation method for selective cesium (Cs) removal from seawater. Characteristics of the adsorbent, and adsorption performance under different environmental conditions including Cs+ ion selectivity, and underlying adsorption mechanism were systematically investigated. The experimental results demonstrated that the adsorption capacity of HCF@LDH was 52.08 mg/g and it effectively removed 100 % of Cs+ from up to 200 mg/L Cs solution within 1 h under an optimal pH of 6.0–10.0. Moreover, the adsorbent displayed high selectivity towards Cs+ even in seawater and more than 90 % of Cs+ was removed from seawater and the highest cesium removal capacity from seawater was 44.64 mg/g. Both the Langmuir isotherm model (R2 = 0.997) and the pseudo-second-order kinetic model (R2 = 0.999) provided a good fit for the adsorption data signifying the adsorption process is homogeneous and formed monolayer through chemisorption. Furthermore, the reusability analysis exhibited this adsorbent was recycled and reused for at least 5 cycles without losing its original adsorption performance. The physicochemical analysis of the HCF@LDH proved that K4Fe (CN)6 successfully intercalated onto LDH and cation exchange between K+ and Cs+ played an important role in effective Cs adsorption. More specifically, the interstitial spaces of the hexacyanoferrate crystals facilitate the cation exchange process. The findings of this study demonstrate that HCF@LDH is a unique, highly effective, and selective adsorbent for Cs+ from complex seawater.

The sensitivity of chitosan/TiO2 film on ammonia detection

Ammonia (NH3) is a toxic gas from various sources, including industrial waste, agriculture, and other human activities. The high concentration can cause negative impacts on air, water, and soil quality and harm human health and ecosystems. The objective of this research was to detect ammonia concentration based on chitosan-CS/titanium dioxide-TiO2 film. The CS solution was supplemented with TiO2 in quantities ranging from 0.01 g to 0.05 g, with increments of 0.01 g. The formed films were characterized using FTIR and SEM, the sensing characteristic of the CS/TiO2 film-based sensor was tested with ammonia by varying concentrations of (1.5, 3, 4.5, 6, and 7.5) mg/L. The FTIR and SEM analytical results indicated that the loading process of TiO2 proceeded only through physical interaction. The test results demonstrate that the CS-TiO2 film-based sensor has a higher maximum output voltage (0.223 V) than the CS film-based sensor (0.078 V) when exposed to 7.5 mg/L of ammonia. From the testing results, it was found that the CS/TiO2 film-based sensor with adding 0.02 g of TiO2 have good sensitivity, selectivity, reproducibility, fast response, compared to CS film-based sensors. However, it was inversely proportional by lifetime test. Finally, it can be concluded that Cs/TiO2 film-based sensor can be used for ammonia concentration detection.

Non-parametric data processing in experimental studies of spirally reinforced concrete samples

Introduction. Statistical methods in the analysis of experimental data can be applied to identify patterns and test hypotheses, determine the quality of experimental data and draw conclusions based on objective data. In addition, experimental data after non-parametric processing can be used in numerical modeling using contemporary computing suites.Aim. To outline a methodology for non-parametric processing of experimental results using SCAD computing suite tools, certified in the territory of the Russian Federation. In the proposed methodology, experimental test data for spirally reinforced concrete samples of various strengths were used.Results. As a result of non-parametric processing of spirally reinforced concrete samples, empirical coefficients of the Prandtl bilinear diagram were determined according to the proposed method. This diagram is used in the SCAD computing suite to set the physical nonlinearity of the material behavior. A method for processing a small volume of experimental results is proposed for using the available data in SCAD CS numerical studies with an acceptable level of probability.Conclusions. The empirical coefficients, obtained in non-parametric processing for setting the Prandtl bilinear diagram, can be used to perform a numerical modeling of the sample bahavior for planning further experimental studies in order to find more general patterns, taking into account other behavioral factors of real structural elements in load-bearing systems of buildings and structures with spiral reinforcement, including high-intensity dynamic effects. According to experimental and theoretical studies, spiral reinforcement can significantly increase the deformability and energy capacity of reinforced concrete structures, which fundamentally affects the behavioral pattern of structures and supporting framework of buildings and structures as a whole. These behavioral features of spirally reinforced structures can be further taken into account for the computational justification of design solutions in the SCAD CS and other software programs using the Padé approximation of the Prandtl bilinear diagram.

Lignocellulose/chitosan hybrid aerogel composited with fluorescence molecular probe for simultaneous adsorption and detection of heavy metal pollutants

The pollution of heavy metals to aquatic ecosystem is getting more and more attention. Therefore, there is an urgent need to develop a low-cost, high-efficient, high-selective and environmental adsorbing material that can simultaneously indicate and adsorb heavy metal ions. Cellulose-based aerogel has attracted much attention due to its strong adsorption capacity, good biodegradability and cost performance. In this paper, cellulose nanofiber/chitosan/polyvinyl alcohol/lactam Rhodamine 6 G composite aerogel (CNF/CS/PVA/SRh6G) was prepared by freeze-drying technology with CNF/CS hybrid aerogel as adsorbent skeleton, SRh6G as fluorescent probe and PVA/glutaraldehyde (GA) as crosslinking agent. When the volume ratio of CNF suspension to CS solution was 10:1, as-prepared composite aerogel had a lower density (145.92 mg/cm3) and a higher specific surface area (0.04293 cm3/g). It also exhibited excellent superhydrophilicity and superoleophobicity underwater (OCA-159°), the underwater OCA of which always kept larger than 150° in the surroundings with pH of 1–14. Therefore, CNF/CS/PVA/SRh6G composite aerogel owned good acid and base resistance, which could be applied to rapid adsorption and real-time detection of metal ions (Hg2+, Ag+, Al3+, Fe3+ and Cu2+) in wastewater. CNF/CS/PVA/SRh6G composite aerogel could display obvious color and fluorescence variations under sunlight and ultraviolet light, and present the good reversibility after regeneration via base solution (pH=14). Under water, such CNF/CS/PVA/SRh6G composite aerogel showed a good compression elasticity with the maximum pressure of 26.2 N. After five cycles, the adsorption of composite aerogel still could reach up to 19 times of its own weight. Results also showed that it had remarkable durability and structural stability, indicating its broad application prospects in the field of wastewater treatment.

Ascorbic acid nanoencapsulation using polyelectrolyte complex formation and optimization using hybrid artificial neural network‐genetic algorithm

AbstractBackgroundsThe polyelectrolyte complex (PEC) formation using chitosan (Cs) and alginate (Alg) has been employed to carry out Vitamin C (VC) nanoencapsulation because of its instability in adverse conditions. This method includes VC nanoencapsulation using physical cross‐linking. The effect of the mixing order as well as the different mass ratios of both the polymer and the VC content, were investigated on the size, pdi, zeta potential, encapsulation efficiency (EE%), and yield%. Hence, considering different mass ratios of both polymer (4:1–1:4) and VC content (10%–30% w/w of Cs) as independent variables, PECs were formed using 0.1% (w/v) of Cs and Alg solution.ResultThe result showed that, for equal mass ratio (1:1) of Cs and Alg, the addition of Alg solution to Cs solution led to lower particle size, while higher particle size was observed with reverse order of addition. However, no significant effect of polymer mass ratios was observed on particle size and NPs stability, while EE varied with VC concentration. Artificial neural network (ANN) was applied to train the experimental parameters Cs: Alg ratios (X1:X2) and VC content (X3) for the output variables. Moreover, process optimization was carried out using multi‐objective genetic algorithm (MOGA) with the goal of lowering particle size and increasing EE while increasing nanoparticle yield.ConclusionThe PEC method effectively encapsulated VC as obtained from higher EE. The Cs: Alg ratio of 4:2.1 and 18% VC content (w/w of Cs) was found optimum for nanoencapsulation. The final ANN‐GA model showed an acceptable agreement with experimental data.

Chitosan–Resole–Pectin Aerogel in Methylene Blue Removal: Modeling and Optimization Using an Artificial Neuron Network

In this study, a novel chitosan–resole–pectin aerogel (CS–R–P) was created from a sol–gel reaction with a solution of Cs and P with resole by a freeze-drying technique, and this adsorbent was proposed for the removal of methylene blue (MB). In addition, with the use of an artificial intelligence technique known as an artificial neural network (ANN), this material was modeled and optimized. Its physical morphology and chemical composition were also characterized with FTIR and XPS, and its adsorption properties were analyzed. For modeling the adsorption process, three main parameters were used: the chitosan–resole–pectin concentration (45–75%), thermal treatment (6–36 h), and known concentrations of methylene blue (25–50 and 100 mg/L), established on the Box–Behnken design. The ANN was coupled with the improved gray wolf optimization (IWGO) metaheuristic algorithm, achieving a correlation coefficient of R2 = 0.99. The characterization indicates that the surface of the aerogels was micro- and mesoporous, the resole gave physical stability, and the polysaccharide base delivered the functional groups necessary for dye adsorption; the aerogels were successful dye adsorbents with a qe of 12.44 mg/g. Finally, the physical and chemical sorption was ascertainable with an adsorption that followed pseudo-second-order kinetics. The MB adsorption was clearly occurring though cation exchange and hydrogen binding as observed in the chemical composition. The ANN with the gray wolf optimizer was used for the prediction of the best operating parameters for MB removal, applying the following conditions—the CS–R–P aerogel concentration (52/30/18), the thermal treatment (9.12 h), and the initial concentration of methylene blue (37 mg/L)—achieving a 94.6% removal. These conclusions suggest that using artificial intelligence such as an ANN can provide an efficient and practical model for maximizing the removal action of new aerogels based on chitosan.

Separation of Cs+ from Rb+ and Cs+ co-existing solution by Cs3Bi2I9 precipitation to produce CsI

Cesium and rubidium are highly-priced rare alkaline elements that are quite difficult to separate from each other. In this paper, Cs+ was successfully separated from co-existing solutions of Cs+, Rb+ and K+ in the form of Cs3Bi2I9 precipitation. The effects of various factors (pH value, Bi3+/Cs+ molar ratio, reaction time, and decomposition temperature) on the separation ratio of Cs+ were explored. The results showed that the maximum recovery of Cs+ was 98.55% from the solution with a Cs/Rb ratio of 1.28. The content of Rb+ in Cs3Bi2I9 was 0.189%, indicating that the method can effectively separate rubidium and cesium from each other. The separation factor of cesium-rubidium was 85. By subsequent vacuum thermal decomposition, Cs3Bi2I9 was directly converted to CsI and BiI3. The purity of CsI was greater than 99.00%, and BiI3 was recycled back to produce Cs3Bi2I9. This process has the advantages of low cost, short process, environment-friendly, and simple operation.

Preparation, Characterization, and Antimicrobial Activity of Chitosan/Kaolin Clay Biocomposite Films

AbstractChitosan (CS) is a polycation found in nature that exhibits many good properties. Kaolin (KAO) clay is a natural inorganic filler and is being used in medicine, ceramic, food additives, etc. Therefore, the mixing of two such biomaterials, a natural polycation (CS) and natural filler (KAO clay) may lead to a biocomposite, chitosan/kaolin (CS/KAO) clay, with many interesting properties. In this study, the composites of CS and KAO clay are prepared by mixing the solution of CS (in dilute acetic acid) with KAO clay at various weight ratios. FT‐IR, UV/Vis, X‐Ray diffraction, SEM, UTM, TGA, and DSC analyses are used to investigate these biocomposites thoroughly. Agar well diffusion method has been used to determine the antibacterial activities of different concentrations of the CS‐ KAO clay against gram ‐positive (Bacillus subtilis) and gram‐ negative (Escherichia coli) bacteria. The biocomposites exhibited antibacterial activities against tested microrganisms. In addition, swelling tests of the biocomposites are also carried out. The CS/KAO clay biocomposite films show better tensile strength than CS film. It is observed that dispersed KAO clay improves the thermal stability and enhances the hardness of the matrix systematically with the increase of its loading.

Atmospheric pressure plasma treatment of chitosan-acrylic acid blends

This study explores the effect of atmospheric pressure plasma (APP) treatment on chitosan-acrylic acid (Cs-AA) blends. The experiment involves a custom-built APP setup used to modify a polymeric blend composed of natural (Cs) and synthetic (AA) polymers. Even with a low process temperature (<40 °C), reactive oxygen and nitrogen species (RONS) were observed in an air plasma plume. The interaction of plasma with the liquid surface was also observed. With de-ionized water as the test liquid, the operating parameters such as the treatment time and flow rate were shown to influence the pH and absorption spectrum of the liquid. The presence of RONS was investigated using optical emission spectroscopy coupled with principal component analysis. The analysis revealed that the air plasma contains the different N systems, NO, OH, H α, monatomic N, and monatomic O species. Varying the gas flow rate influences the production of NO and OH radicals while measuring plasma discharge in different conditions (ambient air, DI H 2O, Cs, and Cs-AA blend) affects the concentration of the N positive and negative systems. The effect of these RONS on the Cs-AA blends was also investigated by assessing the chemical structure, pH, and viscosity of the solution. In correlation with all of the findings, it was observed that plasma treatment could degrade pure Cs solution by dehydrogenation and glycosidic bond cleaving. However, the addition of AA reduces the degradation so that the AA radicals created by plasma form a complex with the Cs that reduces Cs fragmentation and chain entanglement, as observed in the reduction of viscosity. In summary, the rich reactive species created by plasma in the Cs-AA solution not only provided stable species but also introduced more Cs-AA complexes.

Removal of Cesium and Strontium Ions from Aqueous Solutions by Thermally Treated Natural Zeolite.

The radionuclides of cesium (Cs) and strontium (Sr) are dangerous products of nuclear fission that can be accidentally released into wastewater. In the present work, the capacity of thermally treated natural zeolite (NZ) from Macicasu (Romania) to remove Cs+ and Sr2+ ions from aqueous solutions in batch mode was investigated by contacting different zeolite quantities (0.5, 1, and 2 g) of 0.5-1.25 mm (NZ1) and 0.1-0.5 mm (NZ2) particle size fractions with 50 mL working solutions of Cs+ and Sr2+ (10, 50, and 100 mg L-1 initial concentrations) for 180 min. The concentration of Cs in the aqueous solutions was determined by inductively coupled plasma mass spectrometry (ICP-MS), whereas the Sr concentration was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The removal efficiency of Cs+ varied between 62.8 and 99.3%, whereas Sr2+ ranged between 51.3 and 94.5%, depending on the initial concentrations, the contact time, the amount, and particle size of the adsorbent material. The sorption of Cs+ and Sr2+ was analyzed using the nonlinear form of Langmuir and Freundlich isotherm models and pseudo-first-order (PFO) and pseudo-second-order (PSO) kinetic models. The results indicated that the sorption kinetics of Cs+ and Sr2+ on thermally treated natural zeolite was described by the PSO kinetic model. Chemisorption dominates the retention of both Cs+ and Sr2+ by strong coordinate bonds with an aluminosilicate zeolite skeleton.

Effect of storage time on the antimicrobial properties of chitosan

AbstractChitosan (CS) is well known as one of the natural polymers. It is one of the familiar antibacterial materials owing to its safety, non‐toxicity and biocompatibility. However, its prolonged capability to act as an antibacterial agent is not yet investigated in detail. i.e., as to how much time it can withstand its ability as an antibacterial agent is very significant for practical purposes. Hence, in the present study, CS solution and thin films in different ratios were prepared and were stored up to 24 months. Later observations were carried on different samples after storage time to assess its potential toward antimicrobial activity. It was noted that CS thin films had superior properties even after storage time of 24 months when compared to solution and powder forms. In addition to the above, morphology of the nanofilms and the presence of functional groups were also studied in detail.

Chitosan-hydroxyapatite composites made from sustainable sources: A morphology and antibacterial study

Chitosan (Cs) and hydroxyapatite (HA) 3D scaffolds/composites were prepared with a sustainable process, as HA was obtained using CaCO3 derived from cork, a natural material used as a template agent. The HA@Cs composites were prepared with HA in situ formation in a Cs solution, with a dissolution-precipitation mechanism.Different reaction times were considered, with time of 72 h leading to the best materials (sample CsHA_72). X-ray Diffraction (XRD) analysis confirmed HA formation. The analysis of Cs unit cell parameters showed that, for the unmodified Cs, the cell had larger dimensions and a higher degree of distortion than previously reported in literature; HA incorporation in the CsHA_72 composite led to a further increase in the cell dimensions.The morphology of the scaffolds was studied with Scanning Electron Microscopy (SEM) and a high level of porosity was observed; a statistical comparison was performed between the unmodified Cs and CsHA_72 to determine the pore size, structure, and distribution. This analysis, the first of this kind for this type of composites, showed smaller and more circular pores for the CsHA_72 composite (average diameter of 70 μm vs. 88 μm for unmodified Cs). The overall level of porosity, however, did not change (>77%); likewise, the Young modulus was not affected by HA incorporation (about 11 kPa).Antibacterial tests, performed on Escherichia coli and Staphylococcus aureus, showed that HA presence did not significantly reduce the antimicrobial properties; the composites were particularly effective towards S. aureus, as a >90% the bacterial population reduction was observed for an incubation time of 2 h. HA@Cs also showed excellent biocompatibility and good cell proliferation.The properties of these 3D scaffolds make them suitable for application as biomaterials.

The removal of total suspended particulates (TSP) using chitosan/PVA electrospun fibers

Total suspended particle (TSP) is the measurement of the amount of suspended particle with a diameter less than 100 micrometers. The exposure of particulate matter can be significant for human health and environment. It can cause respiratory and cardiovascular effects, reduce visibility, and reduce water quality. Electrospun fibers is a versatile technology that can produce large surface area, controllable fiber diameter and interconnected pore structure. In this study, the effectiveness of chitosan-polyvinyl alcohol (CS-PVA) fibers incorporated with activated carbon (AC) for capturing TSP in the air was investigated. The CS-PVA fibers was prepared by combining CS and PVA solutions at ratio of 30:70 with various AC concentrations ranging from 0-3 wt.%. The CS-PVA fibers prepared were fitted in the low-volume air samplers (LVAS) and placed nearby the main road of UMK Campus Jeli, for the collection of PM2.5 and PM10. Additionally, the weathering data during the sampling days was requested from My MET website to observe the influence of weather on TSP collection. Based on the results, as the AC concentration increased in the CS-PVA fibers, the concentration of PM10 and PM2.5 also increased. The CSPVA-3 showed the highest collection of PM10 and PM2.5 compared to other CS-PVA fibers and standard quartz filter. However, the collection of TSP on the filter paper were also influence by the humidity, rainfall, and wind speed of the sampling day.

Retardation and compressive strength enhancement effect of upcycling waste carrot as bio-admixture for cement mortars

The use of bio-admixtures instead of traditional chemical admixtures to prepare green concrete has attracted immense attention. In this study, a new and clean method to upcycle waste carrot into a novel natural admixture for cement mortars was proposed, and the effect of carrot extract (CS) on the properties of cement-based materials was systematically studied at the macro and micro levels through multiple means of detection. The results revealed that CS effectively inhibited the early hydration of cement and prolonged its setting time. The setting time of the pastes containing CS was 1.1–2.7 times that recorded for the control group (without CS) (CON), and the retarding effect was positively correlated with CS concentration. The compressive strength of the mortar of the M-CS1 (the value of CS to water was 1:100) group was increased by 12.5%, 11.6%, and 4.5% at 3-, 7-, and 28 d, respectively,which was due to the fact that CS accelerated the generation of calcium hydroxide (CH) and calcium silicate hydrate(C–S–H). In summary, CS can be used as a retarder and compressive strength enhancer in concrete simultaneously, and the experimental results in this study can provide experimental data and a basis for the preparation of green concrete. • The setting time of the pastes containing CS was 1.1–2.7 times that recorded for CON, and the addition of CS with appropriate concentration can also improve the compressive strength of the mortar. • CS contains a large number of hydrophilic group - hydroxyl, which has good water retention performance in cement. • The CS solution did not lead to the formation of new hydration products but promoted the formation of CH and CSH in the system, which has a positive effect on the compressive strength of mortars. • CS can improve the micro pore structure of mortar. • The use of low dose CS exhibited better sustainability and higher cost-effectiveness as confirmed by the economic and environmental analysis.

Hydrothermal synthesis and sorption performance to Cs(I) and Sr(II) of zirconia-analcime composites derived from coal fly ash cenospheres

The paper is concerned with (i) the hydrothermal synthesis of hydrous zirconium dioxide (HZD) bearing analcime (HZD-ANA, zirconia-analcime) and (ii) its sorption properties with respect to Cs+ and Sr2+. The HZD-ANA particles were synthesized from coal fly ash cenospheres composed of aluminosilicate glass with (SiO2/Al2O3)wt.=3.1 and characterized by PXRD, SEM-EDS, STA, and low-temperature N2 adsorption. The non-radioactive simulant solutions of different acidity (pH=2–10) and Cs+/Sr2+ content (0.5–50.0 mg/L) were used in the work. The effect of synthesis conditions on the HZD-ANA particle size, zirconia content and localization as well as the sorption behavior with respect to Cs+ and Sr2+ (capacity, KD) were clarified. It was found that the small-sized HZD-ANA composites surpasses the Zr free analcime and large-sized HZD-ANA material in the Cs+ and Sr2+ sorption parameters (KD ~104–106 mL/g). The conditions to synthesize the zirconia-analcime composite of the highly enhanced sorption ability with respect to Sr2+ (KD ~106 mL/g) were determined. The high-temperature solid-phase re-crystallization of Cs+/Sr2+-exchanged HZD-ANA composites was shown to occur at 1000 °C resulting in a polyphase system based on nepheline, tetragonal ZrO2, and glass phase.

Study and Characterization of Super Paramagnetic Nanoparticles Coated with Chitosan Polymer (SPIONs-CS)

Preparation of iron salts Fe + 3 Fe+2 This study aims to prepare super-magnetic nanoparticles coated with chitosan-CS SPIONs in an easy and inexpensive chemical way, which is the method of co-precipitation mediated in aqueous solution and mixing it with a solution of chitosan CS dissolved in dilute citric acid 1 % and precipitation of this mixture in a solution of NaOH and sodium citrate acid as a surfactant inside a closed system using an inert atmosphere for nitrogen gas N2 and a packaging method during the preparation. These particles were diagnosed by (XRD), and it was found that the particles coated with chitosan SPIONs-CS contain the crystal structure of iron oxide and that the polymer shell did not affect its crystal phase. It has a super magnetic property that decreases with increasing concentrations of the chitosan polymer encapsulating the particles, but it is sufficient to respond to the magnetic field. It was found from the diagnostic results that the prepared secondary particles were within the nanoscale 20 nm according to in TEM, which is Converging with the obtained size of 22.8 nm XRD technique, Zeta potential analysis results showed that the SPIONs-CS had a negative surface charge after encapsulation with a zeta voltage of -28.4mv at 0.125 chitosan concentration.g CS . (SEM) diagnosis results showed that the particles are spherical in shape and spaced according to the CS chitosan concentrations used for encapsulation with an average diameter of (27.58nm, 20.023nm and 35.127nm) for three concentrations (0.100g, 0.125g, 0.150g), respectively.

Preparation, Characterization, and Properties of Chitosan‐Based Semi‐Interpenetrating Polymer Networks and Poly(2‐hydroxyethyl methacrylate) Structure

AbstractIn this study, semi‐interpenetrating polymer networks (semi‐IPNs) based on chitosan and poly(2‐hydroxyethyl methacrylate) (CS/PHEMA) are successfully fabricated through free radical polymerization of HEMA in the presence of CS solution with potassium persulfate (KPS) as an initiator and triethylene glycol dimethacrylate (TEGDMA) as a crosslinking agent, aiming to develop semi‐IPNs CS/PHEMA structure properties by different feed ratios of CS/HEMA and TEGDMA. The resulting semi‐IPNs CS/PHEMA structure shows the presence of the two polymeric components in the polymer structure. The crosslinking results in the morphological structure, high porosity and pore structure, as well as interconnected pores on the surface, indicating that a semi‐IPNs hydrogel structure formed after polymerization. Moreover, the degree of swelling is excellent in different media ranging from 140 to 220%. The semi‐IPNs CS/PHEMA samples exhibit highly enhanced mechanical strength with crosslinking and show features of brittle materials in the dry state and rubber‐like materials in the wet state. Compressive structure exhibits retaining after stress removal. The polymeric decomposition occurs, corresponding to linear CS and PHEMA networks. The degradation behavior of semi‐IPNs CS/PHEMA promotes enzymatic biodegradation under simulated physiological conditions. Therefore, these CS/PHEMA semi‐IPNs materials can be suitable for use as biodegradable polymers and engineering scaffold materials.

Sorption Studies of Cesium on Kunipia-F Bentonite and Silicon Dioxide

Adsorption is one of the effective methods used for the removal of contaminants from radioactive wastewater. In this research, removal efficiency of Cs from the prepared low-concentration Cs solution (100 μg/L) was studied using two different adsorbents namely high purity Kunipia-F bentonite and Silicon dioxide (SiO2). After performing the adsorption tests, the Cs ions in liquid and solid phases were analyzed using the inductively coupled plasma mass spectrometry (ICP-MS) technique. The adsorption capacities of both materials were then compared. It was found that the Cs adsorption capacity of bentonite was higher than that of SiO2. The distribution coefficient of Cs in the bentonite was 1.0 L-sol/g-solid, which was 100 times greater than that of SiO2. The highest sorption of Cs on bentonite could be attributed to its smaller particle size (0.362 μm), compared to the SiO2 particle size (0.625 μm). Bentonite is natural clay and is generally used as a buffer material in geological disposal systems for high-level nuclear waste. The results of this research indicate that bentonite could be an effective absorbent for decontaminating low concentration Cs in radioactive wastewater.

Electrospinning of PANI/GO nanocomposite and PANI/CS blend for high removal efficiency of Ni (II) from aqueous solution

Polyvinyl alcohol-polyaniline/graphene oxide nanofiber (PVA-PANI/GO)NF and polyvinyl pyrrolidone/polyvinyl alcohol-polyaniline/chitosan nanofiber (PVP/PVA-PANI/CS)NF were prepared by mixing PANI with GO suspension and CS solution respectively using different amounts of GO and CS (1, 10 wt %), followed by electrospinning. Nanofibers were created using a proportion (1:2) mixture of PVP and PVA, where the PVA was used to improve the viscosity and the PVP was utilized to boost the conductivity of the nanocomposite. X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier Transform Infrared Spectroscopy (FTIR) were used to characterize the produced materials. The adsorbents (PVA-PANI/GO)NF and (PVP/PVA-PANI/CS)NF are used to remove Ni (II) from aqueous solution. Several variables were investigated in order to compare (PVA-PANI/GO)NF and (PVP/PVA-PANI/CS)NF removal efficiency and adsorption capacity, such as contact time, concentration, dose quantity, and temperature. Langmuir and Freundlich adsorption isotherm models were used to describe the equilibrium isotherm and the adsorption followed Freundlich adsorption isotherm. Nickel ion adsorption kinetics on (PVA-PANI/GO)NF and (PVP/PVA-PANI/CS)NF followed a pseudo second-order kinetic model.