Simple Adsorption Research Articles

Preparation of high-purity manganese sulfate and removal of unwanted metal ions using resin-based purification

ABSTRACT High purity manganese sulfate(MnSO4) is of great importance due to its applications in lithium-ion batteries, pharmaceutical applications, and within feed additives. As manganese always occurs in combination with iron, laterite and other minerals, co-leaching of Mn and Fe complicates the purification procedure of MnSO4. Obtaining high purity MnSO4 without contamination of calcium and magnesium is difficult, because of their similar chemical properties. Current research involved preparation of highly pure MnSO4 from low purity MnO2. A simple and efficient procedure has been developed for purification of MnSO4 by using a carbon adsorbent followed by treatment with iminodiacetate functionalised resin polymer. The two-step procedure enabled an extremely pure MnSO4 generally exceeding 99.9%. Iron has been efficiently removed to below 5 ppm (>99% reduction from ∼1000 ppm), calcium was reduced to ∼100 ppm (>90% reduction from ~1600 ppm) and magnesium was reduced to below 10 ppm (>99% reduction from ~1400 ppm). Adiitionally, simple carbon adsorption effectively reduced lead and zinc to below their detection levels (< 0.050 and 5.00 ppm, respectively) and arsenic was reduced to below its level of quantification (< 0.375 ppm). Careful adaptation of the procedure allows for producing high purity manganese salts at a larger scale.

Development an effective adsorptive treatment strategy for the removal of cadmium from textile wastewater by CuBi2O4@Fe3O4 nanocomposites

In this study, copper-bismuth oxide/iron oxide (CuBi2O4@Fe3O4) nanocomposites were prepared by microwave-assisted synthesis and used as adsorbents for the adsorptive removal of cadmium from textile wastewater. The pH/volume of buffer solution, mixing type/period and adsorbent dosage were optimized univariately to enhance the removal efficiency of the adsorbent and determined as 1.5 mL of pH 8.0 buffer solution, vortexing for 60s, and 30 mg of CuBi2O4@Fe3O4 nanocomposite material. Following the determination of the optimum parameters, equilibrium adsorption studies were performed at five different initial concentrations of cadmium within the range of 0.50 − 10 mg L−1 in textile wastewater. A matrix-matching calibration strategy was utilized for the accurate and precise quantification of cadmium in the wastewater matrix with a R 2 value of 0.9961. The percent removal efficiencies were calculated within the range of 77.2 − 81.5% for the adsorptive removal of cadmium ions from textile wastewater in the equilibrium adsorption experiments. Furthermore, the Langmuir, Freundlich, and Sips adsorption isotherm models were employed for modeling the equilibrium data, and the results showed that all the models fitted well with the experimental data with R2 values higher than 0.99. The simple and efficient batch adsorption process developed was successfully utilized to remove cadmium ions from textile wastewater.

A highly sensitive Photothermal Immunochromatographic test strip for detection of aflatoxin B1 based on CoS@TA Nanospheres

A novel photothermal immunochromatographic test strip (PITS) with tannic acid (TA) modified cobalt sulfide (CoS) nanospheres (CoS@TA) as immuno-probe element was developed for the detection of aflatoxin B1 (AFB1). CoS nanospheres (CoS NPs) with excellent photothermal conversion efficiency (η = 47.5 %) was synthesized and skillfully chelated with TA to improve its dispersion, biocompatibility, and chromatographic properties. After modification, the CoS@TA coupled with monoclonal antibody (mAb) against AFB1 (CoS@TA-mAb) by simple physical adsorption. The CoS@TA based PITS achieved highly sensitive detection of AFB1 with the limit of detection in photothermal signal (photothermal-LOD) of 0.00503 μg/L, which was 19.88-fold higher than the LOD in visual signal (visual-LOD, 0.1 μg/L). The application of TA in the modification of CoS provided ideas to improve the properties of functional nanomaterials such as dispersion and biocompatibility, and the application of CoS@TA in PITS construction laid a methodological foundation for further improving the detection sensitivity of trace targets.

Flexible Tactile Sensors with Gradient Conformal Dome Structures.

The trade-off between high sensitivity and wide detection range remains a challenge for flexible capacitive pressure sensors. Gradient structure can provide continuous deformation and lead to a wide sensing range. However, it simultaneously augments the distance between two electrodes, which diminishes the variation in the relative distance and results in a decreased sensitivity. Herein, a conformal design is introduced into the gradient structure to construct a flexible capacitive pressure sensor. The gradient conformal dome structure is fabricated by a simple reverse dome adsorption process. Taking advantage of the progressive deformation behavior of the gradient dielectric, and the significant improvement of relative distance variation between two electrodes from the conformal design, the sensor achieves a sensitivity of 0.214 kPa-1 in an ultrabroad linear range up to 200 kPa. It maintains high-pressure resolution under the preload of 10 and 100 kPa. Benefiting from the rapid response and excellent repeatability, the sensor can be used for physiological monitor and human motion detection, including arterial pulse, joint bending, and motion state. The gradient conformal design strategy may pave a promising avenue to develop pressure sensors with high sensitivity and wide linear range.

Facile constructing core-shell F–CIP@O/N-SWCNHs composites for high-performance microwave absorption and anti-corrosion

The development of electromagnetic wave-absorbing materials (EWAMs) with good environmental adaptability has emerged as a focal point of research in the realm of electromagnetic protection. Herein, a core-shell structure composite EWAMs, in which flake carbonyl iron powders and O, N co-doped single-walled carbon nanohorns are respectively a core and a shell (F–CIP@O/N-SWCNHs), has been prepared by a simple electrostatic adsorption method. The high-shape anisotropy of the F–CIP core exhibits strong specific saturation magnetization (160.47 emu/g) and excellent magnetic loss capacity. The tunable O/N-SWCNHs shell effectively enhances the dielectric properties and improves impedance matching, while the oxygen and nitrogen doping strengthens the dipole polarization. The surface protection provided by O/N-SWCNHs imparts favorable corrosion resistance and anti-oxidation properties to the F-CIP@O/N-SWCNHs. Moreover, F–CIP@O/N-SWCNHs exhibit excellent wave absorption performance. When the sample thickness is 1.53 mm, the minimum reflection loss reaches −74.8 dB. This study provides a feasible approach for the preparation of efficient EWAMs with strong environmental adaptability for the practical application of composite-absorbing materials.

Preparation of chiral polyether dendrimer and its non-bonding immobilized CALB for high enantioselective synergy resolution of amines

Monodisperse polyethylene glycol monomethyl ether and chiral glycidyl tosylate were utilized as substrates in the synthesis of the chiral monomer unit epoxypropyl polyethylene glycol monomethyl ether (MPEGn-EPO). The initiator propargyl-terminated polyethylene glycol alkyne-PEG3-OH was employed, while the phosphazene base P4-t-Bu facilitated the controlled ROP of MPEGn-EPO, resulting in clickable dendritic P(MPEGn-EPO) with terminal alkyne. The chiral four-arm dendritic polymer 4-Arm-PEG3-Mn was synthesized through a click reaction between 4-Arm-PEG3-N3 and P(MPEGn-EPO) using Cu(PPh3)3Br/CuBr as a catalyst. Candida antarctica lipase B (CALB) was chosen as a model enzyme for the preparation of a non-covalently immobilized biocatalyst (CALB-M) via a simple adsorption process with magnesium silicate and 4-Arm-PEG3-M4-20. The immobilized lipase CALB-M16 demonstrated high enzyme activity in the resolution of racemic amines, yielding chiral amines with enantioselectivity up to 99 % ee. Circular dichroism (CD) analysis indicated the formation of helical conformation in the dendritic polyethers 4-Arm-PEG3-M16-20 in the presence of magnesium silicate at 5 °C. The polyethylene glycol side groups of 4-Arm-PEG3-M16-20 are suggested to potentially form a crown ether-like structure with magnesium ions, which could enhance steric hindrance and induce a right-handed helix. Furthermore, the helical structure of this dendritic polyether is thought to work in synergy with CALB, improving the enantioselective resolution of amines.

Enhanced Fenton catalytic degradation of methylene blue by the synergistic effect of Fe and Ce in chitosan-supported mixed-metal MOFs (Fe/Ce-BDC@CS)

Methylene blue (MB) is a refractory organic pollutant that poses a potential threat to the aquatic environment. Fenton reaction is considered a primrose strategy to treat MB. However, the traditional Fenton process is plagued by narrow pH application range, poor stability, and secondary pollution. To solve these problems, many Fenton-like catalysts including metal-organic frameworks (MOFs) have been prepared. Herein, a novel bimetallic MOF (Fe/Ce-BDC@CS) was prepared through simple adsorption for the effective removal of MB, where chitosan (CS) was used as the carrier. The degradation performance of Fe/Ce-BDC@CS (100 % within 20 min) was better than that of most reported monometallic MOFs. Moreover, Fe/Ce-BDC@CS exhibited good repeatability and its anti-interference performance of some inorganic ions was also remarkable. Column loading experiments showed that the removal efficiency of MB was still about 50 % over 155 h with a flowing speed of 0.30 L/h. Comparative analysis indicated that such excellent performances could be attributed to the synergistic effect between Fe and Ce. Furthermore, the results of quenching tests indicate that OH, O2−, and 1O2 contributed to MB degradation. In brief, Fe/Ce-BDC@CS has promising prospects in MB treatment, which can provide scientific references for the design and application of bimetallic MOFs.

Study of heavy metals adsorption using a silicate-based material: Experiments and theoretical insights

Heavy metal toxicity in water is a serious problem with harmful effects on human health and the ecosystem. This research studied a silicate-based material as an adsorbent for removing four heavy metals from aqueous solutions. The target metal pollutants selected include manganese (Mn2+), copper (Cu2+), cobalt (Co2+), and zinc (Zn2+). First, theoretical tools including potential energy surface analysis, Natural Population Analysis, AIM, Wiberg Bond Index, QTAIM, and topological methods offer profound insights into the nature of interactions present in the Mg2O8Si3M (M = Mn2+, Cu2+, Co2+, Zn2+) clusters. Second, the synthesis and characterization of eco-friendly hydrated amorphous magnesium silicate (MgOSiO2nH2O) was developed. Last, a simple kinetic adsorption test was applied to assess the material selectivity towards heavy metals and support theoretical results. The kinetic adsorption study was analyzed through the pseudo-first and second-order kinetics, Elovich, and the intraparticle diffusion models. The theoretical analysis of the adsorption energies indicates that the adsorption of four metal ions on the Mg2O8Si3 surface is energetically favorable in all cases. The material displayed the following adsorption sequence: Cu2+ (59 mg g-1) > Zn2+(25 mg g-1) ≈ Co2+ (23 mg g-1) > Mn2+ (15 mg g-1). This knowledge can then be used to design and optimize low-cost silicate-based materials for effective heavy metal removal, contributing to efforts to address environmental pollution and protect public health.

Removal of levofloxacin from aqueous solutions by using micro algae: optimization, isotherm, and kinetic study

This study was focused on the response surface methodology modeling of the removal of levofloxacin residue using microalgae as adsorbent. The microalgae categories Cladophora was characterized by Fourier transform infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and X-ray Diffraction (XRD) analysis techniques. The efficacy of LEV removal was evaluated by the historical data of different variables (time, pH, algal dosage, and LEV concentration) using Central Composed Design (CCD). The predicted results of the model demonstrated that the expected responses are reasonably close to the actual data, demonstrating the efficiency of this method in producing an accurate prediction. The model was found to be significant based on its coefficient of determination, which was 0.914, along with the fitted and projected values of 0.9029 and 0.8967. Furthermore, the results of the predicted reaction optimization showed that the maximum LEV elimination could be achieved within a time of 90 min, a pH of 6 and 0.2 g/L of micro algae. The model was validated experimentally with 95.45 % of LEV elimination efficiency. In addition, it is observed that the LEV removal process followed Langmuir model and pseudo-second order kinetic in majority of the cases with R2 of 0.9959. As a result of the dead algae's simple use and high adsorption effectiveness, the results demonstrated the possible use of antibiotics in aqueous solutions.

Synthesis and photocatalytic properties of polyaniline modified cadmium-manganese sulfide materials

In the present paper, polyaniline modification of Mn0.5Cd0.5S composite (PANI/MCS) was fabricated by a simple electrostatic adsorption method. The introduction of PANI makes PANI/MCS composites have better visible light absorption and higher photogenerated carrier segregation efficiency, thus showing better photocatalytic performance. The results show that the 50-PANI/MCS photocatalyst has the best hydrogen production capacity, which was 2.2 times greater than neat MCS. Meanwhile, the nitrogen fixation performance of the best sample 50-PANI/MCS was 4.93 times that of pure MCS. After that, a reasonable reaction mechanism was obtained through various characterization data. A cheap and readily available composite photocatalyst has been synthesized. This paper has good reference value in the area of development of efficient composite photocatalyst.

Efficacy of zeolites in radon adsorption: state of the art and development of an optimized approach

ABSTRACT Radon is a radioactive noble gas omnipresent in the environment, being part of the 238U and 232Th decay chains present in the Earth's crust. The gas can easily leak through the ground but also be present in natural construction materials and migrate into indoor places where it can be a carcinogen when inhaled. Studying the content and removal of indoor radon is crucial for the evaluation and mitigation of its radiological risks to public health. For more than 100 years, the removal by adsorption of the radon has been performed on activated charcoal. There is little progress in the field of radon adsorption at ambient conditions; the main progress is in the use of zeolite materials, having well-defined three-dimensional porous structures and radiation resistance. This study concerns a report on the state of the art of the application of zeolites in radon adsorption. Furthermore, an optimized approach for measuring the radon content in indoor environments and, consequently, its removal has been proposed. Adsorption systems based on zeolites have the potential to replace activated charcoal as a material of choice, allowing to facilitate the development of simple and compact radon adsorption systems.

Water-Catalyzed Formation of Reactive Oxygen Species from NO2 on a Weakly Hydrated Calcite Surface.

The interfaces of weakly hydrated mineral substrates have been shown to serve as catalytic sites for chemical reactions that may not be accessible in the gas phase or under bulk conditions. Currently known mechanisms for the formation of reactive oxygen species (ROS) from nitrogen dioxide (NO2) involve NO2 dimerization. Here, we report the formation of the ROS HONO via a mechanism involving simple adsorption of a single NO2 molecule on a weakly hydrated calcite substrate. First-principles molecular dynamics simulations coupled with enhanced sampling techniques show how an adsorbed water sublayer can enhance NO2 adsorption on calcite compared to adsorption on a bare dry substrate. On the weakly hydrated calcite surface, an interfacial electric field facilitates proton extraction from water, thus allowing HONO formation from a single adsorbed NO2, i.e., without the need for the formation of a NO2 dimer precomplex. HONO formation on calcite is kinetically more favorable than that in the gas phase, with a reaction barrier of 14 kcal/mol on the weakly hydrated calcite surface compared to 27 kcal/mol in the gas phase. Further photocatalysed HONO production by visible light and HONO dissociation are hampered on calcite, unlike the process on silica. NO2 is a significant anthropogenic pollutant, and understanding its chemistry is crucial for explaining the high ROS levels and haze formation in polluted areas or prebiotic ROS generation. These findings emphasize how mineral substrates under water-restricted hydration conditions can trigger chemical pathways that are unexpected in the gas phase or under bulk conditions.

Distinguishing the transitions of fluorescence spectra of tryptophan-134 and 213 in BSA induced by bindings of UV filters, oxybenzone-3, and avobenzone

Abstract Oxybenzone-3 (OBZ) and avobenzone (ABZ), commercially available ultraviolet-light filters for sunscreens, are known to induce photosensitizing allergy as an adverse effect, similar to an analgesic ketoprofen (KTP) due to their benzophenone moiety. The present study focused on OBZ and ABZ's protein binding compared to the related analgesics, KTP, diclofenac (DCF), and ibuprofen (IBP). The bovine serum albumin (BSA) was used as a protein model, measuring the fluorescent spectral peak shifts (i) and Stern–Volmer analysis (i) of its intrinsic tryptophans. Moreover, their adsorption types (iii) were verified using the singular value decomposition (SVD) computation of fluorescence spectra. For (i), (ii), and (iii), KTP and DCF caused a no-shift peak, an ordinary dynamic quenching, and a simple Langmuir adsorption. We found OBZ exhibiting (i) red-shift and (ii) including static quenching, ABZ suggesting (i) blue-shift and (iii) binding to multiple bind sites, and IBP indicating (i) blue-shift and (iii) multivalent bindings. Integrating the results, it can be understood that OBZ interacts with subdomain IA (around W134) in BSA, while ABZ interacts with subdomain IIA (around W213) in BSA. Moreover, IBP is bound to BSA with a cooperative effect, certified by Hill's plot. OBZ and ABZ had their individual binding sites on a protein, suggesting the exchange between OBZ and ABZ might reduce their own adverse effect. The present study verified the effectiveness of the SVD computation in distinguishing the details of the adsorption manner of ligands around the intrinsic fluorescent probes.

Peptides-modified cellulose microspheres for adsorption of ochratoxin A: Performance and mechanism

In this study, peptides with ochratoxin A (OTA) recognition and adsorption capability were designed, among which lysine, histidine, arginine and tyrosine were crucial. Peptide CYFRFYSNLHPK showed the strongest affinity for OTA (Ka = 1.74 × 105 M−1). Theoretical calculations revealed that the differences in the affinity of peptides for OTA were attributed to differences in the type, number and position of amino acids residues. Peptides were conjugated with porous cellulose microspheres to form peptide-modified pretreatment materials (Pep-MPA-RCMs) for adsorption of OTA. The morphology and composition of the prepared Pep-MPA-RCMs were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, fourier transform infrared spectroscopy, thermogravimetric analysis and X-ray diffraction. The effects of pH, adsorption time, initial concentration and temperature on the adsorption process were investigated. The adsorption performance was correlated with the pseudo-second order kinetic and Sips adsorption isotherm model. Thermodynamic studies further proved that the adsorption was exothermic and the prepared Pep-MPA-RCMs showed the maximum adsorption capacity of 9.87 mg/g for OTA at 25℃. A simple adsorption column for OTA was prepared by using Pep-MPA-RCMs as filler material, which still maintained more than 80 % of the removal rate after five consecutive adsorption-elution cycles. The prepared pretreatment material was successfully applied to remove OTA in real samples and was a promising adsorbent for practical applications.

Surface Modification of Hydroxyapatite Coating for Enhanced Antibiotic Therapy

A major strategy to combat implant-associated infections is to develop implant coatings with intrinsic antibacterial activity. Since hydroxyapatite (HAp) coatings and antibiotic administration are commonly used in clinical settings, developing HAp-coated implants with localized antibiotic-releasing properties has attracted popularity. Considering the antibacterial metal species (Ag, Zn, Cu, etc.) in metal–organic frameworks and their drug delivery capacity, in this study, a gentamicin-loaded zeolitic imidazolate framework-8 nanolayer was deposited on a plasma-sprayed HAp coating (HAp/ZIF-8@Gent), which served as a Gent and Zn2+ reservoir. The investigation on the binding interaction between ZIF-8 and HAp indicated that the growth of ZIF-8 was through a Zn2+ seed layer on the HAp coating via an adsorption–replacement mechanism, instead of simple physical adsorption. The HAp/ZIF-8@Gent coating exhibited a sustained drug-release property, and the cumulative concentration of released Gent reached 239.8 ± 7.1 μg/mL on day 8. Compared to the HAp-Zn and HAp/ZIF-8 coatings, the HAp/ZIF-8@Gent coating exhibited significantly higher antibacterial activity against E. coli. This was ascribed to the combined antibacterial effects of Zn2+ and Gent. The cytocompatibility of the HAp/ZIF-8@Gent coating was confirmed via cell proliferation. Above all, the ZIF-8-modified HAp coating with localized delivery of Gent and Zn2+ possessed excellent antibacterial activity and acceptable cytocompatibility, showing potential in mitigating implant-associated infections.

Continuous treatment of chromium picolinate and efficient chromium removal without hexavalent chromium accumulation using the modified Fe-C micro-electrolysis process

Cr(pic)3, an emerging contaminant, is easily degraded to hexavalent chromium (Cr(VI)) in environment, which exacerbates its risk. Because of the complexing structure, removal of this organic chromium is rather difficult through the simple adsorption and precipitation. Herein, disposal of Cr(pic)3 via the modified iron-carbon (Fe-C) micro-electrolysis (abbreviated as Fe-C) process (H2O2 was added simultaneously as the reactant) was first developed in this work. The modified process could accelerate the de-complexation of Cr(pic)3 and promote Cr removal at a lower H2O2 dosage than the Fenton process. Cr(VI) was not accumulated in the process. Almost all the Cr(pic)3 could be degraded and the residual chromium (all was trivalent chromium Cr(III)) was decreased from 520 to 52.7 μg/L within 30 min under optimized conditions in batch experiments (i.e., pHinitial = 3.0, pHfinal = 7.0, [H2O2]0 = 0.3 mM, [Fe-C fillers]0 = 0.1 g/L, respectively). Mechanisms of Cr(pic)3 de-complexation and Cr removal were elucidated based on the products detected and characteristics of the precipitates. Adsorption was the main mechanism for Cr(III) removal. It exchanged the hydroxyl ligand with the iron hydro(oxides) to form inner sphere complex. Factors that potentially affected the performance of the modified Fe-C process were investigated, including the operational parameters and the composition of water matrix. Moreover, the feasibility and stability of the established method were further confirmed by the column test, which realized the continuous operation and maintained the residual Cr in the effluent constant below 10.0 μg/L. Collectively, these findings consistently indicated that the modified Fe-C process is a robust and promising approach for the industrial disposal of Cr(pic)3.

Synthesis of eco-friendly multifunctional dextran microbeads for multiplexed assays

There has been an increasing demand for simultaneous detection of multiple analytes in one sample. Microbead-based platforms have been developed for multiplexed assays. However, most of the microbeads are made of non-biodegradable synthetic polymers, leading to environmental and human health concerns. In this study, we developed an environmentally friendly dextran microbeads as a new type of multi-analyte assay platform. Biodegradable dextran was utilized as the primary material. Highly uniform magnetic dextran microspheres were successfully synthesized using the Shirasu porous glass (SPG) membrane emulsification technique. To enhance the amount of surface functional groups for ligand conjugation, we coated the dextran microbeads with a layer of dendrimers via a simple electrostatic adsorption process. Subsequently, a unique and efficient click chemistry coupling technique was developed for the fluorescence encoding of the microspheres, enabling multiplexed detection. The dextran microbeads were tested for 3-plex cytokine analysis, and exhibited excellent biocompatibility, stable coding signals, low background noise and high sensitivity.

Numerical simulation of foam displacement impacted by kinetic and equilibrium surfactant adsorption

This study explores the effectiveness of foam in reducing gas mobility in porous media impacted by surfactant adsorption in highly heterogeneous porous media. The research focuses on assessing the influence of kinetic and equilibrium adsorption during foam displacement on reservoir sweep efficiency, considering co-injection and SAG (Surfactant Alternating Gas) injection strategies. Including the surfactant on the liquid phase and considering the surfactant adsorption effects fitted by experimental data, the mathematical modeling combines Darcy’s law, fluid phase conservation, surfactant transport equations, and a non-Newtonian foam model in local equilibrium. The simulations utilize FOSSIL (FOam diSplacement SImuLator), an in-house software composed of a stable and conservative numerical algorithm with reduced numerical diffusion. These properties are achieved by combining a hybrid mixed finite element method to solve the Darcy system with a central-upwind finite volume scheme to approximate the transport equations and adopting an implicit adaptive method in time. The results reveal that while omitting adsorption phenomena enhances sweep efficiency due to reduced surfactant loss, differences between equilibrium and kinetic adsorption models are minor (up to 0.3% in production). Consequently, these results suggest using simple adsorption models, such as equilibrium isotherms, rather than more complex models, such as kinetics. Additionally, the SAG approach outperforms co-injection (up to 19% in production), despite the fact that the adsorption is detrimental to both of them, aligning with literature results and previous findings.

Amino functionalization of porous aromatic frameworks for efficient and stable iodine adsorption

In view of the excellent stability, ultra-high specific surface area, and structural versatility, porous aromatic frameworks (PAFs) have shown promising potential in gaseous iodine adsorption. Herein, PAF-1 and PAF-5 were synthesized with high specific surface areas. Amino groups as effective binding sites were introduced to these frameworks through post-modification, which facilitated a shift from simple physical adsorption of iodine vapor to a more robust chemical adsorption process. Meanwhile, PAF-6 was synthesized from nitrogen-rich monomers to demonstrate the role of N-binding site in iodine adsorption. PAF-6 exhibited the highest iodine adsorption capacity, verifying the critical role of N-adsorption active sites. The in situ synthesis of nitrogen-rich porous material show advantages over post-modification in creating effective iodine adsorbents. This work highlights the potential of PAFs as a promising material for the adsorption and fixation of radioactive iodine.

Antibacterial effect and biocompatibility of silver nanoparticle-coated bone allograft substitutes.

Osteoinduction, and/or osteoconduction, and antibacterial characteristics are prerequisites for achieving successful bone grafting. This study aimed to coat bone allografts with silver nanoparticles and assess their antibacterial activity and biocompatibility compared to uncoated bone allografts. In this study, the bone allografts were coated with varying concentrations of silver nanoparticles (5 mg/l, 10 mg/l, and 50 mg/l) through a simple adsorption technique. Subsequently, the coated samples underwent characterization using SEM, FTIR, EDS, and XRD. The Minimal Inhibitory Concentration (MIC) of the silver nanoparticles was determined against Staphylococcus aureus and Streptococcus mutans. Bacterial growth inhibition was evaluated by measuring turbidity and performing a disk diffusion test. Moreover, qualitative investigation of biofilm formation on the coated bone allograft was conducted using SEM. Following this, MG-63 cell lines, resembling osteoblasts, were cultured on the bone allografts coated with 5 mg/l of silver nanoparticles, as well as on uncoated bone allografts, to assess biocompatibility. The MIC results demonstrated that silver nanoparticles exhibited antimicrobial effects on both microorganisms, inhibiting the growth of isolates at concentrations of 0.78 mg/L for Staphylococcus aureus and 0.39 mg/L for Streptococcus mutans. The bone allografts coated with varying concentrations of silver nanoparticles exhibited significant antibacterial activity against the tested bacteria, completely eradicating bacterial growth and preventing biofilm formation. The osteoblast-like MG-63 cells thrived on the bone allografts coated with 5 mg/l of silver nanoparticles, displaying no significant differences compared to both the uncoated bone allografts and the control group. Within the limit of this study, it can be concluded that silver nanoparticles have a positive role in controlling graft infection. In addition, simple adsorption technique showed an effective method of coating without overwhelming the healing of the graft.