Adsorption Of Nanoparticles Research Articles

التحضير الحيوي والتشخيص ودراسات الامتزاز ومضاد الميكروبات لجسيمات اوكسيدالمنغنيز النانوية باستخدام مستخلص قشور الرمان

تضمن العمل في هذا البحث تحضير اوكسيد المنغنيز النانوي من مستخلص النباتي لقشور الرمان و كبريتات المنغنيز في وسط قاعدي وشخص بطرق مختلفة مثل ؛ FT-IR ، الأشعة فوق البنفسجية المرئية ، الفحص المجهري للقوة الذرية وحيود الأشعة السينية ، المجهر الإلكتروني النافذ ، مجهر المسح الإلكتروني ، مطيافية الأشعة السينية المشتتة للطاقة. في حيود الأشعة السينية ، تم تحديد حجم البلورة باستخدام معادلة ديباي شيرر ، والتي وُجد أنها 30.94 نانومتر. تم امتصاص أيونات المعادن التالية (II)M= Co و Ni و Cu بنجاح باستخدام MnO2 NPs ، وأظهرت النتائج أنه يمكن إزالة أيونات المعادن الثلاثة من الماء في وقت واحد, Ni (II) لديه أعلى معدل امتصاص خلال الفترة الزمنية. كانت كفاءة إزالة أيونات Co ، و Ni ، و Cu أيونات 32.79٪ ، 75.00٪ ، 30.20 ٪. تم اختبار جسيمات MnO2 النانوية ضد نوعين من البكتيريا ونوع واحد من الفطريات بثلاثة تراكيز مختلفة, تمت مقارنة النتائج مع تلك التي تم استخدام المضادات الحيوية مثل أموكسيسيلين وميترونيدازول للمقارنة النتائج.

Surface modified single-step nanofluid for improved CO2 absorption and storage Prospects at pore-scale in micromodels: CO2 utilization for saline porous media

The utilization (absorption and areal sweep) of injected carbon dioxide (CO2) can be enhanced if a viscous and agglomeration free nanofluid is used as most of the nanoparticles (NPs) prefer to stay in bulk phase rather than adsorbing on CO2 surface. NP adsorption can be improved if non-participating NPs are surface modified with a suitable surface modifying agent e.g., triethoxy (vinyl)silane (TVS). Thus, in this study, single-step approach was used to synthesize agglomeration free TiO2 nanofluid whose surface modification was carried out in varying proportion of TVS (1–5% v/v) followed by the discussion on comparative CO2 absorption and storage performance by different tools such as DLS, IFT, Rheology, Contact-angle, and Micromodel flow. The basic nanofluid (To) showed greater CO2 absorption after surface modification as demonstrated by molality results. However, surface modification also decreased dispersion stability of surface modified nanofluids (T1, T2, and T3) and T2 was regarded as the most stable nanofluid with −64.4 mV (ζ-potential) and 153 nm (NP size). After surface modification, increase in NP size and settlement was higher for surface modified nanofluids than To, which exhibited dispersion stability of 84 d with −53.4 mV and 15 nm. Contact angle results also showed that surface modified nanofluids possess greater affinity for CO2 absorption than basic nanofluid (To). Rheological analysis was also consistent with other tests where viscosity was found dependent on both storage period and temperature, and NP settlement was found to be the most influential parameter on flow properties of nanofluid. Finally, pore scale analysis was performed to understand areal sweep of injected CO2 in micromodel with and without nanofluid, where nanofluid imparted greater CO2 storage by diverting it in un-swept pore networks of micromodel which were untapped by CO2 without nanofluid.

Microfluidic nanoprecipitation of PEGylated PLGA nanoparticles with rapamycin and performance evaluation

Rapamycin (RAP) is currently being developed as potential antibreast cancer drug. However, its poor solubility completely limits its use. The aim of this study was to develop polyethylene glycol-poly(lactide-co-glycolide) (PEG-PLGA)-based nanoparticles (NPs) to load RAP via microfluidics with an appropriate polyethylene glycol (PEG) content to enhance the bioavailability of RAP. Polydimethylsiloxane (PDMS) chips with a Y-shaped channel were designed to obtain RAP-loaded PEG-PLGA NPs (RAP-PEG-PLGA). The entrapment efficiency (EE) and drug loading (DL) as well as release profile of RAP-PEG-PLGA were evaluated, and their resistance to plasma albumin adsorption of NPs with different PEG contents was evaluated and compared. RAW264.7 and 4T1 cells were used to assess the antiphagocytic and anticancer cells effect of NPs, respectively. RAP-PEG-PLGA of around 124 nm in size were successfully prepared with the EE of 82.0% and DL of 12.3%, and sustained release for around 40 d. A PEG relative content of 10% within the PEG-PLGA molecule was shown superior in resisting protein adsorption. RAP-PEG-PLGA inhibited the growth of breast cancer cells when the concentration was over 10 μg/mL, and the inhibition efficiency was significantly higher than free RAP. Hence, the current RAP-PEG-PLGA could be a potential therapeutic system for breast cancer treatment.

High sensitivity fiber SPR sensor based on InSe nanosheets and Au nanoparticles

Surface Plasmon Resonance (SPR) fiber sensors are widely used in the field of biosensing. However, there are still issues of low sensitivity and poor stability in practical detection processes. This paper proposes a highly sensitive fiber SPR sensor based on InSe nanosheets and Au nanoparticles. This paper investigates the enhancement effects of different thicknesses of InSe films inserted between the Au film and the fiber and the adsorption of Au nanoparticles on the Au film surface of the fiber-InSe-Au sensor. The sensitivity of the fiber-InSe-Au sensor reaches 5534.76 nm/RIU, which is 2.71 times higher than the fiber-Au sensor and a 22% improvement compared to the fiber-Au-InSe sensor. The sensitivity of the fiber-InSe-Au-AuNPs sensor further increases to 5853.75, and the FOM reaches 28.11, a 47% improvement compared to the fiber-InSe-Au sensor. Moreover, the enhancement substance is situated within the Au film, which enhances the sensor's stability. Additionally, due to the low biotoxicity and high biocompatibility of Au nanoparticles, the high-performance sensor designed in this study is exceptionally well-suited for biosensing applications.

Ligand Lipophilicity Determines Molecular Mechanisms of Nanoparticle Adsorption to Lipid Bilayers.

The interactions of ligand-functionalized nanoparticles with the cell membrane affect cellular uptake, cytotoxicity, and related behaviors, but relating these interactions to ligand properties remains challenging. In this work, we perform coarse-grained molecular dynamics simulations to study how the adsorption of ligand-functionalized cationic gold nanoparticles (NPs) to a single-component lipid bilayer (as a model cell membrane) is influenced by ligand end group lipophilicity. A set of 2 nm diameter NPs, each coated with a monolayer of organic ligands that differ only in their end groups, was simulated to mimic NPs recently studied experimentally. Metadynamics calculations were performed to determine key features of the free energy landscape for adsorption as a function of the distance of the NP from the bilayer and the number of NP-lipid contacts. These simulations revealed that NP adsorption is thermodynamically favorable for all NPs due to the extraction of lipids from the bilayer and into the NP monolayer. To resolve ligand-dependent differences in adsorption behavior, string method calculations were performed to compute minimum free energy pathways for adsorption. These calculations revealed a surprising nonmonotonic dependence of the free energy barrier for adsorption on ligand end group lipophilicity. Large free energy barriers are predicted for the least lipophilic end groups because favorable NP-lipid contacts are initiated only through the unfavorable protrusion of lipid tail groups out of the bilayer. The smallest free energy barriers are predicted for end groups of intermediate lipophilicity which promote NP-lipid contacts by intercalating within the bilayer. Unexpectedly, large free energy barriers are also predicted for the most lipophilic end groups which remain sequestered within the ligand monolayer rather than intercalating within the bilayer. These trends are broadly in agreement with past experimental measurements and reveal how subtle variations in ligand lipophilicity dictate adsorption mechanisms and associated kinetics by influencing the interplay of lipid-ligand interactions.

Adsorption methods for arsenic removal in water bodies: a critical evaluation of effectiveness and limitations

The presence of arsenic in water bodies poses a significant risk to both human health and the environment. Arsenic (As) contamination in water sources is a global environmental concern caused by both natural processes and human activities. Due to its toxic and persistent nature, arsenic has detrimental effects on ecosystems and human wellbeing. This study aimed to elucidate the mechanisms behind arsenic accumulation in water bodies. In aquatic environments, arsenic concentrations in drinking water have been reported as high as 1,320 μg/L (Nicaragua), while groundwater levels exceeded 5,000 μg/L (Thailand), and wastewater contained up to 134,000 μg/L (landfill leachate in Brazil). Furthermore, bioaccumulation of arsenic (μg/g) in fish species ranges from 0.4 (catfish in the Paraná River Delta, Brazil) to 362 (Pteromylaeus bovinus, Northern Adriatic Sea). Recent research has predominantly focused on removing arsenic from aqueous solutions through adsorption methods. Notably, nanoparticle adsorbents and graphene-based adsorbents demonstrate a high capacity for arsenic removal from water bodies.

Controlling Adsorption of Diblock Copolymer Nanoparticles onto an Aldehyde-Functionalized Hydrophilic Polymer Brush via pH Modulation.

Sterically stabilized diblock copolymer nanoparticles with a well-defined spherical morphology and tunable diameter were prepared by RAFT aqueous emulsion polymerization of benzyl methacrylate at 70 °C. The steric stabilizer precursor used for these syntheses contained pendent cis-diol groups, which means that such nanoparticles can react with a suitable aldehyde-functional surface via acetal bond formation. This principle is examined herein by growing an aldehyde-functionalized polymer brush from a planar silicon wafer and studying the extent of nanoparticle adsorption onto this model substrate from aqueous solution at 25 °C using a quartz crystal microbalance (QCM). The adsorbed amount, Γ, depends on both the nanoparticle diameter and the solution pH, with minimal adsorption observed at pH 7 or 10 and substantial adsorption achieved at pH 4. Variable-temperature QCM studies provide strong evidence for chemical adsorption, while scanning electron microscopy images recorded for the nanoparticle-coated brush surface after drying indicate mean surface coverages of up to 62%. This fundamental study extends our understanding of the chemical adsorption of nanoparticles on soft substrates.

Effect of Temperature, Oil Type, and Copolymer Concentration on the Long-Term Stability of Oil-in-Water Pickering Nanoemulsions Prepared Using Diblock Copolymer Nanoparticles.

A poly(glycerol monomethacrylate) (PGMA) precursor was chain-extended with 2,2,2-trifluoroethyl methacrylate (TFEMA) via reversible addition-fragmentation chain transfer (RAFT) aqueous emulsion polymerization. Transmission electron microscopy (TEM) studies confirmed the formation of well-defined PGMA52-PTFEMA50 spherical nanoparticles, while dynamic light scattering (DLS) studies indicated a z-average diameter of 26 ± 6 nm. These sterically stabilized diblock copolymer nanoparticles were used as emulsifiers to prepare oil-in-water Pickering nanoemulsions: either n-dodecane or squalane was added to an aqueous dispersion of nanoparticles, followed by high-shear homogenization and high-pressure microfluidization. The Pickering nature of such nanoemulsion droplets was confirmed via cryo-transmission electron microscopy (cryo-TEM). The long-term stability of such Pickering nanoemulsions was evaluated by analytical centrifugation over a four-week period. The n-dodecane droplets grew in size significantly faster than squalane droplets: this is attributed to the higher aqueous solubility of the former oil, which promotes Ostwald ripening. The effect of adding various amounts of squalane to the n-dodecane droplet phase prior to emulsification was also explored. The addition of up to 40% (v/v) squalane led to more stable nanoemulsions, as judged by analytical centrifugation. The nanoparticle adsorption efficiency at the n-dodecane-water interface was assessed by gel permeation chromatography when using nanoparticle concentrations of 4.0, 7.0, or 10% w/w. Increasing the nanoparticle concentration not only produced smaller droplets but also reduced the adsorption efficiency, as confirmed by TEM studies. Furthermore, the effect of varying the nanoparticle concentration (2.5, 5.0, or 10% w/w) on the long-term stability of n-dodecane-in-water Pickering nanoemulsions was explored over a four-week period. Nanoemulsions prepared at higher nanoparticle concentrations were more unstable and exhibited a faster rate of Ostwald ripening. The nanoparticle adsorption efficiency was monitored for an aging nanoemulsion prepared at a copolymer concentration of 2.5% w/w. As the droplets ripened over time, the adsorption efficiency remained constant (∼97%). This suggests that nanoparticles desorbed from the shrinking smaller droplets and then readsorbed onto larger droplets over time. Finally, the effect of temperature on the stability of Pickering nanoemulsions was examined. Storing these Pickering nanoemulsions at elevated temperatures led to faster rates of Ostwald ripening, as expected.

Nanoparticle-Assisted Liquid Crystal Droplet Sensors Enable Analysis of Low-Concentration Species in Aqueous Medium.

We introduce nanoparticle-assisted liquid crystal (LC) droplet-based sensors that allow determination of low-level concentrations of aqueous soluble species. The silica nanoparticles functionalized with mixed monolayers composed of two distinct groups, hydrophobic alkane tail- and charged group-terminated silanes, facilitated ternary physical interactions between the model analytes (methylene blue (MB) or methyl orange (MO)) and the nematic mesogens 5CB (4-cyano-4'-pentylbiphenyl), and the interfacial species of the nanoparticle. The response of the LC droplets was measured upon nanoparticle adsorption as a function of analyte concentration, which was characterized by the optical determination of the configuration distributions of the LC droplets. We highlight the importance of the charging and the composition of the nanoparticle interfaces for analytical purposes that allow accurate determination of the concentration of the analytes on the order of 0.01 ppb. Such a low concentration corresponds to a low interfacial coverage of nanoparticles, indicating the promisingly high sensitivity of the sensor platform to target analytes. Distinct from the past examples of the LC-based sensors, the nanoparticle-assisted LC sensors allow detection of the species that do not directly cause an ordering transition at the LC-water interfaces, which allow a broader range of analytical targets. The sensor platform that we report herein can be easily tunable for a range of target molecules and will find use in the determination of a wide range of micropollutants in aqueous environments.

Conversion of PET Bottle Waste into a Terephthalic Acid-Based Metal-Organic Framework for Removing Plastic Nanoparticles from Water

Micro- and nanoparticles of plastic waste are considered emerging pollutants with significant environmental and health impacts at high concentrations or prolonged exposure time. Here we report the synthesis and characterization of a known metal-organic framework (MOF) using terephthalic acid (TPA) recovered from the hydrolysis of polyethylene terephthalate (PET) bottle waste. This approach adds value to the existing large amounts of bottle waste in the environment. Fully characterized zinc-TPA MOF (MOF-5) was used for the extraction and removal of engineered polyvinyl chloride (PVC) and polymethylmethacrylate (PMMA) nanoparticles from water with a high efficiency of 97% and 95%, respectively. Kinetic and isotherm models for the adsorption of polymer nanoparticles (PNPs) on the MOF surface were investigated to understand the mechanism. The Qmax for PVC and PMMA NPs were recorded as 56.65 mg/g and 33.32 mg/g, respectively. MOF-5 was characterized before and after adsorption of PNPs on the surface of MOF-5 using a range of techniques. After adsorption, the MOF-5 was successfully regenerated and reused for the adsorption and removal of PNPs, showing consistent results for five adsorption cycles with a removal rate of 83–85%. MOF-5 was characterized before and after adsorption of PNPs on the surface using a range of techniques. The MOF-5 with PNPs on the surface was successfully regenerated and reused for the adsorption and removal of polymer nanoparticles, showing consistent results for five extraction cycles. As a proof of concept, MOF-5 was also used to remove plastic particles from commercially available body scrub gel solutions. Such methods and materials are needed to mitigate the health hazards caused by emerging micro- and nanoplastic pollutants in the environment.

AuNP decorated aegle marmelos leaf as SERS substrate for trace detection of antibiotics and machine learning based classification

Surface-enhanced Raman spectroscopy (SERS) has emerged as a reliable molecular spectroscopic technique for trace detection of chemical and biological samples. Present study illustrates a new SERS platform which has been obtained through surface adsorption of gold nanoparticles (AuNP) on a microscopically roughened surface of aegle marmelos (AM) leaf. The micro-structured patterns of the AM leaves promote the generation of hotspot regions for the surface deposited AuNPs thus, aids in electromagnetic enhancement for the scattered Raman signals from the sample. For the proposed SERS platform, with rhodamine6G (R6G) as an analyte, the limit of detection (LoD) was found to be 0.88 nM. The applicability of the designed SERS was realized through detection and quantification of two commonly used antibiotics- Ceftriaxone (CEFTR) and Ceftiofur sodium (CEF-Na) residues from cow milk samples. Furthermore, a dimensionality reduction method known as principal component analysis (PCA) and an optimal machine learning-based model were built to categorize the analytes in the milk samples. The suggested machine learning model’s classification accuracy was found to be 94%.

Breakup dynamics of nanofluid droplets in T-typed microchannels

The breakup behavior and dynamics of nanofluid droplets in the T-shaped microchannel were investigated, focusing on the effect of nanoparticles on droplets breakup. It was found that the solid particle layer formed by the adsorption of nanoparticles at the droplet interface would greatly limit the droplet deformation. Three breakup flow patterns were observed: non-breakup, breakup with partial obstruction, and breakup with permanent obstruction. The droplet breakup could be divided into three stages. In the squeezing stage, the nanoparticles made the droplet breakup slow down, resulting in decrease of power-law exponent α. In the transition stage, the adsorption of nanoparticles changed the surface properties of droplets, reducing the slope k. In the rapid pinching stage, the decrease of nanoparticle concentration or the increase of the dispersed phase capillary number Cad contributed to a growth in power-law exponent β. This study provides crucial data and technical support for applications of nanoparticle-stabilized emulsions.

Evaluation of Interfacial Structure of Self-Assembled Nanoparticle Layers: Use of Standard Deviation between Calculated and Experimental Drop Profiles as a Novel Method.

The self-assembly of nanoparticles (NPs) at interfaces is currently a topic of increasing interest due to numerous applications in food technology, pharmaceuticals, cosmetology, and oil recovery. It is possible to create tunable interfacial structures with desired characteristics using tailored nanoparticles that can be precisely controlled with respect to shape, size, and surface chemistry. To address these functionalities, it is essential to develop techniques to study the properties of the underlying structure. In this work, we propose an experimental approach utilizing the standard deviation of drop profiles calculated by the Laplace equation from experimental drop profiles (STD), as an alternative to the Langmuir trough or precise microscopic methods, to detect the initiation of closely packed conditions and the collapse of the adsorbed layers of CTAB-nanosilica complexes. The experiments consist of dynamic surface/interfacial tension measurements using drop profile analysis tensiometry (PAT) and large-amplitude drop surface area compression/expansion cycles. The results demonstrate significant changes in STD values at the onset of the closely packed state of nanoparticle-surfactant complexes and the monolayer collapse. The STD trend was explained in detail and shown to be a powerful tool for analyzing the adsorption and interfacial structuring of nanoparticles. Different collapse mechanisms were reported for NP monolayers at the liquid/liquid and air/liquid interfaces. We show that the interfacial tension (IFT) is solely dependent on the extent of interfacial coverage by nanoparticles, while the surfactants regulate only the hydrophobicity of the self-assembled complexes. Also, the irreversible adsorption of nanoparticles and the increasing number of adsorbed complexes after the collapse were observed by performing consecutive drop surface compression/expansion cycles. In addition to a qualitative characterization of adsorption layers, the potential of a quantitative calculation of the parameter STD such as the number of adsorbed nanoparticles at the interface and the distance between them at different states of the interfacial layer was discussed.

Experimental Evidence on Nanoparticle Adsorption and Wettability Alteration for Enhancing Oil Recovery from Tight Rocks

Experimental Evidence on Nanoparticle Adsorption and Wettability Alteration for Enhancing Oil Recovery from Tight Rocks

Tailoring morphology for improved dispersibility of hydrophilic silica nanoparticles to fabricate thin-film nanocomposite membranes

Improving the dispersibility of nanomaterials is a promising approach to enhance the performance of thin-film nanocomposite (TFN) membranes. In this study, hydrophilic nonporous, mesoporous, and dendritic mesoporous silica nanoparticles (NSNs, MSNs, and DMSNs) with a uniform particle size were utilized as aqueous phase additives to prepare TFN membranes through in-situ polymerization. The electrostatic adsorption of nanoparticles increased the concentration of amine monomers on the surface of the polysulfone (PSF) substrate. In collaboration with the steric hindrance effect, nanoparticles restricted the diffusion of piperazine (PIP) into the organic phase to polymerize with the acyl chloride monomers. Compared to TFC-0, the TFN membranes exhibited a rougher surface with increased negative charge and had more channels that facilitated the transportation of water molecules. Among the nanoparticles, DMSNs exhibited excellent dispersibility, ensuring their uniform distribution within the polyamide (PA) matrix. Furthermore, DMSNs possessed an open central-radial pore structure, offering more efficient channels for water molecules to cross the membrane. Therefore, a highly crosslinked, defect-free, and hydrophilic PA layer of TFN-DMSNs was achieved. In the performance characterization, TFN-DMSNs demonstrated a high water/salt permselectivity (A/B) of up to 32.25 bar−1, and exhibited good resistance to acidic/alkaline environments as well as foulants during the operation. This study proposes a novel approach to prepare advanced TFN membranes by optimizing the morphological structure of nanoparticles.

Research on the preparation and performance of Ni2P@MOF composite nanomaterials.

The present study employed a solvothermal method utilizing triphenylphosphine and nickel acetylacetonate as precursors for phosphide preparation, followed by analysis and characterization. The Ni-MOF precursor was prepared using benzene diacid, triethylenediamine, and nickel sulfate as raw materials. Ni2P was introduced into the Ni-MOF precursor during its preparation while maintaining the synthesis conditions, allowing for the adsorption of Ni2P nanoparticles during Ni-MOF synthesis to produce Ni2P@MOF composite materials. The materials underwent individual testing for UV, magnetic, and microwave absorption properties. Magnetic testing results demonstrated that the incorporation of Ni2P led to an increase in the saturation magnetization (Ms) of Ni2P@MOFs compared to the Ni-MOF, thereby enhancing its electromagnetic loss capability. Microwave absorption property testing indicated that the Ni2P@MOFs exhibited enhanced dielectric and electromagnetic loss capabilities compared to the Ni-MOF, optimizing impedance matching properties and increasing effective absorption bandwidth compared to pure Ni2P materials.

Removal of anionic azo dye from wastewater using Fe3O4 magnetic nanoparticles adsorbents in a batch system

This work investigates removing the anionic azo dye from wastewater using Fe3O4 magnetic nanoparticle adsorbents in a batch system. The effects of adsorbent dosage (0.1–0.5 g/L), pH (2−10), dye concentration (5–45 mg/L), contact duration (0–140 min), and shaking speed (100–180 rpm) on the removal (adsorption) efficiency at 23 °C were investigated. Besides the kinetic and isothermal studies were applied as well to improve commercial adsorbents’ performance in removing anionic dyes. Fe3O4 magnetic nanoparticles achieve a maximum azo dye removal (adsorption) efficiency of 99.99% at the optimum values of the investigated parameters: 3 g/L of adsorbent dose, 5 mg/L dye concentration, pH 2, and 180 rpm in 120 min at 23 °C. Langmuir adsorption isotherm has the highest correlation coefficient (R2 = 0.977) compared to Freundlich, and Temkin isotherms; the maximum absorption of azo dye is estimated to be 0.4158 mg/g. The values of the equilibrium parameter (RL) in the Langmuir isotherm model are between 0 and 1, indicating the Langmuir isotherm's favorability. The Fe3O4 magnetic nanoparticle adsorption rates follow pseudo-first-order adsorption kinetics, with R2 = 0.973.

Helichrysum arenarium-mediated facile green synthesis, antibacterial, catalytic activity and hydrogen evolution of metallic (Ag, Cu) and bimetallic (Ag/Cu) nanoparticles

Metallic Ag, Cu and bimetallic Ag/Cu nanoparticles (NPs) easily and economically synthesized by green synthesis method using Helichrysum arenarium plant extracts used as reducing agent were characterized with analysis of SEM (Scanning electron microscopy), TEM (Transmission electron microscopy) and BET (Brunauer-Emmett-Teller). The adsorption study of the synthesized nanoparticles for Congo Red (CR) azo dyestuff was carried out and dyestuff removal properties were investigated in detail. At 100 min, the CR removal percentages were found to be 90.2 %, 77.8 % and 66.1 % by Cu NPs, Ag/Cu NPs and Ag NPs, respectively and the adsorption was found to be in accordance with the second order kinetic model and Langmuir isotherm model. In reusability studies of Cu NPs adsorbent, CR removal was found to be 90.2 %, 88.9 % and 83.4 % in three experimental cycles, respectively. For antimicrobial activity of Helichrysum arenarium extract, Cu NPs, Ag/Cu NPs and Ag NPs were used to against 6 pathogenic microorganisms via disc diffusion assay. As a result of the antimicrobial assay, while Helichrysum arenarium extract did not show any effect against the tested pathogenic microorganisms, both Ag NPs and Ag/Cu NPs showed an inhibition zone diameter against the tested pathogenic microorganisms (p < 0.05). It is conceivable that it would be effective in controlling the growth of resistant microorganisms in aqueous media since it produces a similar level of inhibition in methicillin-resistant and non-resistant S. aureus. Finally, the catalytic activity of the synthesized nanoparticles was evaluated in hydrogen (H2) production by hydrolysis of NaBH4. Based on experimental results, the efficiency of hydrogen production was determined as Cu NPs > Ag/Cu NPs > Ag NPs. The optimum conditions for the highest yield of H2 were investigated and the catalysis results were compared with sonocatalysis. This research shows that NPs can be synthesized in a simple, economical and environmentally friendly way and has a wide range of uses.

Green synthesis of NiO nanoparticles using a Cd hyperaccumulator (Lactuca sativa L.) and its application as a Pb(II) and Cu(II) adsorbent

The proliferation of heavy metal contamination, namely, lead and copper, has emerged as a pervasive worldwide peril to human existence. One potential solution for addressing this issue is the utilization of nanoparticle adsorption, specifically for nickel oxide nanoparticles. However, to promote environmental sustainability, scholarly studies have identified green synthesis as a prospective methodology. The process of cadmium phytoremediation, although offering a potential remedy for heavy metal contamination, gives rise to apprehensions surrounding the proper disposal of cadmium hyperaccumulator plant biomass. Hence, it is imperative to establish suitable strategies for the disposition or usage of this biomass. The utilization of hyperaccumulator extracts for the eco-friendly production of nickel oxide nanoparticles remains unexplored in the current literature. The main aim of this research is to explore the possible application of Lactuca sativa L. as a plant species with the ability to accumulate high levels of cadmium. The study also seeks to examine the efficacy of utilizing these plants in the fabrication of nickel oxide nanoparticles and evaluate their capacity to absorb lead and copper ions. The characterization of nickel oxide nanoparticles is conducted through a range of techniques, encompassing scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, X-ray fluorescence, Fourier transform infrared spectroscopy, transmission electron microscopy, Brunauer-Emmett-Teller spectroscopy, and vibrating sample magnetometry. The present work achieved successful utilization of Lactuca sativa L. extract for the manufacture of nickel oxide nanoparticles, which showed notable efficacy as an adsorbent for lead and copper. The synthesis of nickel oxide nanoparticles using an extract from Lactuca sativa L. has demonstrated the viability of utilizing hyperaccumulator biomass in the phytoremediation of cadmium. This finding presents a promising avenue for investigating hyperaccumulator plants as potential sources for nanoparticle synthesis in the field of environment-based nanotechnology development.

Adsorption of zwitterionic oligomer-grafted silica nanoparticles on rock surface in enhanced oil recovery studied by molecular dynamics simulations

The application of surface-functionalized nanoparticles (NPs) in enhanced oil recovery (EOR) has been rapidly increasing. Adsorption of NPs on the rock surface is the key step. In this study, we systematically investigated the adsorption and desorption mechanisms of various brush-like zwitterionic oligomers functionalized silica NPs on the hydrophilic rock surface in an aqueous solution using molecular dynamics simulations. Our simulations show that the adsorption is primarily influenced by the oligomer chains, while the neutral silica NP core contributes very weakly only when it has direct contact with the rock surface at the grafting density of 5 or below. The interactions from SO3⁻ groups located at the tail of zwitterionic side chains account for more than 72% of the non-bonded interaction energy Enb between the NPs and the rock. The adsorption becomes stronger for NPs with shorter (4 monomer units) oligomer chains but slightly weaker for NPs with longer (9 monomer units) oligomer chains when increasing the grafting density, which is well explained by the change in the number of adsorbed SO3⁻ groups. Desorption simulations with the umbrella sampling method indicate that the free energy of desorption decreases with increasing the grafting density. The silica NPs grafted with longer oligomer chains (9 monomer units) require higher free energies of desorption than the ones with shorter oligomer chains. The adsorption of NPs on the rock surface enhances surface hydrophilicity, and the effect of longer oligomer chains is more profound than that of short oligomer chains. This research provides valuable insights into the adsorption and desorption mechanisms of surface-modified silica NPs on the rock surface at the molecular level and thus gives hints to the design of nanofluids.