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Hybrid nanoparticles (NP) of bismutite nanodisks (BSC ND) with gold nanoparticles (Au NP) of different aspect ratios (AR), such as spheres, rods and etched rods were synthesized via a facile sonochemical method. To better control the shapes of Au NP deposited on the substrate, these were pre-synthesized prior to the deposition using a modified seed mediated growth method by altering the pH and supersaturation of the growth solution. The shift in the peak position and shape of the localized surface plasmon resonance (LSPR) absorption band associated with fine-tuning of the shape of Au NP, led to enhanced light harvesting capabilities of the hybrid. Introducing shape anisotropy in the NP brought about narrowing of bandgap and lowering of PL intensity in the hybrids, suggesting better electronic contact of the NP with BSC, and effective suppression of recombination effects. Hybrids of BSC with Au nanorods showed 14% improved degradation of methylene blue (MB) dye compared to the hybrids with nanospheres. With this study, we provide a novel promising strategy to maximize the light harvesting capacity of semiconductors by tailoring the AR of Au NP, for improved solar to chemical energy conversion. [ABSTRACT FROM AUTHOR]

We report the synthesis and properties of temperature- and pH-responsive p([NIPAm-co-PEGMA] (core)/[NIPAm-co-AAc] (shell)) nanogels with narrow size distributions, tunable sizes and increased drug loading efficiencies. The core-shell nanogels were synthesized using an optimized two-stage seeded polymerization methodology. The core-shell nanogels show a narrow size distribution and controllable physico-chemical properties. The hydrodynamic sizes, charge distributions, temperature-induced volume phase transition behaviors, pH-responsive behaviors and drug loading capabilities of the core-shell nanogels were investigated using transmission electron microscopy, zeta potential measurements, dynamic light scattering and UV-Vis spectroscopy. The size of the core-shell nanogels was controlled by polymerizing NIPAm with crosslinker poly(ethylene glycol) dimethacrylate (PEGDMA) of different molecular weights (Mn-200, 400, 550 and 750 g/mol) during the core synthesis. It was found that the swelling/deswelling kinetics of the nanogels was sharp and reversible; with its volume phase transition temperature in the range of 40-42 °C. Furthermore, the nanogels loaded with l-3,4-dihydroxyphenylalanine (L-DOPA), using a modified breathing-in mechanism, showed high loading and encapsulation efficiencies, providing potential possibilities of such nanogels for biomedical applications. [ABSTRACT FROM AUTHOR]

Alkaline–surfactant–polymer (ASP) flooding, a recognized method for oil recovery, encounters limited use due to its expense. In addition, ASP's best composition and injection sequence still remains uncertain today. This study explores conventional ASP flooding using PT SPR Langgak's special surfactants, simulating Langgak oilfield conditions in Sumatra, Indonesia. By comparing the outcomes of this flooding technique with that of starch-assisted ASP performed in another study, the benefits of adding starch nanoparticles to flooding are evident. Nano-starch ASP increased oil recovery by 18.37%, 10.76%, and 10.37% for the three configurations investigated in this study. Water flooding preceded ASP flooding, and flooding operations were carried out at 60 °C. This study employed sodium hydroxide (NaOH), sodium carbonate (Na2CO3), and specialized surfactants from PT SPR. The adopted polymer is solely hydrolyzed polyacrylamide (HPAM) at 2000 ppm. Starch nanoparticles underwent comprehensive characterization and focused more on charge stability. Purple yam nanoparticles (PYNPs) exhibited remarkable stability at −36.33 mV, unlike cassava starch nanoparticles (CSNPs') at −10.68 mV and HPAM's at −27.13 mV. Surface properties affect interactions with fluids and rocks. Crystallinity, a crucial characterization, was assessed using Origin software 2019b. CSNPs showed 24.15% crystallinity, surpassing PYNPs' 20.68%. Higher crystallinity benefits CSNPs' thermal stability. The amorphous behavior found in PYNPs makes them less suitable if applied in harsh reservoirs. This research correlated with prior findings, reinforcing starch nanoparticles' role in enhancing oil recovery. In summary, this study highlighted conventional ASP flooding using HPAM as the sole polymer and compared it with three formations that used two starch nanoparticles included with HPAM, assessing their impact on charge stability, crystallinity, and recovery rate to emphasize their importance in the oil recovery industry. Starch nanoparticles' benefits and limitations guided further investigation in this study. [ABSTRACT FROM AUTHOR]

This study aimed to address the challenges faced by mature oilfields in extracting substantial oil quantities. It focused on improving the efficiency of alkaline–surfactant–polymer (ASP) flooding technique, which is a proven tertiary recovery technology, to overcome scaling issues and other hindrances in its large-scale implementation. Appropriate materials and their suitable concentrations were selected to enhance the ASP flooding technique. Special surfactants from Indonesia were introduced to improve the interfacial tension reduction and wettability alteration. Reservoir rock model that resembling Langgak oilfield in Sumatra was utilized, and low-salinity water was employed to mimic the oilfield conditions. Starches derived from cassava nanoparticles (CSNPs) and purple yam nanoparticles (PYNPs) were combined separately with conventional hydrolyzed polyacrylamide (HPAM) polymer to enhance its performance. Sodium hydroxide and sodium carbonate were used as alkaline in final ASP formula. It was demonstrated from this research that only two combinations of ASP formulations have led to improved oil recovery. One combination utilizing PYNPs resulted in 39.17% progressive recovery, while the other combination incorporating CSNPs achieved 35% incremental oil recovery. The ASP combination that resulted in recovery rate of 39.17% was composed of sodium hydroxide (NaOH) at a concentration of 1.28 wt.%, PSC EOR 2.2 (0.98 wt.%), and a combined polymer consisting of HPAM (0.2 wt.%) and PYNPs nano-starch (0.6 wt.%). The second combination led to 35% recovery rate and involved NaOH also at concentration 1.28 wt.%, PSC HOMF (0.63 wt.%), and a combined polymer comprising from HPAM (0.2 wt.%) and CSNPs nano-starch (0.8 wt.%). These findings of this study highlighted the potential of this modified ASP flooding to enhance oil recovery in mature oilfields, thereby offering valuable insights for oil industry. [ABSTRACT FROM AUTHOR]

We report on the effect of different stimuli-responsive polymer shells on Fe@Au core-shell nanoparticles (NPs) with respect to thermoresponse as well as loading and release characteristics. The hybrid NP systems were investigated using a wide array of characterization techniques including dynamic light scattering, electrophoretic mobility, UV-visible spectroscopy, and scanning transmission electron microscopy. Three different polymeric shells were selected for loading and release of l-dopa: thiolated polyethylene glycol (PEG), poly( N-isopropylacrylamide- co-acrylic acid) (PNIPAAM_AAc) microgel crosslinked with N, N′-methylenebis(acrylamide) (BIS), and finally concomitant PEG and PNIPAAM_AAc microgel (Fe@Au_PEG_Microgel). All three shells were found to exhibit high loading (∼10%) and encapsulation efficiencies up to 100 μg l-dopa/mg. Although the loading efficiencies are comparable for the three systems, Fe@Au_PEG_Microgel has the highest release (87%) at elevated temperature and acidic conditions. The attenuated release from the PEG-based systems can be attributed to stronger dipole-dipole interactions between the carboxyl group of PEG and the amino group of l-dopa. [ABSTRACT FROM AUTHOR]

Here, a synthetic method has been optimized for the synthesis of thermoresponsive and pH-responsive poly( N-isopropylacrylamide-co-acrylic acid) nanogels which are subsequently loaded with cytochrome C by using a modified breathing-in mechanism. Physico-chemical properties mapped by using dynamic light scattering (DLS) and differential scanning calorimetry (DSC) confirm the swelling/deswelling kinetics as reversible with a volume phase transition temperature (VPTT) of ~39 °C. Fe@Au nanoparticles were incorporated inside the nanogel networks by using two different methods: coating and in situ growth. The latter bears closer resemblance to the nanogels only, while the former follows the trend of bare Fe@Au nanoparticles. High loading (~96 %) and encapsulation (500 μg/mg of nanogels) of cytochrome C were obtained. Release experiments performed by using a dialysis set-up and monitored by using UV-vis spectroscopy show the highest release at 40 °C and pH 3.2 (high temperature, low pH), with maximum release from the Fe@Au-coated nanogels that also show a reverse swelling-collapse trend. The location of the drug, the incorporation and presence of Fe@Au nanoparticles and the drug incorporation method are found to control both the drug release mechanism and kinetics. [ABSTRACT FROM AUTHOR]

Fe@Au core–shell nanoparticles (NPs) exhibit multiple functionalities enabling their effective use in applications such as medical imaging and drug delivery. In this work, a novel synthetic method was developed and optimized for the synthesis of highly stable, monodisperse Fe@Au NPs of average diameter ∼24 nm exhibiting magneto-plasmonic characteristics. Fe@Au NPs were characterized by a wide range of experimental techniques, including scanning (transmission) electron microscopy (S(T)EM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS) and UV–vis spectroscopy. The formed particles comprise an amorphous iron core with a crystalline Au shell of tunable thickness, and retain the superparamagnetic properties at room temperature after formation of a crystalline Au shell. After surface modification, PEGylated Fe@Au NPs were used for in vitro studies on olfactory ensheathing cells (OECs) and human neural stem cells (hNSCs). No adverse effects of the Fe@Au particles were observed post-labeling, both cell types retaining normal morphology, viability, proliferation, and motility. It can be concluded that no appreciable toxic effects on both cell types, coupled with multifunctionality and chemical stability make them ideal candidates for therapeutic as well as diagnostic applications. [ABSTRACT FROM AUTHOR]

The year of 2020 was profoundly marked by a global pandemic caused by a strain of coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of coronavirus disease 2019 (COVID-19). To control disease spread, a key strategy adopted by many countries was the regular testing of individuals for infection. This led to the rapid development of diagnostic testing technologies. In Norway, within a week, our group developed a test kit to quickly isolate viral RNA and safely detect SARS-CoV-2 infection with sensitivity comparable to available kits. Herein, the procedure employed for the detection of SARS-CoV-2 in swab samples from patients using the NTNU-COVID-19 test kit is described in detail. This procedure, based on NAxtra magnetic nanoparticles and an optimized nucleic acid extraction procedure, is robust, reliable, and straightforward, providing high-quality nucleic acids within 14 min. The NAxtra protocol is adaptable and was further validated for extraction of DNA and RNA from other types of viruses. A comparison of the protocol on different liquid handling systems is also presented. Due to the simplicity and low cost of this method, implementation of this technology to diagnose virus infections on a clinical setting would benefit health care systems, promoting sustainability. [ABSTRACT FROM AUTHOR]

Significant amounts of oil remain in the reservoir after primary and secondary operations, and to recover the remaining oil, enhanced oil recovery (EOR) can be applied as one of the feasible options remaining nowadays. In this study, new nano-polymeric materials have been prepared from purple yam and cassava starches. The yield of purple yam nanoparticles (PYNPs) was 85%, and that of cassava nanoparticles (CSNPs) was 90.53%. Synthesized materials were characterized through particle size distribution (PSA), Zeta potential distribution, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). The performance of PYNPs in recovering oil was better than CSNPs, as found from the recovery experiments. Zeta potential distribution results confirmed the stability of PYNPs over CSNPs (−36.3 mV for PYNPs and −10.7 mV for CSNPs). The optimum concentration for these nanoparticles has been found from interfacial tension measurements and rheological properties, and it was 0.60 wt.% for PYNPs and 0.80 wt.% for CSNPs. A more incremental recovery (33.46%) was achieved for the polymer that contained PYNPs in comparison to the other nano-polymer (31.3%). This paves the way for a new technology for polymer flooding that may replace the conventional method, which depends on partially hydrolyzed polyacrylamide (HPAM). [ABSTRACT FROM AUTHOR]

Herein, we report the synthesis of silica-modified self-assembled structures of bismutite (BSC) through a facile hydrothermal route. The incorporation of silica into the hybrid led to improved adsorption of cationic methylene blue (MB) dye due to electrostatic and hydrogen bond interactions with the silanol groups present on the catalyst surface. The enhanced adsorption of MB on the catalyst ensured better availability of oxidizing free radicals and charge carriers on the catalyst surface for photocatalytic degradation of MB, resulting in faster mineralization of organic species in the presence of solar light. The faster degradation could be observed as a blue shift in the absorbance of degradation intermediates during the reaction and was supported by further analysis using a mass spectrometer. Results from total organic carbon (TOC) analysis indicated 20 % better mineralization in presence of silica-modified BSC hybrids. This study reveals the importance of controlled incorporation of a suitable adsorbent to the semiconductor photocatalyst to overcome the sluggish reaction kinetics under sunlight, thus promoting faster degradation of organic species. [Display omitted] • Effect of silica modification on bismutite nanodisks was studied. • Two hybrids varying in silica content were synthesized using a hydrothermal route. • Incorporation of silica in the hybrid provides enhanced adsorption of the dye. • Faster mineralization of methylene blue in presence of silica-modified hybrids. [ABSTRACT FROM AUTHOR]

Highlights: [•] Synthesis of metal nanowires. [•] Control over structural and morphological characteristics via seed type nanoparticle. [•] Growth via surfactant or surface diffusion process. [•] Structural and surface characterization. [ABSTRACT FROM AUTHOR]

[Display omitted] Dual stimuli-responsive nanogels (NGs) have gained popularity in the field of bio medicine due to their versatile nature of applicability. Poly(N-isopropylacrylamide)-co-poly(acrylic acid) (pNIPAm-pAAc)-based NGs provide such dual stimuli-response with pNIPAm and pAAc providing thermal and pH-based responses, respectively. Studying the growth of these NGs, as well as, understanding the effect of the incorporation of pAAc in the NG matrix, is important in determining the physico-chemical properties of the NG. Studies have been conducted investigating the effect of increasing pAAc content in the NGs, however, these are not detailed in understanding its effects on the physico-chemical properties of the pNIPAm-pAAc-based NGs. Also, the biocompatibility of the NGs have not been previously reported using human whole blood model. Herein, we report the effect of different reaction parameters, such as surfactant amount and reaction atmosphere, on the growth of pNIPAm-pAAc-based NGs. It is shown that the size of the NGs can be precisely controlled from ~ 130 nm to ~ 400 nm, by varying the amount of surfactant and the reaction atmosphere. The effect of increasing incorporation of pAAc in the NG matrix on its physico-chemical properties has been investigated. The potential of these NGs as drug delivery vehicles is investigated by conducting loading and release studies of a model protein drug, cytochrome C (Cyt C) from the NGs at temperature above the volume phase transition temperature (VPTT) and acidic pH. An ex vivo human whole blood model was used to investigate biocompatibility of the NGs by quantifying inflammatory responses during NG exposure. The NGs did not induce any significant production of chemokine IL-8 or pro-inflammatory cytokines (IL-1 β , IL-6, TNF- α), and the cell viability in human whole blood was maintained during 4 h exposure. The NGs did neither activate the complement system, as determined by low Terminal Complement Complex (TCC) activation and Complement Receptor 3 (CR3) activation assays, thereby overall suggesting that the NGs could be potential candidates for biomedical applications. [ABSTRACT FROM AUTHOR]

Iron oxide nanoparticles (IONPs) are of particular interest in multiple fields and in enhanced oil recovery (EOR) due to their unique advantages and characteristics. Albeit several laboratory research articles on IONPs in EOR are available, a critical review is still elusive in literature. Herein, critical information on the properties, formulation and application of IONPs in oil recovery is depicted. The basic physical, structural and physicochemical properties of IONPs were introduced. Thereafter, the preparation of iron oxide nanofluids (IONFs) was discussed. Likewise, potential application of IONPs, in petroleum industry was elucidated. Subsequently, effectiveness of IONPs in EOR was compared with other nanoparticles and the efficacy of surface coatings were reviewed. Finally, the main challenges hindering the applications of IONPs in oil field reservoir were identified and solutions proffered. Experimental results from the literature indicate that the effectiveness of IONPs in reservoir applications is directly related to their surface coatings. The coatings are used to enhance stability and transportation, minimise rock adsorption, and target specific oil recovery mechanisms, resulting in incremental oil recovery. Hence, surface treatment is a necessity for reservoir condition applications. [Display omitted] • The bottom-up approach offers superior control and flexibility. • Growth process determines the final size, particle distribution and shape of the IONPs. • Salinity has the most devastating effect on the transport, retention and oil recovery system of IONFs. • IONPs are very economical, ecologically benign and has potentials for oil field applications. [ABSTRACT FROM AUTHOR]

Although the world is turning to renewables as a clean alternative source of energy, reliance on oil is expected to continue for more decades. Enhanced oil recovery (EOR) is an efficient way to recover oil after implementing initial methods. Alkali–surfactant–polymer flooding (ASP) has acquired much interest together with nano-fluid that involves using nano metallic oxides in EOR. Nanoparticles have proved their effectiveness in reducing interfacial tension at the interface between the oil and water and have been used with water, polymers, surfactants, alkaline, or a mixture of these components. Incremental oil recovery from applying ASP floods has exceeded 20% OOIP, and this is considered promising performance for unlocking oil reserves for many years to come. Despite that, ASP flooding nowadays faces big challenges presented by fluctuating oil prices, scaling and corrosion of the lifting system, and the formation of relatively strong emulsions that need high-cost treatment after oil production. This review emphasizes ASP flooding and the ASP flooding and the implementation of nanoparticles in extracting more oil using different chemical agents and sheds light on improving the recovery ratio. This study also explains the challenges that face each process and the steps that should be taken in order to overcome these challenges. [ABSTRACT FROM AUTHOR]

Massive growth of electric vehicle (EV) sales in recent years triggers the huge demands of certain elements for lithium-ion battery (LIB) production. To sustain the supply of the elements and contribute to its circularity, LIB recycling is one of the justified routes. Although hydrometallurgy is considered as the most common process in battery recycling, improvements are still required to make the recycling process cleaner by reducing the steps and minimizing the chemical use. To achieve this goal, co-precipitation method is proposed to produce cathode active metals (CAM) of Li, Ni, Mn and Co from the leach solution. As battery chemistry is evolving fast, in near future, the dominant LiNi 1/3 Mn 1/3 Co 1/3 O 2 (LNMC 111) type will be replaced by other types with different NMC ratios. Hence, in this study, co-precipitation was tested to recover Li, Ni, Mn and Co from various leachates with different metal compositions, simulating leachates from different battery chemistries. A hydrometallurgy flowsheet comprising four precipitation steps for metal recoveries from leach solutions was developed. In the first stage, aluminium was removed as Al(OH) 3 by increasing the pH of the leachate to 5.5. Cu was removed in the next stage as sulfide by adding sodium sulfide to the supernatant obtained in the first stage. In the third stage, Ni, Mn and Co were co-precipitated as hydroxide precursor by increasing pH of supernatant to 11. The results showed that >95% of Ni, >83% Co, and >42% of Mn could be precipitated from the leaching liquor. Finally, Li is recovered from the supernatant as carbonate precipitate by adding sodium carbonate. Ni,Mn,Co(OH) 2 precursor was finally mixed with Li 2 CO 3 precipitated and calcined to resynthesize CAM showing the potential of this process to close the loop of recycling. • A compact and robust flowsheet for battery cathode material regeneration is developed. • The hydrometallurgical flowsheet can handle various composition of leach solution. • Aluminium and copper impurities removed as hydroxide and sulfide, respectively. • Nickel, manganese and cobalt are recovered as hydroxides (NMC) and lithium as carbonate. • Battery cathode material is successfully regenerated by calcination of NMC and lithium carbonate mixture. [ABSTRACT FROM AUTHOR]

In recent years, several studies have indicated the impact of nanoparticles (NPs) on various properties (such as viscosity and fluid loss) of conventional drilling fluids. Our previous study with commercial iron oxide NPs indicated the potential of using NPs to improve the properties of a laboratory bentonite-based drilling fluid without barite. In the present work, iron oxide NPs have been synthesized using the co-precipitation method. The effect of these hydrophilic NPs has been evaluated in bentonite and KCl-based drilling fluids. Rheological properties at different temperatures, viscoelastic properties, lubricity, and filtrate loss were measured to study the effect of NPs on the base fluid. Also, elemental analysis of the filtrate and microscale analysis of the filter cake was performed. Results for bentonite-based fluid showed that 0.019 wt% (0.1 g) of NPs reduced the coefficient of friction by 47%, and 0.0095 wt% (0.05 g) of NPs reduced the fluid loss by 20%. Moreover, for KCl-based fluids, 0.019 wt% (0.1 g) of additive reduced the coefficient of friction by 45%, while higher concentration of 0.038 wt% (0.2 g) of NPs shows 14% reduction in the filtrate loss. Microscale analysis shows that presence of NPs in the cake structure produces a more compact and less porous structure. This study indicates that very small concentration of NPs can provide better performance for the drilling fluids. Additionally, results from this work indicate the ability of NPs to fine-tune the properties of drilling fluids. [ABSTRACT FROM AUTHOR]

• Functionalization decreased agglomeration and improved the dispersibility of iron oxide nanoparticles (IONPs). • Oil recovery of functionalized IONPs was 1.9 times greater than that of bare IONPs at reservoir conditions. • Emulsions, reduced pore obstruction and improved sweeping efficiency lead to improved oil recovery. After primary and secondary recovery processes, a substantial amount of oil remains trapped in the reservoir due to pressure and reservoir heterogeneity. Iron oxide nanoparticles (IONPs) are increasingly being considered for use in the oil and gas sectors for oil spill clean-up, emulsion separation, drilling and enhanced oil recovery (EOR) applications owing to their distinctive magnetic properties. However, the major drawback is that the particles quickly agglomerate to diminish their high surface energy, particularly in the presence of reservoir brine. As a result, dispersion is poor and oil recovery is limited due to reservoir pore plugging which might cause reservoir damage. Previous studies have documented the oil recovery mechanisms of bare IONPs leading to incremental oil recovery however, their research work was conducted at ambient condition, which does not present oilfield condition. Therefore, the oil recovery efficiency of functionalised IONPs at reservoir conditions is still tenuous in literature. In this work, IONPs were functionalized with 3-aminopropyltriethyloxysilane to form a novel nanohybrid with improved chemical − synergistic effects on interfacial tension (IFT), wettability alteration, and emulsion formation. The morphology, surface properties, chemical composition and stability of the functionalized IONPs was determined and compared with the conventional IONPs. Likewise, the ability of the functionalized IONPs to decrease IFT and alter the wettability of rock/fluid at reservoir conditions was examined using K20 Easy Dyne Kruss tensiometer and Kruss drop shape analyzer, respectively. Finally, a high temperature high pressure core flooding equipment (Fars EOR) was utilized to ascertain the oil recovery efficiency of the functionalized IONPs at reservoir conditions and the results compared with the conventional IONPs. High resolution transmission electron microscopy (HRTEM) images revealed that the functionalization approach did not alter the morphology of IONPs. The functionalized IONPs were stable with a zeta potential of + 31.2 mV thereby, decreasing IFT from 25.5 to 7.7 mN/m and altering wettability from oil wet (128°) to water wet (22°) at reservoir conditions. The functionalized IONPs also increased oil recovery by 13.3 % compared to 10.3 % increment by IONPs in distilled water (DW). However, at high salinity conditions, the oil recovery of IONPs decreased by 7.5 % while that of functionalized IONPs increased by 1.4 % relative to DW. Therefore, it can be concluded from this experimental study that functionalization of IONPs increased oil recovery at reservoir condition, owing to production of in-situ emulsions, reducing pore obstruction and improving sweep efficiency. These findings contribute towards understanding the influence of functionalization on the oil recovery mechanism and transportation of IONPs under reservoir conditions. [ABSTRACT FROM AUTHOR]