Effects Of Various Nanoparticles Research Articles

The Influence of Exogenous Particles on Saliva Rheology

This study aimed to investigate the effect of exogenous nanoparticles on the rheological properties of artificial saliva. There are four reasons for undertaking this type of research: Firstly, the number of solid particles of various origins present in the air is still high. Secondly, nanoparticles (including silver and gold nanoparticles) are increasingly used in food packaging and can migrate into food. Thirdly, saliva is the first biological fluid that comes into contact with exogenous particles. Finally, the function of saliva is also closely related to its rheological properties. Due to the remarkable properties of nano-objects, nanoparticles of various origins in the body may cause effects that have not been realised until now. Therefore, each type of nanoparticle must be tested in terms of its impact on the body/body fluid. We used silver and gold nanoparticles because they are used in the food industry, and diesel exhaust particles because they are standard components of air pollution. The effect of various nanoparticles (e.g., their size and shape) on the rheology of saliva at two temperatures was investigated. The constants of the power law constitutive equation were also estimated. Studies showing the impact of nanoparticles on the rheology of body fluids are rare because it is one of the less obvious ways of their affecting the human body. However, the results show that nanoparticles are not neutral to the biological fluid, which may translate into a change in its properties and thus disturb its functions.

Investigation of the effects of various nanoparticles on improvement of hydrogen production rate in a solar energy driven alkaline electrolyzer

Present paper aims to investigate effects of nanoparticle addition to thermal oil of parabolic trough collectors which are integrated to Kalina cycle for electricity generation to run an alkaline electrolyzer for hydrogen production. Thermodynamic models for Kalina cycle, thermal model for parabolic collectors and electrochemical models for water electrolyzer are developed for overall plant modeling. Three types of nanoparticles including: copper oxide, alumina and titanium oxide are considered and overall plant performance is investigated using these nanoparticles and is compared with basefluid. The nanofluid thermophysical properties are evaluated as a function of nanoparticles’ properties, volume fraction and the base fluid properties. The effects of key variables such as nanoparticle volume fraction, collector inlet temperature, evaporation pressure and ammonia concentration of Kalina system were evaluated on hydrogen production as well as exergetic efficiencies. Results revealed greater positive influence for CuO compared to TiO2 and Al2O3 on performance improvement for both hydrogen generation and its exergetic efficiency. Also, compared to basefluid (without nanoparticles) case, it was found that CuO particles result in a solar-to-H2 exergy efficiency improvement by 4.7%. Using this nanofluid with a volume fraction of 5%, the H2 production rate enhances from 0.633kg/hto0.664kg/h, indicating 4.9 % improvement.

Local and systemic adverse effects of nanoparticles incorporated in dental materials- a critical review

IntroductionNanotechnology is the science and engineering of nanoparticles whose dimensions range from 1 to 100 nm. Nanoparticles have special characteristics like increased surface area, high reactivity, and enhanced mechanical, thermal, and optical properties that make them attractive for use in dental applications. However, the use of nanoparticles in dental materials can have toxic effects on the human body. The objective of this paper is to discuss the toxic effects of various nanoparticles in dental materials, their adverse effect on human health, and measures to overcome such effects. ObjectivesNanoparticles are used in the diagnosis, prevention, and treatment of oral diseases like dental caries, pulpo periodontal lesions, oral cancer, denture stomatitis, and candidiasis. Exposure to nanoparticles may occur to the dental professional, and the patient during procedures like restoration, finishing, and polishing. Such exposure to nanoparticles through inhalation, and ingestion causes toxic effects in the lungs, skin, brain, liver, and kidney. Proper risk assessment methods and preventive measures may help reduce these toxic effects to some extent. SignificanceToxic effects of nanoparticles that are released during dental procedures, their route of exposure, and the concentration at which nanoparticles can induce toxic effects on the human body are discussed in detail in this review. The paper also aims to create awareness among dental professionals, students, and patients regarding nanoparticle exposure and its adverse effects, and methods to prevent and overcome these effects. Currently, it is ignored or taken lightly by the stakeholders and this review may throw light.

On the mechanical properties and vibrational characteristics of the nanoparticle-reinforced composite cylindrical panels in the acidic environment: Numerical and experimental investigation

The purpose of this study is to determine the impact of nano-clay and nano-silica particles on the vibrational characteristics of composite cylindrical panels in corrosive environments. In this context, due to the presence of diluted sulfuric acid as the corrosive solution, the coupling effects of material degradation and hygroscopic loading on the natural frequencies are taken into consideration. In order to achieve this, it is first explored through experiment how adding nanoparticles affects the coefficient of hygroscopic expansion of the glass/epoxy specimens. Using this coefficient, the in-plane loading caused by corrosive solution is then applied in the equations. The mechanical properties and hygroscopic expansion coefficients of the composite samples exposed to the corrosive environment are first determined by certain experimental testing. The equations of motion are derived using the first-order shear deformation theory (FSDT), and the vibration problem is solved using the generalized differential quadrature (GDQ) technique. Investigation is conducted into the effects of various nanoparticles, immersion time, geometrical elements, and boundary conditions on the natural frequencies of the cylindrical panels. It is found that adding nanoparticles can significantly improve the mechanical properties, the corrosion resistance, and the natural frequencies of composites in which the nano-clay is more effective. For example, adding nano-clay and nano-silica particles, respectively, results in 32.32% and 26.29% increase in elasticity modulus of reinforced glass/epoxy composite. In addition, 12.71% and 47.32% improvements are observed in the natural frequency of the nano-clay reinforced composite panel before and after 90 days of immersion in sulfuric acid. In comparison, the nano-silica particles are responsible for 7.80% and 23.03% increase in natural frequency before and after immersion time.

Reproductive Toxicity of Nanoparticles: A Comprehensive Review.

The unique characteristics of nanoparticles (NPs) have captivated scientists in various fields of research. However, their safety profile has not been fully scrutinized. In this regard, the effects of NPs on the reproductive system of animals and humankind have been a matter of concern. In this article, we will review the potential reproductive toxicity of various types of NPs, including carbon nanomaterials, dendrimers, quantum dots, silica, gold, and magnetic nanoparticles, reported in the literature. We also mention some notable cases where NPs have elicited beneficial effects on the reproductive system. This review provides extensive insight into the effects of various NPs on sperm and ovum and the outcomes of their passage through blood-testis and placental barriers and accumulation in the reproductive organs.

Abstract 2703: Evaluation of the effect of tumor-targeted and immunomodulating nanoparticles on the activity of cytotoxic T cells using CAR T cells as an in vitro model

Abstract In solid tumors, there are multiple barriers that prevent anticancer agents and T cells from being able to be delivered into and reach tumor cells. For effective antitumor activity, it is necessary to have direct interactions between cytotoxic T cells and tumor cells. Hyaluronic acid and Iron oxide both have distinctive properties that are advantageous for the development of biocompatible and biodegradable nanoparticle drug delivery systems for cancer. We have developed several targeting and immunomodulatory ligands that can be conjugated to the nanoparticles while carrying chemotherapy or molecular targeted agents for targeted cancer therapy as shown in Table 1. Although the therapeutic efficacy of those targeted nanoparticles has been demonstrated in mouse tumor models, the effect of nanoparticles and their payload drugs on the activities of tumor specific cytotoxic T cells is still unclear. To determine the effect of those nanoparticles on T cell immune responses, CAR T cells provided a well-suited in vitro cellular model. In this study, anti-mesothelin CAR T cells generated from lentiviral CAR T vector transduced T cells were incubated with nanoparticle/drugs and free drugs. The effect of various nanoparticles on CAR T cell viability, and in vitro cytotoxicity on pancreatic cancer cells was evaluated by live/dead, Alamarblue and SRB proliferation Assays. Our results showed that the incubation of CAR T cells with targeted nanoparticles/drugs did not reduce CAR T cells' viability and did not inhibit T cells' activity in killing tumor cells. The ATFmmp14-HANP/SN38 nanoparticle showed an enhanced effect of CAR T cells. Thus, this nanoparticle/drug has the potential for the development of combination therapy with CAR T cells to improve the CAR T cell delivery while synergizing anti-tumor effect by targeted drug delivery, stroma modulation, and tumor cell killing by drug and CAR T cells. Table 1. Nanoparticle formulations overview Nanoparticle Types Target Payload Mechanism of action Observed Results (in vivo) Observed Results (in vitro) ATFmmp14-HANP/SN38:ATFmmp14 conjugated HANP uPAR CD44 SN38 (an active metabolite of irinotecan) Inhibits DNA topoiso-merase I, causing DNA single strand breaks and DNA damage. Significant tumor growth inhibition in human pancreatic and breast cancer PDX models. HANP more effective towards pancreatic cell line and less toxic against CAR T cells: Greater anti-tumor with combination HANP/GKT831: HANP CD44 Setanaxib (GKT831:an inhibitor of NOX1 and NOX4 Reduce the level of reactive oxygen species (ROS): DNA repair downregulation, increases DNA damage Efficient delivery into mouse breast PDX tumors and sensitizing tumor cells to radiotherapy and DNA damaging agents. Nontoxic towards CAR T cells: limited additional therapeutic effects PDY1-HANP/Avasimibe: PD-L1 blocking PDY1 peptide conjugated HANP PD-L1 CD44 Avasimibe (Ava), an inhibitor of acyl-Coenzyme A:cholesterolacyltransferase Decreases intracellular cholesterol.Inhibit tumor cell growth, Activate cytotoxic T cells Efficient delivery into mouse colon tumors, Inhibition of tumor growth: Increased levels of CD8+ T cells and CD68+ Macrophages in tumors Nontoxic towards pancreatic cell lines and CAR T cells: limited additional therapeutic effects ATFmmp14-IONP-DOX: ATFmmp14 conjugated IONP uPAR Doxorubicin Direct DNA damage and inhibits DNA repair by inhibiting topoisomerase Significantly inhibited tumor growth in human pancreatic and breast cancer PDX model ATFmmp14-IONP/DOX more effective towards pancreatic cancer cell lines and less toxic against CAR T cells: slightly increased killing of tumor cells with combination ATFmmp14: Amino terminal fragment (ATF) of uPA fused with MMP14 catalytic domain; PD1Y: PD1 peptide mimetic that binds to and inhibit PD-L1 HANP: Hyaluronic acid nanoparticle; IONP: Iron oxide nanoparticle Citation Format: Kory Wells, Tongrui Lui, Lei Zhu, Chrystal Paulos, Lily Yang. Evaluation of the effect of tumor-targeted and immunomodulating nanoparticles on the activity of cytotoxic T cells using CAR T cells as an in vitro model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2703.

Enhance the Properties of Lignosulfonate Mud by Adding Nanoparticles of Aluminum Oxide and Iron Oxide

Oil well drilling fluid rheology, lubricity, swelling, and fluid loss control are all critical factors to take into account before beginning the hole's construction. Drilling fluids can be made smoother, more cost-effective, and more efficient by investigating and evaluating the effects of various nanoparticles including aluminum oxide (Al2O3) and iron oxide (Fe2O3) on their performance. A drilling fluid's performance can be assessed by comparing its baseline characteristics to those of nanoparticle (NPs) enhanced fluids. It was found that the drilling mud contained NPs in concentrations of 0,0.25, 0. 5, 0.75 and 1 g. According to the results, when drilling fluid was used without NPs, the coefficient of fraction (CoF) was 44%, when added Al2O3 NP and Fe2O3 NP at 0.75g reduced CoF by 31% and 33% respectively. When Al2O3 and Fe2O3 NPs were used, particularly at a concentration of 1g, the amount of mud filtration decreased from 13.5ml to 9.3 ml and 8.5 ml respectively. Additional improvements rheological properties as well as swelling when Fe2O3NPs and Al2O3 NPs were added at 1g. Overall, it was found that adding NPs to the Lignosulfonate-WBM at a concentration of 1g can improve rheological, swelling, and filtration properties as well as lubrication at 0.75g.

Tension-after-impact analysis and damage mechanism evaluation in laminated composites using AE monitoring

The present paper focuses on the detection of dominant damage mechanisms in tensile loading of laminated composite specimens subjected to low-velocity impact (LVI) using acoustic emission (AE) method. Moreover, the effects of various nanoparticles (NPs) on the tension-after-impact (TAI) strength of glass fiber-reinforced polymer (GFRP) composites have been investigated. The hierarchical method was employed to cluster the acoustic emission data and detect the damage mechanisms of the composites. These damage are matrix cracking, fiber–matrix debonding, fiber breakage, and fiber pull-out, the peak frequency ranges of which were obtained to be (100–200), (250–370), (410–530), and (570–650) kHz, respectively. Subsequently, the existence of these mechanisms was verified using Scanning Electron Microscope (SEM) images, and their shares in composite failure under tensile loading were calculated by wavelet transform method. According to the results, the NPs have enhanced the impact strength of the GFRPs by up to 66% reduction in damage index. Furthermore, they have increased TAI strength by up to 39%, claims also supported by the AE analysis.

APPLICATIONS, NANOTOXICITY, ENVIRONMENTAL ASPECTS AND FUTURE CHALLENGES OF NANOTECHNOLOGY IN THE OIL AND GAS INDUSTRY: A REVIEW

In the present review, applications of nanotechnology are employed to amplify the tendencies of growing traditional and cut-off resources of gas and to improve the process of drilling and production of oil and gas by designing it more accessible to separate oil and gas inside the reservoir. The impact of nanotechnology in many areas is more effective, cheaper, and more environment-friendly than what is presently accessible. A summary of various types of nanomaterials used together with a deep investigation of their compliance in advancing the objective factors is widely described. This paper reviews nanotechnology applications in the various parts of the oil patch such as exploration, production, EOR, wettability alteration, refinery processes, and drilling operations including drilling tools, drilling fluids, and cement. The impacts of numerous nanoparticles in drilling fluids and enhanced oil recovery has been explored. This paper gives a notified analysis of the improvements of nanotechnology in exploration as well as production. Moreover, the toxic effects of various nanoparticles and their environmental aspects have been observed and studied. The oil and gas industry can be made greener by nanotechnology. Finally, an outlook on the recent challenges and a few predictions for future applications is also underlined.

Human Serum Albumin Aggregation and its Modulation Using Nanoparticles: A Review.

Amyloid fibrils are highly stable protein fibrillar aggregates believed to be involved in various neurodegenerative diseases, which include Alzheimer's disease, Parkinson's disease, and prion diseases. Inhibiting the aggregation process is a potential strategy to prevent diseases caused by amyloid formation. In this regard, nanoparticles have emerged as promising candidates owing to their unique physical/chemical properties of small size, large surface area, biocompatibility, biodegradability, non-toxicity, and ease of functionalization. Human Serum Albumin (HSA) is a soluble multidomain monomeric protein that interacts with various ligands and hormones, aiding in their transport, distribution, metabolism in the circulatory system, and also plays a vital role in extracellular fluid volume stabilization. Under certain in vitro conditions, HSA has been reported to undergo conformational changes leading to fibril formation and hence acts as a suitable model for studying amyloidogenesis. In this review, we have explored the effects of various nanoparticles on HSA aggregation and their mechanism of action. The study will throw light on the mechanistic details of nanoparticle-mediated amyloid modulation, which will help in the development of effective therapeutics against amyloidosis.

Effects of Various Nanoparticles on the Rheological Properties of Carboxylic Cellulose Nanofibers and the Compound System’s Application in Enhanced Oil Recovery

Effects of Various Nanoparticles on the Rheological Properties of Carboxylic Cellulose Nanofibers and the Compound System’s Application in Enhanced Oil Recovery

Fate of Antibody-Targeted Ultrasmall Gold Nanoparticles in Cancer Cells after Receptor-Mediated Uptake.

Nanoparticles with ultrasmall sizes (less than 10 nm) offer many advantages in biomedical applications compared to their bigger counterparts, including better intratumoral distribution, improved pharmacokinetics (PK), and efficient body clearance. When functionalized with a biocompatible coating and a target-specific antibody, ultrasmall nanoparticles represent an attractive clinical translation platform. Although there is a tremendous body of work dedicated to PK and the biological effects of various nanoparticles, little is known about the fate of different components of functionalized nanoparticles in a biological environment such as in live cells. Here, we used luminescence properties of 5 nm gold nanoparticles (AuNPs) to study the intracellular trafficking and fate of the AuNPs functionalized with an organic layer consisting of a polyethylene glycol (PEG) coating and epidermal growth factor receptor (EGFR)-targeting antibody. We showed that intracellular uptake of the targeted 5 nm AuNPs results in a strong two-photon luminescence (TPL) that is characterized by broad emission and very short lifetimes compared to the fluorescence of the nanoparticle-conjugated fluorophore-tagged antibody, thereby allowing selective imaging of these components using TPL and two-photon excited fluorescence lifetime microscopy (2P-FLIM). Our results indicate that the nanoparticle’s coating is detached from the particle’s surface inside cells, leading to formation of nanoparticle clusters with a strong TPL. Furthermore, we observed an optically resolved spatial separation of the gold core and the antibody coating of the particles inside cells. We used data from two-photon microscopy, 2P-FLIM, electron microscopy, and in vitro assays to propose a model of interactions of functionalized 5 nm AuNPs with live cells.

Nanoparticles in drilling fluid: A review of the state-of-the-art

Nanoparticles (NPs) as a nanotechnologies unit have a huge potential for improving drilling fluids. However, the role of NPs in this field is still in its infancy and consequently has attracted much more attention in the last years. This review is going to investigate the drilling fluids modified by nanoparticles. Moreover, effects of various nanoparticles include polymeric, ceramic, metal and carbon-based NPs on drilling fluid and technical and economic benefits of them will be inspected. Although various reviews of nano-based drilling fluids have been reported, few papers have provided a comprehensive review and development of nanoparticles application in this issue. This review summarizes the recent research advances in the synthesis and applications of NPs in drilling fluids system. The roles of NPs in rheology and fluid loss control, mud cake thickness, filtration properties, and thermal properties are discussed. Accordingly, various literature reviews demonstrated that use of nano materials in drilling fluid has two main goals: improvement of thermal and physical-mechanical of drilling fluids. The studies in this issue will facilitate the design of advanced functional nano-composites for drilling fluids.

On the prediction of filtration volume of drilling fluids containing different types of nanoparticles by ELM and PSO-LSSVM based models

There is a direct link between the extent of formation damage and the filtration volume of the drilling fluids in hydrocarbon reservoirs. The filtration volume can be diminished by adding different additives to the drilling fluids. Recently, nanoparticles have been extensively used for enhancing the filtration characteristics of the drilling fluids. However, there is no reliable model for investigating the influence of this class of additives on the performance of drilling fluids. Hence in this study, two powerful tools ELM (extreme learning machine) and PSO-LSSVM (particle swarm optimization-least square support vector machine) are applied to determine the effect of various nanoparticles on the filtration volume. The assessment of the models is carried out by computing the statistical parameters, and it is found that ELM has a greater ability to predict the filtration volumes, while PSO-LSSVM performs satisfactorily too. The model predictions and experimental results are in excellent agreement as suggested by the values of root mean squared error (RMSE = 0.2459), coefficient of determination (R2 = 0.999), and mean relative error (MRE = 2.028%) for the dataset. The statistical analysis shows that the suggested model can predict the filtration volume with great accuracy. Moreover, through sensitivity analysis of the input parameters, it is found that for a specified nanoparticle, the filtration volume is highly influenced by nanoparticle concentration and it is the essential variable for the optimization process.

Responses of Medicinal and Aromatic Plants to Engineered Nanoparticles

Medicinal and aromatic plants have been used by mankind since ancient times. This is primarily due to their healing effects associated with their specific secondary metabolites (some of which are also used as drugs in modern medicine), or their structures, served as a basis for the development of new effective synthetic drugs. One way to increase the production of these secondary metabolites is to use nanoparticles that act as elicitors. However, depending on the specific particle size, composition, concentration, and route of application, nanoparticles may have several other benefits on medicinal and aromatic plants (e.g., increased plant growth, improved photosynthesis, and overall performance). On the other hand, particularly at applications of high concentrations, they are able to damage plants mechanically, adversely affect morphological and biochemical characteristics of plants, and show cytotoxic and genotoxic effects. This paper provides a comprehensive overview of the beneficial and adverse effects of metal-, metalloid-, and carbon-based nanoparticles on the germination, growth, and biochemical characteristics of a wide range of medicinal and aromatic plants, including the corresponding mechanisms of action. The positive impact of nanopriming and application of nanosized fertilizers on medicinal and aromatic plants is emphasized. Special attention is paid to the effects of various nanoparticles on the production of valuable secondary metabolites in these plants cultivated in hydroponic systems, soil, hairy root, or in vitro cultures. The beneficial impact of nanoparticles on the alleviation of abiotic stresses in medicinal and aromatic plants is also discussed.

The effect of nanoparticle additives on the tribological properties of various lubricating oils – Review

Eco-friendly lubricants are gaining more attention because of the environmental impacts caused by non-renewable petroleum products. Vegetable and synthetic oils are considered as a potential base-stock for bio-lubricants. It was observed that certain lubricant properties such as oxidative stability, tribological behavior of these bio-lubricants need to be improved. The addition of nanoparticles is considered as an effective solution to enhance the performance of the lubricant. This paper overviewed the effect of various nanoparticles as additives on the tribological properties of different lubricating base oils such as mineral oils, vegetable oils, and synthetic oils. The addition of multiple nanoparticles (0.1 to 0.5 wt%) has indicated an improvement of 3 to 50% in these lubricating oils' tribological properties under different testing conditions. The review has also explained the mechanism of nanoparticles by which the tribological properties are enhanced.

Influence of nanoparticle additions to the electrolyte on the structure, composition and corrosion resistance of oxide layers formed by PEO on cast Mg alloy

The effect of various nanoparticles (NPs) added to the electrolyte on the composition, structure, and properties of oxide layers formed by plasma electrolytic oxidation (PEO) on a cast magnesium alloy AZ81A was studied in this work. The oxide layers were obtained by alternating adding silicon dioxide SiO2, silicon nitride Si3N4, yttrium oxide Y2O3, tungsten carbide WC, and titanium carbide TiC NPs to the electrolyte. The obtained oxide layers were studied by scanning electron microscopy (SEM), energy dispersive X-ray microanalysis (EDXMA), X-ray diffraction analysis (XRD), instrumental indentation and potentiodynamic polarization (PDP). The thickness, roughness, microhardness, adhesion and corrosion resistance of the oxide layers were determined. The greatest increase in the oxide layer thickness, in its hardness and corrosion resistance was observed for TiC and WC NPs added to the electrolyte during PEO. The addition of Si3N4 NPs leads to a decrease in the oxide layer thickness and its hardness, while the corrosion resistance is comparable to the one of the uncoated magnesium alloy.

A Study on the Tribological Performance of Nanolubricants

In recent years, the tribology field has expanded with the advent of nanolubrication. Nanolubricants are the name given to the dispersion of nanoparticles in a base oil, and has attracted researchers due to its potential application. In addition to being used in the tribology field, nanoparticles are also used for medical, space, and composites purposes. The addition of nanoparticles in base oils is promising because it enhances specific tribological characteristics including wear-resistance and friction, and the most important reason is that the majority of them are environmentally friendly. This paper reviews the tribological effect of various nanoparticles as lubricant additives. Parameters of nanoparticles that affect tribological performance, the technique to enhance stability, and lubrication mechanism that is currently believed to function will be delineated in detail. Moreover, this review facilitates an understanding of the role of various nanoparticles, which helps in developing and designing suitable nanolubricants for various applications.

Nanoscale Fe0/Cu0 bimetallic catalysts for Fenton-like oxidation of the mixture of nuclear-grade cationic and anionic exchange resins

Spent resins generated from the nuclear industrial processes are still difficult to be treated and disposed. Fenton-like processes have great application potential in the treatment of spent resins, but the Fenton reaction mechanisms and resin degradation pathways remain challenging. In this study, nanoscale Fe0/Cu0 bimetallic catalysts were prepared and characterized for the Fenton-like degradation of the mixture of cationic and anionic resins. High catalytic property of Fe0/Cu0 bimetallic nanoparticles activated by H2O2 was evaluated, according to the effects of various nanoparticles, temperature, catalyst amount, H2O2 concentration and the mixing ratio of cationic and anionic resins. Combined the shape and color changes of mixed resins with the experimental and calculated characterization results, different degradation difficulty of cationic and anionic resins and their degradation mechanisms were studied. According to the density functional theory calculations of the optimized resin molecules with the Fe0/Cu0 catalyst, the mechanisms of Fenton-like reactions and the degradation of mixed resins through the synergistic effect of Fe and Cu species were proposed. The comprehensive Fenton-like reactions and degradation mechanisms provide new insights to advance the treatment of spent resins and organic polymers by Fenton-like processes.

Effect of Various Nanoparticles (GaF3, ZnF2, Zn(BF4)2 and Ga2O3) Additions on the Activity of CsF-RbF-AlF3 Flux and Mechanical Behavior of Al/Steel Brazed Joints

In this study, brazing AA6061 to Q235 steel using flame brazing was performed with 70.9 wt.% CsF-0.5 wt.% RbF-28.6 wt.% AlF3 fluxes doped with GaF3, ZnF2, Zn(BF4)2 and Ga2O3 nanoparticles, matched with a Zn-15Al filler metal, and the spreadability of the filler metal and the mechanical properties of brazed joints were investigated at the same time. The results showed suitable amounts of GaF3, ZnF2, Zn(BF4)2 and Ga2O3 doped into the base flux could strengthen the filler metal in wetting and spreading on the surface of aluminum alloy and steel to different degrees. The suitable ranges of GaF3, ZnF2, Zn(BF4)2 and Ga2O3, respectively, were 0.0075–0.01 wt.%, 0.0075–0.01 wt.%, 0.0075–0.01 wt.% and 0.009–0.01 wt.%, and the maximum spreading area was obtained via doping with GaF3. The shear strength of brazed joints reached the peak at 126 MPa when 0.075 wt.% GaF3 was added. Comparative tests proved that the activity of the CsF-RbF-AlF3 flux doped with GaF3 was the best. The reason was that the CsF-RbF-AlF3-GaF3 flux was competent in removing oxides of the base metal and decreasing the interfacial tension, in virtue of the activity of Ga3+ as well as F−.