Adding Sodium Dodecyl Sulfate Research Articles

Utility of green chemistry for spectrofluorometric determination of fingolimod via metal complexation; Application to dosage and spiked biological fluid

The goal of the current research was to establisha quick and practical fluorimetric technique for fingolimod analysis. The approach relied on the drug's complex formation with the zinc ion to produce a high-fluorescence product. The fluorescence was further enhanced by adding sodium dodecyl sulfate, and it was observed at 325 nm following excitation at 475 nm. With a correlation coefficient of 0.9999, the association between emission intensity and fingolimod concentration was linear between 5-150 ng mL-1. The quantitation limit was 2.059 ng mL-1,while the detection limit was 0.679 ng mL-1. The buffer type, pH and concentration, type of surfactant and concentration, and finally the diluting solvent were among the reaction conditions that were closely examined. With great precision and reliability, the drug in question was quantified using this method in both spiked human plasma and capsule formulations. The proposed method's level of greenness was assessed using two methodologies: the analytical greenness metric (AGREE) and the Green Analytical Procedure Index (GAPI).

Effect of modified multi-walled carbon nanotubes on mechanical properties and microscopic mechanism of lithium slag geopolymers

This study aims to examine the impact of multi-walled carbon nanotubes (MWCNTs) on the mechanical properties and micro-mechanisms of lithium slag geopolymer (LSG), a novel environmentally friendly building material. Two distinct dispersion methods, which used ultrasonication or added sodium dodecyl sulfate (SDS) dispersants, were employed to disperse both pristine and modified MWCNTs. Subsequently, these dispersed MWCNT solutions were mixed with waste lithium slag and stirred to prepare LSG. Based on the experiments, it is concluded that all of these demonstrated the most significant enhancement of LSG mechanical properties at a 0.1 % mass fraction of modified MWCNTs. In comparison with the reference LSG, the compressive and bending strengths of LSG with modified MWCNTs experienced improvements of 23.29 % and 13.76 %, respectively, after a curing period of 28 days. This was also evident from a microscopic perspective. The LSGs doped with modified MWCNTs and SDS exhibited stronger Ai-O-Si and Si-O-Si vibrational bands, as well as broader N-A-S-H and C-S-H characteristic peaks compared to the pristine LSGs. The porosity of LSG samples mixed with a mass fraction of 0.1 % MWCNTs and SDS was 37.08 % lower than that of pristine LSG. FESEM electron micrographs revealed that the modified MWCNTs functioned as fillers, bridges, and extractors of cracks in the hydration products of LSG. The aforementioned results suggest that well-dispersed modified MWCNTs have a beneficial impact on the mechanical properties and microscopic characteristics of LSG.

Spectrofluorimetric determination of tapinarof via Zn (II) complexation and assessment of its topical dosage application

Topical tapinarof is used to treat plaque psoriasis (a skin disease in which red and scaly patches form are appeared on some areas of the body). The goal of the current research is to establish a facile and rapid fluorimetric technique for tapinarof analysis. The approach relied on the reaction between the drug and zinc ion through metal complexation to produce a highly-fluorescent product. The fluorescence was further enhanced by adding sodium dodecyl sulfate, and it was observed at 542 nm following excitation at 497 nm. With a correlation coefficient of 0.9997, the association between emission intensity and tapinarof concentration was linear between 2.0 and 120 ng mL−1. 1.021 ng mL−1 was the quantitation limit while 0.366 ng mL−1 was the detection limit. The buffer type, pH and concentration, type of surfactant and concentration, and finally the diluting solvent were among the reaction conditions that were closely examined and it was found that the optimum conditions were obtained upon employing teorell-stenhagen buffer optimized at pH 6.0, 1.38 × 10–2 M SDS and distilled water as a solvent are the suitable choice. With great precision and reliability, the drug under study was quantified using this method in ointment formulations. The proposed method's level of greenness was assessed using two methodologies: the analytical greenness metric (AGREE) and the Green Analytical Procedure Index (GAPI), with good recovery results ensuring high efficiency of the proposed approach on analysis of ointment without any interference from additives and excipients.

Utility of green chemistry for feasible spectrofluorometric determination of trifluridine via metal complexation: Application to dosage forms

AbstractThe goal of the current research was to establish a quick and practical fluorometric technique for trifluridine analysis. The approach relied on the drug's complex formation with the zinc ion to produce a high‐fluorescence product. The fluorescence was further enhanced by adding sodium dodecyl sulfate, and it was observed at 450 nm following excitation at 400 nm. With a determination coefficient of 0.9994, the association between emission intensity and trifluridine concentration was linear between 1 and 125 ng mL−1. The quantitation limit was 0.987 ng mL−1 while 0.333 ng mL−1 was the detection limit. The buffer type, pH and concentration, type of surfactant and concentration, and finally the diluting solvent were among the reaction conditions that were closely examined. With great precision and reliability, the drug in question was quantified using this method in dosage formulations. The proposed method's level of greenness was assessed using two methodologies: the analytical greenness metric (AGREE) and the Green Analytical Procedure Index (GAPI).

Development of a Microfluidic Ion Current Measurement System for Single-Microplastic Detection

Microplastics (MPs) can adsorb heavy metals and metalloids and may cause a potential health hazard. Precise measurements of their size, shape, composition, and concentration at a single-MP level are important to evaluate their potential toxicity and identify their original source. However, current single-MP analytical methods such as micro-Raman spectroscopy and scanning electron microscopy have low throughput. Therefore, in this study, we applied the ion current sensing method, which has been used for single cell analysis, to single-MP analysis and examined whether size measurement and composition analysis of MPs at the single particle level are possible. In single-MP measurements, plastic particles must be mono-dispersed in solution at least within the measurement time. The agglomeration behavior was carefully observed after adding sodium dodecyl sulfate to tris-borate-EDTA buffer at 2–16 mM. Under these conditions, the size of polystyrene beads could be measured using the ion current sensing under the mono-dispersed condition. Next, ion current sensing was performed on four pseudo MPs fabricated from different materials (polyethylene, polyethylene terephthalate, polypropylene, and polyvinyl chloride) that were mechanically grazed and UV-irradiated to imitate real marine MPs. Although significant differences in the ion current signals from different material MPs were not observed, fast (100 MPs within 2 s) and precise measurements in the MPs’ sizes at a single-MP level were successfully achieved.

The selective adsorption and flotation separation of spodumene from feldspar using a novel iron-group multiple ligand collector

Spodumene and feldspar have little difference in flotability due to their similar crystal chemistry properties. Fe-octyl hydroxamic acid (OHA) (iron complexes of octyl hydroxamic acid) demonstrates excellent selectivity but restricted collecting performance in spodumene flotation. In this work, we added sodium dodecyl sulfate (SDS) into Fe-OHA to obtain a novel multiple ligand collector, which was named Fe-OHA-SDS to enhance the collection ability of Fe-OHA. The efficient separation of spodumene from feldspar (the recovery difference was about 84 %) was achieved by Fe-OHA-SDS without adding depressants and foaming agents at pH 6.2. The separation mechanisms were explored by Zeta potential, contact angle, in-situ microcalorimetric, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) measurements. The findings revealed that Fe-OHA-SDS was more easily bonded to the spodumene surface than the feldspar surface. Meanwhile, the adsorption of Fe-OHA-SDS significantly expanded the hydrophobicity differences on these two mineral surfaces. The Fe-OHA-SDS was adsorbed on the spodumene surface through the Fe-O bond, which differed from the interaction mechanism of traditional mixed collectors on mineral surfaces. Therefore, Fe-OHA-SDS was an efficient collector with potential application value in spodumene flotation.

Utilizing an anionic surfactant aqueous media for voltammetric sensing of anti-cancer drug imiquimod in the pharmaceutical formulation and urine samples at the boron-doped diamond electrode surface

This work demonstrates an electroanalytical evaluation for voltammetric sensing of the anti-cancer drug imiquimod (IMQ) at the boron-doped diamond electrode. By using cyclic voltammetric technique, IMQ demonstrated a well-defined, adsorption-controlled, irreversible anodic peak at approximately +1.56 V (vs Ag/AgCl) in 0.1 M H2SO4 solution. A possible mechanism for the electro-oxidation of IMQ was proposed based on the pH investigation data. The voltammetric signals of IMQ were improved by adding sodium dodecyl sulfate (SDS), an anionic surfactant, to the selected supporting electrolyte. By utilizing the square wave-adsorptive stripping voltammetric technique, acceptable linearity was obtained in 0.1 M H2SO4 solution with SDS at about +1.49 V (vs Ag/AgCl). The presented approach was linear in the concentration range of 0.005 and 1.0 μg mL−1 (2.1 × 10−8-4.2 × 10−6 M), with a lower limit of detection of 0.0015 μg mL−1 (6.2 × 10−9 M). Eventually, the proposed approach's applicability was investigated by sensing IMQ in pharmaceutical formulations and urine samples.

Enhanced bioleaching efficiency of vanadium from stone coal vanadium ore by adding biochar and plasma treatment

To address the common problem of low vanadium bioleaching efficiency from stone coal, different enhanced bioleaching methods were used in this study. In the single enhancement treatment of adding biochar, plasma pretreatment, and adding sodium dodecyl sulfate (SDS), the addition of 1 g of biochar had the best effect on vanadium leaching by Bacillus mucilaginosus (B. mucilaginosus), with a 9.8% higher vanadium leaching rate compared to the blank group. While, the compound enhanced treatment method, including plasma treatment of stone coal for 6 min and adding 0.1 g/L biochar in bioleaching system, can further improve vanadium leaching. At 20 days of bioleaching, the vanadium leaching rate was 21.7% higher than that of the blank group. It was found that biochar can facilitate bacterial attachment through microbial immobilization and increase bacterial biomass. The flourier transform infrared (FTIR) spectroscopy results show that the plasma pretreatment can introduce oxygen-containing functional groups such as hydroxyl and carboxyl groups to modify the surface of the stone coal, which reduced the contact angle of the stone coal by 22.1° and improved its surface hydrophilicity and reactivity, enhancing the interface reaction between B. mucilaginosus and stone coal vanadium ore. Hence, this work significantly promoted the vanadium bioleaching performance through compound enhanced bioleaching mothed, which appears very promising for the development of practical applications.

Feasible spectrofluorimetric approach for the ultrasensitive determination of lomefloxacin based on synergistic effects of micellization and metal complexation

The purpose of the present work was to establish a fast and convenient strategy for lomefloxacin analysis using a fluorimetric approach. The methodology was based on the complex formation of the drug with aluminum ion to give a product having high fluorescence. Adding sodium dodecyl sulfate led to further boosting the intensity of fluorescence which was recorded at 429 nm after excitation at 332 nm. The relationship of emission intensity with lomefloxacin concentration was linear at 10–130 ng mL−1 with a correlation coefficient of 0.9996. The quantitation limit was 11.4 ng mL−1 and detection limit was 3.8 ng mL−1. The reaction conditions were carefully studied which included the pH, buffer type, its concentration, the type and concentration of surfactant and the diluting solvent. The method was utilized to quantify the aforementioned drug in tablet formulations and in real human plasma with high accuracy and reliability.

The First Electroanalytical Study Of Umifenovir (Arbidol) Used As A Potential Antiviral Drug For The Treatment of SARS-CoV-2: A Voltammetric Quantification On The Boron-Doped Diamond Electrode By Using Anionic Surfactant Media

In this work, an electroanalytical procedure for sensing umifenovir (arbidol) by square wave adsorptive stripping voltammetry (SW-AdSV) was developed utilizing an anodically pretreated boron-doped diamond electrode. Measurements of umifenovir using cyclic voltammetry with phosphate buffer solution (PBS, 0.1 M, pH 2.5) revealed irreversible behaviour, adsorption-controlled as well as an ill-defined (+1.13 V, PA1) and a well-defined (+1.47 V, PA2) two oxidation peaks. Umifenovir oxidations depend critically on supporting electrolytes and pH. The second oxidation peak (PA2) current of the umifenovir was enhanced by adding sodium dodecyl sulfate (SDS, anionic surfactant) in the chosen supporting electrolyte. Umifenovir was quantified using its second oxidation peak (PA2) at about +1.39 V. Using the optimized condition, the oxidation peak current of PA2 showed a linear relationship for umifenovir determination in the concentration range from 0.005 to 1.0 μg ml−1 (9.73 × 10−9−1.95 × 10−6 M), with a detection limit of 0.0014 μg ml−1 (2.72 × 10−9 M) in PBS (PH 2.5) with SDS. Finally, the developed approach was successfully utilized to determine umifenovir in the pharmaceutical formulation and urine samples. To the best of our knowledge, this is the first electroanalytical approach for voltammetric sensing of umifenovir.

INFLUENCE OF THE PHASE TRANSFER CATALYST ON THE ACCUMULATION AND DECOMPOSITION OF ETHYLBENZENEHYDROPEROXIDE

The regularities of ethylbenzene oxidation and hydroperoxide decomposition in microheterogeneous systems formed by adding sodium dodecyl sulphate to hydrocarbon media have been studied. A pronounced influence of surfactant nature on the transformation mechanism has been revealed. Anionic micellar surfactants including a linear hydrocarbon fragment catalytically accelerate ROOH decomposition, whereas hydrocarbon soluble non-ionic surfactants and solid oxides practically do not influence the reaction rate. Detailed study of the degradation kinetics in the presence of anionic alkyl sulphates has shown that the accelerating effect of surfactants is connected with their colloidal properties, namely, with the formation of joint aggregates of inverse micelles type, which facilitate the destruction of the peroxide bond. For the first time, a synergistic inhibitory effect of sodium alkyl sulphate mixtures with phenolic antioxidants in the oxidation of various hydrocarbons has been found. During the oxidation of ethylbenzene with minor additives (<1%) of sodium dodecyl sulphate (DDS) a unique case of effective self-inhibition has been determined, the mechanism of which includes two steps. Hydroperoxide, the main source of free radicals, decomposes heterolytically in joint microaggregates with DDS. The decomposition occurs selectively with the formation of acetaldehyde and phenol. Phenol being an acceptor of free radicals inhibits the oxidation of ethyl benzene. The main oxidation product of RH in this system is phenol and acetaldehyde. It should be noted that phenols formation at decomposition of alkylaromatic ROOH is usually connected with strong acids. In the case of DDS decomposition of ROOH seems to be driven by the successful orientation of ROOH molecules in the microaggregates formed by anionic surfactants. But a number of experimental factors, namely the influence of the carbon chain length in sodium alkyl sulphates on the dodecane oxidation rate and inertness of the Na2SO4 dispersion in the hydroperoxide decomposition reactions, make it possible to suggest the catalytic reaction of ROOH. Suggest that the catalytic effect of DDS on hydroperoxide decomposition is connected with its colloidal properties and decomposition occurs in common microaggregates formed by DDS and ROOH. The effective activation energy of ROOH decomposition at concentration of 10 mm is Eef = 66.3 kJ/mol. The oxidation of ethyl benzene is completely inhibited at low additions of DDS (1 mM), and the decomposition rate in an atmosphere of N2 significantly increases. DDS increases the effective decomposition constant of ROOH. This surfactant can be considered as an effective catalyst of ROOH decomposition. For citation: Kashkay A.M. Influence of the phase transfer catalyst on the accumulation and decomposition of ethylbenzenehydroperoxide. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2023. V. 66. N 2. P. 100-106. DOI: 10.6060/ivkkt.20236602.6684.

Surfactant-Assisted Purification of Hydrophobic DNA Nanostructures.

Purification of functional DNA nanostructures is an essential step in achieving intended functions because misfolded structures and the remaining free DNA strands in a solution can interact and affect their behavior. However, due to hydrophobicity-mediated aggregation, it is difficult to purify DNA nanostructures modified with hydrophobic molecules by conventional methods. Herein, we report the purification of cholesterol-modified DNA nanostructures by using a novel surfactant-assisted gel extraction. The addition of sodium cholate (SC) to the sample solution before structure folding prevented aggregation; this was confirmed by gel electrophoresis. We also found that adding sodium dodecyl sulfate (SDS) to the sample inhibited structural folding. The cholesterol-modified DNA nanostructures prepared with SC were successfully purified by gel extraction, and their ability to bind to the lipid membrane surfaces was maintained. This method will facilitate the purification of DNA nanostructures modified with hydrophobic molecules and expand their applicability in the construction of artificial cell-like systems.

Centrifugally spun lignin fibers with high Cr(Ⅵ) adsorption capacity

Due to its structural cohesiveness, lignin is unable to construct an efficient adsorption structure and exhibits poor adsorption capacity of heavy metal ions. Most of the current studies have been conducted to improve the adsorption performance of lignin by functionalization or construction of spatial network structure to change the aggregation state of lignin. However, this did not develop the adsorption capacity of lignin itself and the enhancement is quite dependent on the introduced materials. In this study, lignin fibers were prepared by facile centrifugal spinning method to expose more effective adsorption sites, and the corresponding Cr(VI) adsorption capacity was improved. The further enhancement of the Cr(VI) adsorption capacity of lignin fibers can be achieved by the formation of porous structure via adding sodium dodecyl sulfate and then dissolving it in aqueous solution during adsorption. The obtained lignin fibers exhibited maximum Cr(VI) adsorption capacity of 339.0 mg/g, which is quite higher than that of modified lignin in previous studies. As-prepared lignin fibers showed monolayer adsorption and chemical adsorption which mainly included reduction, electrostatic attraction, complexation, π-cation interaction, and pore filling. These results are useful for the application of lignin adsorbent materials in wastewater treatment.

Preparation and identification of green polymers towards the production of sustainable latex from β-myrcene and some methacrylate monomers

Sustainable polymers have enough potential to overcome petroleum materials and not completely rely on them for the presence of renewable raw materials, as well as the possibility of developing polymerization methods for renewable raw materials to have these materials recyclability, biodegradability and being a non-toxic material. This has been the focus of recent years. Solvent-free emulsion copolymerization of β-myrcene, a naturally occurring monoterpene monomer, the co-monomers that were used with β-myrcene, tetrahydrofurfuryl methacrylate, iso-bornyl methacrylate, and tert-butyl methacrylate, and each methacrylate monomer was polymerized separately with β-myrcene monomer, β-myrcene –methacrylate monomer (MY/MA) copolymers of different compositions were synthesized under nitrogen atmosphere at 60 ºC, using copolymers composition 50/50 comonomer reactivity ratios, and has been added sodium dodecyl sulfate as emulsifier, and ammonium persulfate as initiator. 1H-NMR, 13CNMR and FTIR spectroscopy were used to confirm the chemical structure and composition. It was found that the copolymerization reaction of each copolymer is influenced with the form of the methacrylate(s) side chain. Furthermore, the thermal properties of copolymers were characterized by DSC and TGA, where the value Tg indicate that random composition copolymers, due to the difference in crystallization of each side chain.

Effect of Hydrogen Bonding on Dynamic Rheological Behavior of PVA Aqueous Solution.

The rheological behavior of polyvinyl alcohol (PVA) aqueous solution is crucial to optimizing the processing technology and performance of PVA products. In this paper, the dynamic rheological behavior of PVA aqueous solution was investigated in detail. PVA solution with a concentration of 10 wt% showed unnormal rheological behaviors, that is, the liquid-like behavior in the high frequency (ω) region and the solid-like behavior in the low ω region. A storage modulus (G′) plateau appears in the relatively low ω region as a gel with a network structure. Different from conventional hydrogel, this plateau has a low modulus, and the corresponding size of the relaxation unit is estimated to be 554 nm, being higher than the size of a whole PVA chain. It is believed that the network mesh is formed by the intermolecular hydrogen bonding interactions among PVA chains. The relaxation time of these meshes is longer than the reptation time of a PVA chain. Based on the relaxation spectrum and calculation analysis, it is found that the destruction of intermolecular hydrogen bonds, such as by heating up, adding sodium dodecyl sulfate, and shear operation, will make the relaxation unit (mesh) larger and lead to the left shift of the intersection of G′ and loss modulus (G″). In a PVA solution with a high concentration, multiple meshes of various sizes could be formed and thus generate multiple relaxation peaks. The large-sized meshes mainly contribute to the left shift of the intersection of G′ and G″, and the small-sized meshes contribute to the high plateau modulus. The results in this paper offer a new angle to analyze polymer solutions with strong intermolecular interaction.

Controlling size, shape, and charge of nanoparticles via low-energy miniemulsion and heterogeneous RAFT polymerization

Size, shape, and charge are key parameters of nanoparticles, and variations in these parameters can significantly impact their properties and applications. Among various nanoparticle synthesis methods, the combination of low-energy miniemulsions with reversible addition-fragmentation chain-transfer (RAFT) polymerization allows for the facile, rapid, and environmentally friendly preparation of uniform nanoparticles. However, this method cannot, yet, simultaneously control the size, shape, and charge of nanoparticles, thereby limiting its potential applications. Here we report the synthesis of polymeric nanoparticles with concurrent control over particle size, shape, and charge via low-energy miniemulsion and heterogeneous RAFT polymerization. Key to our approach is the combination of (i) a macromolecular surface-active agent to facilitate the formation of nanodroplets, (ii) various small-molecule surfactants with different charges to control the size and charge of nanodroplets, and (iii) a molecular transformer to control the morphology of the final polymeric nanoparticles. In particular, negatively charged polystyrene nanoparticles of different sizes (from ∼100 to ∼500 nm) and shapes (sphere, worm, and vesicle) were obtained by simply tuning the amount of added sodium dodecyl sulfate (SDS) and toluene. The nanoparticle charge was then switched from negative to positive by replacing SDS with cetyltrimethylammonium bromide (CTAB), a positively charged surfactant. In addition, biocompatible and neutral surfactants (including Tweens and Span 80) were employed to tune the nanoparticle size yielding challenging-to-synthesize nanoworms. This work provides a simple but powerful approach to produce nanoparticles of different properties, thus expanding the scope of nanomaterials made by RAFT low-energy miniemulsion polymerization.

Stability and thermal conductivity of TiO2/water nanofluids: A comparison of the effects of surfactants and surface modification

In this study, Surface modification technique is applied to prepare γ-glycidoxypropyltrimethoxysilane (GPTMS) modified TiO2/water nanofluids. Three surfactants and unmodified nanoparticles are added into de-ionized water to prepare surfactant added nanofluids. The characteristics of modified nanoparticles are firstly investigated. The results show that the grafting efficiency of GPTMS increases with reacting temperature and reactant mass ratio of GPTMS to nanoparticles. The stability and thermal conductivity of prepared nanofluids are investigated. The results show that the nanofluids prepared by adding Sodium dodecyl sulfate (SDS) and unmodified nanoparticles have moderate stability. The nanofluids prepared by GPTMS modified nanoparticles show excellent stability, which can be stable for 49 days and have the largest zeta potential. For all prepared nanofluids, thermal conductivity increases with temperature and nanoparticle concentration. The addition of SDS has limited contributions in thermal conductivity of nanofluids, while GPTMS modified nanofluids have higher thermal conductivity and long term thermal conductivity consistency.

Safranin T- SDS- GO ternary system: A fluorescent pH sensor

Graphene oxide (GO), one of the popular materials in recent years, has been synthesized according to the modified Hummers' method. Stable dispersions of different amounts of negatively charged GO were prepared in aqueous media. The GO/dye composites were prepared in deionized water by a simple method with the positively charged Safranin T compound (SfT), which is known to have strong fluorescence properties. By changing the GO/dye ratio, it was obtained stable composites in aqueous media. It was investigated the interaction of SfT with GO in an aqueous solution under the critical micelle concentration (CMC), at the CMC and above the CMC by adding sodium dodecyl sulfate (SDS). It was clarified the formation of GO-SfT composites by using spectroscopic techniques. In these composites, the effect of GO layers on the SfT’s photophysical properties was examined by absorption and fluorescence spectroscopy techniques. The change in the quenching effect of GO was monitored both adding a stabilizing electrolyte (NaCl) to the media and changing the pH of the medium. The evaluation was on the probability of the GO-SfT-SDS ternary system being a pH sensing biological sensor material. As a result of this study, it was thought that the GO-SfT-SDS system could be functionalized as a fluorescent pH sensor by taking advantage of GO's sensitivity to pH.

Impact of bubble coalescence in the determination of bubble sizes using a pulsed US technique: Part 1 – Argon bubbles in water

A powerful experimental approach to measure the size distribution of bubbles active in sonoluminescence and/or sonochemistry is a technique based on pulsed ultrasound and sonoluminescence emission. While it is an accepted technique, it is still lacking an understanding of the effect of various experimental parameters, including the duration of the pulse on-time, the nature of the dissolved gas, the presence of a gas flow rate, etc. The present work, focusing on Ar-saturated water sonicated at 362 kHz, shows that increasing the pulse on-time leads to the measurement of coalesced bubbles. Reducing the on-time to a minimum and/or adding sodium dodecyl sulfate to water allows to reducing coalescence so that natural active cavitation bubble sizes can be measured. A radius of 2.9–3.0 µm is obtained in Ar-saturated water at 362 kHz. The effects of acoustic power and possible formation of a standing-wave on coalescence and measured bubble sizes are discussed.

Collective effect of ternary nano fuel blends on the diesel engine performance and emissions characteristics

The present study aims to evaluate the emission and performance characteristics of a CI engine using biodiesel blends with three different nanoparticles. Biodiesel was prepared from palm oil using transesterification process. Biodiesel yield has been optimized using response surface methodology, which develops an interaction among the independent operating parameters reaction temperature methanol to oil ratio, and catalyst concentration, where they are changed as follows: 50–65 °C, 5:1–12:1, and 0.25–1.75, respectively. Nano fuel blends were prepared by dispersing CNT, TiO2 and Al2O3 nanoparticles into the B30 blend. The stability of these nanoparticles was improved by adding sodium dodecyl sulfate (SDS) as a surfactant, and the stability was characterized by ultraviolet–visible spectrometry. These nanoparticles were mingled with palm methyl ester at a proportion of 100 ppm using an ultrasonication water bath. The engine performance and emission characteristics were determined at varying engine speed and a full load condition. At all engine speeds, B30 with Al2O3 ternary fuel blend exhibits a promising reduction in brake specific fuel consumption (BSFC) of 5.98%. A significant improvement of 9.83%, 3.91% and 1.37% in brake thermal efficiency (BTE) has been observed for Al2O3, CNT, and TiO2 additives as compared to B10 blend, respectively. B30 with TiO2 ternary blend shows a sharp reduction of 27.89% and 30.68% in the CO and HC emissions respectively, and 10.37% decrease in NOx level with the addition of CNT as a fuel additive in the ternary fuel blend. Palm biodiesel blended with nanoparticle additives enhanced both engine performance and emission characteristics.