Particle Size Research Articles

Green Synthesis of Iron Oxide from Lathe Waste Using Green Tea Leaves (<i>C</i><i>amellia</i><i> s</i><i>inensis</i>) Extract by Temperature Variations of Synthesis

Iron oxide was produced from lathe waste using green tea leaf extracts. Green tea leaves contain catechins, has been produced as a possible reducing, precipitating, stabilizing, and capping agent. Another advantage of applying green tea leaves to synthesize iron oxide is reducing toxicity. Various temperatures of synthesis utilizing the precipitation method proved successful in the formation of hematite. X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscope (SEM) were used to characterize the synthesis product. According to the XRD results, the magnetite transition phase was obtained after precipitation, while hematite formed after calcination. The crystallite sizes were 50.5 nm, 45.4 nm, and 39 nm, respectively. According to FTIR identification, the iron oxide was generated before and after calcination in the presence of a specific Fe-O group at the wavenumbers 553 cm-1 and 451 cm-1. The SEM results revealed that the particle size ranges from 4.61 nm – 20.74 nm, and the shape was not uniform, and aggregation.

The Optical Forces and Torques Exerted by Airy Light-Sheet on Magnetic Particles Utilized for Targeted Drug Delivery

The remarkable properties of magnetic nanostructures have sparked considerable interest within the biomedical domain, owing to their potential for diverse applications. In targeted drug delivery systems, therapeutic molecules can be loaded onto magnetic nanocarriers and precisely guided and released within the body with the assistance of an externally applied magnetic field. However, conventional external magnetic fields generated by permanent magnets or electromagnets are limited by finite magnetic field gradients, shallow penetration depths, and low precision. The novel structured light field known as the Airy light-sheet possesses unique characteristics such as non-diffraction, self-healing, and self-acceleration, which can potentially overcome the limitations of traditional magnetic fields to some extent. While existing studies have primarily focused on the manipulation of dielectric particles by Airy light-sheet, comprehensive analyses exploring the intricate interplay between Airy light-sheet and magnetic nanostructures are currently lacking in the literature, with only preliminary theoretical discussions available. This study systematically explores the mechanical response of magnetic spherical particles under the influence of Airy light-sheet, including radiation forces and spin torques. Furthermore, we provide an in-depth analysis of the effects of particle size, permittivity, permeability, and incident light-sheet parameters on the mechanical effects. Our research findings not only offer new theoretical guidance and practical references for the application of magnetic nanoparticles in biomedicine but also provide valuable insights for the manipulation of other types of micro/nanoparticles using structured light fields.

Eco-Conscious Approach to Synthesizing Aluminum Oxides Using Nonthermal Plasma Technology

AlO is a prevalent oxide compound composed of aluminum and oxygen, with the chemical formula Al2O3. This study aims to prepare aluminum oxide nanoparticles using aluminum nitrate nonahydrate Al(NO[Formula: see text] 9H2O through direct exposure to a plasma jet system using argon gas, as plasma is the fourth state of matter and a common effective method. The major study in the preparation of Al2O3 nanoparticles, which is a physical method, examines the effect of aluminum oxide nanoparticles against bacteria and fungi. Different methods were used for diagnosis. The X-ray diffraction examination showed an average particle size of 37.8 nm. It was also found through the UV-Vis examination that a surface plasmon resonance was formed at 300 nm with an energy gap value of 4.21 eV. The electron microscope field emission scanning (FE-SEM) was used to study the surface morphology. The results of biological testing showed that aluminum oxide nanoparticles have high antibacterial and antifungal activity.

Rare and Abundant phoD‐Harboring Bacteria Mediate the Mineralization of Organic Phosphorus Fractions in Soil Aggregates During Cut Slope Restoration

ABSTRACTPhosphorus (P) is the key nutritional element in the soil of cut road slopes undergoing ecological restoration, and the transformation of organic P (Po) is a crucial part of the P cycle. However, the role of phoD‐harboring bacteria in driving the mineralization of Po fractions in road slope soil aggregates is unclear. This study analyzed road slope soils that had undergone 7, 11, and 14 years of restoration in the western Sichuan Plateau of China. We examined the differences and associations between the Po fraction content, alkaline phosphatase (ALP) activity, and community composition of rare and abundant phoD‐harboring bacteria in soil aggregates of four particle sizes (0.053–0.25, 0.25–2, 0.053–0.25, and, > 2 mm). The results showed that NaHCO3‐extracted Po (NaHCO3‐Po) content in soil aggregates increased with restoration years, while NaOH‐extracted Po (NaOH‐Po) content decreased. ALP activity in soil aggregates increased with restoration years, but there was no significant relationship between ALP activity with the phoD‐harboring bacterial community. There were significant differences in the composition of rare and abundant phoD‐harboring bacterial communities during slope restoration. Soil moisture, pH, organic carbon, and the C:P ratio in soil aggregates were the primary factors affecting the distribution of the Po fractions and the phoD‐harboring bacterial community. NaHCO3‐Po and NaOH‐Po in soil aggregates were likely the main substrates for ALP‐mediated Po mineralization. More genera were involved in Po mineralization in slope soils restored for 14 years than in soils restored for 7 and 11 years, and rare phoD‐harboring genera were more actively involved in Po mineralization than abundant phoD‐harboring genera. This study provides some theoretical basis for P effectiveness enhancement and P management during slope soil restoration.

The mechanics of extruded polylactic acid: an investigation into the effects of its multiple recycling and the inclusion of fly ash

Abstract This study examines variations in the material properties of the 3D printed polylactic acid (PLA) components after they have been recycled multiple times. Additionally, virgin polylactic acid was supplemented with fly ash from the thermal power plant, and the material’s behavior was examined after it was recycled on multiple times. By means of different tests, the impacts of filler addition on the mechanical behavior of the recycled materials are investigated. Using various forms including broken pieces, flakes, and fine powders, the filament extrusion was performed using used polylactic acid material during recycling. Under multiple recycling conditions, the mechanical characteristics of the polylactic acid and fly ash added polylactic (PLA-FA) were investigated. This work also investigates the impact of the polymer’s particulate size during the filament extrusion process. After recycling, it was found that the fine powder additions during the extrusion process provided high tensile strength of 32.61 MPa and flexural strength of 47.32 MPa for the PLA specimens. After recycling processes, the maximum tensile strength of 25.64 MPa and flexural strength of 50.22 MPa were found in fly ash enriched PLA. In contrast, the hardness of both PLA and fly ash-included PLA increased following each recycling procedure. Multiple recycling of PLA material turned the ductile material into brittle material by means of amorphous phase emergence. When compared to other particle sizes which were bigger in size, the specimens developed with filaments extruded with fine powder showed maximum results in all the tests. The tensile strength of PLA material decreased by 17.25%, while the tensile strength of PLA-FA material decreased by 21.35% after recycling. In PLA, the flexural strength drop following three recycling was 17.56% while in PLA-FA material it was 9.01%. After three times of material recycling, the hardness increased by 3.52% in PLA and by 2.48% in PLA-FA.

In vitro evaluation of lipidic nanocarriers for mebendazole delivery to improve anticancer activity

Objective Enhance the anticancer activity of the repurposed drug Mebendazole (MBZ) against A549 cell lines by developing nanostructured lipid carriers (NLCs). Significance MBZ, an anthelmintic drug, exhibits anticancer properties primarily through the inhibition of Ran GTPase and mitotic spindle assembly. Enhancing its delivery and efficacy via NLC could provide a novel and effective approach for lung cancer treatment. Methods NLCs were prepared by mixing different ratios of solid lipid (Stearic acid) and liquid lipid (Oleic acid) with surfactants and emulsifiers. The NLCs were fully characterized to ensure stability, particle size, zeta potential, and encapsulation efficiency (EE%). The stability of the NLCs was monitored over a 3-week period. The anticancer activity of MBZ-NLCs was evaluated using IC50 assays and in vitro scratch assays. Results The NLCs exhibited an average particle size of 300 ± 10 nm and a zeta potential of -27 ± 0.5 mV, indicating good stability. EE% significantly improved from 40% in conventional liposome formulations to 90.7% in NLCs. The anticancer activity of MBZ-NLCs was markedly enhanced, with an IC50 of 62 nM compared to 581 nM for free MBZ, representing a 10-fold increase in potency. Additionally, in vitro scratch assays revealed that MBZ-NLCs effectively prevented cell-cell contact, further supporting their potential for improved therapeutic efficacy. Conclusions MBZ-NLCs exhibit significantly improved stability, encapsulation efficiency, and anticancer activity compared to free MBZ. These promising results suggest that MBZ-NLCs could be a potent therapeutic approach for lung cancer treatment, warranting further in vivo studies and exploration of different administration routes.

Numerical study on characteristics of spiked electrode electrostatic precipitator

The characteristic of the spiked electrode electrostatic precipitator was numerically studied. The spiked electrode had significant effects on the distribution of electric field and charge density. The electric field and charge density were quite high in the area around the spiked electrode tips while decreased rapidly in other area far from the tips. Complicated electrohydrodynamic flow was observed and strong vortices were formed in the upstream and side areas of the spiked electrode. The gas velocity at the tip of the spiked electrode was as high as 28.1 m/s at the working potential of 45 kV. The working potential was more effective for the removal of large particle. The removal efficiency increased 42.4% for 10 µm particle and 15.2% for 0.25 µm particle as working potential increased from 22.5 kV to 45 kV. Low gas velocity was beneficial to the removal of all size particles. The removal efficiency increased by 10% to 15% for all size particles when the gas velocity decreased from 1.0 m/s to 0.6 m/s.

Synthesis, characterization and photo catalytic activity of silver nano particle derived from Arachis hypogaea L. seed peel extracts

Abstract The study focuses on the green synthesis of silver nanoparticles (AgNPs) using Arachis hypogaea L. seed peel extract (AHSPE) and evaluates their photocatalytic activity against Rhodamine B and Congo Red dyes. The synthesis involved reducing aqueous silver metal ions with AHSPE, characterized by various techniques including UV–visible spectroscopy, X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), and FT-Raman spectroscopy. UV–visible spectroscopy indicated characteristic absorption peaks at 428 and 439 nm, confirming the formation of AgNPs. XRD analysis revealed an average particle size of 4.77–5.6 nm. FT-IR spectra identified biomolecules such as amines, peptides, amides, lactones, and polyphenols in the extract, acting as reducing and capping agents, thereby stabilizing the AgNPs. SEM analysis showed pristine silver nanoparticles with diameters ranging from 1 to 10 µm. The biosynthesized AgNPs demonstrated strong photocatalytic activity in degrading Rhodamine B and Congo Red dyes. This method did not use any synthetic reagents, making it an environmentally safe and cost-effective alternative for synthesizing silver nanoparticles. The process aligns with green chemistry principles, offering potential applications in photocatalysis and environmental cleanup. The study underscores the importance of biosynthesized nanoparticles due to their unique biological properties and the role of plant secondary metabolites in facilitating green synthesis.

Role of enzyme replacement therapy for exocrine and nutritional insufficiency in patients with malignancies: A review

Exocrine pancreatic insufficiency (EPI) is a condition in which the amount of secreted pancreatic enzymes is insufficient to maintain normal digestion. EPI is a frequent complication of pancreatic or other malignancies. The presence of EPI in a cancer patient may be suggested by symptoms of maldigestion, malabsorption, and alteration of nutritional markers; however, it is important to note that the EPI symptoms may be subtle. In the early stages, EPI may be latent and manifested by malnutrition. However, even in the later stages, the symptoms of EPI may be similar to those of cancer or be masked by the condition after chemoradiation therapy. Antitumor therapy itself may also cause EPI. Enzyme replacement therapy (ERT) is the standard of care for EPI, but it is rarely prescribed to cancer patients. However, supportive therapy plays an essential role in treating cancer patients because the quality of life and life expectancy of patients largely depend on the adequacy of the complex treatment. The review discusses the possible causes of EPI and its diagnosis and treatment in cancer patients. Special attention is paid to ERT regimens, including those for improving digestion and the drug's dosage form. It is shown that pancreatin in minimicrospheres is the drug of choice for ERT, since the minimum particle size facilitates the most physiological digestion process.

The short-term biological effects of different particle sizes of bioflocs on Litopenaeus vannamei

The short-term biological effects of different particle sizes of bioflocs on Litopenaeus vannamei

Enhancing stability and bioactivity of Chondrus ocellatus polyphenols through nanoparticle fabrication

This article aimed to fabricate Chondrus ocellatus polyphenols (COPs)-gelatin-chitosan nanoparticles to enhance their stability and bioactivity. Different preparation conditions were tested to investigate the effects of formulation on nanoparticle fabrication. Free radical scavenging activity of COPs and their nanoparticles were compared. The consequences revealed that optimal preparation was obtained with a chitosan (CS) concentration of 0.5 mg/mL, gelatin (Gel) concentration of 1.0 mg/mL, COPs concentration of 5.0 mg/mL, and Gel-CS-COPs mass ratio of 2:1:1. The resultant nanoparticles had the particle size of 39.79 ± 5.15 nm and encapsulation efficiency of 60.95 % ± 1.86 %. The COPs-Gel-CS nanoparticles were distributed uniformly, and no obvious aggregation was observed by transmission electron microscopy. Nanoencapsulation of the COPs significantly improved their antioxidative stability. This study provided a potential formulation for the application of Chondrus ocellatus polyphenols in antioxidant activities.

Nanofillers modified with aluminum carboxylate for application in Polymer composite electrolytes for lithium-ion batteries

AbstractOne of the additives that positively influence the parameters of the electrolyte for lithium-ion cells are ceramic nanoparticles, such as SiO2 and α-Al2O3. However, they tend to agglomerate and sediment, which is an unfavorable phenomenon. An effective strategy to prevent this is to modify the surface of the particles with polymeric compounds, which can increase compatibility and stability in the electrolyte system. To reduce agglomeration and sedimentation, a method was developed to modify aluminum oxide and silica particles using aluminum carboxylate, which chemically combines with inorganic particles that have hydroxyl groups on their surface through an alkoxide bond. This method allows the introduction of oligooxyethylene groups to the ceramic surface, thus obtaining more stable systems. The effectiveness of this modification was confirmed through dynamic light scattering (DLS) measurements of particle size in liquid organic solvents, which are potential solvents for liquid electrolytes in lithium-ion cells. The modified nanosilica and aluminum oxide particles were then used as additives to solid polymer electrolytes made of poly(ethylene oxide) (PEO). This led to higher conductivity values compared to the use of unmodified fillers. The obtained values of lithium transference number for solid polymer electrolyte with PEO/CF3SO3Li and nanosilica or aluminum oxide modified with aluminum carboxylate are equal to 0.32–0.40.

Endowing viscose fabric ultraviolet and antibacterial activities using zinc oxide nanoparticles

To enhance the bioactive functionality of viscose fabrics via a new eco-friendly approach; novel green zinc oxide nanoparticles were biosynthesized and incorporated as functional additives in the finishing formulations encompassing citric acid as a green crosslinking agent and sodium hypophosphite as a potential catalyst using pad-dry-cure method. For this purpose, ZnO-NPs were biosynthesized using zinc acetate as a processor and our formerly prepared and fully characterized starch nanoparticles (SNPs) having particle size ranged from 80-100 nm as a green reducing and stabilizing agent for substituting the traditionally used toxic reducing agents. The zeta sizer determined that the ZnO-NPs were approximately tailored at 18-20 nm in size, while the UV-visible spectra revealed highly symmetric single-band absorption with a maximum peak around 382 nm. In contrast, both FTIR and SEM of finished viscose fabric in the presence of ZnO-NPs-III confirm the presence of ZnO-NPs and the formation of agglomerated nanostructures on the fabric surface. The finished fabric had a UPF of 34.07 compared to 4.0 for untreated fabric, and the antibacterial activities had very good bacteriostatic activity against Staphylococcus aureus and Escherichia coli bacteria, compared to zero for untreated fabric. Furthermore, how the finishing bath ingredients interact with the fabric was projected.

Acidified biochar one-off application for saline-alkali soil improvement: A three-year field trial evaluating the persistence of effects

Salinization is a global soil degradation issue threatening agricultural productivity and environmental sustainability. Native biochar is a promising soil amendment, but its high alkalinity limits its use in saline-alkali lands. Acidified biochar, with a lower pH, is theoretically more suitable. This study aims to evaluate the persistence of effects of acidified biochar one-off application on soil particle size distribution, physicochemical properties, water retention, temperature regulation, and evaporation conditions of saline-alkali soil, thereby verifying its feasibility and exploring the optimal application range. We conducted a three-year cotton field experiment using palm fruit branch biochar as the raw material, acidified with ferrous sulfate, which involved four biochar applications (0, 10, 20, and 30 t ha−1) and four irrigation quotas (60 %, 80 %, 100 % and 120 % ETc). The results indicated that the initial acidified biochar application slightly increased surface soil (0–20 cm) pH by 0.1 %–3.9 %, this negative effect was nearly eliminated by the third year. Biochar application significantly altered surface soil particle size distribution, increasing sand content by 1.6 %–8.4 %, and persistently improved soil hydraulic properties, with water holding capacity still showing a 6.5 %–16.7 % increase in the third year. Biochar enhanced soil thermal insulation and suppressed soil evaporation, but these benefits gradually diminished with increasing cultivation years. Acidified biochar effectiveness was closely linked to irrigation quota. Significant differences in soil water and heat indicators were observed between the 20 and 30 t ha⁻¹ biochar treatments only under low irrigation quotas. Under sufficient irrigation (100 % and 120 % ETc), the optimal biochar application range was 15–20 t ha⁻¹, while under low irrigation (60 % and 80 % ETc), the optimal range was 20–25 t ha⁻¹. This study demonstrated that acidified biochar one-off application has significant multi-year benefits in improving soil structure and hydrothermal properties, providing a scientific basis for the improvement and sustainable utilization of saline-alkali soil.

Particle size is an important factor influencing the effects of biochar return to woodland soils: An evaluation from the perspective of sapling growth and soil microbial carbon processes

Biochar can increase ecosystem carbon sequestration by promoting plant growth and stabilizing soil organic carbon (SOC). Biochar produced from forest waste typically varies in particle size and is frequently applied directly for soil enhancement without pulverization. The effects of different biochar particle sizes on sapling growth, woodland soil properties and microbial carbon processes are unclear. This study used field experiments to compare the effects of different biochar particle sizes on sapling growth and microbial metabolic entropy (qCO2). The impacting mechanisms were explored by examining soil physicochemical properties, enzyme activity, and microbial community structure. The application of forest waste (FW) and small particle biochar (SPBC, particle size<2 mm) did not significantly affect sapling growth. Conversely, middle particle biochar (MPBC, particle size 2–10 mm) and large particle biochar (LPBC, particle size>10 mm) reduced sapling biomass by 20.76% and 38.87%, respectively, compared to SPBC. MPBC and LPBC applications resulted in soil nutrient loss (total nitrogen and available phosphorus), inhibiting sapling growth. After 167 days, qCO2 rankings were as follows: FW (30.37 ± 5.18) (P<0.05)> LPBC (20.91 ± 3.62) > CK (16.21 ± 2.71) > MPBC (15.99 ± 3.54) > SPBC (7.8 ± 0.80) (P < 0.05). The rankings of organic carbon retention rates rankings were as follows: SPBC (85.14%) > LPBC (70.35%) > FW (67.31%) > CK (54.53%) > MPBC (51.96%). SPBC increased biochar-soil-microbe interactions, raised the relative proportion of k/r-strategy bacteria, reduced extracellular cellulase activity thus inhibit qCO2. In conclusion, small particle biochar (<2 mm), compared to larger-particle biochar, improves SOC sequestration without negatively affecting sapling growth. Therefore, particle size should be considered as a management indicator for biochar applications in artificial forest practices.

Determination of Particle Size for Optimum Biogas Production from Ouagadougou Municipal Organic Solid Waste

Anaerobic digestion’s contribution to sustainable development is well established. It is a sustainable production process that enables energy to be saved and produced and efficient pollution control processes to be implemented, thereby contributing to the sustainable development of our societies. Optimizing biogas yields from the anaerobic digestion of municipal organic waste is crucial for maximum energy recovery and has become an important topic of interest. Substrate particle size is a key process parameter in biogas production and precedes other pretreatment methods for most organic materials. This study aims to evaluate the impact of particle size and incubation period on biomethane production from municipal solid waste. Sampling of municipal solid waste was carried out in waste pre-collection in the city of Ouagadougou, Burkina Faso. Waste characterization showed lignocellulolytic green waste (grass, dead leaves), waste composed of fruit and leafy vegetables and leftover food waste. TableCurve 3D v4.0 software was used to develop an optimal mathematical model to correlate particle size and biomethane productivity to describe optimal production parameters. Particle sizes ranging from 2000 to 63 µm high biogas production values, specifically 385.33 and 201.25 L·kg−1 of MSV. PCA analysis clearly showed a high correlation between particle size and biogas production, with optimum production recorded for size 250 µm with a biomethane production value of 187.53 L·kg−1 of MSV. The average relative errors and RMSE for CH4 content were improved by 24.31% and 44.97%, respectively. The data calculated with the developed mathematical model and the existing experimental data were compared and permutated to validate the model. This work enabled the identification of a mathematical model that describes the correlations between the input parameters of an experiment and the monitored parameters, as well as the definition of the particle size that allows for the optimal production of biomethane.

Microbiological Characteristics of Beef Sausage Enriched With Roselle (Hibiscus sabdariffa L.) Sepal Extract

ABSTRACTAdding plant extracts to sausage and other meat products is very important to improve their quality, safety, and durability. The aim of this study was to evaluate the microbiological properties of beef sausage enriched with roselle (Hibiscus sabdariffa L.) sepal extract. The total content of phenolic and flavonoid compounds in hydroalcoholic extract of Roselle sepals was measured by Folin‐Ciocalteu test and aluminum chloride colorimetric method, and antioxidant activity was measured by DPPH method. Pectin was used to encapsulate the extract. The characteristics of capsules, including particle size, zeta potential, and capsule efficiency were measured. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of extracts were performed by tube dilution method. Microbial tests were performed on sausage treatment samples. Analysis of the obtained data was done using SPSS and Excel software. The study revealed that the total phenolic and flavonoid compounds in the extract were 174.6 mg of gallic acid per gram and 16.8368 mg of quercetin, respectively. The extract displayed the highest antioxidant activity at elevated concentrations. Particle size ranged from 16.833 to 640.534 μm. The zeta potential and capsule efficiency were found to be satisfactory. Compared to the encapsulated extract, the free roselle extract better inhibited Staphylococcus aureus (s. aureus), Salmonella typhimurium (S. typhimurium), and Escherichia coli (E.coli). During storage until day 20, these bacteria did not grow in the free or encapsulated extract groups. However, S. aureus appeared in the free extract group from day 25 and the encapsulated extract group from day 20. Roselle extract has antimicrobial properties that can improve the quality and safety of beef sausage during storage.

Preparation and Characterization of Ozonated Liposomes Loaded with Curcumin: A Potential Approach for Diabetic Retinopathy Treatment

Background: Limitations in drug penetration are overcome by nanotechnology, particularly liposomes, which enhance targeted administration of ocular medications. Liposomes can augment the therapeutic effects of curcumin, a natural compound with positive impacts on the retina. Treatments for eye diseases can also benefit from the antibacterial properties of ozonated oil liposomes. Objectives: This study aims to develop and evaluate ozonated liposomes loaded with curcumin for ocular drug delivery applications, specifically targeting diabetic retinopathy (DR). Methods: Liposomal nanoparticles were prepared using thin-film hydration, incorporating phospholipids, lecithin, cholesterol, ozonated oil, and curcumin. We assessed physicochemical properties including particle size, zeta potential, encapsulation efficiency (EE), and morphology. Drug release profiles and stability studies were also conducted. Results: The optimized liposomes showed a particle size of 84.77 nm, a zeta potential of -16.8 mV, and an EE of 94.73%. The formulation exhibited sustained curcumin release over 24 hours, reaching 82.09% cumulative release. Stability studies indicated minimal changes in key parameters over three months at room temperature. Conclusions: The developed ozonated liposomal formulation demonstrates promising characteristics for curcumin delivery, potentially enhancing its therapeutic efficacy in ocular applications, particularly for DR.

Preparation and characterization of calcium-doped graphene oxide-chitosan Nanocarrier to enhance the gene delivery in MCF-7 cell line

Gene delivery has emerged as a novel and effective method in the treatment of malignancies within medical interventions by applying nanotechnology. Consequently, the development of appropriate nanocarriers is a key focus of this research. Dynamic light scattering (DLS), fourier transform infrared (FT-IR) spectroscopy, x-ray diffraction (XRD), and thermal gravimetric analysis (TGA) were employed for the characterization of the synthesized nanocarrier. Furthermore, to assess the gene transfer capability of the nanocarrier, various techniques such as gel retardation assay, nuclease resistance assay, cytotoxicity assay, flow cytometry, and transfection were employed. The average particle size and zeta potential of the GO-CS@Ca nanocarrier were obtained as 319.8 nm and + 92.8 mv, respectively. In the gel retardation test, it was observed that pDNA was effectively condensed by the GO-CS@Ca nanocarrier. The results of the MTT assay indicated that both GO-CS@Ca nanocarrier and the GO-CS@Ca/pDNA nanoplex with low toxicity. In flow cytometry analysis, it was observed that the complexation of pDNA with the GO-CS@Ca nanocarrier resulted in effective gene delivery to the MCF-7 cell line and consequently increased apoptosis induction.

Preparation of Diisooctyl Phosphate‐Modified Ultra‐Small Zinc Oxide Nanoparticle and Investigation of Its Tribological Properties as Additive in Alkylnaphthalene

ABSTRACTZnO nanoparticle surface‐modified by diisooctyl phosphate (P204) was prepared by liquid‐phase in situ surface modification technique with zinc acetate as the raw material, P204 as the modifier and anhydrous ethanol as the solvent. The morphology and microstructure of the P204‐ZnO nanoparticle were characterised by transmission electron microscopy, X‐ray diffraction and Fourier transform infrared spectrometry. Its thermal stability was evaluated by thermogravimetric analysis; and its tribological properties as the additive in alkylnaphthalene were evaluated with an SRV‐5 friction and wear tester in reciprocal sliding mode. The results show that the as‐prepared P204‐ZnO nanoparticle has an average particle size of about 4 nm and a P204 content of about 42% (mass fraction); and the surface modifier is grafted onto the surface of ZnO nanoparticle by physical adsorption. With a mass fraction of 0.5% in alkylnaphthalene base oil, P204‐ZnO nano‐additive can mildly reduce the friction coefficient and drastically reduce the wear rate of the steel–steel sliding pair. This is due to the formation of the composite tribofilm via the adsorption and deposition of the nano‐additive on rubbed steel surfaces as well as the tribochemical reactions of the modifier P204 yielding phosphate and of steel substrate yielding iron oxides. The as‐formed composite tribofilm with a thickness of about 20 nm, consisting of phosphate and iron oxides as the binder as well as deposited ZnO nanoparticle as the filling phase, is responsible for the excellent friction‐reducing and antiwear abilities of P204‐ZnO nano‐additive for the steel sliding contact.