Zeta Potentiometer Research Articles

Preparation of high oil absorption microfiber cryogels by mechanical method

Poplar alkaline peroxide mechanical pulp (APMP) was used as plant fiber raw material, and it was graded according to the lignin content. The graded raw materials were used to prepare lignin-containing microfibers (LCMFs) by micro-grinding, and then, the lignin-containing microfiber cryogels (LCMF-cryogels) were prepared by vacuum freeze-drying. The particle size distribution, micromorphology and dispersion stability of LCMFs were characterized by laser diffraction particle size analyzer, transmission electron microscopy and Zeta potentiometer. Then, the crystalline structure, pore structure, surface morphology and adsorption properties of LCMF-cryogels were analyzed. In addition, LCMF-cryogels were compared with the microfiber cryogels (MF-cryogels) which use commercial eucalyptus chemical bleaching pulp as raw material. It was proved that using poplar APMP as raw material to prepare cryogels is more advantageous. The results showed that the lower the lignin content in plant materials, the better the oil adsorption ability of cryogels. This is because the binding effect of lignin on the fiber is reduced, which makes the fibrillation of the fiber easier by external mechanical action. The maximum adsorption capacity of LCMF-cryogel for methyl silicone oil is 215 g/g, while that of MF-cryogel prepared from commercial eucalyptus chemical bleaching pulp is 102.5 g/g. The analysis of the properties of raw fiber and the gel pores shows that the change in the fiber morphology caused by different pulping methods has important influence on the development of LCMF-cryogels by mechanical refining. Poplar APMP is more suitable for preparing fiber-based cryogels oil-absorbing materials than commercial eucalyptus chemical bleaching pulp.

Study on the demulsification of refinery oily sludge enhanced by microwave irradiation

Demulsification is usually a necessary step for the treatment of oily sludge, which is also an important and urgent task in the petroleum industry. Since the inefficient and difficult demulsification for the refinery oily sludge by traditional methods, a new method using microwave irradiation to strengthen the demulsification efficiency was proposed in this work. A series of demulsification runs were carried out to investigate the effects of microwave heating temperature and power, upon the droplet-size distribution and the total demulsification efficiency of oily sludge. The demulsification process of the oily sludge heated by microwave irradiation and water bath were compared in terms of demulsification efficiency, demulsification temperature, demulsification time and centrifugal speed. At the same time, characterization tests were performed by viscometer, DSC analyzer, Zeta potentiometer, etc. Results showed that the demulsification temperature of the oily sludge should be kept below 77 °C. The demulsification efficiency of oily sludge increased first and then decreased with the increase of microwave heating temperature and power, which reached maximum (67.4%) at 55 °C, with the microwave power of 700 W. Compared with conventional heating (55 °C), the demulsification efficiency of oily sludge increased by 25.3% under microwave irradiation (700 W, 55 °C). Besides, microwave irradiation can simultaneously reduce the demulsification temperature (>40 °C), the demulsification time (>95%), and the centrifugal speed (~36.7%), which proves that microwave demulsification is a rapid, high-efficiency, low consumption demulsification method.

Preparation of Nano-spherical Iron Phosphate by Hydrothermal Method and Its Application as the Precursor of Lithium Iron Phosphate

Abstract First, nano-spherical iron phosphate was prepared using the hydrothermal method. Then, the carbothermal reduction method was applied to synthesize the LiFePO4/C composite material capable of good carbon coating effect with the prepared nano-spherical iron phosphate as a precursor. By means of scanning electron microscope, transmission electron microscope, Zeta potentiometer, inductively coupled plasma spectrometer, X-ray diffraction, X-ray photoelectron spectroscopy, electrochemical testing, and other methods, the material was characterized and tested for its morphology, particle size, composition, structure, and electrochemical performance. According to the test results, when the initial mass concentration of Fe3+ in the reaction solution is 2%, the amount of N and S impurity is merely 19 and 27 ppm, respectively. In the meantime, particle size is small, with a range of roughly 50–100 nm, and a spherical morphology is shown. The synthesized LiFePO4/C retains its nano-spherical morphology, which leads to a desirable carbon coating effect and an excellent electrochemical performance. The first charge–discharge specific capacity at 0.1 C rate reached 163.7 and 161.4 mAh/g, the charge–discharge efficiency was 98.6%, and the capacity retention rate at 50 charge–discharge cycles at 1 C rate reached 98.52%.

Surface Potential/Charge Sensing Techniques and Applications.

Surface potential and surface charge sensing techniques have attracted a wide range of research interest in recent decades. With the development and optimization of detection technologies, especially nanosensors, new mechanisms and techniques are emerging. This review discusses various surface potential sensing techniques, including Kelvin probe force microscopy and chemical field-effect transistor sensors for surface potential sensing, nanopore sensors for surface charge sensing, zeta potentiometer and optical detection technologies for zeta potential detection, for applications in material property, metal ion and molecule studies. The mechanisms and optimization methods for each method are discussed and summarized, with the aim of providing a comprehensive overview of different techniques and experimental guidance for applications in surface potential-based detection.

Property Improvement of Cement Emulsified Asphalt Paste Modified by Graphene Oxide

Cement emulsified asphalt paste (CEAP) is widely used as a construction and building material by combining the advantages of cement rigidity and asphalt flexibility. However, the properties of CEAP can be evidently reduced due to the addition of emulsified asphalt. In this work, graphene oxide (GO) was prepared by the Hummers method and was innovatively used to improve the workability and strength of CEAP. The viscosity of CEAP was tested by Brookfield viscometer. In addition, the effects of GO on the setting time of CEAP were studied. The adsorption between cement and asphalt with GO was tested through an ultraviolet‐visible spectrophotometer and the stability of CEAP was tested by zeta potentiometer. The effects of GO on the strength of CEAP were studied. The reinforcement effects of GO on CEAP were analyzed. The results show that the viscosity of CEAP and cement hydration products can increase after adding a reasonable dosage of GO to CEAP. The setting time of CEAP first decreases and then increases with the increase of GO dosage. The adsorption and viscosity of cement and asphalt increase with the increase of GO dosage. GO can reduce CEAP stability and make the paste easier to agglomerate. The flexural strength and the compressive strength of CEAP at 28 curing days first increase and then decrease with the increase of GO dosage, but excessive GO can hinder cement hydration. The reasonable dosage of GO in CEAP can be determined as 0.06% in asphalt weight.

Assessing the Dispersion Quality of Carbon Nanotubes Suspensions by Low Field Nuclear Magnetic Resonance

In this study, a novel method based on low field nuclear magnetic resonance measurements were used to characterize the dispersion quality of carbon nanotube suspensions. The liquid specific surface area, which calculated with the relaxation time, were used as an indicator of dispersion quality of the carbon nanotubes suspensions. The experimental results were compared with those measured by the conventional method methods, including Zeta potentiometer method and ultraviolet visible spectrophotometer method. The results show that low field nuclear magnetic resonance has the advantages in the characterizing the dispersion quality of high concentration carbon nanotube suspensions and tracking its re-agglomeration process non-destructively.

An investigation on surface modified TiO2 incorporated with graphene oxide for dye-sensitized solar cell

In the present study, titanium dioxide (TiO2) nanoparticles were amine functionalized by using (3-aminopropyl)triethoxysilane (APTES) for the incorporation with graphene oxide (GO) to resolve the rapid agglomeration of nanoparticles. The zeta potentiometer revealed a significant increment of surface charge from 8.31 mV (untreated) to 34.5 mV (treated) for the TiO2 nanoparticles which promotes strong electrostatic attraction with GO. Electrophoretic deposition technique was then employed for the fabrication of the photoanodes by generating an electric field for the transportation of the composite material. This work aimed to find the optimum loading content of GO-TiO2 for a higher photoconversion efficiency of the dye-sensitized solar cell (DSSC). Among the samples, the sample loaded with 0.5 g TiO2 showed the lowest emission peak intensity (Raman PL) which indicates efficient trapping of photogenerated electrons. By applying the Kubelka-Munk (K-M) expression, the absorbance spectra were converted into Tauc plots through which the aforementioned sample was found to exhibit a band gap energy of 2.91 eV (suitable for light absorption in the visible light region). The electron transfer efficiency for the sample loaded with 0.5 g TiO2 was relatively higher than the other samples in the DSSCs yielding a photoconversion efficiency of 6.86% because of the effective reduction in electron recombination.

Ultrasensitive and ultrawide range electrochemical determination of bisphenol A based on PtPd bimetallic nanoparticles and cationic pillar[5]arene decorated graphene

This study proposed an ultrasensitive and ultrawide range electrochemical sensing platform based on PtPd bimetallic nanoparticles (PtPd NPs) and cationic pillar [5]arene (CP5) decorated graphene for bisphenol A (BPA). CP5-decorated reduced graphene oxide (RGO) (CP5@RGO) was synthesized via a reported assay. PtPd NPs-loaded CP5@RGO nanocomposites (PtPd-CP5@RGO) were then prepared through a simple approach at room temperature. The as prepared materials were characterized by various technologies, including EDX, FT-IR, XRD, TG analysis, XPS, zeta potentiometer, TEM, and AFM. The current response of PtPd-CP5@RGO modified glassy carbon electrode (GCE) to BPA oxidation was higher than that of Pt NPs-, Pd NPs-, or CP5-modified GCE. An electrochemical sensor based on PtPd-CP5@RGO-modified GCE was utilized to determine BPA through differential pulse voltammetry. The sensor yielded the wider linear ranges of 0.01–50 μM and 50–1000 μM, respectively, with a lower limit of detection of 3.3 nM (S/N = 3) for BPA determination. The constructed sensor showed some advantages, such as satisfactory reproducibility, good stability, and excellent selectivity, which was applied to determine BPA concentration in real samples. BPA and CP5 likely formed a stable complex mainly via supramolecular interactions, such as electrostatic and hydrophobic interaction.

Study on the properties of the Sb2O3 nanoparticles modified by different surfactants

In order to enhance the interface adhesion between polymer matrix and Sb2O3 nanoparticles, the surface of Sb2O3 nanoparticles was modified via the mechanochemical method and using different surfactants including stearic acid, coupling agent of organic titanate (NDZ-201) and silane coupling agent KH-560. The dispersibility, hydrophobicity, microstructures, particle size distributions, thermal stability and surface potential of the modified and unmodified Sb2O3 nanoparticles were characterized by transmission electron microscopy (TEM), surface contact angle measurement, x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analyzer, laser particle size analyzer and zeta potentiometer, respectively. The results show that the surface chemistry of the nanoparticles was grafted from hydroxyl groups to alkyl groups by reacting different surfactants with Sb2O3 nanoparticles and physical coating. Stearic acid can be effectively coated on the surface of Sb2O3 nanoparticles. Besides, the modified Sb2O3 nanoparticles have the better dispersibility than the unmodified Sb2O3 nanoparticles in octane due to the fact that the steric hindrance of modifier between nanoparticles prevents aggregation. The mean particle size of the modified Sb2O3 nanoparticles is smaller than that of the unmodified Sb2O3 nanoparticles. The mean particle size of Sb2O3 nanoparticles modified by 3 wt% KH-560 is 57 nm as a result of steric hindrance and lower surface potential. Furthermore, the water contact angle of Sb2O3 nanoparticles modified by 5 wt% stearic acid reached to 114°.

Highly efficient removal of nickel and cadmium from water using sawdust-derived cellulose nanocrystals

Bioresources are renewable raw materials which can be utilised for multiple purposes including the development of various materials for water treatment. In this study, cellulose nanocrystals (CNC) derived from sawdust was modified and utilised as coagulants for the removal of Ni2+ and Cd2+ ions from water. The modified CNC was characterized using Fourier transform infra-red, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and zeta potentiometer. Analyses revealed that the modified CNC is porous and exhibited narrow particle size distribution and needle-like morphology. The functional group responsible for the coordination and removal of the metals was mainly carboxylate anion (COO2−). Zeta potential measurement showed a reduction in negative surface charge value of modified CNC. The effects of solution pH, CNC coagulant dosage and initial metal concentration were investigated using jar test experiment. Results revealed that the removal of metal ions increased with an increase in the coagulant dosage and solution pH, and that the best pH for the investigation was pH 7.10. Metal removal efficiency, however, reduced with an increase in the initial concentration of the metal ions. Experimental uptake values of 956.6 mg Ni/g and 2207 mg Cd/g were obtained, which in comparison with uptake values of other cellulosic materials gives indication that CNC derived from sawdust is highly competitive material for the amelioration of water containing metals.

Extending Viability of Bifidobacterium longum in Chitosan-Coated Alginate Microcapsules Using Emulsification and Internal Gelation Encapsulation Technology.

Bifidobacteria are considered one of the most important intestinal probiotics because of their significant health impact. However, this ability is usually limited by gastrointestinal fluid and temperature sensitivity. Emulsification and internal gelation is an encapsulation technique with great potential for probiotic protection during storage and the gastrointestinal transit process. This study prepared microcapsules using an emulsification and internal gelation encapsulation method with sodium alginate, chitosan, and Bifidobacterium longum as wall material, coating material, and experimental strain, respectively. Optical, scanning electron, and focal microscopes were used to observe the microcapsule surface morphology and internal viable cell distribution, and a laser particle size analyzer and zeta potentiometer were used to evaluate the chitosan-coating characteristics. In addition, microcapsule probiotic viability after storage, heat treatment, and simulated gastrointestinal fluid treatment were examined. Alginate microcapsules and chitosan-coated alginate microcapsules both had balling properties and uniform bacterial distribution. The latter kept its balling properties after freeze-drying, verified by scanning electronic microscopy (SEM), and had a clear external coating, observed by an optical microscope. The particle size of chitosan-coated alginate microcapsules was slightly larger than the uncoated microcapsules. The zeta potential of alginate and chitosan-coated alginate microcapsules was negative and positive, respectively. Heat, acid and bile salt tolerance, and stability tests revealed that the decrease of viable cells in the chitosan-coated alginate microcapsule group was significantly lower than that in uncoated microcapsules. These experimental results indicate that the chitosan-coated alginate microcapsules protect B. longum from gastrointestinal fluid and high-temperature conditions.

Surface modification of Sb2O3 nanoparticles with dioctylphthalate

Dioctylphthalate (DOP) was used as the surface modifier to modify the surface of Sb2O3 nanoparticles by mechanical ball milling in this paper. The surface properties of Sb2O3 nanoparticles were characterized by XRD, Fourier transform infrared spectroscopy (FT-IR), surface contact angle measuring instrument, Zeta potentiometer and transmission electron microscope (TEM). The surface structure of Sb2O3 nanoparticles and the adsorption mode of DOP were studied, and the effects of different mass fraction of DOP on the dispersion and stability of Sb2O3 nanoparticles were analyzed. The results show that DOP can successfully coat on the surface of Sb2O3 nanoparticle by using mechanochemical method and significantly improve the dispersion of the modified Sb2O3 nanoparticles. With increasing of the mass fraction of DOP, the dispersion of Sb2O3 nanoparticles was gradually improved. When the mass fraction of DOP was 7 wt%, the average particle size of Sb2O3 nanoparticles was the smallest, and was 48 nm. However, with the increase of the mass fraction of DOP, the absolute Zeta potential of Sb2O3 nanoparticles gradually decreased and then tended to be stable finally.

Effect of Ca2+ on viscosity and microstructure of water‐soluble triblock terpolymer used as thicker in the hydraulic fracturing

ABSTRACTCa2+ tolerance of water‐soluble polyacrylamide is a key problem in application fields. It is urgent to make the mechanism of between the polyacrylamide and Ca2+ clear. A terpolymer polyacrylamides including the sulfonate group with different monomer concentrations is synthesized. The effect of the CaCl2 concentration on the rheological properties is measured by a rheological rheometer. The zeta potential of the copolymer solution is obtained by a zeta potentiometer to learn about the electrical characteristics of the copolymers in solution. The microcosmic shape of the copolymer aqueous solution is investigated by a laser particle analyzer and an environmental scanning electron microscope. The results show that more sulfonate groups on the molecule can enhance the salt tolerance of the polyacrylamide. Sulfonate groups can weaken the effect of Ca2+ on the copolymer through the formation of complexes, whereas the self‐aggregation process of the copolymer cannot be stopped at high Ca2+ concentrations. This study provides theoretical guidance to elucidate the influencing rules and mechanism of calcium salt on the polyacrylamide containing a sulfonate group, which can be helpful for polyacrylamide modification and can improve the application of polyacrylamide under the condition of higher salt concentration. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47539.

Eco-friendly synthesis of gold nanoparticles using fruit extracts and in vitro anticancer studies

Gold nanoparticles are biocompatible and are having several applications in biomedical Sciences and Engineering. Integration of nanoscience in medicine leads to the development of biomedical products that helps the Society in a faster and safer manner. In the present research work, bioreduction and biofunctionalization of gold nanoparticles are performed with fruit extracts of Aegle marmelos, Eugenia jambolana and soursop. The nanoparticles are characterized using UV–Vis spectroscopy, Transmission Electron Microscopy, Fourier Transform Infrared Spectroscopy and Zeta potentiometer. The qualitative phytochemical analysis of the fruit extracts shows the presence of alkaloids, amino acid, flavonoids, phenol, proteins, tannin, reducing sugars and total Sugars. The in vitro anticancer activity was confirmed by MTT assay on the human breast cancer cell line MCF-7 at different concentrations. The flavonoids present in the fruit extracts are potential reducing agent which is responsible for the formation of gold nanoparticles. Stabilization of gold nanoparticles are performed by the carboxylate group present in the proteins. Also, the nanoparticles are held apart from each other by the electrostatic repulsions that exist due to the presence of like charges surrounding the gold nanoparticles. This study proves that the fruit extracts can be used for the synthesis and stabilization of gold nanoparticles. Further, the engineered nanoparticles capped with bioactive compounds are potential anticancer agents against breast cancer cell line MCF-7.

PSB0739 inhibits formation of semen-derived amyloid fibril

To explore the inhibitory effect of PSB0739 on the formation of semen-derived amyloid fibrils. PAP248-286 (440 μmol/L) was incubated with PSB0739 at different concentrations, and at different time points of incubation, aliquots were taken from each sample for Congo red staining to detect the formation of amyloid fibers. The morphology of amyloid fibrils incubated in the presence or absence of PSB0739 was visualized using transmission electron microscope. The effect of PSB0739 on amyloid fibril formation was determined using virus infection assays at different time points, and the surface charges of amyloid fibril incubated with PSB0739 were calculated using a Zeta potentiometer. The cytotoxicity of PSB0739 in Hela cells was determined using MTT assay. The antiviral effect of PSB0738 against HIV- 1 was evaluated by infection assay. PSB0739 inhibited SEVI fibril formation in a dose-dependent manner in vitro. At 48 h of incubation, 220 μmol/L of PSB0739 obviously inhibited the formation of amyloid fibrils in 440 μmol/L of SEVI. Transmission electron microscopy revealed that 220 μmol/L PSB0739 prevented PAP248- 286 (440 μmol/L) from forming amyloid fibrils. PSB0739 antagonized SEVI-mediated enhancement of HIV-1 infection, and 1760 μmol/L of PSB0739 completely reversed the positive charge of SEVI (P < 0.05). PSB0739 below the concentration of 62.5 μmol/L showed no obvious cytotoxicity in Hela cells in vitro (P>0.05). PSB0739 showed a direct anti-HIV activity with an IC50 of 21.77±5.15 μmol/L. PSB0739 can inhibit the formation of semen-derived amyloid fibrils in vitro.

Enhanced performance of polyvinylidene fluoride ultrafiltration membranes by incorporating TiO2/graphene oxide

Aiming to enhance the water flux and anti-fouling performance of poly(vinylidene fluoride) (PVDF) ultrafiltration membranes, TiO2–GO/PVDF membranes were first fabricated via blending and immersion precipitation phase inversion. Following that, TiO2–GO nanocomposites grafted with different polyethylene glycol (PEG) were employed as the additives to prepare the novel PVDF hybrid membranes. FTIR spectroscope, SEM, zeta potentiometer, and static contact angle analyzer were employed to characterize the structure and surface properties of the hybrid membranes. Ultrafiltration was used to evaluate the membrane performance. Results showed that the interaction between GO and TiO2 led to the good distribution of TiO2–GO in the polymeric membrane, which increased the polarity and porosity of the hybrid membranes, thus increasing their water flux and anti-fouling performance. The maximum flux of hybrid membranes was four times that of the neat PVDF membrane. The PEG grafted on the TiO2–GO nanocomposites did not only act as a pore-forming additive, but also improved the hydrophilicity and porosity of the hybrid membrane due to the enhancement on the distribution and surface polarity of TiO2–GO. Therefore, both the flux and anti-fouling performance of PVDF membranes containing PEG-modified TiO2–GO were significantly higher than those of membranes including unmodified TiO2–GO.

Sustainable carbon microtube derived from cotton waste for environmental applications

Given its natural state and cost-effectiveness, cotton can be an ideal material for the fabrication of high performance catalyst and pollutant removal from the environment. In this study, novel carbon microtube derived from cotton waste were successfully prepared by thermal treatment of cotton in an argon atmosphere and used as a tannic acid sorbent. Carbon microtube (CMT) properties were investigated by electron microscopy (SEM, TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), zeta potentiometer and N2 adsorption − desorption. The most stable solutions in water were established using CMT treated at 900 and 1300 °C and in tannic acid (TA) at 1100 and 1300 °C, respectively. Maximum TA sorption capacity, 596.5 mg g−1, was found for CMT treated at 1100 °C. The suitability of Langmuir model with simultaneously good fitting of other tested models of sorption implied that monolayer sorption was the first step of TA sorption onto CMT via π–π interactions and hydrogen bonds. Given the repeatability, high removal performance and cost effectiveness of the cotton based carbon microtubes when compared to other well-known sorbent such as carbon nanotubes, the carbon microtubes demonstrated great potential as low-cost and effective tannic acid (and dissolved organic matter) adsorbent.

Adsorption Characteristics of Anionic Surfactant Sodium Dodecylbenzene Sulfonate on the Surface of Montmorillonite Minerals.

The adsorption characteristics of sodium dodecylbenzene sulfonate (SDBS) on the surface of montmorillonite can lay a foundation for obtaining the optimum concentration of the anionic surfactant. The best absorption wavelength of SDBS was determined using an ultraviolet spectrophotometer. The standard curves of concentration and absorbance of SDBS were established. The amount of SDBS adsorbed on the surface of montmorillonite at various concentrations was calculated by stirring adsorption method. Scanning electron microscopy–energy dispersive X-ray spectrometry (SEM-EDS), X-ray diffraction (XRD), zeta potentiometer, and Fourier transform infrared (FTIR) spectroscopy were used to observe the changes of the structure, main ions, interlayer spacing, potential, and main functional groups on the montmorillonite surface before, and after, adsorption. The test results of SEM with EDS (SEM–EDS) showed that the surface of the montmorillonite after SDBS adsorption was rougher, and the adsorption capacity of the surface was enhanced as the SDBS concentration increased. The XRD results indicated that SDBS adsorbed on the interlayer of montmorillonite repulsed interlayer water and reduced the interlayer water content. With the increase of SDBS concentration, the interlayer spacing of the montmorillonite available for adsorbing SDBS decreased further. Additionally, interlayer adsorption and surface adsorption exist simultaneously in montmorillonite in SDBS solution. The distribution of total adsorption capacity of SDBS in the layers and on the surface of montmorillonite accords with the adsorption result simulated by a pseudo-second-order kinetic model. The increase in concentration of SDBS adsorbed by montmorillonite is the main reason for the decreased initial adsorption rate. The zeta potential test showed that the addition of H+ to the SDBS solution could reduce electrostatic repulsion and promote the adsorption of SDBS on montmorillonite. The results of this study provide an experimental basis for the study of the mechanism of SDBS adsorption on montmorillonite.

Cholesterol and vitamin E-conjugated PEGylated polymeric micelles for efficient delivery and enhanced anticancer activity of curcumin: evaluation in 2D monolayers and 3D spheroids

A newly synthesized PEGylated cholesterol/α-tocopheryl succinate (α-TOS) linked polymer (CV) was self-assembled and loaded with curcumin to form a micellar system (C-CVM). The tri-functionalized amphiphilic polymer was constituted of hydrophobic cholesterol and α-TOS connected to hydrophilic PEG via a lysine linker. The synthesized polymer and the micelles were characterized by 1H NMR, DLS, zeta potentiometer, TEM, CMC determination and hemolysis studies. CVM displayed low CMC value of 15 µM with extent of hemolysis as less than 4%. The stable C-CVM with optimum % drug loading (14.2 ± 0.24) displayed Z average of 175.8 ± 0.68 nm with PDI (0.248 ± 0.075) and released curcumin in sustained manner in the in vitro drug release study. C-CVM demonstrated dose-dependent cellular uptake and cytotoxicity in murine melanoma, B16F10 and human breast cancer, MDA-MB-231 cell lines. CV exhibited marked reversal of drug resistance as indicated by significantly higher retention of P-glycoprotein substrate, rhodamine-123 in the resistant B16F10 cell line compared to standard P-glycoprotein inhibitor, verapamil. C-CVM demonstrated significantly higher spheroidal growth inhibition compared to C-PPM. The results provide strong evidence for CVM as promising drug delivery system and confirm the potential of C-CVM as chemotherapy in cancer.

Green synthesis and characterization of silver nanoparticles by Allium cepa L. to produce silver nano‐coated fabric and their antimicrobial evaluation

This research work was proposed to study the antimicrobial activity of the silver nanocoated fabric with the purpose of producing good dressing and clothing material. We synthesized simple, ecofriendly, cost‐effective and sustainable silver nanoparticles by using the aqueous extract of Allium cepa L. Here, A. cepa L. acts as a good reducing and capping agent that produced stable silver nanoparticles having particle size of range 36 ± 1 to 98 ± 2 nm, Poly dispersiblity index 0.234 ± 0.61 to 1.023 ± 0.33 and Zeta potential ‐12 ± 1.5 mV to ‐26 ± 1.2 mV. The effect of temperature and extract volume used was considered for optimization of synthetic procedure. The nanocoated fabric was characterized for morphological study, size (using transmission electron microscopy (TEM) and field emission scanning electron microscopy (FE‐SEM) and zeta‐potential (Zeta Potentiometer). The presence of functional groups were observed by using attenuated total reflection‐Fourier transform infrared (ATR‐FTIR) and Raman spectroscopy. The crystallinity and structural property of the synthesized silver nanoparticles were studied in terms of Powder X‐ray diffraction (PXRD). An IC50 value and zone of inhibition was studied which demonstrate that the silver nanocoated fabric have an excellent antibacterial property against Gram‐negative (Escherichia coli) and Gram‐positive (Staphylococcus aureus) bacteria. Further nanocoated fabric material was washed (with function of time 0, 10, 25, and 50 laundry cycles) and still retained their anti‐bacterial activity towards both strain. Initially there was 52 μg/ml of silver nanoparticles on the cotton fabric but after 50 laundry cycle in 500 ml of distilled water the fabric showed 92% efficiency against gram positive and 90% efficacy toward gram negative bacteria. It was found that 4.16 μg/ml nano particles leached in case of S. Aureus and 5.2 μg/mL silver nanoparticles leached in case of E. coli. Nanocoated fabric material synthesized using green synthesis was found to be economical with good resistance to washing.