Zeta Potentiometer Research Articles

Nano‐Calcium Carbonate with Core–Shell Structure was Prepared by Dopamine Chelation Using Pluronic F‐127 as Template

AbstractHerein, a new template carbonization method is used to prepare calcite‐type nano‐calcium carbonate (CaCO3) with a core–shell structure using calcium hydroxide as a solute and Pluronic F‐127 as a templating and pore‐forming agent. Dopamine hydrochloride is added to control the size of calcium hydroxide particles. The morphology, particle size, and crystal type of CaCO3 are characterized via transmission electron microscopy, X‐ray diffraction, nanoparticle size, and zeta potentiometer. The creation of core–shell calcium carbonate nanoparticles is examined in relation to reaction circumstances (i.e., additive sequence, additive amount, and additive mixing time), carbonization temperature, liquid flow rate, and templates with varying chain lengths. Furthermore, a discussion is held regarding the formation mechanism of spherical core–shell calcium carbonate that is created using the innovative template carbonization method. The results show that the order, amount, liquid flow rate, and template type of additives have a significant effect on the crystal shape of calcium carbonate nanoparticles. The mixing time of additives has a significant effect on the particle size of calcium carbonate nanoparticles. Interestingly, the thickness of the shell depends on the carbonization temperature, and too slow or too fast flow rate will lead to the formation of cyclic calcium carbonate nanoparticles.

Efficacy and Mechanism of Tetracycline Adsorption by Boron-doped Mesoporous Carbon

Using coconut shell and boric acid as raw materials， a new boron-doped coconut shell mesoporous carbon material （B-CSC） was prepared using a simple one-step pyrolysis method for efficient adsorption and removal of tetracycline pollutants in water. The effects of pyrolysis temperature and boron-carbon mass ratio on the adsorption performance under key preparation conditions were systematically studied， and their microstructure and physicochemical properties were characterized using a specific surface area and pore size analyzer （BET）， field emission scanning electron microscopy （SEM）， X-ray photon spectroscopy （XPS）， Raman spectrometer （Raman）， and Zeta potentiometer （Zeta）. The effects of initial pH， different metal cations， and different background water quality conditions on the adsorption effect were systematically investigated. Combined with material characterization and correlation analysis， the enhanced adsorption mechanism was discussed and analyzed in depth. The results showed that one-step pyrolysis could incorporate boron into the surface and crystal lattice of coconut shell charcoal， resulting in a larger specific surface area and pore volume， and the main forms of boron introduced were H3BO3， B2O3， B， and B4C. The adsorption capacity of B-CSC to tetracycline reached 297.65 mg·g-1， which was 8.9 times that of the original coconut shell mesoporous carbon （CSC）. At the same time， the adsorption capacity of B-CSC for rhodamine B （RhB）， bisphenol A（BPA）， and methylene blue （MB）， common pollutants in aquatic environments， was as high as 372.65， 255.24， and 147.82 mg·g-1， respectively. The adsorption process of B-CSC to tetracycline was dominated by physicochemical interaction， mainly involving liquid film diffusion， surface adsorption， mesoporous and microporous diffusion， and active site adsorption， and H3BO3 was the main adsorption site. The adsorption strengthening mechanism mainly reduced the chemical inertness of the carbon network and enhanced its π-π interaction and hydrogen bonding with tetracycline molecules.

Targeted cytotoxicity against MDA-MB- 231 triple-negative breast cancer cells with Borassus flabellifer haustorium-derived silver nanoparticles: An integrated in silico and experimental approach

TNBC, Triple-negative breast cancer is a challenging threat, particularly affecting young women who continue to lack effective treatments. In spite of missing typical surface receptors like ER, PR, and HER2, recent research hints at the possible emergence of hormonal receptors ER, EGFR, and CD44 in TNBC cells. Exploiting this insight, Borassus flabellifer haustorium-derived phytocompounds were screened in silico, revealing efficient targeting of hormonal receptors. Subsequent in-vitro work employed, silver nanoparticles synthesized from Borassus flabellifer haustorium (BFHNPs), characterized through UV–Vis Spectrophotometer, FTIR, DLS, and Zeta Potentiometer. These nanoparticles exhibited cytotoxicity against MDA-MB- 231 cell lines, presenting a promising therapeutic avenue for TNBC, potentially addressing its aggressive nature and unmet medical need.

Cell-wall based aerogels for Ce (III) adsorption from leaching tailings: Properties and mechanistic research

Efficient separation of rare earth elements (REEs) from leaching tailings is necessary for environmental protection and full utilization of resources. Cell walls are rich in various active groups that can efficiently adsorb REEs. In this work, a series of composite aerogels based on pectin and cellulose (the key active components in cell walls) were fabricated for effective adsorption of Ce (III) from leaching tailings. Physical and chemical properties of composite aerogels were characterized by Scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), contact angle measuring, and a zeta potentiometer. Adsorption capacity was measured under different conditions. Adsorption corresponded to the Langmuir model and the maximum adsorption capacity of Ce (III) was 337.36 mg/g. Kinetic fitting showed that the adsorption process corresponds to the second-order kinetic model. Composite aerogels have excellent regeneration performance. The adsorption process occurred by electrostatic interaction, ion exchange with –COO−, and chelation with C-NH2. Adsorption in a sample of leaching tailings showed that the adsorption efficiency of composite aerogels for Ce (III) and Eu (III) reached 68% and 81%, respectively, demonstrating good practicability.

Targeted Anticancer Drug Delivery Using Chitosan, Carbon Quantum Dots, and Aptamers to Deliver Ganoderic Acid and 5-Fluorouracil.

Breast cancer is a malignancy that affects mostly females and is among the most lethal types of cancer. The ligand-functionalized nanoparticles used in the nano-drug delivery system offer enormous potential for cancer treatments. This work devised a promising approach to increase drug loading efficacy and produce sustained release of 5-fluorouracil (5-FU) and Ganoderic acid (GA) as model drugs for breast cancer. Chitosan, aptamer, and carbon quantum dot (CS/Apt/COQ) hydrogels were initially synthesized as a pH-sensitive and biocompatible delivery system. Then, CS/Apt/COQ NPs loaded with 5-FU-GA were made using the W/O/W emulsification method. FT-IR, XRD, DLS, zeta potentiometer, and SEM were used to analyze NP's chemical structure, particle size, and shape. Cell viability was measured using MTT assays in vitro using the MCF-7 cell lines. Real-time PCR measured cell apoptotic gene expression. XRD and FT-IR investigations validated nanocarrier production and revealed their crystalline structure and molecular interactions. DLS showed that nanocarriers include NPs with an average size of 250.6 nm and PDI of 0.057. SEM showed their spherical form, and zeta potential studies showed an average surface charge of +37.8 mV. pH 5.4 had a highly effective and prolonged drug release profile, releasing virtually all 5-FU and GA in 48 h. Entrapment efficiency percentages for 5-FU and GA were 84.7±5.2 and 80.2 %±2.3, respectively. The 5-FU-GA-CS-CQD-Apt group induced the highest cell death, with just 57.9 % of the MCF-7 cells surviving following treatment. 5-FU and GA in CS-CQD-Apt enhanced apoptotic induction by flow cytometry. 5-FU-GA-CS-CQD-Apt also elevated Caspase 9 and downregulated Bcl2. Accordingly, the produced NPs may serve as pH-sensitive nano vehicles for the controlled release of 5-FU and GA in treating breast cancer.

Preparation and properties of functional emulsion based on bio‐macromolecules self‐assembled colloidal particles

AbstractBio‐macromolecules alginic acid (ALG), lysozyme (Lys) and calcium ion can self‐assemble to prepare ALG/Ca2+/Lys colloidal particles by electrostatic interaction. The size and morphology of the colloidal particles were characterized by BI‐90PIus Zeta potentiometer and scanning electron microscope. The results showed that the formed colloidal particles have a spherical structure with a particle size of 480 nm. The colloidal particles can be reassembled at the oil (containing fat‐soluble vitamin D3)‐water interface to stabilize oil‐in‐water functional Pickering emulsions. The effects of pH values and salt concentrations on the properties and emulsifying properties of colloidal particles were investigated in detail. The sustained release properties of the emulsion to Ca2+ and vitamin D3 functional factors were studied. The results show that the emulsion has better sustained release performance for both Ca2+ and vitamin D3. Using zinc ion (Zn2+) instead of Ca2+ and bio‐macromolecule hyaluronic acid (HA) instead of ALG, the colloidal particles ALG/Zn2+/Lys and HA/Zn2+/Lys were prepared. The Pickering emulsion prepared with colloidal particles still has good sustained release performance for functional factors. The prepared functional emulsion has potential applications in the fields of food, medicine and cosmetics.

A new perception to the spectroscopic, dielectric and impedance behavior of graphene oxide

The present study explores the synthesis of graphene oxide (GO) using Hummer’s method followed by a characterization that uses XRD, FTIR, Raman spectroscopy, UV, zeta potential, dielectric, and impedance study. The study of XRD, FTIR, UV, and Raman spectra revealed the presence of polar functional groups containing oxygen and structural deformity induced in GO. The nature of the surface charge, hydrodynamic diameter, and stability of graphite and GO in colloidal solution was ascertained from the zeta potentiometer. Raman spectra and zeta potential showed the presence of defects. The dielectric study of GO pellets with variation in frequency (1 Hz to 1 MHz) revealed the large dielectric constant of GO (∼105 at 26 °C and 1 Hz), which is comparable to conventional perovskite titanates dielectric materials. Both Lydanne–Sachs–Teller (LST) and Debye’s models of dielectric relaxation were taken into account while explaining the findings of giant dielectric constant in GO. Various mechanisms such as the presence of polar groups, Dirac fermions, and surface plasmon resonance have been discussed to explain the giant dielectric constant and its subsequent variation with frequency. The frequency dependence impedance and dielectric spectra were fitted using origin software to analyze poly dispersive nature and departure from Debye’s relaxation with an appraisal of static dielectric constant, static resistance, optical dielectric constant, optical resistance, mean relaxation time, and spreading factor. Nyquist plot was exploited to study the conductivity behavior of the GO by measuring grain capacitance, grain resistance, grain boundary capacitance, grain boundary resistance, and electrode resistance as well as capacitance. An equivalent electrical circuit was proposed for the measured data and it was correlated with the experimental findings. The findings suggest that synthesized GO pellets can be used for replacing perovskite materials and ferroelectric materials in high-performance electronic devices and energy storage devices such as supercapacitors.

Green Synthesis of Silver Nitrate Nanoparticles using L. of Pyracantha crenulata and its Anticancer Activity on Liver Cancer

The next-generation of anti-cancer medications have a lot of potential, thanks to the biocompatible silver nanoparticles (AgNPs). Here, AgNPs were produced utilizing Pyracantha crenulata leaves in a biogenic manner. Several spectroscopic methods were used to characterize and verify the produced AgNPs. The peak of the AgNP’s Surface Plasmon Resonance (SPR) at 455 nm was discovered by UV spectroscopy research. Transmission electron microscope (TEM) examination was used to determine the precise size and morphology of AgNPs, which were discovered to be 60 nm in size and spherical, triangular, and hexagonal in form. X-ray Diffraction (XRD) spectrum data supported AgNPs crystallinity. The existence of elemental Ag was confirmed by (EDX) spectra, which displayed a clear, strong signal at 3.0 KeV. Particle size analysis was used to characterize the produced Ag nanoparticles. In order to characterize the silver nanoparticles, a (DLS) zetasizer particle size analysis was performed. According to a DLS investigation, the biosynthesized silver nanoparticles are 1340.8 nm in size and have a polydispersity index (PDI) of 0.6%. Silver nanoparticle stability was assessed using a zeta potentiometer. The nanoparticles generated had a zeta potential of -18.7 mV. The leaf extract's functional groups and the AgNPs that were produced, were identified using the analytical technique, FTIR. Examining AgNPs anti-cancer efficacy against liver (hep-2) cancer revealed its strong anti-cancer potential. Our findings suggest that generated AgNPs greatly inhibit the growth of liver cancer cell (hep-2) as measured by the MTT test.

Robust superhydrophobic TiO2@carbon nanotubes inhibitor with bombax structure for strengthening wellbore in water-based drilling fluid

Shale gas has become one of the most promising energies to cope with the ever-increasing energy demand, while wellbore instability incidents frequently occur due to the hydration and subsequent swelling of shale during the long horizontal drilling process. In this paper, a novel superhydrophobic carbon nanotube composite for high-efficiency water-based drilling fluid was prepared by the combination of the chemical vapor deposition method and the in-situ precipitation method. The prepared composite can form a superhydrophobic adsorption layer with high roughness and low surface free energy on the rock surface, achieving hydration inhibition by wettability alteration. The functional groups, surface morphology, electrical properties, and element valence of the synthesized composite were characterized by FTIR, SEM, zeta potentiometer, and XPS technique, result evidenced that the product was prepared as expected design. The effect of superhydrophobic carbon nanotube composites on the rheology and filtration properties of drilling fluid was studied, the drilling fluid can maintain favorable viscosity and shear force after adding the composite; the linear expansion rate test, the contact angle measurement, and lubrication experiments were performed to evaluate the inhibition and lubrication performance, the linear expansion rate of core decreased from 59.1 % to 21.9 % after treated with 1 % composite solution for 16 h, the wettability of rock surface can be altered from liquid-wetting to strong hydrophobicity, the reduction rate of extreme pressure lubrication coefficient was 46.9 %, and the zeta potential of shale decreased with the increasing concentration of composite. The possible explanation for its excellent performance could be that the superhydrophobic carbon nanotube composite can form a dense hydrophobic adsorption layer on the shale surface through electrostatic attraction, and an anchoring structure between the neighboring crystal lattices can be preferentially formed by the amino groups in the non-polar end of the molecule, which can alleviate the intrusion of drilling fluid, achieving the inhibition of the hydration and expansion of shale.

Antifouling enhancement of thin-film composite polyamide reverse osmosis membrane by surface immersion deposition and in-situ crosslinking method with NaAlg-GA hydrogel

In order to optimize antifouling performance to organic foulants, a commercial polyamide reverse osmosis membrane of composite polyamide material was modified by surface gelation using sodium alginate (NaAlg) as surface coating agent, which was widely known as a natural polymer and environmentally friendly materials. NaAlg-GA hydrogel layer was successfully deposited on commercial membrane surface by combining immersion coating with in-situ crosslinking method and the chemical structure was verified by FT-IR spectroscopy. SEM and AFM was adopted to analyze the changes of morphology and roughness. Zeta potentiometer, and contact Angle analyzer were all used to analyze the hydrophilicity and charge property of relevant NaAlg modified membranes in detail. Specific separation performance was also evaluated by cross-flow filtration tests. Results from above experiments confirmed that NaAlg modified membranes exhibited a surface with more hydrophilic, smoother and more regular, denser negative charge, slightly improved selectivity and lower permeability. Long-term monitored the performance of 100 ppm NaAlg modified membrane, it was found that the rejection rate fluctuated between 98.96% and 99.17%, and the flux ranged from 25.15 ∼ 26.06 L/m2 h during the whole test period, which fully proved that modified membrane had good durability. BSA pollution experiment results showed that the flux attenuation rate of 100 ppm NaAlg modified membrane decreased from 40.87% to 25.01%, and flux recovery rate of contaminated membrane after washing was as high as 90.8%. In addition, the flux of 100 ppm NaAlg modified membrane exceeded that of unmodified membrane after filtrating 20 h. Moreover, with the extension of time, the cumulative flux loss of modified membrane caused by additional resistance at the initial filtration stage would soon be compensated, and it completely exceeded that of unmodified membrane after 40 h. All above results showed that NaAlg-GA hydrogel layer can effectively improve the antifouling performance.

Selective removal of Hg(II) by UiO-66-NH2 modified by 4-quinolinecarboxaldehyde: from experiment to mechanism.

In wastewater, heavy metal Hg causes serious harm to ecology, so it needs to be removed. In this paper, a novel MOF adsorbent (UiO-66-QU) was prepared by modifying UiO-66-NH2 with 4-quinolinecarboxaldehyde, which was used to selectively remove Hg(II) from water. The adsorbent was characterized using Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), zeta potentiometer, and X-ray photoelectron spectroscopy (XPS). In order to investigate the Hg(II) adsorption performance of UiO-66-QU, the effect of time, initial concentration, pH, and temperature were carried out. Langmuir model fitting shows that the maximum adsorption capacity of UiO-66-QU for Hg(II) is 556mg/g at 298K. The experimental results show that UiO-66-QU has better Hg(II) adsorption capacity than UiO-66-NH2. The isotherm is in accordance with pseudo-second-order models. It is indicated that the adsorption process is mainly monolayer chemical adsorption. The thermodynamic parameters also indicate that the adsorption process is spontaneous and endothermic. It has excellent reusability and selectivity. XPS and the zeta potential showed that the adsorption mechanism was the complex reaction of Hg(II) with nitrogenous group. Therefore, the adsorbent has potential application prospects in removal of Hg(II) from wastewater.

Study of the solvothermal method time variation effects on magnetic iron oxide nanoparticles (Fe3O4) features

Magnetic iron oxide nanoparticles (MIONPs) possess the unique advantages of both magnetic features and nanomaterials. Using ferric trichloride hexahydrate and sodium acetate as crude materials, polyethylene glycol 1000 (PEG1000) as the surfactant, and ethylene glycol as the dispersion medium, Fe3O4 nanoparticles were prepared by solvothermal method. Furthermore, through scanning electron microscope (SEM), high-resolution transmission electron microscope (HRTEM), vibrating sample magnetometer (VSM),X-ray diffractometer (XRD), synchronous thermal analyzer (TGA), Fourier transform infrared spectrometer (FT-IR), Zeta potentiometer, the structure, morphology and phase composition of MIONPs were characterized. Results evidenced that the particle size of MIONPs was inversely proportional to the specific surface area, and gradually increased until 8 h (ca. 200–300 nm) when superparamagnetic iron oxide nanoparticles (SIONPs) clusters were obtained. This research has demonstrated a new way of viewing this synthesis procedure upon variation of time and subsequent features of clusters.

Nanoencapsulation of aptamer-functionalized 5-Fluorouracil liposomes using alginate/chitosan complex as a novel targeting strategy for colon-specific drug delivery

Two important challenges in clinical application of 5-Fluorouracil (5-FU) in the treatment of colon cancer are preventing the release or degradation of the drug in the stomach/small intestine, and its delivering the colon as the site of action. The preparation of targeted liposomes using a suitable ligand and their encapsulation may be a promising method for the targeted treatment of colon cancer. The targeted liposomes were prepared by the optimized thin film method, and anti-nucleolin aptamer (AS1411) was used as the ligand. The nanocapsules were then prepared by coating of the synthesized liposomes with alginate and chitosan solution. The chemical structure, particle size and morphology of the liposomes and the nanocapsules were examined by Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), zeta potentiometer and field emission scanning electron microscopy (FESEM). MTT cytotoxicity studies were performed in vitro on the colon cancer cell line (HT-29). The liposomes and nanocapsules prepared were spherical with approximate sizes of 120 and 170 nm, respectively. The cytotoxicity studies on HT-29 cells showed that aptamer-conjugated liposomes induced significantly more cell death than aptamer-free liposomes and free drug. The results of the drug release experiments under simulated conditions including stomach, small intestine, and colon showed the excellent efficiency of the nanocapsules in releasing their cargo only under colonic condition.

Selective removal of Cr (VI) from hydrometallurgical effluent using modified cellulose nanocrystals (CNCs) with succinic anhydride and ethylenediaminetetraacetic acid: Isotherm, kinetics, and thermodynamic studies

AbstractBiological sources are renewable basic resources that may be used for several purposes, including the development of green materials for the removal of heavy metal ions. Cellulose nanocrystals (CNCs) extracted from waste papers via acid hydrolysis were modified and utilized as adsorbents to remove Cr (VI) ions from metallurgical effluent in this work. X‐ray diffraction, scanning electron microscopy, Fourier‐transform infrared spectroscopy, thermogravimetric analysis, and zeta potentiometer were used to characterize the CNCs. The CNCs treated with succinic anhydride and ethylenediaminetetraacetic acid tetrasodium salt have thin particle sizes and are porous. The carboxylate functional group is primarily engaged in the coordination and selective removal of metal ions (–COO2−) and thermal degradation of 85%, observed at temperatures between 250–380°C. On the surface of the modified CNCs, the zeta potential data showed a decrease in negative value. The results revealed that the modified CNCs had a maximum adsorption capacity of 387.25 ± 0.88 mg L−1 at pH 5, at CNCs doses of 25 and 400 mg L−1 as starting concentrations. The adsorption equilibrium period was 300 min and the temperature was 313 K. The equilibrium results fit the Langmuir isotherm model with an R2 of 0.993 and a qmax of 340 ± 0.97. The Chi‐square (X2) and Marquardt's percent standard deviation tests confirmed that the adsorption process was pseudo‐second‐order with an R2 of 0.998, and the Elovich model revealed that Cr (VI) complexed with the adsorbent's functional groups. The reaction was endothermic due to positive ΔH and spontaneous due to negative ΔG. The positive ΔS indicates that the adsorption process enhances the unpredictability of the solid/liquid interface, according to thermodynamic analysis. After acid treatment, the CNCs may be effectively reused for six cycles with an adsorption capacity of 220 ± 0.78 mg g−1.

The Effects of Chemical Oxidation and High-Temperature Reduction on Surface Functional Groups and the Adsorption Performance of Biochar for Sulfamethoxazole Adsorption

Biochar is a beneficial adsorbent for the treatment of organic pollutants in the environment. The association of oxygen functional groups and adsorption behaviors has not been well investigated. In this paper, the oxidation-modified biochar (O-BC) and the reduction-modified biochar (R-BCX) were prepared by Co2+/peroxymonosulfate chemical oxidation and high-temperature reduction, respectively. The modified biochars were used to remove sulfamethoxazole (SMX) from water, and the adsorption amounts of biochar followed the order of R-BC700 (14.66 mg·L−1) > O-BC (4.91 mg·L−1) > BC (0.16 mg·L−1). Additionally, the effects of water chemical conditions (i.e., ionic strength, solution pH and humic acid (HA) concentration) on the adsorption of SMX on biochar, were further investigated. Combining physical adsorption, X-ray electron spectroscopy, and zeta potentiometer characterization techniques, the effect of functional groups on the adsorption mechanism was further explored, revealing the importance of various oxygen functional groups for SMX adsorption. The results showed that C=O and C=C, resulting in π–π interaction, were in favor of the adsorption of SMX, while C-O was not conducive to the adsorption of SMX, due to the steric hindrance and the negative surface charge. Additionally, the hydrophobic effect of the biochar was also one of the adsorption mechanisms.

Different Methods, Novel Tools towards the Synthesis of Nanoparticles and Applications in Engineering, Chemical, Physical Sciences and Technology

Nano particles have gained special attention in recent years due to their remarkable electrical, magnetic, optical, and mechanical capabilities, and they offer a variety of uses in all sectors of engineering. Gold nanoparticles, for instance, are catalytic when they are 10 nm in size, whereas nanoparticles with a short radius of curvature and angular forms have better catalytic capabilities. Co-precipitation nanoparticle production is a simple approach that results in a wide range of nanoparticle sizes. Top-down and bottom-up techniques used to create mono-dispersed spherical bismuth (Bi) NPs. These Nanoparticles have outstanding colloidal characteristics. Sputtering is the technique for creating NPs that involves hitting solid surfaces with the high energy particles like gas or plasma. In an aqueous solution, gold nanoparticles were created by using a laser ablation approach. A zeta potentiometer is often used to assess surface charges and their dispersal constancy in a solution. Several industry and technology sectors, including IT, medicine, energy, transportation, homeland security, food safety, and environmental research, are being significantly improved, if not revolutionized, by nano-technology.

Methyl orange assisted dispersion of graphene oxide in the alkaline environment for improving mechanical properties and fluidity of ordinary portland cement composites

Graphene oxide (GO) as a nano-reinforcing filler has great potential to improve the performance of cement-based composites, however, many challenges must be solved. Recent research has shown that GO tends to coagulate in the alkaline cement pore solution , limiting its reinforcement efficiency to improve the properties of cement composites . In this study, with polycarboxylic ether superplasticizer (PCE) as the main dispersant, methyl orange (MO) was further added to improve the dispersity of GO. The effect of MO on the dispersion of GO in saturated Ca(OH) 2 solution was investigated by UV-Vis spectrophotometer, Zeta potentiometer and atomic force microscope . Very low content of MO could significantly improve the colloidal stability of GO in CH solution and the optimal dispersion of GO was achieved when the mass ratio of GO to MO was 1:1. The effect of MO-dispersed GO on cement composites was investigated through mechanical strength analysis, microscopic analysis and chloride ion permeation analysis. The results showed that when the mass ratio was 1:1 and the content of GO was 0.03%, the 3d and 28d flexural strengths of cement mortar (0.03%-GO@MO) were increased by 27.4% and 15.4%, and the compressive strengths were increased by 21.8% and 15.3%, respectively, compared with the 0.03% GO-reinforced cement mortar(0.03%-GO). The chloride ion migration coefficient of 0.03%-GO@MO was 8.18%, lower than that of 0.03%-GO, which was caused by the denser internal structure of the former. Microscopic tests showed that the addition of MO could promote the dispersion of GO in cement pore solution, regulate the growth of cement hydration crystal and make the cement slurry structure denser. The addition of MO could reduce the loss of fluidity of the fresh slurry caused by GO. This study might provide a low-cost method to simultaneously improve the dispersion of GO in cement pore solution and the workability of GO-blended cement mortar and had many potential practical applications. • In the presence of PC, methyl orange could significantly improve the dispersion of GO in cement pore solution. • MO compensated the loss of the fluidity of the fresh cement slurry caused by the addition of GO. • Compared with GO-reinforced cement, the mechanical properties of MO@GO modified cement had been further improved. • The low-priced MO affords good dispersion of GO for the potential engineering application of cement-based composite.

Optimization, Characterization, and Antibacterial Activity of Copper Nanoparticles Synthesized Using Senna didymobotrya Root Extract

The economic burden and high mortality associated with multidrug-resistant bacteria is a major public health concern. Biosynthesized copper nanoparticles (CuNPs) could be a potential alternative to combat bacterial resistance to conventional medicine. This study for the first time aimed at optimizing the synthesis conditions (concentration of copper ions, temperature, and pH) to obtain the smallest size of CuNPs, characterizing and testing the antibacterial efficacy of CuNPs prepared from Senna didymobotrya (S. didymobotrya) roots. Extraction was done by the Soxhlet method using methanol as the solvent. Gas chromatography-mass spectrometry (GC-MS) analysis was performed to identify compounds in S. didymobotrya root extracts. Box–Behnken design was used to obtain optimal synthesis conditions as determined using a particle analyzer. Characterization was done using ultraviolet-visible (UV-Vis), particle size analyzer, X-ray diffraction, zeta potentiometer, and Fourier transform infrared (FT-IR). Bioassay was conducted using the Kirby–Bauer disk diffusion susceptibility test. The major compounds identified by GC-MS in reference to the NIST library were benzoic acid, thymol, N-benzyl-2-phenethylamine, benzaldehyde, vanillin, phenylacetic acid, and benzothiazole. UV-Vis spectrum showed a characteristic peak at 570 nm indicating the formation of CuNPs. The optimum synthesis conditions were temperature of 80°C, pH 3.0, and copper ion concentration of 0.0125 M. The FT-IR spectrum showed absorptions in the range 3500–3400 cm−1 (N-H stretch), 3400–2400 cm−1 (O-H stretch), and 988–830 cm−1 (C-H bend) and peak at 1612 cm−1 (C=C stretch), and 1271 cm−1 (C-O bend). Cu nanoparticle sizes were 5.55–63.60 nm. The zeta potential value was −69.4 mV indicating that they were stable. The biosynthesized nanoparticles exhibited significant antimicrobial activity on Escherichia coli and Staphylococcus aureus with the zone of inhibition diameters of 26.00 ± 0.58 mm and 30.00 ± 0.58 mm compared to amoxicillin clavulanate (standard) with inhibition diameters of 20 ± 0.58 mm and 28.00 ± 0.58 mm, respectively.

Effects and mechanism of copper oxide nanozymes on wound healing of full-thickness skin defects in diabetic mice

Effects and mechanism of copper oxide nanozymes on wound healing of full-thickness skin defects in diabetic mice

Particle Size Distribution and Yield Analysis of Different Charged Cellulose Nanofibrils Obtained by TEMPO-mediated Oxidation

Cellulose Nanofibrils (CNF) was successfully obtained by TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidation with the addition of different oxidant namely NaClO (Sodium Hypochlorite) i.e. 3, 4, 7, 10 and 15 mL followed by ultra-sonication treatment. Size distribution of nanocellulose was observed using particle size analyzer, while surface charged was measured using zeta potentiometer. At different level of oxidant, CNF obtained different charged with different size distribution. As the amount of oxidant increased, the size distribution of CNF increased which correlated to the higher CNF yield, however it decreased at maximum oxidant addition. Although, in general the yield for nanocellulose was very low. With zeta potential value about -48 mV, it showed very stable suspension in water for more than 8 months observation. An optimum oxidant level promoted thinner and longer CNF which further beneficial for better entanglement in the hydrogel formation application.