Scattering Particle Size Research Articles

Effect of Hydrophilic Function Groups on the Properties of Short‐Chain Fluorocarbon Surfactants

AbstractShort‐chain fluorocarbon surfactants grafted with alcohol, carboxyl and ester functional groups were prepared by quaternization with short‐chain perfluorobutyl sulfonyl fluoride as raw material. The structures of surfactants were characterized by infrared spectroscopy, nuclear magnetic resonance and mass spectrum. The surface activity, micelle formation process and micelle aggregation behavior of surfactants were studied by surface tensiometer, dynamic light scattering particle size analyzer and fluorescent spectrophotometer. The results show that the critical micelle concentration (CMC) of surfactants are 19.3, 7.8 and 2.2 mmol L−1, and the surface tension of the surfactant solution at CMC are as low as 17.3, 19.2 and 18.5 mN m−1, respectively. The standard Gibbs free energy ( ) values of surfactants are negative, and the absolute values of are less than the standard Gibbs adsorption energy ( ), illustrating that the adsorption process is easier than the micelle formation process. In addition, the size distribution of the aggregates is much larger than that of spherical micelles, showing that the surfactant self‐assembled into larger aggregates in solution. The grafted hydrophilic functional groups show a significant effect on the performance of surfactants. The ester‐based surfactant has a lower CMC value, which has the advantages of small dosage, good economy and excellent application value.

Nitrogen-Doped Carbon Dots: A New Powerful Fluorescent Dye with Substantial Effect on Bacterial Cell Labeling.

Carbon dots (CDs)-minute carbon nanoparticles with remarkable luminescent properties, photostability, and low toxicity-show potential for various applications. CDs synthesized using citric acid and urea are the least toxic to biological environments. Here, we aimed to explore the effect of CDs synthesized using citric acid and urea at 50, 33, and 25% (CDs 1/1, 1/2, and 1/3, respectively) weight ratios in a microwave on bacterial cell fluorescence sensing and labeling. The nanoscale properties of CDs were investigated via transmission electron microscopy and dynamic light scattering particle size analysis. X-ray powder diffraction confirmed the graphitic structures of CDs. X-ray photoelectron spectroscopy revealed that the nitrogen content increased gradually with increasing urea ratios, indicating functional group changes. Transient photoluminescence decay periods demonstrated superior fluorescence intensity of CDs 1/3 under blue, green, and red lights. The use of CDs was notably more efficient than traditional methods in staining bacterial cells. Fluorescence microscopy of 10 g-positive and 10 g-negative bacteria revealed enhanced staining of Gram-positive strains, with CDs 1/3 presenting the best results. The CDs exhibited excellent photostability, maintaining poststaining fluorescence for 100 min, surpassing the performance of conventional dyes. CDs could serve as potential fluorescent dyes for the rapid discrimination of Gram-positive and Gram-negative bacteria.

Investigation on the plugging mechanism of nanocomposite polyacrylate copolymers in water-based drilling fluids: Experiments and applications

The plugging of nanopores and cracks in shale formation has become the critical technology that promotes the development of shale gas. Herein, nanocomposite polyacrylate (Poly-TALC) copolymers were successfully prepared by emulsion polymerization using butyl acrylate and triallyl isocyanurate as the raw material. Poly-TALC was characterized by fourier transform infrared spectroscopy (FTIR), laser light scattering particle size analysis, scanning electron microscope (SEM) and thermogravimetric analysis (TGA). The rheological properties and plugging performance of Poly-TALC were evaluated by a six-speed rotational viscometer, filter cake permeability test, core permeability test and pressure transfer experiment. Results revealed that Poly-TALC exhibited a particle size distribution ranging from 75.27 to 95.29 nm, while maintaining notable stability at 327.75 °C. Upon the addition of Poly-TALC to the drilling fluid, both the apparent viscosity and plastic viscosity insignificantly changes. At a Poly-TALC dosage of 1.0%, the filter cake's permeability was 1.2 × 10−5 μm2 with a plugging rate of 56.9%, while the permeability of the core was 1.2 × 10−6 μm2 with a plugging rate of 84.0%. The decrease in permeability was not significant beyond a Poly-TALC dosage of 1.0 wt%. Pressure transfer experiments demonstrate that Poly-TALC is able to form a multi-stage dense seal within the rock core, which can effectively prevent formation water from immersing into shale formation and improve shale wellbore stability.

Investigation of the use of cobalt and nickel based nanoalloys as cement mortar additives

The usage potential of chemical and green synthesized cobalt (Co) and nickel (Ni) nanoalloys (CoNiNAs) as mortar additives at different ratios was evaluated. The CoCl2 and NiCl2 metallic salt solutions were mixed in volume ratios of 1-1, 1-2, and 2-1 and reduced with NaBH4 and St. John's Wort aqueous extract, respectively. The obtained Co-Ni based complex nanoalloys were analyzed by Ultraviolet-Visible Spectroscopy (UV-Vis), X-Ray Diffraction Analysis (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Fourier Transform Infrared Spectroscopy (FT-IR), and Dynamic Light Scattering Particle Size Analyzer (DLS). The effect of CoNiNAs was investigated based on the amount used in mortar, flexural and compressive strengths of mortar, setting time retarder properties, and carbonation depth measurements of mortars and nanoalloy form based on whether they were solid (chemical synthesise) or liquid (green synthesise). The results revealed that the chemical synthesized CoNiNAs were amorphous metal-metal-oxide complexes with small spherical particles and a low dispersity index, whereas the green synthesized complexes had a more crystalline structure and smaller sizes. The mortar properties were affected by Co and Ni synthesis ratios and addition amounts. The incorporation of CoNiNAs led to an increase in the setting times of mortar. Furthermore, the ‘CN’ 2% sample exhibited the highest compression (49.10±1.19 MPa) and flexural (8.19±0.20 MPa) strengths. In addition, the ‘CN2’ 1% sample exhibited the lowest carbonation depth (2.95±0.35 mm) compared to other samples. Overall, mortars with CoNiNAs additives may be used in high temperature environments, and long shipment times require remote locations due to setting time retarder effect without losing necessary physical properties.

Selective detection of thallium by prussian blue-coated gold nano-colorimetric probe

Thallium as a highly dispersed and toxic heavy metal element, is distributed in soil and water due to a result of industrial activities. Thallium is extremely accumulative, which not only makes it harmful to the environment, but also enriches in living organisms and eventually poses a serious threat to human health. In order to detect thallium ions in water quickly and effectively, a PB@AuNPs nano-colorimetric probe based on gold nanoparticles coated with soluble prussian blue was proposed and characterized by UV–visible photometer, dynamic light scattering particle size distribution, Fourier transform infrared spectroscopy and X-ray diffraction. When Tl+ ions were present in the test sample, PB@AuNPs tended to adsorb Tl+ in the system and agglomerated, which exhibited a remarkable color change from wine red to blue. Meanwhile, the intensity and displacement of surface plasmon resonance (SPR) absorption peak changed. PB@AuNPs nanoprobe exhibited a 0.67 μM of limit of detection (LOD) for UV–vis spectra under the optimal pH being 6 with a good linear relationship between the absorbance ratios and the concentrations of Tl+ ions in the range of 10.0 ∼ 30.0 μM, y = 0.04239 x − 0.07483, R2 = 0.99137. The results showed that PB@AuNPs nanoprobe had high selectivity and good anti-interference, which could be used in the detection of actual water samples.

Enhanced reduction of COD in water associated with natural gas production using iron-based nanoparticles.

The natural gas production industry faces the problem of the proper disposal of produced water and its treatment with significantly advanced technologies to meet the minimum quality standard for irrigation activities, commercial purposes, and consumption by living organisms. This study describes an effective method for reducing the COD (chemical oxygen demand) content in formation water using different metal oxide nanoparticles such as iron oxide (FO), iron zinc oxide (FZO), and iron vanadium oxide (FVO) nanoparticles. These nanoparticles were synthesized and fully characterized using powder X-ray diffraction (XRD) analysis, Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, dynamic light scattering particle size (DLS) analysis and zeta potential analysis. The experimental results revealed that the maximum reduction of COD content was 42.18% using FVO nanoparticles with a dose of 3 g L-1 at 25 °C and pH = 6. Compared to commercial products [Redoxy and Oxy(OXYSORB)], the synthesized FO, FZO, and FVO nanoparticles demonstrated their superiority by achieving excellent results in decreasing the COD content of wastewater associated with natural gas production by more than 86%. This study introduces a promising technique for decreasing the COD content using metal oxide nanoparticles, which are eco-friendly, bio-safe, cheap, and nontoxic materials, and improving the quality of wastewater associated with natural gas production for its safe disposal through sewage and treatment plants.

<i>In Vitro</i> Studies on Antioxidant Potential of Apple (<i>Malus domestica</i>) Fructus Extract Nanoparticle

Oxidative stress results from an imbalance of free radicals and antioxidants in the body. Antioxidants are needed to prevent oxidative stress. A diet rich in fruits and vegetables, which are high in antioxidants, should help avoid oxidative stress. One source of antioxidants is apples (Malus domestica) from the Rosaceae family because they have some bioactive compounds such as catechin, chlorogenic acid, quercetin, and phloridzin. Recently, many studies have used nanotechnology to formulate plant extracts. Due to their size and distinctive physicochemical properties, nanoparticles in plant extracts have various benefits. Analyzing apple extract nanoparticles’ antioxidant capacity was the goal of this work. The synthesized nanoparticles of apples were made by using chitosan, glacial acetic acid, propylene glycol, ethanol, DMSO, and Na-TPP. A dynamic light scattering particle size analyser was used to measure the zeta potential and particle size. Antioxidant activity was measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging, Hydrogen Peroxide (H2O2) scavenging activities, and Ferric Reducing Antioxidant Power (FRAP) assay using colorimetric methods. At a concentration of 100 g/ml, the most DPPH was scavenged (80.35%). Apple extract nanoparticles have strong DPPH scavenging activity with IC50 = 12.16 ± 2.98 µg/ml and H2O2 scavenging activity with IC50 = 81.96 ± 7.23 µg/ml. The highest H2O2 scavenging activity was at 200 µg/ml concentration (84.47%) and the highest FRAP activity was at a concentration of 50 µg/ml (444.29%). The concentration is directly proportional to the antioxidant activity of apple extract nanoparticles. Based on this study, apple extract nanoparticle has strong antioxidant activity.

Enhancing the Functional Properties of Tea Tree Oil: In Vitro Antimicrobial Activity and Microencapsulation Strategy.

In the context of addressing antimicrobial drug resistance in periocular infections, Tea Tree Oil (TTO) has emerged as a promising therapeutic option. This study aimed to assess the efficacy of TTO against bacterial strains isolated from ocular infections, with a particular focus on its ability to inhibit biofilm formation. Additionally, we designed and analyzed microcapsules containing TTO to overcome certain unfavorable physicochemical properties and enhance its inherent biological attributes. The quality of TTO was confirmed through rigorous analysis using GC-MS and UV-Vis techniques. Our agar diffusion assay demonstrated the effectiveness of Tea Tree Oil (TTO) against ocular bacterial strains, including Corynebacterium spp., coagulase-negative Staphylococcus spp., and Staphylococcus aureus, as well as a reference strain of Staphylococcus aureus (ATCC 25923). Notably, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for all tested microorganisms were found to be 0.2% and 0.4%, respectively, with the exception of Corynebacterium spp., which exhibited resistance to TTO. Furthermore, TTO exhibited a substantial reduction in biofilm biomass, ranging from 30% to 70%, as determined by the MTT method. Through the spray-drying technique, we successfully prepared two TTO-containing formulations with high encapsulation yields (80-85%), microencapsulation efficiency (90-95%), and embedding rates (approximately 40%). These formulations yielded microcapsules with diameters of 6-12 μm, as determined by laser scattering particle size distribution analysis, and exhibited regular, spherical morphologies under scanning electron microscopy. Importantly, UV-Vis analysis post-encapsulation confirmed the presence of TTO within the capsules, with preserved antioxidant and antimicrobial activities. In summary, our findings underscore the substantial therapeutic potential of TTO and its microcapsules for treating ocular infections.

Characterization of the angular memory effect of dynamic turbid media.

The optical angular memory effect (AME) is a basic feature of turbid media and defines the correlation of speckles when the incident light is tilted. AME based imaging through solid scattering media such as ground glass and biomedical tissue has been recently developed. However, in the case of liquid media such as turbid water or blood, the speckle pattern exhibits dynamic time-varying characteristics, which introduces several challenges. The AME of the thick volume dynamic media is particularly different from the layer scatterers. In practice, there are more parameters, e.g., scattering particle size, shape, density, or even the illuminating beam aperture that can influence the AME range. Experimental demonstration of AME phenomenon in liquid dynamic media and confirm the distinctions will contribution to complete the AME theory. In this paper, a dual-polarization speckle detection setup was developed to characterize the AME of dynamic turbid media, where two orthogonal polarized beams were employed for simultaneous detection by a single CCD. The AME of turbid water, milk and blood were measured. The influence of thickness, concentration, particle size and shape, and beam diameter were analyzed. The AME increasement of upon the decrease of beam diameter was tested and verified. The results demonstrate the feasibility of this method for investigating the AME phenomenon and provide guidance for AME based imaging through scattering media.

Investigating Key Molecular Descriptors Affecting Particle Size: A Predictive Exemplary Approach for Self-Emulsifying System.

The self-nano/microemulsifying drug delivery system is one of the well-established techniques for enhancing the solubility of poorly water-soluble drug molecules. The ratio of oil:surfactant:cosolvent plays a key role in globule size on dispersion into water, but there is very limited information on how a drug molecule affects the size. The rationale of this project was to illustrate the correlation between the particle size of nanoemulsion droplets and molecular descriptors of a drug. In the study, a self-nanoemulsifying preconcentrate containing drug with medium chain triglycerides (oil), dimethylacetamide (DMA, cosolvent), and Kolliphor EL (surfactant) was prepared for 40 drug molecules with diverse physicochemical properties. The self-nanoemulsifying preconcentrate was dispersed in water, and dynamic light scattering particle size was analyzed. A majority of drugs showed a significant increase in globule size compared to blank formulation, while few drugs showed a stark reduction in globule size. It is interesting to understand the attributes of molecules driving the self-emulsification and the diameter of nanoglobules. A systematic correlation of resultant particle size with 1D, 2D, and 3D molecular descriptors (overall more than 700 descriptors) was carried out for the data set using the PaDEL tool kit. The data compilation, curation, and analysis were performed using the SIMCA14 software. In the process of molecular descriptors screening, thereafter curation, 50 descriptors were selected using the genetic algorithm screening. The PLS-DA statistical method was employed for conversion of data into binomial systems. Final group of 5 descriptors: SpMiSpMin2_Bhe, RNCS, TDB9i, JG17, and ETA_Shape showed the correlation with particle size and classifying the drug molecules facilitating increase or decrease in particle size.

An effective strategy to synthesize water-soluble iron heterocomplexes containing Dubb humic acid chelating agent as efficient micronutrients for iron-deficient soils of high pH levels

Humic acid (HA), the most known and popular water-soluble organic matter extracted from a variety of sources, has many applications in agriculture. Moreover, Fe-HA complexes are water-insoluble at high pH levels and thus they cannot be applied for iron-delivery to alkaline Fe-deficient soils. To solve this issue and to increase solubility and stability of Fe-HA complexes in alkaline soils (iron delivery to plants), herein, Dubb humic acid (DHA) extracted from lignite source was used and characterized by various techniques including X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), Brunauer-Emmett-Teller (BET) surface area, UV–Visible (UV–Vis) absorption and photoluminescence (PL) spectra, diffuse reflectance spectra (DRS), Fourier-transform infrared (FT-IR) spectra, gel permeation chromatography (GPC), and laser scattering particle size distribution analysis. To achieve iron complexes which were suitable for application in iron-deficient soils, firstly, some heterocomplexes containing non-DHA primary complexing agents were designed and synthesized using ammonium citrate (AC), ammonium sulfate (AS), and fulvic acid (FA) ligands. These complexes were water-soluble and could be easily used to synthesize final iron heterocomplexes with DHA coordinating agent, which were water-soluble in neutral and alkaline conditions. The desired heterocomplex structures with general formula of (A)n-(Metal)x-(B)m (A = DHA, Metal = Fe, B = AC, AS or FA) were synthesized through optimizing pH, DHA percentage, and initial iron ion concentration. Structural characterizations of the synthesized heterocomplexes were conducted by above-mentioned techniques. Elemental analysis of these heterocomplexes (particularly the AS containing sample) showed very much higher iron contents compared with commercial iron containing chelates. These results established that iron heterocomplexes designed in this study had an extraordinary potential for acting as valuable inorganic micronutrients for iron-deficient soils in alkaline conditions.

A rapid multispectral endoscopic imaging system for in vivo assessment of the morphological and physiological characteristics of mouse intestines.

Accurate assessment of blood content in biological tissues is critical for the diagnosis and monitoring of various diseases, including cardiovascular disease, tumors, trauma, and the success rate of organ transplants. In this study, a multispectral endoscopic imaging system was built for capturing tissue reflection optical images in 18 bands across the wavelength range from 400 nm to 760 nm, non-invasively. The system was characterized by six tri-channel narrowband filters installed in front of the light source to achieve spectral separation and was equipped with a specially designed color CCD for achieving a speed of 24 multispectral imaging cubes per second. A method based on linear matrix inversion was proposed to calibrate the CCD spectral response overlaps, while a spectral analysis algorithm was developed for evaluating blood content and detecting tissue composition. The developed system was implemented in an in vivo mouse model for illustrating the blood volume, blood oxygen saturation index, and scattering particle size of the intestinal wall mucosa. The observations not only helped us to understand the blood supply situation in the intestinal mucosa, but also further testified the feasibility of our presented system. Meanwhile, the developed system could provide critical non-invasive optical information for intracavitary cancer diagnosis, surgery guidance, and treatment assessment.

Study on factors affecting the synthesis of selenium nanoparticles by solution plasma method

The solution plasma process (SPP) is a revolutionary approach for production of nanomaterials employing plasma discharge in liquid. The SPP can quickly deionize metal into the neutral state in the absence of a reducing agent. Selenium nanoparticles are created in solution plasma in this investigation. The approach is capable of producing selenium nanoparticles with uniform size in water and great stability without the use of a stabilizer. UV-Visible Spectrophotometry (UV-vis), X-Ray Diffraction (XRD), Dynamic Light Scattering Particle Size Analyzer (DLS), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) techniques are used to analyze the produced selenium nanoparticles. In an ethanol/water mixture, the better solvent compares to distilled water, the SeNPs forms uniform flower-like nanostructures with diameters ranging from 50÷70 nm. Also, the effects of other parameters such as voltage, electrode spacing and reaction time on the production of nano selenium are investigated. The findings show that solution plasma can help form selenium nano particle in a very short time which is about 60 minutes. In addition, the electrodes must be separated by a minimum distance which is 0.5 mm . The ideal voltage to achieve a highly efficient process is 2 kV The higher voltage cause the reaction solution boil leading to the loss of reactants while the lower value cannot ignite the reaction. The reaction efficiency reaches 100% when applied those conditions. Also, those parameters help to shorten the reaction time which is an advantage of the synthesis method. As a result, the solution plasma method of synthesising nanoselenium makes it extremely promising for use in biomedical applications.

Development of a water-based functional additive by using isobornyl acrylate copolymer to improve ink-adhesion on untreated polypropylene surfaces: A comparative approach

The good barrier and hot-fill properties of polypropylene (PP) films and sheets make packaging industries advantageous. However, printing over a PP substrate is a major issue encountered in the packaging industry. The present study intends to prepare, characterise, and compare isobornyl acrylate (IBOA)-co-acrylic acid (AA) and isobornyl acrylate (IBOA)-co-methacrylic acid (MAA) based non-halogenated functional additives by using oil in water emulsion processes. The bornyl group of IBOA helps in enhancing molecular bonding with the polypropylene (PP) surface. The various properties of these synthesised functional additives were characterised using dynamic light scattering-particle size and zeta potential analysis, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), thermal gravimetric analysis (TGA), and gel permeation chromatography (GPC). The adhesion of these functional additive incorporated ink samples on different untreated PP surfaces was compared using the cross-cut adhesion test. The methacrylic acid based functional additive shows better adhesion properties as compared to acrylic acid.

CHITIN NANOFIBRES AS REINFORCEMENT FOR HYDROXYAPATITE-BASED COMPOSITE PREPARATION

The development and improvement of chitin applications have drawn special attention from the global scientific community due to their extraordinary features and abundance. In this study, β-chitin nanofibres were obtained using the ultrasonication treatment method. Then, hydroxyapatite/nanochitin (HAp/NCh) composites were prepared at different maturation times. In this case, mixtures of various amounts of β-chitin nanofibres (1%, 2%, and 5%) were added during the HAp precipitation approach. The prepared HAp/NCh materials were characterised with Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, and energy-dispersive X-ray spectroscopy. The surface of prepared specimens was observed using scanning electron microscopy. The presence of nanofibres was confirmed by non-invasive backscattering with dynamic light scattering particle size analysis. Moreover, the synergic effect of chitin nanofibres on the mechanical resistance of HAp-based composite was investigated. The sample with 5% of chitin nanofibres exhibited about 10 times higher compression strength than the pure HAp. All these results essentially indicate that the prepared material can be a potential candidate for bone tissue engineering applications and further development.

Multifunctional nanocomposite based on lactose@layered double hydroxide-hydroxyapatite as a pH-sensitive system for targeted delivery of doxorubicin to liver cancer cells

Developing porous nanocarriers through simple methods is one of the main approaches to produce the drug delivery systems. In this study, a pH-sensitive multifunctional nanocomposite of doxorubicin/Lactose@layered double hydroxidehydroxyapatite (DOX/Lactose@LDH-HAp) was designed for drug targeted delivery and controlled release to enhance the cancer treatment efficacy. To the best of our knowledge, there are a very few literatures in which LDH is used as carrier for loading drug DOX, which is a useful extension for only a limited number of anti-cancer drugs (usually anionic drugs) loaded in LDH based carriers. The structure and morphology of the prepared nanocomposite were thoroughly analyzed by various techniques such as X-ray diffraction analysis (XRD), Brunauer-Emmett-Teller (BET), Energy Dispersive X-Ray Analysis (EDX), Fourier-transform infrared spectroscopy (FTIR), Dynamic Light Scattering Particle Size (DLS) and Zeta Potential, and Scanning Electron Microscopy (SEM). The prepared system achieved an encapsulation efficiency (EE) and drug-loading content (DLC) of 88.4 % and 18.84 %, respectively. The DOX release experiments from nanocomposite showed a controlled and pH-dependent behavior. In-vitro cytotoxicity and DAPI staining tests of the DOX/Lactose@LDH-HAp showed high cancer-cell suppression on human liver cancer cell lines (HepG2 cells). Thus, the obtained results in this study suggest that the designed multifunctional nanocomposite could be used as an efficient system for targeted and controlled delivery of various anti-cancer drugs and other biomedical applications. Data availabilityNot applicable.

Polyacrylic Acid-Ca(Eu) Nanoclusters as a Luminescence Sensor of Phosphate Ion.

In this study, we synthesized polyacrylic acid (PAA)-Ca (Eu) nanoclusters as a luminescence sensor of phosphate ion by a complex method, and we aimed to achieve the quantitative detection of PO43− based on the sensitivity of the charge transfer band of Eu3+ to anionic ligand. The resulting PAA-Ca(Eu) nanoclusters showed a well-dispersed and a dot-like morphology, with an ultra-small diameter (the average size of 2.17 nm) under high resolution transmission electron microscopy(HRTEM) observation. A dynamic light scattering particle size analyzer (DLS) showed a hydrodynamic size of 2.39 nm. The (PAA)-Ca (Eu) nanoclusters as a luminescence sensor showed a significantly higher sensitivity for PO43− than other anions (CO32−, SiO32−, SO42−, SO32−, Br−, Cl−, F−). The luminescence intensity displayed a linear increase (y = 19.32x + 74.75, R2 > 0.999) in a PO43 concentration range (0–10 mM) with the concentration of PO43− increase, and the limit of detection was 0.023 mM. The results showed good recovery rates and low relative standard deviations. These (PAA)-Ca (Eu) nanoclusters are hopeful to become a luminescence sensor for quantitatively detecting PO43−.

Fabrication and characterization of Pickering high internal phase emulsions stabilized by debranched starch-capric acid complex nanoparticles

High internal phase emulsions (HIPEs) stabilized by debranched starch-capric acid (DBS-CA) complex nanoparticles were fabricated and their performance was evaluated. DBS-CA was prepared through enzymatic debranching and solid encapsulation methods, and displayed V-type crystalline structure. Contact angle measurements show enhanced hydrophobicity of DBS-CA compared to native starch. The DBS-CA nanoparticles have an average size of 463.77 nm and tended to be aggregating as analyzed by scanning electron microscope and dynamic light scattering particle size analysis. When used as a particulate emulsifier, DBS-CA could stabilize HIPEs with oil volume fraction as high as 80%. The HIPEs showed pH-dependent properties; good storage stability and mechanical strength were achieved within pH range from 3 to 11, especially under alkaline conditions. It was proposed that smaller particle size and higher surface charging were responsible for the more tightly connected gel structure and thus their performance. This study demonstrates a novel approach to fabricate food-grade Pickering HIPEs, which may have many promising potential applications in the food industry.

Metal nanoparticles assisted revival of Streptomycin against MDRS Staphylococcus aureus.

The ability of microorganisms to generate resistance outcompetes with the generation of new and efficient antibiotics. Therefore, it is critically required to develop novel antibiotic agents and treatments to control bacterial infections. Green synthesized metallic and metal oxide nanoparticles are considered as the potential means to target bacteria as an alternative to antibiotics. Nanoconjugates have also attracted attention because of their increased biological activity as compared to free antibiotics. In the present investigation, silver nanoparticles (AgNPs), zinc oxide nanoparticles (ZnO NPs), copper oxide nanoparticles (CuO NPs), and iron oxide nanoparticles (FeO NPs) have been synthesized by using leaf extract of Ricinus communis. Characterization of nanoparticles was done by using UV–Vis Spectroscopy, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Energy Dispersive X-Ray Analyzer, X-ray Diffraction Analysis, and Dynamic Light Scattering Particle Size Analyzer. Interestingly, Streptomycin when combined with AgNPs, ZnO NPs, CuO NPs, and FeO NPs showed enhanced antibacterial activity against clinical isolates of S. aureus which suggested synergism between the nanoparticles and antibiotics. The highest enhanced antibacterial potential of Streptomycin was observed in conjugation with ZnO NPs (11 ± 0.5 mm) against S. aureus. Minimum inhibitory concentration of conjugates of AgNPs, ZnO NPs, CuO NPs, and FeO NPs with streptomycin against S. aureus was found to be 3.12, 2.5,10, and 12.5 μg/mL respectively. The considerable point of the present investigation is that S. aureus, which was resistant to streptomycin becomes highly susceptible to the same antibiotic when combined with nanoparticles. This particular observation opens up windows to mitigate the current crisis due to antibiotic resistance to combat antimicrobial infections efficiently.

Green compounds of SBR with nanofibrilated cellulose and palm oil in replacement to traditionally compounds used

Silica and carbon black (CB) are the most used reinforcement fillers in elastomeric compositions; however, their obtention and usage might result in environmental and human health damages. The same happens to the plasticizers used in elastomeric compounds, which contain a high content of polycyclic aromatics. To use reinforcement and plasticizer loads from natural sources, the performance of an elastomeric compound by partially replacing CB with nanofibrillated cellulose (CEL) provided with Eucalyptus spp. shavings was evaluated in this work, as well as, the use of palm oil to replace aromatic oils. Nanofibrilated cellulose was obtained by grinding in a micronizing mill. As a characterization of the raw material, the thermal, chemical and morphological properties, as well as particle size analysis of the cellulose suspension were evaluated by the particle size analyzer. From the vulcanized material, the physical, mechanical, dynamic-mechanical properties, cross-link density, and swelling index in solvents were evaluated. As the main results obtained, the presence of CEL clusters seen by scanning electron microscopy with nanofibers with diameters of 100–85 nm was observed. The dynamic light scattering particle size analyzers (DLS) showed nanoparticles from 1 to 100 nm. The rheometric properties showed lower values for the parameters of safety time, optimal vulcanization time, and maximum and minimum torques when compared to samples with CEL as CB. For tear resistance properties, samples with the presence of nanofibrilated cellulose showed 48% more resistance than samples with CB, in the modulus of elasticity, cross-link density, and swelling index, a better performance was also achieved for the samples with CEL, along with presenting a similar behavior in the hardness property between samples with the presence of nanofibrillates and those with CB. Palm oil, a substitute for aromatic oil, was found to be similar in the evaluated properties results, with interaction with CEL, by chemical affinity, which can replace aromatic oil.