Size Of Spherical Nanoparticles Research Articles

Impact of deposition parameters on the optical properties of Fe2O3 thin films prepared by SILAR method

In order to explore the structures, morphology, and optical features of Fe2O3 nanofilms, the successive ionic layer adsorption and reactions (SILARs) technique was utilized to deposit the nanofilms onto glassy slides at varying concentrations of the precursor. Three precursor concentrations (0.025, 0.05 and 0.075) M were used. Analysis using X-ray diffraction (XRD) presented the crystalline structure of the Fe2O3 thin films. Field emission-scanning electron microscopy (FE-SEM) was used to evaluate the morphological features of the films. The results demonstrate that the surfaces of the films are nonporous and that there is a good distribution for spherical nanosize particles. The number of cycles is another important parameter that has been tested and its effect on the optical properties of prepared films was evaluated. The optical properties like optical absorption and energy gaps are affected directionally by changing the concentration and cycle numbers during the preparation. The latest objective of our study is to determine the role of precursor concentrations and deposition cycles in preparing thin films that have electronic applications such as sensors and solar cells.

Response surface method and finite element-based investigation of uniform/nonuniform hydromagnetic convection of nanofluids inside a quarter-circular enclosure

Under the influence of magnetohydrodynamics (uniform, periodic, and inclined), the current research evaluates the two-dimensional unsteady dynamics of natural convection flow and heat transportation in the quarter-circular domain considering the Brownian motion of nanoparticles. The nonlinear partial differential equations (PDEs) solver finite element method (FEM) of the Galerkin type is used for the numerical simulation. In addition, the central composite design-based response surface methodology (RSM) is applied to analyze the optimization of the outcomes. To assess the models’ significance in learning the optimum thermal transport efficiency of nanofluids, an analysis of variance is performed. The impacts of several physical characteristics such as Rayleigh number, nanoparticles volume fraction, mean Nusselt number, Brownian effects, size, and shape of the nanoparticles, and magnetic effects (uniform, periodic, and inclined) are examined. The heat transfer rate is significantly influenced by the magnetic field’s period and inclined angle. As an illustration, the optimal heat transmission is noted at λ = 0.75 and γ = 0°. When Brownian effects are included, the heat transfer rate increases by 23.44% and it rises by 39.34% as nanoparticle size drops from 100 nm to 10 nm. Moreover, compared to spherical nano-sized particles, blade-shaped nano-sized particles can improve the transportation of heat by 9.56%. Furthermore, the optimization of the independent factors (Ra, Ha, ϕ, and d p) on the response function Nu (average) is demonstrated by the statistical RSM technique, and a novel correlation is proposed based on FEM numerical data. The optimal thermal transport (Nu av = 24.045) is found when Ra = 10, Ha = 0, ϕ = 0.05, and d p = 10 nm. The model’s average Nusselt number’s R 2-value of 0.9927 indicates that the results are effective.

Interaction of Y and impurity P on the synergistic enhancement of elongation and electrical conductivity of single crystal copper rod

Single-crystal copper rods with high conductivity and mechanical properties are the decisive material for the production of microwires for chip bonding. To further improve the product of strength and elongation as well as electrical conductivity, rare earth Y is added to a single-crystal copper rod to adjust the microstructure and impurity state. The results show that Cu-0.03Y copper rods have excellent comprehensive properties. The electrical conductivity improves to 103.72 % IACS, and the product of strength and elongation improves to 8.772 GPa%. The precipitates in the Cu-0.03Y single crystal copper rod are nano-sized spherical particles composed of YP (NaCl type) and Cu5Y (Cu5Ca type) phases. The enthalpy of formation of Y and P is calculated using Miedema thermodynamics as ΔH = −173.45 kJ·mol−1. The precipitates formed by the preferential reaction of Y and P reduce the solid dissolved atoms in the copper, and the electrical conductivity increases accordingly. The 〈001〉 texture of a single-crystal copper rod decreases with the addition of Y, while the 〈101〉 texture increases with good plasticity, leading to an improvement in elongation.

Study the Impact of Silica Nanoparticles on the Properties of Several Dyes for the Fabrication of a Random Laser Gain Medium

Random laser gain media is synthesized with different types of dye at the same concentration (1×10-3 M) as an active material and silicon dioxide NPs (silica SiO2) as scatter centers through the Sol-Gel technique. The prepared samples are tested with UV–Vis spectroscopy, Fluorescence Spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), and Energy Dispersive X-ray Diffraction (EDX). The end result demonstrates that doped dyes with silica nanoparticles at a concentration of 0.0016 mol/ml have lower absorbance and higher fluorescence spectra than pure dyes. FESEM scans revealed that the morphology of nanocrystalline silica is clusters of nano-sized spherical particles in the range (25-67) nm. It is concluded that the various dyes with SiO2 as a scattering center can be proposed to build laser media.

Efficient Fluoride Removal from Aqueous Solution Using Graphene/Ce Composite Supported on Activated Carbon

Background: More than 260 million people worldwide are affected by excess fluoride (F- > 1.5 mg/L) in their drinking water. Fluorosis of the teeth and skeleton, among other health issues, is caused by it. Objective: The aim of this study is to evaluate the fluoride removal from contaminated water using graphene-based new adsorbent material. Method: Graphene (G) was prepared by a facile liquid-phase exfoliation method. CeO2 nanoparticles (NPs) were synthesized by the co-precipitation method. G was treated with CeO2 NPs in a probe sonicator to generate G/Ce material in solution. Finally, the impregnation evaporation process synthesized the G/Ce supported on activated carbon composite (G/Ce/AC). Results: FE-SEM analysis shows that the crumpling and scrolling sheets of G, the nanosized spherical shape of CeO2 NPs and a thick layer of nano-sized spherical particles has built up on the surface of graphene in G/Ce/AC composite. After conversion to G/Ce/AC Composite, the specific surface area of graphene was increased from 3.08 to 485.3621 m2/g. The adsorption of fluoride on G/Ce/AC was investigated using batch systems (effects of pH, contact time, adsorbent dosage and the initial fluoride concentration), adsorption isotherm and kinetic studies. The pseudo-second order was the one that best described the kinetic data, while the Langmuir isotherm best described the equilibrium data with a maximum adsorption capacity equal to 27.9 mg/g. Conclusion: Therefore, the results show that the G/Ce/AC composite was well synthesized and has excellent fluoride adsorption capacity compared to other materials already evaluated for this purpose.

AS1411 aptamer tagged PEGylated liposomes as a smart nanocarrier for tumor-specific delivery of Withaferin A for mitigating pulmonary metastasis

Metastasis is the most challenging health problem contributing to about 90 % of cancer-related deaths worldwide. Metastatic tumors are highly aggressive and resistant to the most available therapeutic options. Hence, innovative therapeutic approaches are required to target metastatic tumors selectively. In this study, we prepared AS1411 functionalized Withaferin A loaded PEGylated nanoliposomes (ALW) and investigated its therapeutic effect in B16F10 induced in pulmonary metastasis mice models. The prepared formulations' size and morphological properties were evaluated using dynamic light scattering system and Transmission electron microscope. ALW had spherical-shaped nanosized particles with a size of 118 nm and an encapsulation efficacy of 82.5 %. TEM analysis data indicated that ALW has excellent dispersibility and uniform spherical nano-size particles. ALW inhibited cell viability, and induced cell apoptosis of B16F10. In vivo, the pulmonary metastasis study in C57BL/6 mice revealed that the ALW significantly (p < 0.01) improved the encapsulated WA anti-metastatic activity and survival rate compared to WA or LW treated groups. ALW significantly (p < 0.01) downregulated the levels of IL-6, TNF-α, and IL-1β and significantly reduced the lung collagen hydroxyproline, hexosamine, and uronic acid content in metastatic tumor bearing animals compared to WA or LW. Gene expression levels of MMPs and NF-κB were downregulated in ALW treated metastatic pulmonary tumor-bearing mice. These findings demonstrate that the AS1411 functionalized Withaferin A loaded PEGylated nanoliposomes could be a promising nanoliposomal formulation for targeting metastatic tumors.

Impact of nickel substitution on structural, dielectric, magnetic, and electrochemical properties of copper ferrite nanostructures for energy storage devices

Nickel-substituted copper ferrite nanoparticles (NP) (Cu1-xNixFe2O4) were prepared using a cost-effective hydrothermal method. X-ray diffraction (XRD) pattern revealed a single-phase cubic spinel structure. The increase in lattice parameters and decrease in crystallite size are associated with the replacement of Cu ions by Ni ions in the host lattice of copper ferrite. The optimized Cu0.95Ni0.05Fe2O4 composition was subsequently annealed at 750 °C and 850 °C for further studies. Fourier transform infrared (FT-IR) analysis shows the existence of two promising fundamental adsorption peaks at 465 and 582 cm−1, related to the metal ion stretching vibrations at the tetrahedral (A) and octahedral (B) sites, respectively. The local disorder at both the A and B sublattices upon the incorporation of Ni was observed from the Raman analysis. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM) images shows the formation of agglomerates composed of nano-sized spherical particles. A high Barrett-Joyner-Halenda (BJH) surface area was achieved 17.25 m2/g with a particle stability of −11.1 mV obtained by the zeta potential. Both the dielectric loss and dielectric constant are decreased, whereas the AC conductivity gets increased with increasing frequency. The magnetization-field hysteresis curves exhibited ferromagnetic behavior with a pseudo-single domain, and the cyclic voltammetry study revealed a pseudocapacitive trend. This study highlights the importance of Ni substitution to control the physicochemical properties of spinel-phase CuFe2O4 for diverse applications, such as energy storage and lithium-ion batteries.

Upcycling sulphidic copper tailings into alkali-activated slag materials: effect of the sulfur content.

Sulfidic copper tailings (SCTs) with excessive sulfur content are prone to oxidation, leading to the generation of sulfates and causing compatibility issues with cement. To address this problem, this paper proposes upcycling SCTs into alkali-activated slag (AAS) materials to fully utilize the produced sulfates for slag activation. The influence of the sulfur content of the SCTs compound (quartz, SCTs, and fine pyrite) on the properties of AAS was investigated from various aspects including setting time, compressive strength, hydration products, microstructure, and pore structure. The experimental results showed that adding SCTs compound enabled the generation of S-rich expansive products, such as ettringite, sodium sulfate, and gypsum. Moreover, nano-sized spherical particles were formed and well-distributed in pores or micro-cracks in the microstructure of AAS mortars. Consequently, AAS mortars with SCTs compound developed higher compressive strength at all ages than the blank ones, with an increase of 40.2-144.8% at 3days, 29.4-115.7% at 7days, and 29.3-136.3% at 28days. Furthermore, AAS mortars with SCTs compounds enjoyed significant economic and environmental benefits, as demonstrated by cost-benefit and eco-efficiency analyses. The optimal sulfur content of the SCTs compound was found to be 15%.

Preparation and Application of Fe-Al-SiO2 Poly-Coagulants for Removing Microcystis aeruginosa from Water

Novel Fe-Al-SiO2 (FAS) poly-coagulants were prepared by the ball milling method using ferrous sulfate, aluminum sulfate, hydrophobic silica, and sodium carbonate as raw materials. The optimal preparation conditions and effects of preparation parameters on removal efficiencies were obtained by Response Surface Methodology (RSM) and Analysis of Variance (ANOVA). Removal efficiencies were investigated by employing FAS as the poly-coagulant for algae-laden water. Furthermore, obtained FAS samples were characterized by SEM, FTIR, XRD, and TGA. Results showed that the optimal preparation conditions were n(Fe):n(Al) of 2:1, m(Si):m(Fe+Al) of 1:2, and n(CO32−):n(Fe+Al) of 1.75:1, and the most significant influencing factor was n(CO32−):n(Fe+Al). FAS13 prepared under the above condition had the highest coagulation efficiency for simulated algae-laden water. Removal efficiencies for OD680, TP, and residual Al and Fe concentrations were 92.86%, 90.55%, 0.142 mg/L, and 0.074 mg/L, respectively. Nano-sized spherical particles, excellent thermal stability, and functional groups such as Al–O–Si, Fe–O–Si, and Fe–OH, corresponding to Al2Si2O5(OH)4, Fe7Si8O22(OH)2, and Fe2(OH)2CO3, were observed in FAS13. The coagulation performance of FAS13 was splendid when applied in real algae-laden water. The removal rates of TP, OD680, turbidity, and Chl-α were above 93.87%. The residual Al concentration was at the range of 0.057–0.128 mg/L.

Characterization, catalytic, and recyclability studies of nano-sized spherical palladium particles synthesized using aqueous poly-extract (turmeric, neem, and tulasi)

Green synthesis of noble metal nanoparticles (NPs) has gained immense significance compared to other metal ions owing to their unique properties. Among them, palladium ‘Pd’ has been in the spotlight for its stable and superior catalytic activity. This work focuses on the synthesis of Pd NPs using the combined aqueous extract (poly-extract) of turmeric (rhizome), neem (leaves), and tulasi (leaves). The bio-synthesized Pd NPs were characterized to study its physicochemical and morphological features using several analytical techniques. Role of Pd NPs as nano-catalysts in the degradation of dyes (1 mg/2 mL stock solution) was evaluated in the presence of a strong reducing agent (sodium borohydride; SBH). In the presence of Pd NPs and SBH, maximum reduction of methylene blue (MB), methyl orange (MO), and rhodamine-B (Rh–B) dyes was observed under 20nullmin (96.55 ± 2.11%), 36nullmin (96.96 ± 2.24%), and 27nullmin (98.12 ± 1.33%), with degradation rate of 0.1789 ± 0.0273 min−1, 0.0926 ± 0.0102 min−1, and 0.1557 ± 0.0200 min−1, respectively. In combination of dyes (MB + MO + Rh–B), maximum degradation was observed under 50nullmin (95.49 ± 2.56%) with degradation rate of 0.0694 ± 0.0087 min−1. It was observed that degradation was following pseudo-first order reaction kinetics. Furthermore, Pd NPs showed good recyclability up to cycle 5 (72.88 ± 2.32%), cycle 9 (69.11 ± 2.19%) and cycle 6 (66.21 ± 2.72%) for MB, MO and Rh–B dyes, respectively. Whereas, up to cycle 4 (74.67 ± 0.66%) during combination of dyes. As Pd NPs showed good recyclability, they can be used for several cycles thus influencing the overall economics of the process.

Transition-metal blends incorporated into CuO nanostructures: Tuning of room temperature spin-ferromagnetic order

In this study, notable ferromagnetic features were realized in lightly multidoped Cu0·97Mn0·01Fe0·01Ni0·01O composition at room temperature. Variable and dilute multidoped compositions composed of CuO, Cu0·97Cr0·01Mn0·01Fe0·01O, Cu0·97Mn0·01Fe0·01Ni0·01O, and Cu0·97Mn0·01Co0·01Ni0·01O powders were fabricated via coprecipitation approach. The crystal structural analysis of the synthesized compositions indicated that a high purity mono-phase of monoclinic CuO structure was formed and also ruled out the existence of any other impurities. The Fourier-transform infrared (FT-IR) spectra demonstrated the characteristic vibrational absorption modes of CuO structure. The transmission electron microscopy (TEM) images revealed that the pure CuO has approximately nano-sized spherical particles while Cu0·97Cr0·01Mn0·01Fe0·01O, Cu0·97Mn0·01Fe0·01Ni0·01O and Cu0·97Mn0·01Co0·01Ni0·01O powders have nano-spherical particles as well as some elongated particles. Optically, the incorporation of these transition metals blends leads to formation of long absorption tails and obvious red shifts for the band gap energy of CuO. Exactly, CuO, Cu0·97Cr0·01Mn0·01Fe0·01O, Cu0·97Mn0·01Fe0·01Ni0·01O and Cu0·97Mn0·01Co0·01Ni0·01O samples exhibit infrared band gap energies of 1.42, 1.4, 1.25 and 1.2 eV, respectively. Magnetically, at room temperature Cu0·97Mn0·01Fe0·01Ni0·01O exhibits a perfect ferromagnetic performance with high saturation magnetization of 1.15 emu/g and coercivity of 76 Oe. It seems that the multidoping induced a robust ferromagnetic state via Cu2+-Mn + or Mn + -Mn + exchange interactions (M = Mn, Fe, Ni) into CuO, leading to remarkable room temperature magnetic characteristics.

Nanolatex architectonics: Influence of cationic charge density and size on their adsorption onto surfaces with a 2D or 3D distribution of anionic groups

HypothesisIt is theoretically predicted and hypothesized that the charge density and size of spherical nanoparticles are the key factors for their adsorption onto oppositely charged surfaces. It is also hypothesized that the morphology and charge of the surface are of great importance. In-plane 2D (silica) or a volumetric 3D (regenerated TEMPO-oxidized cellulose model surfaces) distribution of charged groups is expected to influence charge compensation and, thus, the adsorption behavior. ExperimentsIn this work, self-stabilized nanolatexes with a range of cationic charge densities and sizes were synthesized through reversible addition − fragmentation chain-transfer (RAFT) polymerization coupled with polymerization-induced self-assembly (PISA). Their adsorption onto silica and anionic cellulose model surfaces was investigated using stagnation point adsorption reflectometry (SPAR) and quartz crystal microbalance with dissipation (QCM-D). FindingsExperiments and theory agree and show that the size of the nanolatex and the difference in charge density compared to the substrate determine the charge compensation and, thus, the surface coverage. Highly charged or large nanolatexes overcompensate the surface charge of non-porous substrates leading to a significant repulsive zone where other particles cannot adsorb. For porous substrates like cellulose, the vertical distribution of charged groups in the 3D volume prevents overcompensation and thus increases the adsorption. This systematic study investigates the isolated effect of surface charge and size and paves the way for on-demand particles specifically designed for a surface with particular characteristics.

Ameliorative effect of chitosan nanoparticles against carbon tetrachloride-induced nephrotoxicity in Wistar rats

Context Chitosan is a biocompatible polysaccharide that has been widely exploited in biomedical and drug delivery applications. Objective This study explores the renoprotective effect of chitosan nanoparticles in vivo in rats. Materials and methods Chitosan nanoparticles were prepared via ionotropic gelation method, and several in vitro characterizations were performed, including measurements of particle size, zeta potential, polydispersity index, Fourier transform-infrared spectroscopy, differential scanning calorimetry, and transmission electron microscopy (TEM) imaging. Wistar rats were divided randomly into four groups; negative control, CCl4-induced nephrotoxicity (untreated), and two groups receiving CCl4 + chitosan NPs (10 and 20 mg/kg) orally for 2 weeks. The renoprotective effect was assessed by measuring oxidative, apoptotic, and inflammatory biomarkers, and via histopathological and immunohistochemical examinations for the visualization of NF-κB and COX-2 in renal tissues. Results Monodisperse spherical nanosized (56 nm) particles were successfully prepared as evidenced by dynamic light scattering and TEM. Oral administration of chitosan nanoparticles (10 and 20 mg/kg) concurrently with CCl4 for 2 weeks resulted in 13.6% and 21.5% reduction in serum creatinine and increase in the level of depleted reduced glutathione (23.1% and 31.8%), respectively, when compared with the positive control group. Chitosan nanoparticles (20 mg/kg) revealed a significant (p ˂ 0.05) decrease in malondialdehyde levels (30.6%), tumour necrosis factor-α (33.6%), interleukin-1β (31.1%), and caspase-3 (36.6%). Conclusions Chitosan nanoparticles afforded significant protection and amelioration against CCl4-induced nephrotoxicity. Thus, chitosan nanoparticles could afford a potential nanotherapeutic system for the management of nephrotoxicity which allows for broadening their role in biomedical delivery applications.

Influence of Addition of Ti Particles and Processing Condition on Microstructure and Properties of Selectively Laser-Melted Invar 36 Alloy.

Invar 36 exhibits extremely low thermal expansion coefficients at low temperatures but also low yield strength (YS), which greatly restricts its application as a structural material. In this study, a small fraction of pure titanium powder particles was added into Invar 36 by powder mixing and selective laser melting (SLM) with the aim of further improving tensile strengths of Invar 36. It was found that increased laser power led to increased grain size and to slight decrease in YS in Invar 36. During SLM, amorphous SiO2 nanoparticles were formed and homogeneously distributed in Invar 36. With the addition of 2 at% Ti powder particles, grains became larger and the crystallographic texture along <001> and <111> increased to some extent. Moreover, the bottom of solidified melt pools was segregated with Ti while the matrix was homogeneously decorated by a great number of nano-sized spherical Ti2O3 particles. These particles were found to have effectively impeded dislocation motion during plastic deformation, leading to significant improvement in 0.2% YS and ultimate tensile strength. The above precipitation led to consumption of a small amount of Ni from the matrix, which caused a minor compromise in thermal expansion properties. Nonetheless, the newly synthesized Invar 36-Ti alloy still exhibits low thermal expansion coefficients at low temperatures and remarkably enhanced tensile strengths.

Hydrothermal synthesis of bentonite carbon composites for ultra-high temperature filtration control in water-based drilling fluid

In this study, bentonite hydrothermal carbon composites (BHCCs) were fabricated by green and facile hydrothermal carbonization, employing glucose as the carbon source and bentonite as the template. BHCCs were characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The effects of the BHCCs on the rheological and filtration properties of bentonite dispersions were investigated before and after thermal aging at 220 °C and 240 °C, respectively. The results demonstrated that, unlike conventional synthetic polymers, the BHCCs exhibited a minor influence on the rheology of bentonite dispersion and had extraordinary filtration control both before and after ultra-high-temperature aging. The incorporation of BHCCs helped introduce the oxygenated groups with carbon species, thereby enhancing the dispersion stability of bentonite particles. The spherical nano-sized carbon particles in BHCCs filled the gaps between large particles in the filter cake. The above factors contributed to excellent filtration control under hostile, high-temperature conditions.

High-performance microwave absorbers based on (CoNiCuZn)1−xMnxFe2O4 spinel ferrites

(CoNiCuZn) 1−x Mn x Fe 2 O 4 ferrite powders (x = 0.05, 0.1, 0.2, and 0.3) were easily prepared by the solution combustion method for absorption of electromagnetic microwaves. The effects of Mn contents on the structure, microstructure, and magnetic and microwave absorption properties were studied by various characterization methods. Single-phase spinel ferrites with a space group of Fd 3 ̅ m were directly formed by the combustion method without further heat treatment. The lattice parameter increased with adding the Mn 2+ ions, and the fraction of Fe 3+ cations in (A) sites decreased because of the redistribution of various cations. The average size of spherical nanoparticles increased from 55 to 130 nm for x = 0.1 and decreased up to 70 nm for x = 0.3. The saturation magnetization first decreased from 69 to 54 Am 2 /kg for x = 0.2 and then increased to 70 Am 2 /kg for x = 0.3. The coercivity decreased from 17.9 to 11.6 kA/m with Mn 2+ substitution. The (CoNiCuZn) 0.95 Mn 0.05 Fe 2 O 4 /paraffin composite sample exhibited the maximum reflection loss of − 40 dB at Ku band (17 GHz) in the matching thickness of 5.3 mm. With the increase of Mn 2+ content, the reflection loss decreased to − 33 dB at the matching frequency of 4.2 GHz (C2 band). However, the (CoNiCuZn) 0.7 Mn 0.3 Fe 2 O 4 sample had a wide effective bandwidth of 3.2 GHz at the matching thickness of 4.3 mm because of its good impedance matching caused by the proper combination of permittivity and permeability values. • Single-phase (CoNiCuZn) 1−x Mn x Fe 2 O 4 powders were directly synthesized by the solution combustion method. • The Hc decreased from 225 to 146 Oe, while the Ms remained increased up to 69 emu/g with adding Mn. • The 70 wt% (CoNiCuZn) 0.7 Mn 0.3 Fe 2 O 4 /paraffin composite sample exhibited a high reflection loss of − 33 dB with the bandwidth of 3.9 GHz.

Effect of preparation conditions on the size of nanoparticles based on poly(D,L-lactide-co-glycolide) synthesized with bismuth subsalicylate

Spherical nano-sized particles of poly(D,L-lactide-co-glycolide) (PLGA) with molar composition of D,L-lactide and glycolide 75:25 mol.% synthesized with non-toxic catalyst bismuth subsalicylate were produced by a nanoprecipitation method. The effect of the formulation parameters (i.e. concentrations of PLGA in the organic phase and poly(vinyl alcohol) (PVA) in the aqueous phase) on the average hydrodynamic diameter, polydispersity index and electrokinetic potential of the PLGA particles was revealed. A formation mechanism of the PLGA particles based on the “nucleation and aggregation” model was proposed and supported by experimental data. Steric and electrokinetic stabilization factors of the PLGA particles were analyzed and discussed.

Long term antifouling performance of superhydrophobic surfaces in seawater environment: Effect of substrate material, hierarchical surface feature and surface chemistry

Biofouling is a serious concern for the materials that are in contact with seawater or brackish water. Superhydrophobic (SHP) surfaces have the potential to lower fouling. Although good progress is made on the design of SHP surfaces, the long-term antifouling performance of SHP surfaces is still a major concern. We report the effect of substrate material, hierarchical surface features, chemistry, and the nature of bacteria on the long-term antifouling properties of superhydrophobic for the first time. Three different superhydrophobic coatings on aluminum, Cr-Mo steel, and Ti substrates were studied in a seawater bacterial consortium. Silane based SHP Al with a water contact angle (WCA) ~170 ± 1.5°, cerium myristate based SHP Cr-Mo of WCA ~ 162 ± 2.4° and stearic acid based SHP Ti of WCA ~168 ± 3.3° were prepared by dip coating, electrodeposition, and rapid breakdown anodization, respectively. After 120 h of exposure in seawater bacterial consortium, the cell viability reductions were three, two and one order in SHP Al, SHP Cr-Mo, and SHP Ti, respectively. The SHP Al samples possessed both micron-sized structures (~2 µm) along with nano-sized spherical particles (~ 57 nm). The quat silane-like structures gave better antibacterial resistance to SHP Al. The predominant bacteria present on bare Al,Ti, Cr-Mo and SHP Al, and Ti surfaces after exposure were Bacillus and Pseudomonas sp., whereas cocci bacteria was seen on the SHP Cr-Mo. After 240 h of exposure, a thicker biofilm was seen on the SHP Cr Mo surface due to the densely populated nanostructures of sizes comparable to cocci diameter, which was favorable for the cocci bacterial attachment. Though the average WCA followed the trend SHP Ti> SHP Al>SHP Cr Mo, the bacterial adhesion trend was SHP Ti> SHP Cr Mo> SHP Al, after 120 h of exposure. This suggests that wettability is not the only parameter determining the antifouling performance of an SHP coating but is also influenced by the surface charge density, surface roughness, stiffness, topography, and environmental variables such as fluid dynamics, bacterial motility, and size and morphology of bacteria. Both the surface morphology and the chemical nature were responsible for this reduced cell viability of the SHP Al surface. These findings not only provide new insights into the understanding of long-term biofouling of SHP surfaces but also would provide new directions in the design of robust SHP surfaces.

Role of deposition temperature and Sn content on structural, optical & electrical properties of In2O3 thin films

High quality indium tin oxide (ITO) thin films (In2−xSnxO3: x = 0, 0.1 and 0.2) have been grown by using pulsed laser deposition technique on quartz substrates. The structural, morphological, optical and electrical investigations of deposited films have been studied as a function of substrate deposition temperatures and the Sn compositions. X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) patterns affirm that each film is polycrystalline in nature with cubic bixbyite single phase structure which preferentially oriented along (222) Miller plane. The existence of chemical bonding and functional groups was investigated by FTIR spectroscopy. The TEM micrograph of films (@450°C) for x = 0.1 and x = 0.2 reveal spherical morphology with average particle size 63 nm and 51 nm, respectively. The SEM and AFM images show uniform flower like surface morphology and well-demonstrated nanosized spherical particles, respectively. The widening of the band gap of all the films were exclusively defined by Burstein-Moss shift. The Hall measurement reveals that each film is degenerate with n-type semiconducting nature along with high mobility. Low resistivity (2.024 × 10−4 Ω-cm) and high transparency (92.58%) along with high carrier concentration (8.915 × 1020cm−3) were optimized for x = 0.1 film at 450°C deposition temperature.

Characterization, Catalytic, and Recyclability Studies of Nano-Sized Spherical Palladium Particles Synthesized Using Aqueous Poly-Extract (Turmeric, Neem, and Tulasi)

Characterization, Catalytic, and Recyclability Studies of Nano-Sized Spherical Palladium Particles Synthesized Using Aqueous Poly-Extract (Turmeric, Neem, and Tulasi)