Nano Size Research Articles

Monitoring the Rheological Properties of Asphalt Cement after Digestion with Micro and Nano Size Additives

Monitoring the Rheological Properties of Asphalt Cement after Digestion with Micro and Nano Size Additives

Biosynthesized Silver Nanoparticles Using Alnus nitida Leaf Extract as a Potential Antioxidant and Anticancer Agent.

Biogenic synthesis of silver nanoparticles (AgNPs) using plant extracts is gaining attention as a substitute to the conventional physical and chemical synthesis methods. This study reports a facile, cost-effective, and ecofriendly synthesis of AgNPs using leaf extract of Alnus nitida (A. nitida) and their antioxidant and antiproliferative activities. The biosynthesized AgNPs were characterized using various analytical techniques including UV-visible spectroscopy, energy-dispersive spectrometry, scanning electron microscopy (SEM), Fourier transform infrared (FTIR), X-ray diffraction (XRD), and dynamic light scattering. The antioxidant and cytotoxic potential of the extract and AgNPs was evaluated using different in vitro models. The UV-vis analysis revealed a surface plasmon resonance peak of 400 nm corresponding to the synthesis of AgNPs. SEM analysis confirmed the formation of heterogeneously dispersed particles of nano size, while the XRD and FTIR spectra confirmed the crystallinity and existence of different functional groups that helped in capping and stability of AgNPs. The antioxidant activity of AgNPs and extract, studied by 1,1-diphenyl 2-picryl hydrazyl (DPPH), fluorescence recovery after photobleaching (FRAP), 2, 2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and H2O2 scavenging assays, showed a dose-dependent effect. The AgNPs at 1000 μg/mL significantly scavenged DPPH, FRAP, ABTS, and H2O2 by 66.45, 74.65, 78.81, and 72.56% with an average IC50 value of 33.31, 18.50, 16.46, and 15.65 μg/mL, respectively. The cytotoxic potential investigated by MTT assay revealed promising antiproliferative effects against different cancer cell lines. The IC50 values of AgNPs on MDA-MB-231, A549, and Hep-G2 cells were 14.88, 3.6, and 5.38 μg/mL, respectively. The results showed that AgNPs were more effective against lung and hepatocellular carcinoma. The selectivity index showed that AgNPs remained highly selective in retarding the growth of A549 and Hep-G2 cells as compared to normal cell lines HPAEpiC and HRPTEpiC. Overall, this study showed that biosynthesized AgNPs were associated with considerable antioxidant and cytotoxic effects. Our work suggests that A. nitida-mediated AgNPs should be evaluated further in order to develop safe and effective formulations for the treatment of different degenerative diseases.

Recent advances in the effective removal of hazardous pollutants from wastewater by using nanomaterials—A review

Environmental nanotechnology has developed rapidly over the past few decades due to the fast advancement of nanotechnology and nanomaterials (NMs). Due to their nanoscale size, NMs are receiving immense attention in research and development worldwide. Their nano size has led to better catalysis, high reactivity, and high adsorption capacity. In wastewater treatment, nanotechnology has significant potential to improve the performance and efficiency of water decontamination; more effectively, it provides a sustainable way to keep water supplies safe. Numerous studies have found that removing harmful components from wastewater by employing nanoparticles in conjunction with various treatment methods is effective. The purpose of the current investigation is to conduct a review of the envisioned applications of various NMs in the treatment of wastewater. These NMs include carbonaceous NMs, metal-containing nanoparticles, and nanocomposites, all of which will be reviewed and highlighted in depth.

3D bioprinting for diagnostic and therapeutic application

Application 3D printing technology in medical diagnosis and therapeutics had revolutionaries the health care sector. 3 D bioprinting based on additive manufacturing process which helps in development of smart, low cost, precise, patient specific medical solution. It deals from designing and development of artificial implants, orthotic, prosthetics to development of wound healing dressing material, mems-based biosensors arrays that could be used for diagnostic and therapeutic applications. Advances in 3D printing methods could help in synthesizing precise drug to its nano size and development of smart controlled patient specific drug release system. 3D bioprinting from macro scale to nanoscale involves the method known as solid free form fabrication in combination of bio-ink or biomaterials. The development of patient specific 3D model done from medical images like Computer Tomography (CT) and Medical Resonance imaging (MRI) and its analysis is done on commercially available simulating software. In this paper the detailed latest applications and methods of 3D bioprinting in various emerging diagnostic and therapeutic techniques was discussed.

The Effect of Milling Time on Band Gap Value in Thin Layers of Nano Photocatalyst MnO2/CuO/Fe2O3

Waste from laundry washing discharged into waterways without pre-treatment can cause problems that hurt water quality because they contain oxidizing agents such as bleach for clothes. This study aims to determine the effect of milling time variations on the value of the band gap in thin film MnO2/CuO/Fe2O3 and their photocatalytic activity capabilities. This study’s milling time variations were 5 hours, 10 hours, and 15 hours. They were grinding MnO2/CuO/Fe2O3 materials using a High Energy Milling (HEM-E3D) tool to obtain the nano size of these particles. Synthesis of MnO2/CuO/Fe2O3 nanocomposites using the sol-gel method and the spin coating method to manufacture thin films using a glass substrate to be sampled in testing photocatalyst activity. Characterization testing uses a spectroscopy (Uv-Vis) tool to obtain a band gap value. The band gap values were 5 hours milling at 1.87 eV, 10 hours milling at 1.72 eV, and 15 hours milling at 1.64 eV. Here it shows that the longer the milling time, the smaller the band gap energy obtained. Shrinking the energy gap will experience a good photocatalyst process. The results of this study show the effect of the catalyst in degrading pollutants with the best degradability of 50.67%.

In-situ constructing pearl necklace-shaped heterostructure: Zn2+ substituted Na3V2(PO4)3 attached on carbon nano fibers with high performance for half and full Na ion cells

Na3V2(PO4)3 (NVP) emerges as prospective cathode for sodium ion batteries. However, the poor electronic and ionic conductivity hinders its development. Traditional synthesis methods only allow ex-situ bonding between the NVP grains and carbon-based substrate, leading to unstable combination. Herein, a simultaneous modification strategy to optimize the morphological features and crystal construction of NVP system is proposed. The in-situ synthesized framework consisting of NVP and high conductive carbon nano fibers (CNFs) can efficiently elevate the electrochemical performance. A distinctive pearl necklace-shaped heterostructure is successfully constructed by electrospinning and carbon-thermal reduction routes. The necklace substrate is derived from the CNFs, possessing the unique unidimensional morphology and bridging well with each other to build a high conductive network. The Zn2+-substituted NVP grains with nano size are grown on the surface of the substrate. The shortened size provides short pathway for Na+ migration, resulting in the improved kinetic characteristics. Furthermore, the substitution of Zn2+ generates p-type doping to introduce favorable hole carriers, enhancing the ionic conductivity. The reduced band gap and migration energy barrier of Na+ for Zn2+ doped NVP is demonstrated by DFT calculations. Accordingly, the modified Zn0.07-ES-800 sample releases a high capacity of 117.5 mA h g−1 at 0.1C. It delivers a capacity of 92.3 mA h g−1 at 100C and maintains 72.7 mA h g−1 after 1000 cycles. Moreover, the Zn0.07-ES-800//Zn0.07-ES-800 full cell shows a high capacity of 94.4 mA h g−1 at 0.1C and keeps 80 mA h g−1 at 1C with a high retention of 95% after 70 cycles.

Geomorphometry and microelectronic metrology: Converged realms

AbstractThis article discusses the application of geomorphometric methods in microelectronic metrology. Six typical microelectronic items were geomorphometrically analyzed using their digital elevation models with nano‐ and micrometer‐range resolution and elevation difference: (1) a silicon–quartz structure; (2) a mechanically polished silicon wafer; (3) a photovoltaic blend sample; (4) an X‐ray optical element (a fused quartz spherical concave substrate); (5) a Bosch process‐formed, 20 aluminum layered membrane; and (6) a silicon–glass assembly with a volumetric defect. Geomorphometric modeling increases significantly the visibility and informativeness of data presentation, allowing to identify effectively the spatial distribution of nano‐ and microforms of the surface of microelectronic items. Geomorphometric methods provide an opportunity to study the size, location, and characteristic features of nano‐ and microtopographic inhomogeneities of microelectronic items using maps of minimum, maximum, mean, and unsphericity curvatures as well as other morphometric variables.

Catalytic dechlorination of 1,2-DCA in nano Cu0-borohydride system: effects of Cu0/Cun+ ratio, surface poisoning, and regeneration of Cu0 sites

Aqueous-phase catalyzed reduction of organic contaminants via zerovalent copper nanoparticles (nCu0), coupled with borohydride (hydrogen donor), has shown promising results. So far, the research on nCu0 as a remedial treatment has focused mainly on contaminant removal efficiencies and degradation mechanisms. Our study has examined the effects of Cu0/Cun+ ratio, surface poisoning (presence of chloride, sulfides, humic acid (HA)), and regeneration of Cu0 sites on catalytic dechlorination of aqueous-phase 1,2-dichloroethane (1,2-DCA) via nCu0-borohydride. Scanning electron microscopy confirmed the nano size and quasi-spherical shape of nCu0 particles. X-ray diffraction confirmed the presence of Cu0 and Cu2O and x-ray photoelectron spectroscopy also provided the Cu0/Cun+ ratios. Reactivity experiments showed that nCu0 was incapable of utilizing H2 from borohydride left over during nCu0 synthesis and, hence, additional borohydride was essential for 1,2-DCA dechlorination. Washing the nCu0 particles improved their Cu0/Cun+ ratio (1.27) and 92% 1,2-DCA was removed in 7 h with kobs = 0.345 h−1 as compared to only 44% by unwashed nCu0 (0.158 h−1) with Cu0/Cun+ ratio of 0.59, in the presence of borohydride. The presence of chloride (1000–2000 mg L−1), sulfides (0.4–4 mg L−1), and HA (10–30 mg L−1) suppressed 1,2-DCA dechlorination; which was improved by additional borohydride probably via regeneration of Cu0 sites. Coating the particles decreased their catalytic dechlorination efficiency. 85–90% of the removed 1,2-DCA was recovered as chloride. Chloroethane and ethane were main dechlorination products indicating hydrogenolysis as the major pathway. Our results imply that synthesis parameters and groundwater solutes control nCu0 catalytic activity by altering its physico-chemical properties. Thus, these factors should be considered to develop an efficient remedial design for practical applications of nCu0-borohydride.

Investigation of Free Vibrations of Stepped Nanobeam Embedded In Elastic Foundation

The free vibration of stepped nanobeams embedded in the elastic foundation was investigated using Eringen's nonlocal elasticity theory. It is fixed at the system ends with a simple-simple support. The stepped nanbeam’s equations of motion are obtained by using Hamilton's principle. Multi-time scale, which is the perturbation methods, was used for the analytical solution of the equations. To observe the effects of nano size effect, elastic basis coefficient and step location, natural frequencies of the first three modes of the system were obtained for different non-local parameter values, elastic foundation coefficients, step rates and step positions. In the results, it was seen that the non-local parameter had a negative effect on the natural frequency. The elastic foundation coefficient has been shown to reduce vibration amplitudes.

Novel and Advanced Method of Tracking the Dementia cases using Global Positioning System (GPS) Incorporated Cheek Plumper an Indispensable System in Dentistry

New inventions will lay a new path,accordingly this is a novel technique in which GPS (Global Positioning System)is technically incorporated into the cheek plumpers of complete dentures. This technology will help to track a wide range of applications like patients with Alzheimer’s disease,dementia,old age patients suffering from neurological disorders, mental disorders and patients missing through natural calamities.Furthermore, in corporation of nano size GPS in denture makes it more comfortable for the patient. Also, it will help their families to point out them easily. This new approach will bring about a drastic change in dentistry.

Thermal and Surface Area Properties of Micro and Nano Sized Pumice

Raw pumice samples were modified with nano carbon black, borax, and nano carbon-borax using the sol-gel method by applying surface modification processes, and the changes in the thermal behavior of the surface modification of the raw pumice were studied by characterizing them with FE-SEM, EDX, FT-IR, XRD, BET and TGA-DTA. In the analyses made with FE-SEM, it was observed that the surface and pore structure of the raw pumice changed after the modified process, and in the EDX analysis, it was determined that nano carbon black and borax adhered to the surface of the raw pumice. In the XRD results, no change in the crystal structure of the raw pumice was observed after the modified treatment. TGA-DTA analysis showed that the mass loss of raw pumice (P) was greater than pumice-nano carbon black (PC), pumice-borax (PB), and pumice-borax-nano carbon black (PBC). Accordingly, raw pumice showed a mass loss of approximately 25%, pumice-borax (PB) and pumice-nano carbon black (PC) 0.45%, and pumice-borax-nano carbon black (PBC) nearly 3%. According to the BET analysis results, it was determined that the raw pumice has a surface area of 28.126 m2/g. After the surface modification process, the surface area of the raw pumice was determined as 52.127 m2/g in the pumice-nano carbon black sample, 49.125 m2/g in the pumice-borax sample, and 32.523 m2/g in the pumice-borax-carbon black sample. Considering the data obtained, the best surface properties were showed in pumice-nano carbon black (PC). Research results showed that; the modification process with nano carbon black and borax changed the thermal behavior of raw pumice.

Enrichment of free oil in alkaline lacustrine Fengcheng Formation in Mahu Sag

Estimation of free hydrocarbon quantities in tight formations where pore sizes are at the nano and micron size is very important to understand formation producibility. In the Mahu sag, the Fengcheng Formation is being considered as an important source rock. Although the importance, characteristics of the Fengcheng Formation in terms of controlling factors on the enrichment of free vs. adsorbed hydrocarbons in pore spaces is still not clear. In this study, 13 samples were collected from the Fengcheng Formation and a combination of analytical techniques: X-ray diffraction analysis (XRD), nitrogen gas adsorption, total organic content (TOC), and Rock Eval pyrolysis were employed to analyze the microstructures and geochemical properties of the samples. These analyses were performed on two groups: 1) intact samples and 2) when the soluble hydrocarbon were extracted from the samples. The pore surface area and pore volume were measured slightly higher in the latter group, which were around 2.12 and 1.23 times of the intact samples, respectively. Moreover, deconvolution of pore size distribution (PSD) curves demonstrated that soluble oil mainly exists in the pore phases: 1, 2, 3, and 4 with the mean pore diameter of 15, 35, 51, and 67 nm, respectively. Overall, the oil in the samples of the Fengcheng Formation can become enriched with mobile (vs. adsorbed) fluids if the quantities of the free generated oil and pore size, each exceeds 0.7 wt% and 10.94 nm, respectively. This study can help researchers deepen their understandings of oil mobility and the evaluation of formation producibility in reservoirs deposited in an alkaline lake sedimentary environment.

Synthesis of Bio Nanocatalyst of ZnO Nanoparticles using Ocimum Basilicum Leaves

The aqueous extract of Ocimum basilicum leaves and zinc salts (zinc sulphate) was used as precursors in this investigation to create zinc oxide nanoparticles. ultraviolet-visible spectroscopy, scanning electron microscopy, Dynamic light scattering (DLS) were used to characterize the produced nanoparticles. (SEM), Energy-dispersive X-ray analysis (EDX), Because UV-Vis spectra exhibit absorption peaks in the 350 nm range. DLS analysis prove the nano size for the prepared colloidal of zinc oxide nanoparticles. SEM investigations showed a spherical shape with an average size of (30-80) nm. Analysis of (EDX) showed that elementary analysis was which are 31.8% and oxygen is 21.3%.

Engaging Preschoolers in STEAM Education: An Adaptation of a Nano-Literacy Program in Distance Education

The aim of this paper is to present a program in nanoscience and nanotechnology (NST) to pre-school children through distance education. The activities followed the teaching learning sequence (TLS) methodology and dealt with: a) the nano scale and size, b) exposing children to appropriate instruments/tools through which they investigated elements of the nanoworld and c) raising pre-school children’s awareness of applications of nanotechnology, based on the interdisciplinary STEAM approach. For this reason, a series of organized activities which had been implemented at an earlier time in a kindergarten setting were redesigned to meet the current needs of the children in the context of distance learning during the pandemic lockdown. The results from the implementation of the learning sequence were very encouraging in terms of the perceptual and exploratory abilities of the preschool children. By the end of the program, the children were able to identify "nano" size materials. In addition, they seemed to be able to reflect on the application of nanotechnology in their daily lives.

Gum Arabic polysaccharide embedded L-cysteine capped copper oxide nanocarriers selectively inhibit fluconazole-resistant C. albicans biofilm and remove the toxic dye from wastewater

Copper oxide nanocarriers have attracted increasing interest in the scientific community, including antimicrobial applications. Candida biofilm developed causes serious clinical problems, leading to drug failure caused by its inherent drug tolerance. Nanocarriers are a good alternative approach to solving this challenge because of their excellent penetration power inside biofilms. Hence, main objectives of this research were to prepare gum arabic-embedded L-cysteine-capped copper oxide nanocarriers (GCCuO NCs) and tested against C. albicans and explore another application. To achieve the main research objectives, GCCuO NCs were synthesized and investigated for antibiofilm potency against C. albicans. Various methods were employed to measure antibiofilm potency such as biofilm assay etc., of NCs. The nano size of GCCuO NCs is advantageous for augmenting penetration power and retention into biofilms. GCCuO NCs at 100 μg/mL exhibited significant antibiofilm activity against the C. albicans DAY185 by switching of yeast-to-hyphae and gene perturbation. The level of CR dye adsorption was 58.96 % using 30 μg/mL of NCs. Based on effective C. albicans biofilm inhibition and CR dye adsorption capacity of NCs, it can be suggested that present research work opens an innovative path to treat biofilm-associated fungal infections, and these NCs can be used for environmental remedies.

Development of creep resistant high yttria 18Cr ferritic ODS steel through hot powder forging route

The present work reports the creep behaviour of a high yttria Fe-18Cr-2W-0.57Ti-1Y2O3 (all compositions in wt.%) ferritic oxide dispersion strengthened (ODS) steel produced by powder forging. The creep tests were carried out in a temperature range of 873 K to1023K and a stress range of 150 MPa to 425 MPa. Creep data is analysed using the power law creep equation. A large value of stress exponents (n ∼ 10 at 873 K, ∼ 18 at 923 K and 8.5 at 973 K) and a high activation energy (Q ∼581 kJ/mol) are obtained. These high values are attributed to threshold stress (σth) generated due to attractive interaction between dislocation and oxide particles. Threshold stress for different creep conditions was determined. True stress exponent values of 4 to 5 were obtained after accounting for the threshold stress. Electron back scattered diffraction (EBSD) revealed an equiaxed strain free grain structure in the powder forged ODS steel. Transmission electron microscopy (TEM) of creep tested samples indicates that microstructure remains stable after creep with no significant coarsening of nano size oxide particles. Dislocation pinning by the oxide particles was observed in creep tested samples. The observed values of true stress exponent suggest dislocation climb over the nano oxide particles to be the creep mechanism operating in the ODS steel. Samples sections close to creep fracture surfaces were investigated by EBSD. Void formation at triple junctions followed by crack propagation normal to the loading direction was observed. All the samples exhibited mixed mode (cleavage + ductile dimple) failure. Conventional ODS steel compositions contain up to 0.35% yttria. A significant improvement in creep life as well as an increase in activation energy for creep was observed because of high (1%) yttria content used in the ODS steel studied.

Application of nano size ZSM-48 zeolite framework for toluene methylation to p-xylene

Methylation of toluene with methanol to p-xylene over conventional HZSM-5 zeolites is accompanied by various unwanted reactions. Narrowing of pores and lowering of acidity of HZSM-5 zeolites to maximize p-xylene have resulted into trade-off between p-xylene selectivity and toluene conversion. ZSM-48 zeolites, owing to narrower pores and lower acidity than ZSM-5, can be useful for direct utilization for toluene methylation. Further, such zeolites with reduced crystal sizes can shorten the pore retention time for small and highly reactive methanol and eliminate diffusion limitations to toluene and p-xylene molecules respectively to avoid methanol overuse in side reactions and to improve catalytic activity for toluene methylation. Envisaging above advantages, objective of the present work is to synthesize nano size ZSM-48 zeolite and demonstrate combined role of its narrow pore, less acidity and small crystals in maximization of p-xylene in toluene methylation reaction. Morphology and crystal information for prepared ZSM-48 are obtained from Field Emission Scanning Electron Microscopy and High Resolution Transmission Electron Microscopy. Results revealed 44% p-xylene selectivity and 26% toluene conversion at 400 °C, improved methanol utilization and remarkable catalyst stability with no sign of drop in catalyst activity for 120 h time on stream study.

Biosynthesis and characterization of copper nanoparticles from Stenotrophomonas maltophilia and its effect on plant pathogens and pesticide degradation

Nanotechnology has gained popularity in recent years despite its early stage of development due to its capability of modulating metals into their Nano size, which leads to changes in the chemical, physical and optical properties of metals. Due to their distinctive characteristics, which make them useful in several domains of science and technology, the production of nanostructured materials, notably metallic nanoparticles, has attracted enormous interest over the past few decades. Strain SCS1.1 (Stenotrophomonas maltophilia) was chosen for the in vitro production of copper nanoparticles based on its greatest capacity to synthesize copper nanoparticles. Maximum copper nanoparticle synthesis was accomplished using 5.0% peptone, 4.0 mM copper sulfate, 3.0% beef extract, as well as 4.0% microbial inoculum size after 48 h of incubation at 30 °C and pH 8.0. Under ideal conditions, copper nanoparticles were produced in vitro through biosynthesis, and they were examined using TEM, SEM, FTIR, XRD, UV–visible spectroscopy, and DLS. The copper nanoparticles made from the S. maltophilia strain SCS1.1 were also tested for their ability to suppress several bacterial infections. The outcome demonstrates that the NPs were created and exhibited strong antibacterial, as well as antifungal activity and suspension and have the potential to break down these pesticides.

Metformin-loaded nanoerythrosomes: An erythrocyte-based drug delivery system as a therapeutic tool for glioma

Glioma is an intra-cranial malignancy with the origin of neural stem cells or precursor cells, the most prevalent brain tumor worldwide. Glioblastoma, the fourth-grade glioma, is a common brain tumor whose incidence rate is 5–7 people per 100,000 populations annually. Despite their high mortality rate, all efforts for treatment have yet to achieve any desirable clinical outcome. The Wnt signaling pathway is a conserved pathway among species that seems to be a candidate for cancer therapy by its inhibition. Metformin is a known inhibitor of the Wnt signaling pathway. Its effects on glioma treatment have been observed in cellular, animal, and clinical experiments. Nanoerythrosomes are drug carriers obtained from the cellular membrane of red blood cells in nano size which can offer several characteristics to deliver metformin to brain tumors. They are good at loading and carrying hydrophilic drugs, they can protect metformin from its metabolizing enzymes, which are present in the blood-brain barrier, and they can extend the period of metformin presence in circulation. In this study, nanoerythrosomes were prepared by using the hypotonic buffer. They had particle sizes in the range of 97.1 ± 34.2 nm, and their loading efficiency and loading capacity were 72.6% and 1.66%, respectively. Nanoerythrosomes could reserve metformin in their structure for a long time, and only 50% of metformin was released after 30 h. Moreover, they released metformin at a low and approximately constant rate. Besides, nanoerythrosomes could tolerate various kinds of stress and maintain most of the drug in their structure. Altogether, nanoerythrosome can be a suitable drug delivery system to deliver therapeutic amounts of metformin to various tissues.

An electrochemical sensor for the detection of arsenic using nanocomposite-modified electrode

The aim of this research is to develop an electrochemical sensor based on a conducting polymer, polyaniline, and a cationic polymer, poly(diallyldimethylammonium chloride), reinforced with graphene oxide nanosheets functionalized with acrylic acid. The two-dimensional nature of acrylic acid functionalized graphene oxide nanosheets and clusters made of conductive polymers and acrylic acid functionalized graphene oxide nanosheets were confirmed by microscopic tests. The prepared nanocomposite was deposited on the glassy carbon electrode in order to prepare an electrochemical sensor for the detection of arsenic by cyclic voltammetry and differential pulse voltammetry methods. It should be mentioned that the presence of acrylic acid functionalized graphene oxide nanosheets increases the surface area due to the nano size effect and better dispersion of this nanomaterial, poly(diallyldimethylammonium chloride), increases the adsorption capacity of the analyte due to electrostatic interaction between the negatively charged analyte and positively charged surface, and polyanilin increases the charge transfer rate due to the good conductivity. The results show that the prepared electrode has a sensitivity equal to 1.79 A/M with 0.12 μM as the detection limit. The proposed sensor could be used for the determination of total inorganic arsenic by first oxidative pretreatment for conversion of As(III) to As(V).