Nanomembranes Research Articles

Influence of Novel Nano Membranes on Quality Characterizes of Cucumber During Storage

The influence of novel nano membranes on the quality characterizes of cucumber fruits during storage was evaluated. Chitosan (C), Titanium dioxide nanoparticles (T), and sodium tripolyphosphate (S) were used for the synthesis of novel nano membranes. Samples were divided into four lots. One lot was coated with water; another with C-Film, another with C/T-Film, and the fourth lot with C/T/S-Film. All the samples were dried with forced air at 25 °C for 1 h. Samples were stored in plastic trays for 21 days and evaluated every 7 days (0, 7, 14, and 21 days) at 10 °C. Quality characterizes included texture-profile analysis, pitting and warts appearances rates, acidity, pyruvate enzyme oxidation, and microbial population, especially psychrophilic bacteria. Results revealed that the C/T-Film treated cucumber samples showed the lowest values loss in almost all the texture analysis, gumminess (N) 441.79, resilience 0.035, hardness (N) 1145.02, and cohesiveness 0.19, compared to other coating treatments; while cucumber samples treated with (C/T/S-Film) established the lowest values loss in chewiness (N) 231.41. Cucumber samples treated with C/T/S-Film showed the lower value of pitting and appearance rates 0.67 and 0.21, respectively. For cucumber samples treated with C/T-Film and C/T/S-Film reported the same acidity values as 4.63 at the end of the storage period. The pyruvate enzyme oxidation was higher (187.53 n mol/kg FW) in cucumber fruits treated with C/T/S-Film, compared with cucumber treated with C/T-Film that recorded value of 166.09 n mol/kg FW. After 21 days of the storage period, C/T/S-Film-coated samples had the least psychrophilic bacterial counts 7.03 Log CFU/g, lower than C/T-Film-coated samples 7.6 Log CFU/g. So, in the current work novel nano membranes, consisting of chitosan, titanium dioxide nanoparticles, and sodium tripolyphosphate were effective to extend the shelf-life of cucumbers until 21 days during storage.

Analysis of Expression of Diabetic Nephropathy-Related Protein and Stem Cell Tissue Repair Under Nano Membrane Concentration Technology

This study aimed to study protein expression in diabetic nephropathy (DN) rats and stem cell tissue repair based on nanomembrane concentration technology. Based on the polymer porous self-assembled nanomembrane technology, the content of total protein and albumin in the serum of rats in the control and experimental groups were measured. The obtained images were adopted to analyze the expression of cytoplasmic proteins and membrane proteins, and then the mechanism of stem cell tissue repair function was studied. The results showed that at 56 weeks of age, in contrast to control group, the total protein content in the serum of the experimental group evidently decreased. At 36 weeks of age, the cytoplasmic protein samples of diabetic rats in the experimental group were subjected to three two-dimensional protein electrophoresis. It was found that there were about 701 spots in each gel, and the matching rate was about 87.5%. In contrast to control group, 16 cytoplasmic proteins and 23 membrane proteins of the experimental group changed. The results of the differentially expressed protein analysis indicated that the change trends of protein spots. Based on polymer porous self-assembled nano-film technology, the expression of differential proteins in DN rats was analyzed, which would supplement new research assistance to the mechanism of DN.

Development of SiC–TiO2-Graphene neem extracted antimicrobial nano membrane for enhancement of multiphysical properties and future prospect in dental implant applications

This paper presents the coating technology on Nano membrane using SiC–TiO2-Graphene with varying percentages of Azadirachta indica (Neem) extract with an objective to develop new coating materials. The nanomembranes have been synthesized by electrospinning machine over aluminum foil paper using the raw materials PVA grain, SiC, TiO2, Graphene, and neem. The nanomembranes have been characterized by SEM, XRD, FTIR, Surface Roughness, antibacterial, and Cytotoxicity test. FTIR analysis established the presence of PVA and neem indicating the formation of different organic compounds. It also confirmed that no chemical reaction occurred during the synthesis process. The membrane's roughness analysis obtained average roughness values from 1.15 to 3.84. The formation of homogeneous and smooth membranes with the formation of micropores was confirmed by SEM analysis. Miller Indices identified different types of crystal structures in XRD analysis. Antibacterial activity increased with the increase of the percentage of neem confirmed by the antibacterial test. No toxic effects were observed from the membrane during the cytotoxicity test. The obtained data confirmed that the synthesized nanomembrane could be used in different biomedical applications.

Low contact-resistivity and high-uniformity Ni/Au ohmic contacts on Si nanomembranes grafted to Si substrates via low-temperature rapid thermal annealing

Grafted lattice-mismatched semiconductor heterostructures have the potential to simultaneously achieve low on-resistance and high breakdown performance. These novel semiconductor devices are typically fabricated by grafting single-crystal semiconductor nanomembrane (NM) layers onto a foreign substrate. The optimal temperature for grafting often prevents the use of high temperatures to achieve optimal ohmic contacts. Herein, we present a method to form low temperature Ni/Au ohmic contacts for the anode electrode to a p + Si NM that is grafted to a Si substrate. Ohmic contact resistivity (ρc) and its device-to-device uniformity are characterized against different annealing temperatures and are also compared against contact resistivity of p + SOI structure. Low resistivity ohmic contacts (ρc = 5.92 × 10-6 Ω cm2) and high uniformity were achieved on grafted NM structure. Demonstration of low ρc for NM-transferred layers via a low-temperature metallization scheme achieves an important step towards further developing high performance lattice-mismatched heterostructure-based devices.

Transient characteristics of β-Ga2O3 nanomembrane Schottky barrier diodes on various substrates

In this paper, transient delayed rise and fall times for beta gallium oxide (β-Ga2O3) nanomembrane (NM) Schottky barrier diodes (SBDs) formed on four different substrates (diamond, Si, sapphire, and polyimide) were measured using a sub-micron second resolution time-resolved electrical measurement system under different temperature conditions. The devices exhibited noticeably less-delayed turn on/turn off transient time when β-Ga2O3 NM SBDs were built on a high thermal conductive (high-k) substrate. Furthermore, a relationship between the β-Ga2O3 NM thicknesses under different temperature conditions and their transient characteristics were systematically investigated and verified it using a multiphysics simulator. Overall, our results revealed the impact of various substrates with different thermal properties and different β-Ga2O3 NM thicknesses on the performance of β-Ga2O3 NM-based devices. Thus, the high-k substrate integration strategy will help design future β-Ga2O3-based devices by maximizing heat dissipation from the β-Ga2O3 layer.

Highly stable silver nanowire networks with tin oxide shells for freestanding transparent conductive nanomembranes through all‐solution processes

Freestanding nanomembranes (NMs) with nanoscale thickness, are mechanically flexible, which are novel building blocks with potential applications in future wearable conformal electronics. Here, we demonstrate a highly stable, ultrathin, freestanding, transparent, and conductive hybrid NM, consisting of a silver nanowire network with tin oxide shell embedded in a colorless polyimide (cPI). The entire fabrication processes are all solution based and non-vacuum, which are simple, scalable and low-cost, enabling facile large-area integration with wearable electronic devices. Our hybrid NMs possess high optical transmittance of 86.7% with low sheet resistance of 9.6 Ω/sq. and can be conformal attached to human skin. In addition, our hybrid NMs exhibit excellent stability to resist moisture, long-term storage, solvent damage, strong oxidant, ultrasonication and acid/base should stem. Particularly, the hybrid NMs are robust and able to withstand high temperature of 300 ℃, without deterioration of performance. As a conformal/skin-attachable device application, a skin-attachable capacitive NM sensor is presented, which provides excellent pressure sensing capabilities.

Flexible micro–nano composite membranes based on a two‐step strategy: charge recovery and efficient gradient air filtration

AbstractA two‐step strategy is used to produce micro–nano composite filters that are flexible and exhibit charge recovery. Polytetrafluoroethylene (PTFE) electret powders are incorporated during the process to provide melt‐blown micro–nano membranes with good charge recovery and improved fiber fineness. Then the advantages of the nanofiber membrane are utilized to load the PTFE suspension onto the surface of melt‐blown microfiber membranes to construct a composite filtration membrane with a micro–nano structure, to achieve high‐efficiency and gradient filtration. The test results indicate that the gradient filtration composite membranes exhibit 100% filtration efficiency against 2.5 μm particles, 94.96% filtration efficiency against 0.200–2.5 μm particles and 95.39% filtration efficiency against 0.200–4.595 μm particles, which is 232.02% higher than that of polypropylene membranes. In addition, the gradient filtration composite membranes have a pressure drop that is only 86 Pa and a quality factor of 0.0358 Pa−1. Featuring excellent electret property and charge recovery rate, the gradient filtration micro–nano composite membranes are outstanding filters that have high filtration efficiency, low pressure drop, stable surface potential and excellent thermal stability. © 2022 Society of Industrial Chemistry.

Field emission characteristics of ZnO nanowires grown by catalyst-assisted MOCVD on free-standing inorganic nanomembranes

ZnO field emitters on freely suspended inorganic nanomembranes (NMs) were synthesized by catalyst-assisted metal organic chemical vapor deposition (MOCVD) using the precursors zinc acetylacetonate hydrate and oxygen. The morphology and the possibly involved growth mechanisms of the randomly distributed ZnO nanostructures were investigated by scanning electron microscopy and by energy-dispersive x-ray spectroscopy. The findings indicate a growth process that involves the vapor–liquid–solid as well as the vapor–solid–solid mechanism. The field emission (FE) properties of such ZnO nanowire (NW) samples showed to be highly reproducible and independent of the investigated Si-based substrate types. Herein, a new type of flexible substrate for the MOCVD process has been introduced that allows for the direct growth of ZnO NWs on free-standing membranes for potential FE-based sensor applications. A turn-on field of 4.1 V µm−1 was detected for a macroscopic emission current density of 10 µA cm−2 and the stability test revealed fluctuations of only 9% around the mean emission current over a duration of 3 h proving a reliable and stable operation of such devices. Moreover, approaches were identified to further enhance the FE characteristics of the ZnO NWs by variation of the synthesis parameters and by enlargement of the NM area.

Influences of Native Oxide on the Properties of Ultrathin Al2O3‐Interfaced Si/GaAs Heterojunctions

AbstractThe structure property of non‐ideal Si/GaAs heterostructures that are integrated with the ultra‐thin oxide (UO) tunneling interfacial layer is systematically investigated. Si nanomembranes (NMs) are oxidized in different time periods prior to the hetero‐integration process to create the non‐ideal single‐side passivated Si/GaAs heterostructure. The atomic‐level oxygen distribution and the degree of oxygen content in Si NM and GaAs are carefully investigated using atom probe tomography (APT) and X‐ray photoelectron spectroscopy (XPS) to trace changes in the chemical composition and reactional mechanism across the UO interface when the surface of Si NM is exposed to air for different periods of time. The negatively induced charges at the UO layer cause oxygen diffusion to the GaAs layer and form the unwanted GaAs oxide layer. This native oxide stack noticeably degrades the thermal properties of the Si/GaAs heterostructure as Si NMs become more oxidized. This study reveals that the poor surface passivation on one side of the heterointerface leads to a both‐side oxidation, thus severely deteriorating the transport properties across the heterojunction formed with the UO layer.

PURIFYING WASTEWATER USING EARTHEN MATERIALS AND NANO MEMBRANES

Water purification for human consumption purposes consists in the removal of different contaminants as chemicals (i.e., pollutants, toxic metals), biological contaminants (algae, bacteria, fungi, parasites, and viruses), suspended solids, and gases. But we will use simple method to clean water which has algae, parasites activities, etc. by simple gravel, sand, and earthen materials. Filtration is the process in which the solid particles are removed in a liquid or gaseous fluid are removed by use of filter medium. And control the amount of TDS, EC, pH, and other parameters. We applied simple law of physics that is gravity. We filtered the wastewater from tube containing layer of earthen materials and lastly, we filtered the semi cleaned water from UV membranes (Nano membrane). We used three boxes in which 1st box had small gravels and in other 2nd box had sand and charcoal passed through water from these medium and final products collect in 3rd box and checked the different medias of water. This experiment was performed with different sources of water, and this gave good results with good efficiency of medias like TDS, EC, PH etc. this experiment is performed with low income and with the help of natural coagulants.

Preparation and characterization of electrospun nanofiber membrane from polyvinyl alcohol loaded with Glycyrrhiza glabra extract

This study was designed to form an electrospun nanofiber membrane generated from different ratio of polyvinyl alcohol (PVA) and Glycyrrhiza glabra (licorice) extract. The electrospinning process was used to fabricate the nanofiber membrane using maximum amount of licorice extract solution. 90% licorice extract solution was successfully electrospun to fabricate nano membrane with 10% PVA solution. Antibacterial, cytotoxicity, scanning electron microscope (SEM) test were performed on resulted sample. The outstanding performance against Staphylococcus aureus ( S. aureus) by forming inhibition zone of 15 mm was observed. On the vero cell line, cell cytotoxicity was found, with only a few numbers of cells (less than 5%) surviving after exposure to the material. SEM investigation reveals fiber production with a diameter of (245.54 ± 55.19) nm on average. Moreover, Fourier transforms infrared spectroscopy (FT-IR) and moisture management test were performed. FT-IR spectra analysis confirmed the presence of licorice components in the membrane. Moisture analysis proved it as a better absorbing material. Since the fabricated membrane were proven to have bacteriostatic activity, it can be employed as wound healing.

Designing a Molecularly Imprinted Polymer-Based Nanomembrane for the Selective Removal of Staphylococcus aureus from Aqueous Media

Background and Objective: Conventional applied techniques used for detecting pathogenic microorganisms that generally are based on plating, serological and biochemical assays are unreliable and expensive while lacking sensitivity and specificity compared to new analytical methods. Investigation of reliable and rapid analytical diagnosis methods seems a necessity today. In the present study, a high accurate method was developed aiming to pre-concentrate and improve identification of Staphylococcus aureus as a major bacterial human pathogen by using a molecular imprinted polymer (MIP) based membrane. Materials and Methods: Cellulose acetate was used as the basic membrane with a pore size of 1.2 μm, methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linking monomer, antibody buffer medium as the template molecule, and 2,2'-Azobis(2-methylpropionitrile) as the initiator agent. After selecting the best membrane composition resulting from the optimum ratio of antibody to imprinted monomer, electron microscopy testing was used to evaluate the characterization and stabilization of the molecular imprinting of templates on the membrane. Results and Conclusion: According to the results, the suspension of Staphylococcus aureus with a dilution of 3×105 after being adjacent to MIPs modified membranes had the highest bacterial mass absorption in MIP4 filter and reduced to a level of 1.3×104. The manufactured nano membrane could lead to a significant development in quality control of food industry compared to traditional methods due to a very shorter required time of bacterial mass diagnosis with a very higher accuracy. Keywords: Antibody; Molecular Imprinted Polymer; Nano Membrane; Staphylococcus aureus

PREPARATION AND STUDY OF THE OPTICAL AND STRUCTURAL PROPERTIES NANOMEMBRANE

The adoption of nanotechnology to work within a field of sustainable energy within the preparation and manufacture of nano membrane ( CO3O4, TiO ) for fuel cell, which has prepared chemically. addition, using modern technology spraying ultrasound, to improve the structural, studied nano membrane have annealed in a vacuum and different temperature. studied optical properties membrane using UV- VIS spectroscopy, results of structural properties X-ray diffraction (XRD) showed that nanoparticles have polycrystalline also grain size decreased, composite nano membrane , Morphological studies using Scanning electron microscopy (SEM).

Hollow Fiber Nano Membrane as Liquid Phase Microextraction for Determination of Enrofloxacin in the Prsence of Florfenicol and Tylosin in Chicken Tissues

Hollow Fiber Nano Membrane as Liquid Phase Microextraction for Determination of Enrofloxacin in the Prsence of Florfenicol and Tylosin in Chicken Tissues

Raman scattering study of GeSn under 〈1 0 0〉 and 〈1 1 0〉 uniaxial stress

The application of strain into GeSn alloys can effectively modulate the band structures, thus creating novel electronic and photonic devices. Raman spectroscopy is a powerful tool for characterizing strain; however, the lack of Raman coefficient makes it difficult for accurate determination of strain in GeSn alloys. Here, we have investigated the Raman-strain function of Ge1−x Sn x along 〈1 0 0〉 and 〈1 1 0〉 directions. GeSn nanomembranes (NMs) with different Sn compositions are transfer-printed on polyethylene terephthalate substrates. External strain is introduced by bending fixtures with different radii, leading to uniaxial tensile strain up to 0.44%. Strain analysis of flexible GeSn NMs bent along 〈1 0 0〉 and 〈1 1 0〉 directions are performed by Raman spectroscopy. The linear coefficients of Raman-strain for Ge0.96Sn0.04 are measured to be −1.81 and −2.60 cm−1, while those of Ge0.94Sn0.06 are decreased to be −2.69 and −3.82 cm−1 along 〈1 0 0〉 and 〈1 1 0〉 directions, respectively. As a result, the experimental ratio of linear coefficient (ROLC) of Ge, Ge0.96Sn0.04 and Ge0.94Sn0.06 are 1.34, 1.44 and 1.42, which agree well with theoretical ROLC values calculated by elastic compliances and phonon deformation potentials (PDPs). In addition, the compositional dependence of PDPs is analyzed qualitatively. These fundamental parameters are important in designing high performance strained GeSn electronic and photonic devices.

Negative differential resistance in Si/GaAs tunnel junction formed by single crystalline nanomembrane transfer method

Negative differential resistance (NDR) region was established in Si/GaAs tunnel junction (TJ) formed by single crystalline nanomembrane (NM) transfer method. P + Si NM was transfer-printed onto n + GaAs epi-wafer, leading to the formation of Si/GaAs pn TJ diode comprised of crystalline semiconductors with no biaxial strain. Atomic-scale features at the Si/GaAs junction interface were analyzed by high-resolution transmission-electron-microscopy. The mechanism for NDR phenomenon in the electrical characteristics of Si/GaAs TJ diode was explained by the energy band diagram with a quantum mechanical band-to-band tunneling of carriers. The peak-to-valley-ratio value of TJ diode was 2.32. The results can be applicable to the fabrication of low-power circuits with a combination of lattice-mismatched crystalline semiconductors.

Si nanomebranes: Material properties and applications

Silicon (Si) has widely been used as an essential material in the modern semiconductor industry. Recently, new attempts have been actively made to apply Si to a variety of fields such as flexible electronic devices and biosensors by manufacturing Si nanomembranes (NMs) having nanometer thickness. In particular, as the thickness of Si is reduced to a nanometer scale, its mechanical, electrical, and optical properties differ from that of its bulk form, which provides opportunities for the development of new conceptual devices. In this review, we present recent advances in Si NM technology that exhibit functional features different from the bulk materials. In addition, we discuss the opportunities and current challenges related to this field.

High yield preparation of flexible single-crystalline 4H-silicon carbide nanomembranes via buried micro-trenches

We present the fabrication of flexible single-crystalline 4H-silicon carbide (SiC) nanomembranes (NMs) with a centimeter size. The 4H–SiC NMs has been released from a 4H–SiC-on-insulator (4H–SiCOI) wafer and transferred to a flexible adhesive tape. By introducing buried micron trenches (BMTs) in the sacrificial buried oxide (BOX) layer in 4H–SiCOI, the lateral etching rate is increased by about three times, crucial to the fabrication of large-size 4H–SiC NMs with a high yield. The prepared 4H–SiC NMs show single-crystalline quality, ultra-smooth surface, and excellent ultraviolet (UV) absorption performance, paving the way toward the development of 4H–SiC based flexible and stretchable optoelectronic devices. The proposed BMTs assisted release method also provides a universal and effective way to obtain large scale and intact single-crystalline NMs for flexible applications. We present the fabrication of flexible single-crystalline 4H-silicon carbide nanomembranes (NMs) with a high yield. The introduced buried micron trenches (BMTs) in the sacrificial layer in 4H–SiCOI facilities the release of NMs. The prepared 4H–SiC NMs show single-crystalline quality, ultra-smooth surface, and excellent ultraviolet (UV) absorption performance. • Flexible, intact and single-crystalline 4H–SiC nanomembranes (NMs) were prepared with high yield. • The SiC NMs show excellent ultraviolet absorption performance. • The demonstrated method provides an effective way to obtain single-crystalline NMs for flexible applications.

An overview of nanomaterial technologies in the management of wastewater treatment

Nanomaterials are the foundation stone of nanotechnology. It is a broad and trans disciplinary section of exploration. Its developmental commotion has been rising intensively across the world in the last few years. Applications of nanotechnology are abundant in various fields like medicines, electronics, machines, and so on. This paper describes one such application that is nanotechnology in wastewater treatment viz nanosorption, nanophotocatalysis and Nano membrane technology. The Nano compounds engaged in such treatments have been discussed here. As of now the world is in distress from the non-availability of drinking water and even the very existence of drinking water in nature are becoming toxic due to the addition of chemicals and heavy metals by man-made and by natural happenings as well. The distinctive properties of nanomaterial such as surface area, competent to toil at required and even at low concentration and their potential have prodigious prospects to reform wastewater treatment. Carbon based nanomaterial, metal oxide nanomaterials and nanomebranes have been discussed at this juncture. There are several disputes in treating wastewater with nanomaterials such as insufficient information about the nanomaterial. Still researchers have a lack of knowledge about how these materials are travelling and the effect of nanomaterial on human health. Though the nanostructured catalytic membranes, Nano sorbents and nanophotocatalyst are the established methods to eliminate water pollutants from wastewater, they need more energy and additional investment.

A simplified method of measuring thermal conductivity of β-Ga2O3 nanomembrane

In this work, we report a simplified method to measure thermal conductivity from the typical Raman thermometry method by employing a much simpler dispersion relationship equation and the Debye function, instead of solving the heat equation. Unlike the typical Raman thermometry method, our new method only requires monitoring of the temperature-dependent Raman mode shifting without considering laser power-dependent Raman mode shifting. Thus, this new calculation method offers a simpler way to calculate the thermal conductivity of materials with great precision. As a model system, the β-Ga2O3 nanomembrane (NM) on a diamond substrate was prepared to measure thermal conductivity of β-Ga2O3 NMs at different thicknesses (100 nm, 1000 nm, and 4000 nm). Furthermore, the phonon penetration depth was investigated to understand how deep phonons can be dispersed in the sample so as to guide the dimensional design parameter of the device from the thermal management perspective.