scholarly journals Fabrication of PVA/Carbon-Based Nanofibers Using Electrospinning

2021 ◽  
Author(s):  
Gatut Yudoyono ◽  
Diky Anggoro ◽  
Lutfi Fitria Ningsih ◽  
Rizki Romadoni
Keyword(s):  
Flow Rate ◽  
High Voltage ◽  
High Surface ◽  
High Surface Area ◽  
Fiber Spinning ◽  
Water Filtration ◽  
Syringe Pump ◽  
Natural Polymers ◽  
Pump Flow Rate ◽  
Small Pore

Nanofibers are widely used in various fields, including water filtration. In the development of nanofibers as water filtration, a mixture of carbon in a polymer solution is often used. Nanofibers can be made by several methods such as multicomponent fiber spinning techniques, melt blowing, electrospinning. Electrospinning is currently a simple development method but can produce nanofibers with a small fiber diameter, it is easy to develop and many parameters can be controlled. Parameters that affect the results of the nanofibers that are formed include flow rate or syringe pump flow rate and high voltage dc high voltage. Various types of nanofibers can be produced from various types of polymers, both natural polymers and synthetic polymers. Generally, because they have properties and characteristics such as high surface area, small pore size, and the possibility to be developed in various applications. Therefore, this chapter discusses the electrospinning of carbon nanofibers using PVA polymer.

Preparation and Characterization of Poly(Methyl Methacrylate) (PMMA) Fibers by Electrospinning

2019 ◽  
Vol 811 ◽  
pp. 163-169 ◽  
Author(s):  
Ervin Tri Suryandari ◽  
Muhammad Ali Zulfikar ◽  
Rino R. Mukti ◽  
Muhamad Nasir
Keyword(s):  
Methyl Methacrylate ◽  
Flow Rate ◽  
Supply Voltage ◽  
High Surface ◽  
Polymer Concentration ◽  
Diameter Distribution ◽  
Solution Flow Rate ◽  
Simple Method ◽  
Poly Methyl Methacrylate ◽  
Small Pore

Fibers are materials with advantageous properties such as lightweight material properties, has small pore size, and has high surface area, porosity,and permeability. An easy and simple method to prepare fibers is electrospinning. Using this method poly(methyl methacrylate) (PMMA) fibers were prepared. Several parameters include polymer concentration, solution flow rate, the distance of the nozzle tip to the collector, and the applied voltage were investigated to control the morphology, structure, and diameter of PMMA fibers. The Optimal electrospinning conditions for PMMA fibers production were a PMMA concentration is 8% (w/v), a power supply voltage is 20 kV, a distance of the tip of the nozzle to the ground collector is 15 cm, and a flow rate is 0.004 mL/min. The diameter distribution and morphology of the fibers were determined and characterized by Optical Microscopy and Scanning Electron Microscope (SEM), which showed that the produced fiber had an average diameter of 1.4925 µm, the contact angle of fiber PMMA is 125.307o and the spreading time of fibers PMMA is about 360 minutes

Investigation of BTEX Adsorption on Carbon Nanotubes Cartridges from Air Samples

2019 ◽  
Vol 889 ◽  
pp. 216-222 ◽  
Author(s):  
Huu Quynh Anh Le ◽  
Dinh Tuan Phan
Keyword(s):  
Carbon Nanotubes ◽  
Adsorption Capacity ◽  
Flow Rate ◽  
Gas Flow ◽  
High Surface ◽  
High Surface Area ◽  
Operating Conditions ◽  
Multiwalled Carbon ◽  
Air Samples ◽  
Environmental Treatment

The volatile organic compounds (VOCs) contribute to serious air pollution problems in Viet Nam. Many studies have investigated in air quality monitoring and treatment, in order to determine the average concentrations of Benzene, Toluene, Ethylbenzene and Xylene (BTEX). Carbon nanotubes (CNTs) have been widely used as adsorbent in environmental treatment, especially for VOCs. This paper aims to determine the adsorption capacity of multiwalled carbon nanotubes for removal of BTEX from air samples. In preliminary study, the effects of various parameters during adsorption experiments were monitored such as flow rate, temperature and BTEX concentrations in air samples. The equipment for BTEX removal was developed by our research team consisting of filter columns, air sample bags, adsorption cartridge. The air samples containing BTEX were conducted directly through a cartridge packed with adsorbent. The adsorption experiments were carried out under various operating conditions such as temperature (30 - 40°C), gas concentration (0,57 - 4,77 mg/L) and the gas flow rate (10 - 90 mL/min). In addition, isotherm studies of CNTs for BTEX removal were achieved by using Langmuir and Freundlich models. The results showed that the experimental parameters were optimized at a flow rate of 30 mL/min and an ambient temperature at 30°C. The adsorption capacity of CNTs increased proportionally with BTEX concentrations. The specific affinity of CNTs for BTEX from air samples was in order of X > E > T > B. The experimental isotherm data were well-fit with the Langmuir model for Benzene and Xylene removal, and the Freundlich model for Toluene and Ethylbenzene adsorption. The CNTs presented highly potential application for BTEX adsorption thanks to their microporous structure and high surface area.

Design and fabrication of conductive nanofibrous scaffolds for neural tissue engineering: Process modeling via response surface methodology

2018 ◽  
Vol 33 (5) ◽  
pp. 619-629 ◽  
Author(s):  
Maryam Soleimani ◽  
Shohreh Mashayekhan ◽  
Hossein Baniasadi ◽  
Ahmad Ramazani ◽  
Mohamadhasan Ansarizadeh
Keyword(s):  
Nervous System ◽  
Response Surface Methodology ◽  
Peripheral Nervous System ◽  
Process Parameters ◽  
Flow Rate ◽  
Applied Voltage ◽  
Syringe Pump ◽  
Cell Compatibility ◽  
Nanofibrous Scaffolds ◽  
Pump Flow Rate

Peripheral nervous system in contrary to central one has the potential for regeneration, but its regrowth requires proper environmental conditions and supporting growth factors. The aim of this study is to design and fabricate a conductive polyaniline/graphene nanoparticles incorporated gelatin nanofibrous scaffolds suitable for peripheral nervous system regeneration. The scaffolds were fabricated with electrospinning and the fabrication process was designed with Design-Expert software via response surface methodology. The effect of process parameters including applied voltage (kV), syringe pump flow rate (cm3/h), and PAG concentration (wt%), on the scaffold conductivity, nanofibers diameter, and cell viability were investigated. The obtained results showed that the scaffold conductivity and cell viability are affected by polyaniline/graphene concentration while nanofiber diameter is more affected by the applied voltage and syringe pump flow rate. Optimum scaffold with maximum conductivity (0.031 ± 0.0013 S/cm) and cell compatibility and suitable diameter were electrospun according to the software introduced values for the process parameters (voltage of 13 kV, flow rate of 0.1 cm3/h, and PAG wt.% of 1.3) and its morphology, cell compatibility, and biodegradability were further investigated, which showed its potential for applying in peripheral nervous system injury regeneration.

scholarly journals Electrospun nanofibers: A nanotechnological approach for drug delivery and dissolution optimization in poorly water-soluble drugs

ADMET & DMPK ◽  
2020 ◽  
Author(s):  
Luis Castillo-Henríquez ◽  
Rolando Vargas-Zúñiga ◽  
Jorge Pacheco-Molina ◽  
Jose Vega-Baudrit
Keyword(s):  
Drug Delivery ◽  
High Surface ◽  
High Surface Area ◽  
Electrospun Nanofibers ◽  
Water Soluble ◽  
Poorly Water Soluble Drugs ◽  
Small Pore ◽  
Water Soluble Drugs ◽  
Poorly Water Soluble ◽  
Surface Morphologies

<p class="ADMETabstracttext">Electrospinning is a novel and sophisticated technique for the production of nanofibers with high surface area, extreme porous structure, small pore size, and surface morphologies that make them suitable for biomedical and bioengineering applications, which can provide solutions to current drug delivery issues of poorly water-soluble drugs. Electrospun nanofibers can be obtained through different methods asides from the conventional one, such as coaxial, multi-jet, side by side, emulsion, and melt electrospinning. In general, the application of an electric potential to a polymer solution causes a charged liquid jet that moves downfield to an oppositely charged collector, where the nanofibers are deposited. Plenty of polymers that differ in their origin, degradation character and water affinity are used during the process. Physicochemical properties of the drug, polymer(s), and solvent systems need to be addressed to guarantee successful manufacturing. Therefore, this review summarizes the recent progress in electrospun nanofibers for their use as a nanotechnological tool for dissolution optimization and drug delivery systems for poorly water-soluble drugs.</p>

Tailored Silica Based Xerogels and Aerogels for Insulation in Space Environments

2010 ◽  
Vol 63 ◽  
pp. 41-46 ◽  
Author(s):  
Luisa Durães ◽  
Marta Ochoa ◽  
António Portugal ◽  
Nelson Duarte ◽  
João Paulo Dias ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Acid Base ◽  
Highly Porous Materials ◽  
Small Pore ◽  
Space Environments ◽  
Highly Porous ◽  
Very High

In this work, the sol-gel technology is used to produce silica based xerogels and aerogels suitable for insulation applications in Space. The properties of the obtained materials are tailored varying the precursor – Methyltrimethoxysilane (MTMS) or Methyltriethoxysilane (MTES), and the solvent – methanol or ethanol. A two-step acid-base catalyzed synthesis is used, being the obtained gels dried at atmospheric pressure, in the case of xerogels, and in supercritical conditions, for aerogels. Density and thermal conductivity must be made as low as possible for the sought application and only highly porous materials can fulfill this requirement. The obtained xerogels and aerogels, either with MTMS or MTES, show very promising properties for thermal insulation in Space, when methanol is used as solvent. The more suitable materials are obtained with MTMS and exhibit very low density (80-100 kg/m3), very high surface area (~ 400 m2/g) and small pore size (~ 30-40 Å). They also show moderate flexibility and a remarkable hydrophobic character (~ 150º).

Inhibiting Corrosion of Biomedical-Grade Ti-6Al-4V Alloys with Graphene Nanocoating

2020 ◽  
Vol 99 (3) ◽  
pp. 285-292 ◽  
Author(s):  
R. Malhotra ◽  
Y.M. Han ◽  
J.L.P. Morin ◽  
E.K. Luong-Van ◽  
R.J.J. Chew ◽  
...  
Keyword(s):  
Titanium Alloys ◽  
Electrochemical Impedance ◽  
High Surface ◽  
High Surface Area ◽  
Surface Oxidation ◽  
Chemical Degradation ◽  
Anticorrosion Coatings ◽  
Grade 5 ◽  
Small Pore ◽  
High Structural Stability

The identification of metal ions and particles in the vicinity of failed implants has raised the concern that biomedical titanium alloys undergo corrosion in healthy and infected tissues. Various surface modifications and coatings have been investigated to prevent the deterioration and biocorrosion of titanium alloys but so far with limited success. Graphene is a cytocompatible atom-thick film made of carbon atoms. It has a very high surface area and can be deposited onto metal objects with complex shapes. As the carbon lattice has a very small pore size, graphene has promising impermeability capacity. Here, we show that graphene coating can effectively protect Ti-6Al-4V from corrosion. Graphene nanocoatings were produced on Ti-6Al-4V grade 5 and 23 discs and subjected to corrosive challenge (0.5M NaCl supplemented with 2-ppm fluoride, pH of 2.0) up to 30 d. The linear polarization resistance curves and electrochemical impedance spectroscopy analysis showed that the graphene-coated samples presented higher corrosion resistance and electrochemical stability at all time points. Moreover, the corrosion rate of the graphene-coated samples was very low and stable (~0.001 mm/y), whereas that of the uncoated controls increased up to 16 and 5 times for grade 5 and 23 (~0.091 mm/y) at the end point, respectively. The surface oxidation, degradation (e.g., crevice defects), and leaching of Ti, Al, and V ions observed in the uncoated controls were prevented by the graphene nanocoating. The Raman mappings confirmed that the graphene nanocoating presented high structural stability and resistance to mechanical stresses and chemical degradation, keeping >99% of coverage after corrosion challenge. Our findings open the avenues for the use of graphene as anticorrosion coatings for metal biomedical alloys and implantable devices.

scholarly journals New Trends in Bio-Based Aerogels

Pharmaceutics ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 449 ◽  
Author(s):  
Loredana Elena Nita ◽  
Alina Ghilan ◽  
Alina Gabriela Rusu ◽  
Iordana Neamtu ◽  
Aurica P. Chiriac
Keyword(s):  
Biomedical Applications ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Acoustic Properties ◽  
High Porosity ◽  
Natural Polymers ◽  
Flame Resistance ◽  
Strength Limit ◽  
Properties Of Materials

(1) Background: The fascinating properties of currently synthesized aerogels associated with the flexible approach of sol-gel chemistry play an important role in the emergence of special biomedical applications. Although it is increasingly known and mentioned, the potential of aerogels in the medical field is not sufficiently explored. Interest in aerogels has increased greatly in recent decades due to their special properties, such as high surface area, excellent thermal and acoustic properties, low density and thermal conductivity, high porosity, flame resistance and humidity, and low refractive index and dielectric constant. On the other hand, high manufacturing costs and poor mechanical strength limit the growth of the market. (2) Results: In this paper, we analyze more than 180 articles from recent literature studies focused on the dynamics of aerogels research to summarize the technologies used in manufacturing and the properties of materials based on natural polymers from renewable sources. Biomedical applications of these bio-based materials are also introduced. (3) Conclusions: Due to their complementary functionalities (bioactivity, biocompatibility, biodegradability, and unique chemistry), bio-based materials provide a vast capability for utilization in the field of interdisciplinary and multidisciplinary scientific research.

scholarly journals Nanofibres made from biocompatible and biodegradable polymers, with potential application as medical textiles

2018 ◽  
Vol 69 (01) ◽  
pp. 55-58 ◽  
Author(s):  
SUBTIRICA ADRIANA-IOANA ◽  
BANCIU CRISTINA ANTONELA ◽  
CHIVU ANDREEA ANA-MARIA ◽  
LAURENTIU CHRISTIAN DINCA
Keyword(s):  
Biodegradable Polymers ◽  
Textile Industry ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Electrospun Nanofibers ◽  
Electrospinning Process ◽  
High Porosity ◽  
Medical Textiles ◽  
Small Pore

An important and growing part of the textile industry is the medical and related healthcare and hygiene sector. Recently, ultrafine fiber webs made from biocompatible and biodegradable polymers have been obtained by the electrospinning process. Their unique properties such as high surface area-to-volume ratio, small pore sizes, high porosity, and the possibility of incorporation therapeutic compounds into the electrospun nanofibers has attracted the researcher’s attention lately. This paper presents the obtaining of PEO and PVA nanofibers.

Bioaerogels: Synthesis Approaches, Biomedical Applications and Cell Uptake

2021 ◽  
pp. 43-56
Keyword(s):  
Drug Delivery ◽  
Dielectric Constant ◽  
New Technologies ◽  
High Surface ◽  
High Surface Area ◽  
Cell Uptake ◽  
Mechanical Resistance ◽  
Low Density ◽  
Natural Polymers ◽  
Cellular Environment

Bioaerogels are a special class of aerogels, produced from natural polymers, are porous structures with promising physicochemical properties for various applications. This chapter focus on the latest bioaerogel findings, addressing the synthesis, impregnation of bioactive compounds, pharmacological applications and aspects of cell uptake, biodegradability and toxicity. Bioaerogels are biomaterials with interesting properties such as high surface area, high thermal and mechanical resistance, low density and dielectric constant. It has been reported that these biomaterials can be used for drug delivery and molecular scaffolding production. Furthermore, it has been shown that bioaerogels are biocompatible, biodegradable, non-toxic, and can be absorbed and degraded by the cellular environment. Finally, bioaerogels are promising, inexpensive, environmentally friendly and versatile materials and can be the basis for the manufacture of new technologies and biomaterials.

In Situ microscopy of the anodic etching of silicon

1995 ◽  
Vol 53 ◽  
pp. 232-233
Author(s):  
Frances M. Ross ◽  
Peter C. Searson
Keyword(s):  
Composite Structures ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Selective Etching ◽  
Silicon On Insulator ◽  
Second Phase ◽  
Porous Layers ◽  
New Class ◽  
Porous Semiconductors

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.

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