scholarly journals Size Also Matters in Biodegradable Composite Microfiber Reinforced by Chitosan Nanofibers

2014 ◽  
Vol 1621 ◽  
pp. 59-69
Author(s):  
Elisabete D. Pinho ◽  
Albino Martins ◽  
José V. Araújo ◽  
Rui L. Reis ◽  
Nuno M. Neves
Keyword(s):  
Biomedical Applications ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Electrospun Nanofibers ◽  
Butylene Succinate ◽  
Biodegradable Composite ◽  
Biological Performance ◽  
Different Diameters ◽  
Kinetics Of

ABSTRACTPioneer works on nanocomposites were focused in carbon nanofibers or nanotubes dispersed in epoxy matrix, a viscous liquid facilitating the compounding stage. The interest in developing new composites aimed for biomedical applications led us to design new nanocomposites based in biodegradable polymers with demonstrated biological performance.We report herein the development of micro-nano composites by extruding poly(butylene succinate) (PBS) microfibers with two different diameters, 200 and 500 µm, reinforced with electrospun chitosan nanofibers. Analysis of the microfibers showed high levels of alignment of the reinforcing phase and excellent distribution of the nanofibers in the composite. Its geometry facilitates the development of orthotropy, maximizing the reinforcement in the axial fiber main axis.The biodegradable microfiber composites show an outstanding improvement of mechanical properties and of the kinetics of biodegradation, with very small fractions (0.05 and 0.1 wt.%) of electrospun chitosan nanofibers reinforcement. The high surface area-to-volume ratio of electrospun nanofibers combined with the increased water uptake capability of chitosan justify the accelerated kinetics of biodegradation of the composite as compared with the unfilled synthetic polymer.

scholarly journals Electrospun Nanofibers for Sensing and Biosensing Applications—A Review

2021 ◽  
Vol 22 (12) ◽  
pp. 6357
Author(s):  
Kinga Halicka ◽  
Joanna Cabaj
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Toxic Metal ◽  
Volume Ratio ◽  
Electrospun Nanofibers ◽  
Clinical Diagnostics ◽  
Loading Capacity ◽  
Electrospun Nanofiber ◽  
Sensing Platforms ◽  
Different Types

Sensors and biosensors have found applications in many areas, e.g., in medicine and clinical diagnostics, or in environmental monitoring. To expand this field, nanotechnology has been employed in the construction of sensing platforms. Because of their properties, such as high surface area to volume ratio, nanofibers (NFs) have been studied and used to develop sensors with higher loading capacity, better sensitivity, and faster response time. They also allow to miniaturize designed platforms. One of the most commonly used techniques of the fabrication of NFs is electrospinning. Electrospun NFs can be used in different types of sensors and biosensors. This review presents recent studies concerning electrospun nanofiber-based electrochemical and optical sensing platforms for the detection of various medically and environmentally relevant compounds, including glucose, drugs, microorganisms, and toxic metal ions.

scholarly journals Research Progress on the Applications of Electrospun Nanofibers in Catalysis

Catalysts ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 9
Author(s):  
M. Olga Guerrero-Pérez
Keyword(s):  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Electrospun Nanofibers ◽  
Internal Diffusion ◽  
Research Progress ◽  
Bibliographic Analysis ◽  
Low Resistance ◽  
Electro Catalysis

During the last two decades, electrospinning has become a very popular technique for the fabrication of nanofibers due to its low cost and simple handling. Nanofiber materials have found utilization in many areas such as medicine, sensors, batteries, etc. In catalysis, these materials also present important advantages, since they present a low resistance to internal diffusion and a high surface area to volume ratio. These advantages are mainly due to the diameter–length proportion. A bibliographic analysis on the applications of electrospun nanofibers in catalysis shows that there are two important groups of catalysts that are being investigated, based on TiO2 and in carbon materials. The main applications found are in photo- and in electro-catalysis. The present study contributes by reviewing these catalytic applications of electrospun nanofibers and demonstrating that they are promising materials as catalysts, underlining some works to prove the advantages and possibilities that these materials have as catalysts. On one hand, the possibilities of synthesis are almost infinite, since with coaxial electrospinning quite complex nanofibers with different layers can be prepared. On the other hand, the diameter and other properties can be controlled by monitoring the applied voltage and other parameters during the synthesis, being quite reproducible procedures. The main advantages of these materials can be grouped in two: one related to their morphology, as has been commented, relative to their low resistance and internal diffusion, that is, their fluidynamic behavior in the reactor; the second group involves advantages related to the fact that the active phases can be nanoscaled and dispersed, improving the activity and selectivity in comparison with conventional catalytic materials with the same chemical composition.

scholarly journals Applications of electrospun nanofibers in the biomedical field

SURG Journal ◽  
2012 ◽  
Vol 5 (2) ◽  
pp. 63-73 ◽  
Author(s):  
Nishath Khan
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Electrospun Nanofibers ◽  
Ease Of Use ◽  
The Past ◽  
Wide Range ◽  
Novel Method ◽  
Biomedical Field ◽  
Highly Porous

Electrospinning is a technology that has been widely used as a novel method for the generation of nano scale fibres. Electrospun fibres are used in a wide range of applications from electronics to textile. The viability and popularity of this technology can be evidenced by its ease of use and the simplicity of the science behind building the electrospinning machine. The generated fibres have a high surface area- to- volume ratio, the fibrous mats are highly porous and display excellent mechanical properties when compared to other materials of the same scale. In the past decade, this technology has taken off with the use of biocompatible and biodegradable polymers. This review is a summary of the different ways in which electrospinning can be used in the biomedical field. This article analyzes the recent advances of this technology in tissue engineering, drug delivery and in enzyme immobilisation, which once again showcases the versatility of the electrospinning procedure.

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.

scholarly journals NANOFIBRAS ELETROFIADAS E SUAS APLICAÇÕES: AVANÇOS NA ÚLTIMA DÉCADA

Química Nova ◽  
2021 ◽  
Author(s):  
Luiza Mercante ◽  
Rafaela Andre ◽  
Juliana Macedo ◽  
Adriana Pavinatto ◽  
Daniel Correa
Keyword(s):  
Mechanical Performance ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Electrospun Nanofibers ◽  
Electrospinning Technique ◽  
Structures And Properties ◽  
Wide Range ◽  
Simple Processing

ELECTROSPUN NANOFIBERS AND THEIR APPLICATIONS: ADVANCES IN THE LAST DECADE. In recent years there has been an increasing interest in the development of nanomaterials with improved properties compared to their counterparts at the micro- and macroscopic scale. In this context, nanofibers obtained by electrospinning technique are highly attractive due to the unique combination of high surface area/volume ratio, porosity, flexibility, mechanical performance, simple processing and relatively low cost. In addition, the possibility to buildup nanofibers with different compositions, structures and properties allows the design of nanostructures for a wide range of applications. In this review, we will discuss the advances of the last decade in the use of the electrospinning to obtain nanofibers with different compositions and morphologies for varied applications. Specifically, we are interested in providing an overview of the state of the art in relation to the application of nanofibers in different areas, including healthcare, environment, sensing and energy. Finally, we will discuss the real perspective in terms of industrial application and future trends that have been pursued to improve the performance of electrospun nanofibers. This review will help researchers to understand the evolution and challenges of the area and will also stimulate even more interest in the development of new devices based on electrospun nanofibers

scholarly journals Water uptake of various electrospun nonwovens

2020 ◽  
Vol 6 (3) ◽  
pp. 155-158
Author(s):  
Katharina Wulf ◽  
Volkmar Senz ◽  
Thomas Eickner ◽  
Sabine Illner
Keyword(s):  
Contact Angle ◽  
Surface Modification ◽  
Water Absorption ◽  
Water Uptake ◽  
Biomedical Applications ◽  
High Surface ◽  
Volume Ratio ◽  
Polymer Composition ◽  
Water Wetting ◽  
Morphology Changes

AbstractIn recent years, nanofiber based materials have emerged as especially interesting for several biomedical applications, regarding their high surface to volume ratio. Due to the superficial nano- and microstructuring and the different wettability compared to nonstructured surfaces, the water absorption is an important parameter with respect to the degradation stability, thermomechanic properties and drug release properties, depending on the type of polymer [1]. In this investigation, the water absorption of different non- and plasma modified biostable nanofiber nonwovens based on polyurethane, polyester and polyamide were analysed and compared. Also, the water absorption by specified water wetting, the contact angle and morphology changes were examined. The results show that the water uptake is highly dependent on the surface modification and the polymer composition itself and can therefore be partially changed.

scholarly journals Design Considerations for Borehole Thermal Energy Storage (BTES): A Review with Emphasis on Convective Heat Transfer

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-26 ◽  
Author(s):  
Helge Skarphagen ◽  
David Banks ◽  
Bjørn S. Frengstad ◽  
Harald Gether
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Theoretical Calculations ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Thermal Recovery ◽  
Conductive Heat ◽  
Geological Environment

Borehole thermal energy storage (BTES) exploits the high volumetric heat capacity of rock-forming minerals and pore water to store large quantities of heat (or cold) on a seasonal basis in the geological environment. The BTES is a volume of rock or sediment accessed via an array of borehole heat exchangers (BHE). Even well-designed BTES arrays will lose a significant quantity of heat to the adjacent and subjacent rocks/sediments and to the surface; both theoretical calculations and empirical observations suggest that seasonal thermal recovery factors in excess of 50% are difficult to obtain. Storage efficiency may be dramatically reduced in cases where (i) natural groundwater advection through the BTES removes stored heat, (ii) extensive free convection cells (thermosiphons) are allowed to form, and (iii) poor BTES design results in a high surface area/volume ratio of the array shape, allowing high conductive heat losses. The most efficient array shape will typically be a cylinder with similar dimensions of diameter and depth, preferably with an insulated top surface. Despite the potential for moderate thermal recovery, the sheer volume of thermal storage that the natural geological environment offers can still make BTES a very attractive strategy for seasonal thermal energy storage within a “smart” district heat network, especially when coupled with more efficient surficial engineered dynamic thermal energy stores (DTES).

Biological weathering in soil: the role of symbiotic root-associated fungi biosensing minerals and directing photosynthate-energy into grain-scale mineral weathering

2008 ◽  
Vol 72 (1) ◽  
pp. 85-89 ◽  
Author(s):  
J. R. Leake ◽  
A. L. Duran ◽  
K. E. Hardy ◽  
I. Johnson ◽  
D. J. Beerling ◽  
...  
Keyword(s):  
Carbon Allocation ◽  
High Surface ◽  
Turgor Pressure ◽  
High Surface Area ◽  
Volume Ratio ◽  
Mineral Weathering ◽  
Mycorrhizal Associations ◽  
P Content ◽  
Biological Weathering

AbstractBiological weathering is a function of biotic energy expenditure. Growth and metabolism of organisms generates acids and chelators, selectively absorbs nutrient ions, and applies turgor pressure and other physical forces which, in concert, chemically and physically alter minerals. In unsaturated soil environments, plant roots normally form symbiotic mycorrhizal associations with fungi. The plants provide photosynthate-carbohydrate-energy to the fungi in return for nutrients absorbed from the soil and released from minerals. In ectomycorrhiza, one of the two major types of mycorrhiza of trees, roots are sheathed in fungus, and 15—30% of the net photosynthate of the plants passes through these fungi into the soil and virtually all of the water and nutrients taken up by the plants are supplied through the fungi. Here we show that ectomycorrhizal fungi actively forage for minerals and act as biosensors that discriminate between different grain sizes (53—90 μm, 500—1000 μm) and different minerals (apatite, biotite, quartz) to favour grains with a high surface-area to volume ratio and minerals with the highest P content. Growth and carbon allocation of the fungi is preferentially directed to intensively interact with these selected minerals to maximize resource foraging.

scholarly journals Preparation and Characterization of Biocompatible Electrospun Nanofiber Scaffolds

2018 ◽  
Vol 62 (4) ◽  
Author(s):  
Edit Hirsch ◽  
Márió Nacsa ◽  
Ferenc Ender ◽  
Miklós Mohai ◽  
Zsombor K. Nagy ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Surface Characteristic ◽  
Poly Lactic Acid ◽  
Nanofibrous Scaffolds ◽  
Plasma Surface Treatment ◽  
Nanoscale Fibers ◽  
Solution Electrospinning

Nanoscale fibers were prepared for the fabrication of scaffolds by using a strong electrostatic field on the polymer solution. Electrospinning is widely applied for production of drug delivery, tissue engineering, and regenerative medicine systems as well as biosensors and enzyme immobilization. Nanofibers, thanks to their high surface area to volume ratio, can also mimic the extracellular matrix, thus it has been recognized as a suitable technique for the fast fabrication of scaffolds. This article demonstrates the fabrication of several nanofibrous scaffolds from biopolymers such as polycaprolactone, poly(lactic acid), poly(lactide-co-glycolide), poly(lactide-co-caprolactone) and poly(hydroxybutyrate-co-hydroxy valerate). The characterization and comparison of the scaffolds were achieved based on the morphology and surface characteristic of the nanofibers. The samples showed hydrophobic characteristic, thus a plasma surface treatment was applied successfully to increase hydrophilicity and the effect of the treatment was evaluated based on the wettability and the change in elemental composition of the surface based on X-ray photoelectron spectroscopy.

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