scholarly journals Perspective on Nanofiber Electrochemical Sensors: Design of Relative Selectivity Experiments

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3706
Author(s):  
Stanley G. Feeney ◽  
Joelle M. J. LaFreniere ◽  
Jeffrey Mark Halpern
Keyword(s):  
Electrochemical Sensors ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Electrochemical Sensing ◽  
High Porosity ◽  
Specific Recognition ◽  
Materials Used ◽  
New Applications ◽  
Speed And Accuracy

The use of nanofibers creates the ability for non-enzymatic sensing in various applications and greatly improves the sensitivity, speed, and accuracy of electrochemical sensors for a wide variety of analytes. The high surface area to volume ratio of the fibers as well as their high porosity, even when compared to other common nanostructures, allows for enhanced electrocatalytic, adsorptive, and analyte-specific recognition mechanisms. Nanofibers have the potential to rival and replace materials used in electrochemical sensing. As more types of nanofibers are developed and tested for new applications, more consistent and refined selectivity experiments are needed. We applied this idea in a review of interferant control experiments and real sample analyses. The goal of this review is to provide guidelines for acceptable nanofiber sensor selectivity experiments with considerations for electrocatalytic, adsorptive, and analyte-specific recognition mechanisms. The intended presented review and guidelines will be of particular use to junior researchers designing their first control experiments, but could be used as a reference for anyone designing selectivity experiments for non-enzymatic sensors including nanofibers. We indicate the importance of testing both interferants in complex media and mechanistic interferants in the selectivity analysis of newly developed nanofiber sensor surfaces.

scholarly journals Nanotechnology for Environmental Remediation: Materials and Applications

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1760 ◽  
Author(s):  
Fernanda Guerra ◽  
Mohamed Attia ◽  
Daniel Whitehead ◽  
Frank Alexis
Keyword(s):  
Organic Compounds ◽  
Environmental Remediation ◽  
Organophosphorus Compounds ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Chlorinated Organic Compounds ◽  
Environmental Media ◽  
Chlorinated Organic ◽  
Materials Used

Environmental remediation relies mainly on using various technologies (e.g., adsorption, absorption, chemical reactions, photocatalysis, and filtration) for the removal of contaminants from different environmental media (e.g., soil, water, and air). The enhanced properties and effectiveness of nanotechnology-based materials makes them particularly suitable for such processes given that they have a high surface area-to-volume ratio, which often results in higher reactivity. This review provides an overview of three main categories of nanomaterials (inorganic, carbon-based, and polymeric-based materials) used for environmental remediation. The use of these nanomaterials for the remediation of different environmental contaminants—such as heavy metals, dyes, chlorinated organic compounds, organophosphorus compounds, volatile organic compounds, and halogenated herbicides—is reviewed. Various recent examples are extensively highlighted focusing on the materials and their applications.

Apatite Forming Ability of a Non-Woven Silica Fabric Containing Calcium

2007 ◽  
Vol 330-332 ◽  
pp. 699-702 ◽  
Author(s):  
Sang Hoon Rhee ◽  
Il Yong Chung ◽  
Yong Keun Lee ◽  
Bum Soon Lim ◽  
Yang Jo Seol
Keyword(s):  
Electric Field ◽  
Bone Grafting ◽  
Salt Water ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
High Porosity ◽  
Heat Treated ◽  
High Voltage Supply ◽  
Low Crystalline

Non-woven silica fabric was made by electro-spinning method for the potential application as a bone grafting material. The silica gel, the source material for electro-spinning, was prepared by the hydrolysis of tetraethyl orthosilicate in the presence of calcium salt, water, hydrochloric acid and ethanol. It was transferred to a syringe, which was connected to the high voltage supply generating a high electric field between the spinneret and the ground collecting drum. The silica fibers containing calcium were spun under the electric field of 2 KV/cm. Their diameters were in the range from about 0.3 μm to 8 μm. It was heat-treated at 300 oC for 3 hours. After soaking in the SBF for 1 week, low crystalline apatite crystals were observed to occur on their surfaces. From the results, it can be concluded that the non-woven silica fabric containing calcium made by electro-spinning method and then heat-treated has a bioactivity. It means it has a potential to be used as a bone grafting material because of its apatite-forming ability, high surface area to volume ratio and high porosity.

scholarly journals Enzymatic microreactors in biocatalysis: history, features, and future perspectives

Biocatalysis ◽  
2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Enzo Laurenti ◽  
Ardson dos Santos Vianna Jr.
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Immobilized Enzymes ◽  
Reaction Rates ◽  
Chemical Processes ◽  
Biochemical Processes ◽  
Enzymatic Microreactors ◽  
Materials Used ◽  
Broad Overview

AbstractMicrofluidic reaction devices are a very promising technology for chemical and biochemical processes. In microreactors, the micro dimensions, coupled with a high surface area/volume ratio, permit rapid heat exchange and mass transfer, resulting in higher reaction yields and reaction rates than in conventional reactors. Moreover, the lower energy consumption and easier separation of products permit these systems to have a lower environmental impact compared to macroscale, conventional reactors. Due to these benefits, the use of microreactors is increasing in the biocatalysis field, both by using enzymes in solution and their immobilized counterparts. Following an introduction to the most common applications of microreactors in chemical processes, a broad overview will be given of the latest applications in biocatalytic processes performed in microreactors with free or immobilized enzymes. In particular, attention is given to the nature of the materials used as a support for the enzymes and the strategies employed for their immobilization. Mathematical and engineering aspects concerning fluid dynamics in microreactors were also taken into account as fundamental factors for the optimization of these systems.

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.

Bioactive Non-Woven Silica Fabric Made Through Electro-Spinning Method

2006 ◽  
Vol 309-311 ◽  
pp. 465-468 ◽  
Author(s):  
Hanna Yoon ◽  
Yong Keun Lee ◽  
Bum Soon Lim ◽  
Sang Hoon Rhee
Keyword(s):  
Electric Field ◽  
Bone Grafting ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
High Porosity ◽  
Silica Fibers ◽  
High Voltage Supply ◽  
Low Crystalline ◽  
Hydrolysis Of

Non-woven silica fabric was made by electro-spinning method for the application as a bone grafting material. The silica gel, the source material for electro-spinning, was prepared by the hydrolysis of tetraethyl orthosilicate in the presence of water, hydrochloric acid and ethanol. It was transferred to a syringe (spinneret), which was connected to the high voltage supply generating a high electric field between the spinneret and the ground collecting drum. The silica fibers were spun under the electric field of 2 KV/cm. Their diameters were in the range from about 100 nm to 5 µm. After soaking in the SBF for 4 week, low crystalline apatite crystals were observed to occur partly on their surfaces. From the results, it can be concluded that the non-woven silica fabric made by electro-spinning method has the apatite forming ability in the SBF and it means it has a potential to be used as a bone grafting material because of its apatite-forming ability, high surface area to volume ratio and high porosity.

scholarly journals Electrospinning Nanotechnology-A Robust Method for Preparation of Nanofibers for Medicinal and Pharmaceutical Application.

2020 ◽  
Vol 8 (3) ◽  
pp. 176-184
Author(s):  
Bhadarge Meghana ◽  
Dhas Umesh ◽  
Shirode Abhay ◽  
Kadam Vilasrao
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Delivery Systems ◽  
Successful Implementation ◽  
Theoretical Principle ◽  
High Porosity ◽  
Pharmaceutical Application

Nanotechnology has evolved as a preferred choice in current research arena due to the advantages offered by it. The current research in pharmaceutical development is all about exploring and/or adopting different approaches for preparation of nanostructured drug delivery systems. Electrospinning nanotechnology has made its mark as a technology of choice for preparation of nanofibers for different applications. Electrospinning is a novel, robust and efficient fabrication process that is widely accepted and used to assemble nanofibers with distinct features such as length of several kilometers and diameter less than 300 nm. One of the most striking features of nanofibers is that they provide exceptionally high surface area-to-volume ratio and high porosity, making them a robust and attractive candidate for many advanced applications. Many researchers working on development of medicinal and pharmaceutical product design and development have reported their studies indicating successful implementation of electrospinning nanotechnology for preparation of nanofibers with distinct medicinal and pharmaceutical drug delivery applications. Authors of this article aims to provide a comprehensive review of electrospinning method for preparation of nanofibers with respect to theoretical principle, mechanics of electrospinning, critical process parameters, polymers and drug loaded nanofibers incorporated in different drug delivery systems for various pharmaceutical application.  

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 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).

Highly stable metal-organic framework UiO-66-NH2 for high-performance triboelectric nanogenerators

2021 ◽  
Author(s):  
Yong-Mei Wang ◽  
Xinxin Zhang ◽  
Dingyi Yang ◽  
Liting Wu ◽  
Jiaojiao Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
Metal Organic Framework ◽  
High Surface ◽  
High Surface Area ◽  
Triboelectric Nanogenerator ◽  
High Porosity ◽  
Chemically Modified ◽  
Metal Organic ◽  
Triboelectric Nanogenerators ◽  
Organic Framework

Abstract The high porosity, controllable size, high surface area, and chemical versatility of a metal-organic framework (MOF) enable it a good material for a triboelectric nanogenerator (TENG), and some MOFs have been incorporated in the fabrication of TENGs. However, the understanding of effects of MOFs on the energy conversion of a TENG is still lacking, which inhibits the improvement of the performance of MOF-based TENGs. Here, UiO-66-NH2 MOFs were found to significantly increase the power of a TENG and the mechanism was carefully examined. The electron-withdrawing ability of Zr-based UiO-66-family MOFs was enhanced by designing the amino functionalized 1,4-terephthalic acid (1,4-BDC) as ligand. The chemically modified UiO-66-NH2 was found to increase the surface roughness and surface potential of a composite film with MOFs embedded in polydimethylsiloxane (PDMS) matrix. Thus the total charges due to the contact electrification increased significantly. The composite-based TENG was found to be very durable and its output voltage and current were 4 times and 60 times higher than that of a PDMS-based TENG. This work revealed an effective strategy to design MOFs with excellent electron-withdrawing abilities for high-performance TENGs.

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