scholarly journals Lignosulfonate-Based Conducting Flexible Polymeric Membranes for Liquid Sensing Applications

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5331
Author(s):  
Sandra Magina ◽  
Alisa Rudnitskaya ◽  
Sílvia Soreto ◽  
Luís Cadillon Costa ◽  
Ana Barros-Timmons ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Potentiometric Sensors ◽  
Polymeric Membrane ◽  
Sensitive Material ◽  
Multiwalled Carbon ◽  
Sensor Applications ◽  
Sensing Applications ◽  
Wide Range ◽  
Filler Dispersion ◽  
Liquid Sensing

In this study, lignosulfonate (LS) from the acid sulfite pulping of eucalypt wood was used to synthesize LS-based polyurethanes (PUs) doped with multiwalled carbon nanotubes (MWCNTs) within the range of 0.1–1.4% w/w, yielding a unique conducting copolymer composite, which was employed as a sensitive material for all-solid-state potentiometric chemical sensors. LS-based PUs doped with 1.0% w/w MWCNTs exhibited relevant electrical conductivity suitable for sensor applications. The LS-based potentiometric sensor displayed a near-Nernstian or super-Nernstian response to a wide range of transition metals, including Cu(II), Zn(II), Cd(II), Cr(III), Cr(VI), Hg(II), and Ag(I) at pH 7 and Cr(VI) at pH 2. It also exhibited a redox response to the Fe(II)/(III) redox pair at pH 2. Unlike other lignin-based potentiometric sensors in similar composite materials, this LS-based flexible polymeric membrane did not show irreversible complexation with Hg(II). Only a weak response toward ionic liquids, [C2mim]Cl and ChCl, was registered. Unlike LS-based composites comprising MWCNTs, those doped with graphene oxide (GO), reduced GO (rGO), and graphite (Gr) did not reveal the same electrical conductivity, even with loads up to 10% (w/w), in the polymer composite. This fact is associated, at least partially, with the different filler dispersion abilities within the polymeric matrix.

scholarly journals Ion-selective Electrodes Based on PVC Membranes for Potentiometric Sensor Applications: A Review

2021 ◽  
Vol 8 (2) ◽  
pp. 76-84
Author(s):  
Mohan Chandra ◽  
Kumar Vinod
Keyword(s):  
Electrochemical Sensors ◽  
Research Work ◽  
Analytical Techniques ◽  
Potentiometric Sensors ◽  
Polymeric Membrane ◽  
Ion Selective Electrodes ◽  
Fast Method ◽  
Toxic Substances ◽  
Electroactive Material ◽  
Sensor Applications

Ion-selective electrodes (ISEs) are potentiometric sensors used to measure some of the most critical analytes in environmental laboratory. Recently ion sensors are taking place of various analytical techniques, as they provide a convenient and fast method of electroanalysis. Ion-selective electrodes are simple, relatively inexpensive, robust, durable, and ideal to be used for the detection of heavy metal ions. Important characterisctics of ISEs are selectivity, response time, detection limit, working range, effect of pH etc. Lot of research work is being done for the formation of ISEs by using polymeric membrane incorporated with ionophores or electroactive material. Various types of Schiff bases, macromolecules and metal complexes may be used as ionophores along with plasticizer, ion-excluder for the membrane preparation. Ion-selective electrodes will be optimized for pH range, selectivity, sensitivity, working concentration range and lifetime before their use as sensor electrode for determining the concentration of ions in solution. Various researchers are working in the field to develop Ion-selective electrodes which shows better selectivity and sensitivity than the previously reported electrodes and can be used as electrocatalysts. These ISEs can be used as electrochemical sensors for the analysis of food products, drinking water, beverages, fertilizers, and for the analysis of sample containing toxic substances.

scholarly journals Latest Advances in Sensor Applications in Agriculture

Agriculture ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 362 ◽  
Author(s):  
Ahmed Kayad ◽  
Dimitrios S. Paraforos ◽  
Francesco Marinello ◽  
Spyros Fountas
Keyword(s):  
Food Systems ◽  
Human Life ◽  
Health Assessment ◽  
Life Quality ◽  
Farm Management ◽  
Special Issue ◽  
Post Harvest ◽  
Sensor Applications ◽  
Sensing Applications ◽  
Wide Range

Sensor applications are impacting the everyday objects that enhance human life quality. In this special issue, the main objective was to address recent advances of sensor applications in agriculture covering a wide range of topics in this field. A total of 14 articles were published in this special issue where nine of them were research articles, two review articles and two technical notes. The main topics were soil and plant sensing, farm management and post-harvest application. Soil-sensing topics include monitoring soil moisture content, drain pipes and topsoil movement during the harrowing process while plant-sensing topics include evaluating spray drift in vineyards, thermography applications for winter wheat and tree health assessment and remote-sensing applications as well. Furthermore, farm management contributions include food systems digitalization and using archived data from plowing operations, and one article in post-harvest application in sunflower seeds.

scholarly journals Nanocomposite Polymeric Materials Based on Eucalyptus Lignoboost® Kraft Lignin for Liquid Sensing Applications

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1637 ◽  
Author(s):  
Sónia S. Leça Gonçalves ◽  
Alisa Rudnitskaya ◽  
António J.M. Sales ◽  
Luís M. Cadillon Costa ◽  
Dmitry V. Evtuguin
Keyword(s):  
Solid State ◽  
Polymeric Materials ◽  
Kraft Lignin ◽  
Electrical Impedance Spectroscopy ◽  
Potentiometric Sensors ◽  
Scanning Calorimetry ◽  
Mir Spectroscopy ◽  
Sensing Applications ◽  
Specificity And Sensitivity ◽  
Liquid Sensing

This study reports the synthesis of polyurethane–lignin copolymer blended with carbon multilayer nanotubes to be used in all-solid-state potentiometric chemical sensors. Known applicability of lignin-based polyurethanes doped with carbon nanotubes for chemical sensing was extended to eucalyptus LignoBoost® kraft lignin containing increased amounts of polyphenolic groups from concomitant tannins that were expected to impart specificity and sensitivity to the sensing material. Synthesized polymers were characterized using FT-MIR spectroscopy, electrical impedance spectroscopy, scanning electron microscopy, thermogravimetric analysis, and differential scanning calorimetry and are used for manufacturing of all solid-state potentiometric sensors. Potentiometric sensor with LignoBoost® kraft lignin-based polyurethane membrane displayed theoretical response and high selectivity to Cu (II) ions, as well as long-term stability.

scholarly journals Rapid Growth of TiO2 Nanoflowers via Low-Temperature Solution Process: Photovoltaic and Sensing Applications

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 566 ◽  
Author(s):  
M. Akhtar ◽  
Ahmad Umar ◽  
Swati Sood ◽  
InSung Jung ◽  
H. Hegazy ◽  
...  
Keyword(s):  
Low Temperature ◽  
Anatase Phase ◽  
Three Dimensional ◽  
Solution Process ◽  
Dye Sensitized Solar Cell ◽  
Sensor Applications ◽  
Dye Sensitized ◽  
Sensing Applications ◽  
Density Growth ◽  
Temperature Solution

This paper reports the rapid synthesis, characterization, and photovoltaic and sensing applications of TiO2 nanoflowers prepared by a facile low-temperature solution process. The morphological characterizations clearly reveal the high-density growth of a three-dimensional flower-shaped structure composed of small petal-like rods. The detailed properties confirmed that the synthesized nanoflowers exhibited high crystallinity with anatase phase and possessed an energy bandgap of 3.2 eV. The synthesized TiO2 nanoflowers were utilized as photo-anode and electron-mediating materials to fabricate dye-sensitized solar cell (DSSC) and liquid nitroaniline sensor applications. The fabricated DSSC demonstrated a moderate conversion efficiency of ~3.64% with a maximum incident photon to current efficiency (IPCE) of ~41% at 540 nm. The fabricated liquid nitroaniline sensor demonstrated a good sensitivity of ~268.9 μA mM−1 cm−2 with a low detection limit of 1.05 mM in a short response time of 10 s.

scholarly journals Influence of Carbon Nanotube-Pretreatment on the Properties of Polydimethylsiloxane/Carbon Nanotube-Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1355
Author(s):  
Astrid Diekmann ◽  
Marvin C. V. Omelan ◽  
Ulrich Giese
Keyword(s):  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Mechanical Performance ◽  
Softening Effect ◽  
Electrical Percolation ◽  
Optimum Parameters ◽  
Lauryl Ether ◽  
Solvent Residues ◽  
Electrical Percolation Threshold ◽  
Filler Dispersion

Incorporating nanofillers into elastomers leads to composites with an enormous potential regarding their properties. Unfortunately, nanofillers tend to form agglomerates inhibiting adequate filler dispersion. Therefore, different carbon nanotube (CNT) pretreatment methods were analyzed in this study to enhance the filler dispersion in polydimethylsiloxane (PDMS)/CNT-composites. By pre-dispersing CNTs in solvents an increase in electrical conductivity could be observed within the sequence of tetrahydrofuran (THF) > acetone > chloroform. Optimization of the pre-dispersion step results in an AC conductivity of 3.2 × 10−4 S/cm at 1 Hz and 0.5 wt.% of CNTs and the electrical percolation threshold is decreased to 0.1 wt.% of CNTs. Optimum parameters imply the use of an ultrasonic finger for 60 min in THF. However, solvent residues cause a softening effect deteriorating the mechanical performance of these composites. Concerning the pretreatment of CNTs by physical functionalization, the use of surfactants (sodium dodecylbenzenesulfonate (SDBS) and polyoxyethylene lauryl ether (“Brij35”)) leads to no improvement, neither in electrical conductivity nor in mechanical properties. Chemical functionalization enhances the compatibility of PDMS and CNT but damages the carbon nanotubes due to the oxidation process so that the improvement in conductivity and reinforcement is superimposed by the CNT damage even for mild oxidation conditions.

scholarly journals Strain Sensor via Wood Anomalies in 2D Dielectric Array

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1022
Author(s):  
Rashid G. Bikbaev ◽  
Ivan V. Timofeev ◽  
Vasiliy F. Shabanov
Keyword(s):  
Higher Plants ◽  
Numerical Study ◽  
Reciprocal Lattice ◽  
Strain Sensing ◽  
Photonic Materials ◽  
Sensing Applications ◽  
Wide Range ◽  
Sensor Structure ◽  
Optical Behavior ◽  
Chlorophyll Absorption

Optical sensing is one of many promising applications for all-dielectric photonic materials. Herein, we present an analytical and numerical study on the strain-responsive spectral properties of a bioinspired sensor. The sensor structure contains a two-dimensional periodic array of dielectric nanodisks to mimic the optical behavior of grana lamellae inside chloroplasts. To accumulate a noticeable response, we exploit the collective optical mode in grana ensemble. In higher plants, such a mode appears as Wood’s anomaly near the chlorophyll absorption line to control the photosynthesis rate. The resonance is shown persistent against moderate biological disorder and deformation. Under the stretching or compression of a symmetric structure, the mode splits into a couple of polarized modes. The frequency difference is accurately detected. It depends on the stretch coefficient almost linearly providing easy calibration of the strain-sensing device. The sensitivity of the considered structure remains at 5 nm/% in a wide range of strain. The influence of the stretching coefficient on the length of the reciprocal lattice vectors, as well as on the angle between them, is taken into account. This adaptive phenomenon is suggested for sensing applications in biomimetic optical nanomaterials.

scholarly journals Femtosecond Laser Fabrication of Hybrid Metal-Dielectric Structures with Nonlinear Photoluminescence

Photonics ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 121
Author(s):  
Ekaterina Ponkratova ◽  
Eduard Ageev ◽  
Filipp Komissarenko ◽  
Sergei Koromyslov ◽  
Dmitry Kudryashov ◽  
...  
Keyword(s):  
Visible Spectral Region ◽  
Single Step ◽  
Hybrid Nanostructures ◽  
Nonlinear Properties ◽  
Nanophotonic Devices ◽  
Sensing Applications ◽  
Structure Morphology ◽  
Wide Range ◽  
Nonlinear Signal ◽  
Dielectric Structures

Fabrication of hybrid micro- and nanostructures with a strong nonlinear response is challenging and represents a great interest due to a wide range of photonic applications. Usually, such structures are produced by quite complicated and time-consuming techniques. This work demonstrates laser-induced hybrid metal-dielectric structures with strong nonlinear properties obtained by a single-step fabrication process. We determine the influence of several incident femtosecond pulses on the Au/Si bi-layer film on produced structure morphology. The created hybrid systems represent isolated nanoparticles with a height of 250–500 nm exceeding the total thickness of the Au-Si bi-layer. It is shown that fabricated hybrid nanostructures demonstrate enhancement of the SHG signal (up to two orders of magnitude) compared to the initial planar sample and a broadband photoluminescence signal (more than 200 nm in width) in the visible spectral region. We establish the correlation between nonlinear signal and phase composition provided by Raman scattering measurements. Such laser-induced structures have significant potential in optical sensing applications and can be used as components for different nanophotonic devices.

scholarly journals A Nanoplasmonic-Based Biosensing Approach for Wide-Range and Highly Sensitive Detection of Chemicals

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1961
Author(s):  
Francesco Arcadio ◽  
Luigi Zeni ◽  
Aldo Minardo ◽  
Caterina Eramo ◽  
Stefania Di Di Ronza ◽  
...  
Keyword(s):  
Optical Fibers ◽  
Limit Of Detection ◽  
Slab Waveguide ◽  
Grating Pattern ◽  
Transparent Substrate ◽  
Synthetic Receptor ◽  
Sensing Applications ◽  
Wide Range ◽  
Plastic Optical Fibers ◽  
Highly Sensitive Detection

In a specific biosensing application, a nanoplasmonic sensor chip has been tested by an experimental setup based on an aluminum holder and two plastic optical fibers used to illuminate and collect the transmitted light. The studied plasmonic probe is based on gold nanograting, realized on the top of a Poly(methyl methacrylate) (PMMA) chip. The PMMA substrate could be considered as a transparent substrate and, in such a way, it has been already used in previous work. Alternatively, here it is regarded as a slab waveguide. In particular, we have deposited upon the slab surface, covered with a nanograting, a synthetic receptor specific for bovine serum albumin (BSA), to test the proposed biosensing approach. Exploiting this different experimental configuration, we have determined how the orientation of the nanostripes forming the grating pattern, with respect to the direction of the input light (longitudinal or orthogonal), influences the biosensing performances. For example, the best limit of detection (LOD) in the BSA detection that has been obtained is equal to 23 pM. Specifically, the longitudinal configuration is characterized by two observable plasmonic phenomena, each sensitive to a different BSA concentration range, ranging from pM to µM. This aspect plays a key role in several biochemical sensing applications, where a wide working range is required.

scholarly journals Wide range and highly linear signal processed systematic humidity sensor array using Methylene Blue and Graphene composite

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Muhammad Umair Khan ◽  
Gul Hassan ◽  
Rayyan Ali Shaukat ◽  
Qazi Muhammad Saqib ◽  
Mahesh Y. Chougale ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Linear Combination ◽  
Linear Function ◽  
Humidity Sensor ◽  
Sensor Array ◽  
Combination Method ◽  
Humidity Sensing ◽  
Sensing Applications ◽  
Wide Range ◽  
Graphene Flakes

AbstractThis paper proposes a signal processed systematic 3 × 3 humidity sensor array with all range and highly linear humidity response based on different particles size composite inks and different interspaces of interdigital electrodes (IDEs). The fabricated sensors are patterned through a commercial inkjet printer and the composite of Methylene Blue and Graphene with three different particle sizes of bulk Graphene Flakes (BGF), Graphene Flakes (GF), and Graphene Quantum Dots (GQD), which are employed as an active layer using spin coating technique on three types of IDEs with different interspaces of 300, 200, and 100 µm. All range linear function (0–100% RH) is achieved by applying the linear combination method of nine sensors in the signal processing field, where weights for linear combination are required, which are estimated by the least square solution. The humidity sensing array shows a fast response time (Tres) of 0.2 s and recovery time (Trec) of 0.4 s. From the results, the proposed humidity sensor array opens a new gateway for a wide range of humidity sensing applications with a linear function.

scholarly journals Universal mobility characteristics of graphene originating from charge scattering by ionised impurities

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jonathan H. Gosling ◽  
Oleg Makarovsky ◽  
Feiran Wang ◽  
Nathan D. Cottam ◽  
Mark T. Greenaway ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Carrier Density ◽  
Carrier Mobility ◽  
Carrier Transport ◽  
Analytical Models ◽  
Pristine Graphene ◽  
High Electron ◽  
Boltzmann Transport ◽  
Transport Parameters ◽  
Wide Range

AbstractPristine graphene and graphene-based heterostructures can exhibit exceptionally high electron mobility if their surface contains few electron-scattering impurities. Mobility directly influences electrical conductivity and its dependence on the carrier density. But linking these key transport parameters remains a challenging task for both theorists and experimentalists. Here, we report numerical and analytical models of carrier transport in graphene, which reveal a universal connection between graphene’s carrier mobility and the variation of its electrical conductivity with carrier density. Our model of graphene conductivity is based on a convolution of carrier density and its uncertainty, which is verified by numerical solution of the Boltzmann transport equation including the effects of charged impurity scattering and optical phonons on the carrier mobility. This model reproduces, explains, and unifies experimental mobility and conductivity data from a wide range of samples and provides a way to predict a priori all key transport parameters of graphene devices. Our results open a route for controlling the transport properties of graphene by doping and for engineering the properties of 2D materials and heterostructures.

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