Understanding Micro-Droplet Interface Bilayers for Developing Bioinspired Sensors

2013 ◽  
Author(s):  
Guru Venkatesan ◽  
Andy Sarles
Keyword(s):  
Water Droplet ◽  
Morphological Changes ◽  
High Surface ◽  
High Surface Area ◽  
Material System ◽  
Modes Of Operation ◽  
New Class ◽  
Wide Range ◽  
Droplet Sizes ◽  
The Stability

Droplet-based biomolecular arrays form the basis for a new class of bioinspired material system, whereby decreasing the sizes of the droplets and increasing the number of droplets can lead to higher functional density for the array. In this paper, we report on a non-microfluidic approach to form and connect nanoliter-to-femtoliter, lipid-coated aqueous droplets in oil to form micro-droplet interface bilayers (μDIBs). Two different modes of operation are reported for dispensing a wide range of droplet sizes (2–200μm radius). Due to the high surface-area-to-volume ratios of microdroplets at these length scales, droplet shrinking is prominent, which affects the stability and lifetime of the bilayer. To better quantify these effects, we measure the shrinkage rates for 8 different water droplet/oil compositions and study the effect of lipid placement and lipid type on morphological changes to μDIBs.

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.

scholarly journals Recent Advances in Applications of Ceramic Nanofibers

2021 ◽  
Author(s):  
Nuray Kizildag
Keyword(s):  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Ceramic Materials ◽  
Water Remediation ◽  
Mechanical And Thermal Properties ◽  
Chemical Erosion ◽  
Recent Advances ◽  
Wide Range ◽  
Ceramic Nanofibers

Ceramic materials are well known for their hardness, inertness, superior mechanical and thermal properties, resistance against chemical erosion and corrosion. Ceramic nanofibers were first manufactured through a combination of electrospinning with sol–gel method in 2002. The electrospun ceramic nanofibers display unprecedented properties such as high surface area, length, thermo-mechanical properties, and hierarchically porous structure which make them candidates for a wide range of applications such as tissue engineering, sensors, water remediation, energy storage, electromagnetic shielding, thermal insulation materials, etc. This chapter focuses on the most recent advances in the applications of ceramic nanofibers.

scholarly journals Removal of organic contaminant by municipal sewage sludge-derived hydrochar: kinetics, thermodynamics and mechanisms

2018 ◽  
Vol 78 (4) ◽  
pp. 947-956 ◽  
Author(s):  
Jia Wei ◽  
Yitao Liu ◽  
Jun Li ◽  
Hui Yu ◽  
Yongzhen Peng
Keyword(s):  
Sewage Sludge ◽  
High Surface ◽  
High Surface Area ◽  
Correlation Coefficients ◽  
Hydrothermal Carbonization ◽  
Municipal Sewage ◽  
Municipal Sewage Sludge ◽  
Wide Range ◽  
Pseudo Second Order ◽  
Physical Interactions

Abstract In this work, a microporous municipal sewage sludge-derived hydrochar (MSSH) with relatively high surface area and abundant surface organic functional groups was produced through hydrothermal carbonization. Based on the adsorption results over a wide range of conditions, the prepared MSSH was suggested as a promising adsorbent for CV because of its high and efficient adsorption capability. The experimental data were fitted to several kinetic models. Based on calculated respective parameters such as rate constants, equilibrium adsorption capacities and correlation coefficients, the pseudo second-order model proved the best in describing the adsorption behavior of MSSH. Through kinetics, thermodynamic modeling studies and material characterization, a plausible adsorption process was discussed under the conditions used in this study. It can be confirmed that the adsorption of CV onto MSSH is via both physical interactions (electrostatic interaction and Van der Waals' force) and chemical interactions (formation of H-bonding).

Enhanced Specific Heat of Silica Nanofluid

2010 ◽  
Vol 133 (2) ◽  
Author(s):  
Donghyun Shin ◽  
Debjyoti Banerjee
Keyword(s):  
Electron Microscopy ◽  
Specific Heat ◽  
Unit Volume ◽  
High Surface ◽  
High Surface Area ◽  
Lithium Carbonate ◽  
Sem Image ◽  
Surface Energies ◽  
Transmission Electron ◽  
The Stability

Silica nanoparticles (1% by weight) were dispersed in a eutectic of lithium carbonate and potassium carbonate (62:38 ratio) to obtain high temperature nanofluids. A differential scanning calorimeter instrument was used to measure the specific heat of the neat molten salt eutectic and after addition of nanoparticles. The specific heat of the nanofluid was enhanced by 19–24%. The measurement uncertainty for the specific heat values in the experiments is estimated to be in the range of 1–5%. These experimental data contradict earlier experimental results reported in the literature. (Notably, the stability of the nanofluid samples was not verified in these studies.) In the present study, the dispersion and stability of the nanoparticles were confirmed by using scanning electron microscopy (SEM). Percolation networks were observed in the SEM image of the nanofluid. Furthermore, no agglomeration of the nanoparticles was observed, as confirmed by transmission electron microscopy. The observed enhancements are suggested to be due to the high specific surface energies that are associated with the high surface area of the nanoparticles per unit volume (or per unit mass).

scholarly journals Effect of polythiophene thickness on hybrid sensor sensitivity

2021 ◽  
Vol 60 (1) ◽  
pp. 839-845
Author(s):  
Samia Belhousse ◽  
Fatma-Zohra Tıghılt ◽  
Sarah Bennıa ◽  
Sarah Adjtoutah ◽  
Sabrina Sam ◽  
...  
Keyword(s):  
Room Temperature ◽  
Secondary Ion Mass Spectrometry ◽  
High Surface ◽  
High Surface Area ◽  
Conductive Polymer ◽  
High Sensitivity ◽  
Electrochemical Anodization ◽  
Sensing Applications ◽  
The Stability ◽  
Electrical Characterizations

Abstract In recent years, hybrid structures have attracted wide consideration because they generate new very interesting properties. In this study, a hybrid gas sensor was developed using a simple fabrication process from the combination of porous silicon (PSi) and polythiophene (PTh). The study of the effect of electropolymerization rate and film thickness of PTh on the sensitivity and the stability of sensor was realized at room temperature. PSi was formed by electrochemical anodization, and it is an interesting material for sensing applications due to its high surface area. However, to avoid its degradation and to preserve its properties over the time, PSi surface was functionalized electrochemically with PTh subsequently to thermal oxidation. PTh as a conductive polymer is known for its high sensitivity and stability to environmental change. Several thicknesses of PTh have been electropolymerized onto the oxidized PSi surface to determine the best conditions for developing a sensitive and stable sensor. PTh thickness was controlled by the number of applied voltammogram cyclic. The characterizations of the different elaborated surfaces were carried out by Fourier transform infrared spectroscopy, scanning electron microscopy, cyclic voltammetry, contact angle, and secondary ion mass spectrometry. Finally, we studied the sensitivity, the response time, and the stability of PSi/PTh structures with different PTh thicknesses in the presence of CO2 gas and under cigarette smoke, by performing electrical characterizations, at room temperature.

scholarly journals Hydrothermal preparation of Phyllostachys pubescens – nanocellulose/graphene aerogel as a simple device for supercapacitors

BioResources ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 677-690
Author(s):  
Yan-Yun Wang ◽  
Qing-Jin Fu ◽  
Xiao Ning ◽  
Ge-Gu Chen ◽  
Chun-Li Yao
Keyword(s):  
High Performance ◽  
High Surface ◽  
High Surface Area ◽  
High Specific Capacitance ◽  
Phyllostachys Pubescens ◽  
Graphene Aerogel ◽  
Hydrothermal Preparation ◽  
Energy Devices ◽  
Wide Range ◽  
Extreme Stability

Bamboo nanocellulose can be regarded as a promising biomass material for the preparation of sustainable energy devices due to its unique structure, excellent properties, and wide range of sources. A highly conductive electrochemical energy storage was synthesized due to the excellent electrical conductivity of graphene and the high surface area of nanocellulose and graphene, which was beneficial for producing a network structure. The symmetric capacitor assembled from the Phyllostachys pubescens nanocellulose/graphene aerogel (CGA) electrode exhibited a high specific capacitance of 125.5 F/g at 5 mV/s and extreme stability of 98.3% capacitance retention ratio after 5000 cycles at 2 A/g. This nanocellulose-graphene electrode showed potential for future high-performance supercapacitors.

scholarly journals Let-down stability and screen printability of inks prepared using non-printing ink grades of carbon black pigment

2019 ◽  
Vol 48 (6) ◽  
pp. 523-532
Author(s):  
Muhammad Ali ◽  
Long Lin ◽  
Saira Faisal ◽  
Syed Rizwan Ali ◽  
Syed Imran Ali
Keyword(s):  
Carbon Black ◽  
High Surface ◽  
High Surface Area ◽  
Volatile Matter ◽  
Matter Content ◽  
Content Type ◽  
Binder Free ◽  
Series Of Experiments ◽  
The Stability ◽  
Printing Ink

Purpose This paper aims to analyse the let-down stability of the binder-free dispersion of non-printing ink grades of carbon black and to assess the screen-printability of the finished inks formulated thereof from these pigment dispersions. Design/methodology/approach Binder-free pigment dispersions that were prepared and optimised following a ladder series of experiments (reported in a separate study by the authors) were let-down with three different binders such that inks containing various amounts of a binder were prepared followed by a rheological characterisation immediately after formulation and after four weeks of storage. The screen printability of the inks that displayed considerable stability was assessed, so was the ink film integrity. Findings The pigment dispersions that were considered in the present study were generally found to be stable after let-down with different binders. This was indicated by the fact that the finished inks possessed a shear thinning viscosity profiles, after formulation and after storage, in most of the cases. Furthermore, the screen printability of the inks was also found to be good in terms of registration quality of a selected design. The structure of the ink film deposits on uncoated and binder-coated textile fabrics was also highly integrated and free from discontinuities. Originality/value Carbon blacks with very low volatile matter content and/or high surface area are generally not considered suitable for use in the formulation of printing inks. This is because of their generally poor dispersability and inability to form dispersions that remain stable over extended periods. This work, which is a part of a larger study by the authors, concerns with the stability of inks formulated from binder-free dispersions of such non-printing ink grades of carbon black. The major advantage of using such pigments in inks is that the required functionality is achieved at considerably low pigment loadings.

A Multiscale Simulation Approach for the Mechanical Response of Copper/Nickel Nanofoams With Experimental Validation

2021 ◽  
pp. 1-27
Author(s):  
Hang Ke ◽  
Alexandra Loaiza ◽  
Andres Jimenez ◽  
David Bahr ◽  
I. Mastorakos
Keyword(s):  
Mechanical Response ◽  
Morphological Changes ◽  
High Surface ◽  
High Surface Area ◽  
Multiscale Simulation ◽  
Woven Fabric ◽  
Multiscale Approach ◽  
Brittle Behavior ◽  
Copper Nickel ◽  
Dislocation Movement

Abstract Metallic nanofoams, cellular structures consisting of interlinked thin nanowires and empty pores, create low density, high surface area materials. These structures can suffer from macroscopically brittle behavior. In this work, we present a multiscale approach to study and explain the mechanical behavior of metallic nanofoams obtained by an electrospinning method. In this multiscale approach, atomistic simulations were first used to obtain the yield surfaces of different metallic nanofoam cell structures. Then, a continuum plasticity model using finite elements was used to predict the alloy nanofoam's overall strength in compression. The manufactured metallic nanofoams were produced by electrospinning a polymeric non-woven fabric containing metal precursors for alloys of copper-nickel and then thermally processing the fabric to create alloy metallic nanofoams. The nanofoams were tested with nanoindentation. The experimental results suggest that the addition of nickel increases the hardening of the nanofoams. The multiscale simulation modeling results agreed qualitatively with the experiments by suggesting that the addition of the alloying can be beneficial to the hardening behavior of the metallic nanofoams, and helps to isolate the effects of alloying from morphological changes in the foam. This behavior was related to the addition of solute atoms that prevent the free dislocation movement and increase the strength of the structure.

Synthesis and characterization of mesalamine silica nanoparticles

2021 ◽  
Vol 16 ◽  
Author(s):  
Balaji Maddiboyina ◽  
Ramya Krishna Nakkala ◽  
Prasanna Kumar Desu ◽  
Vikas Jhawat
Keyword(s):  
Particle Size ◽  
Silica Nanoparticles ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Silica Nanoparticle ◽  
Water Soluble ◽  
Infrared Spectrometry ◽  
Burst Release ◽  
Wide Range

Background: Nanoparticles made of silica are new materials that can be used in a wide range of drug delivery methods because they are biocompatible and biodegradable. Mesalamine, a classic water-soluble medication, remains loaded into the synthesized silica nanoparticle and is considered for sustained release proficiency. Precipitation approach using high surface area and pore volume tetraethyl orthosilicate yielded mesalamine-loaded silica nanoparticles. Methods: The drug-loaded nanoparticle was created and produced using two different techniques. Fourier transform infrared spectrometry, differential scanning calorimetry, X-ray powder diffraction, Brauer Emmett teller, scanning electron microscopy, particle size measurements, and dissolution investigations have all been used to analyse the substance in some way or another. Results: Because of the high surface area, well-known results like the complete silica nanoparticle created using method-2 remained mesoporous. The onset peak of the method-2 formulation's DSC was 182.27°c, and the offset peak was 192.14°c, consistent with the DSC results. The particle size range varies from 205-225nm. The results demonstrate that the uptake of the mesalamine by burst release it for 30 minutes initial, followed by sustained maintenance of dose even after 240 minutes. The results indicate that the loading process has an effect on the extent of loading. When silica nanoparticles were impregnated with mesalamine, the amount of the drug contained was significantly higher than when they were wetted. Conclusion: In addition, the XRD results show that both the pure mesalamine and the formulation did not show any polymorphic deviation.

scholarly journals Optical-Based (Bio) Sensing Systems Using Magnetic Nanoparticles

2019 ◽  
Vol 5 (4) ◽  
pp. 59 ◽  
Author(s):  
Recep Üzek ◽  
Esma Sari ◽  
Arben Merkoçi
Keyword(s):  
Magnetic Nanoparticles ◽  
Near Infrared ◽  
High Surface ◽  
High Surface Area ◽  
Surface Enhanced Raman Spectroscopy ◽  
High Mass ◽  
Sensing Systems ◽  
Sensing Platform ◽  
Wide Range ◽  
Surface Enhanced Raman

In recent years, various reports related to sensing application research have suggested that combining the synergistic impacts of optical, electrical or magnetic properties in a single technique can lead to a new multitasking platform. Owing to their unique features of the magnetic moment, biocompatibility, ease of surface modification, chemical stability, high surface area, high mass transference, magnetic nanoparticles have found a wide range of applications in various fields, especially in sensing systems. The present review is comprehensive information about magnetic nanoparticles utilized in the optical sensing platform, broadly categorized into four types: surface plasmon resonance (SPR), surface-enhanced Raman spectroscopy (SERS), fluorescence spectroscopy and near-infrared spectroscopy and imaging (NIRS) that are commonly used in various (bio) analytical applications. The review also includes some conclusions on the state of the art in this field and future aspects.

Sign in / Sign up

Export Citation Format

Share Document