The Experts below are selected from a list of 13872 Experts worldwide ranked by ideXlab platform

Zhengfang Wang - One of the best experts on this subject based on the ideXlab platform.

  • robust multifunctional superhydrophobic fabric with uv induced reversible wettability photocatalytic self cleaning property and oil water separation via thiol ene click chemistry
    Applied Surface Science, 2019
    Co-Authors: Chi Jiang, Weiqu Liu, Maiping Yang, Chunhua Liu, Yankun Xie, Zhengfang Wang
    Abstract:

    Abstract Robust superhydrophobic fabric (SF) was successfully achieved by surface modification with anatase TiO2 sol and mercapto silanes, subsequently followed by hydrophobization with perfluorooctyl methacrylate (PFOMA) via thiol-ene click reaction. The resultant SFs not only exhibited excellent superhydrophobicity with a water contact angle of 157.7° and a water shedding angle of 4°, but also showed the considerable photocatalytic activity by the degradation of oil red O under UV irradiation. Moreover, the SFs exhibited a wetting transition from a superhydrophobic state to a superhydrophilic state by the alternation of UV exposure and thermal treatment. The SF could be utilized to separate oil-water mixture owing to its superhydrophobicity and superoleophilicity. Importantly, the SFs were tolerant towards strong acidic or alkaline environments, corrosive organic solvents, laundering, and Mechanical Abrasion. In addition, this facile preparation process could impart the superhydrophobicity to other substrates (such as PET fabrics, nonwoven fabrics, and sponges). Therefore, superhydrophobic materials with multi-functionality of UV induced reversible wettability, photocatalytic self-cleaning property, and oil-water separation are regarded as promising candidates for a wide range of applications.

Timothy M. Swager - One of the best experts on this subject based on the ideXlab platform.

  • Employing Halogen Bonding Interactions in Chemiresistive Gas Sensors
    2015
    Co-Authors: Jonathan G. Weis, Jens B. Ravnsbæk, Katherine A. Mirica, Timothy M. Swager
    Abstract:

    This paper reports the use of halogen bonding interactions for gas-phase detection of pyridine in SWCNT-based chemiresistive sensors with sub-ppm theoretical detection limits. The chemiresistors are prepared by solvent-free ball-milling of single-walled carbon nanotubes (SWCNTs) and aryl halide-based selectors, compression into a pellet, and subsequent Mechanical Abrasion between gold electrodes on paper. The sensing responses reflect halogen bonding trends, with few exceptions. The predominant signal transduction mechanism is likely attributed to swelling of the insulating haloarene matrix

  • fully drawn carbon based chemical sensors on organic and inorganic surfaces
    Lab on a Chip, 2014
    Co-Authors: Kelvin Mitchell Frazier, Katherine A. Mirica, Joseph J Walish, Timothy M. Swager
    Abstract:

    Mechanical Abrasion is an extremely simple, rapid, and low-cost method for deposition of carbon-based materials onto a substrate. However, the method is limited in throughput, precision, and surface compatibility for drawing conductive pathways. Selective patterning of surfaces using laser-etching can facilitate substantial improvements to address these current limitations for the abrasive deposition of carbon-based materials. This study demonstrates the successful on-demand fabrication of fully-drawn chemical sensors on a wide variety of substrates (e.g., weighing paper, polymethyl methacrylate, silicon, and adhesive tape) using single-walled carbon nanotubes (SWCNTs) as sensing materials and graphite as electrodes. Mechanical mixing of SWCNTs with solid or liquid selectors yields sensors that can detect and discriminate parts-per-million (ppm) quantities of various nitrogen-containing vapors (pyridine, aniline, triethylamine).

  • rapid prototyping of carbon based chemiresistive gas sensors on paper
    Proceedings of the National Academy of Sciences of the United States of America, 2013
    Co-Authors: Katherine A. Mirica, Joseph M Azzarelli, Jonathan G Weis, Jan M Schnorr, Timothy M. Swager
    Abstract:

    Chemically functionalized carbon nanotubes (CNTs) are promising materials for sensing of gases and volatile organic compounds. However, the poor solubility of carbon nanotubes hinders their chemical functionalization and the subsequent integration of these materials into devices. This manuscript describes a solvent-free procedure for rapid prototyping of selective chemiresistors from CNTs and graphite on the surface of paper. This procedure enables fabrication of functional gas sensors from commercially available starting materials in less than 15 min. The first step of this procedure involves the generation of solid composites of CNTs or graphite with small molecule selectors—designed to interact with specific classes of gaseous analytes—by solvent-free Mechanical mixing in a ball mill and subsequent compression. The second step involves deposition of chemiresistive sensors by Mechanical Abrasion of these solid composites onto the surface of paper. Parallel fabrication of multiple chemiresistors from diverse composites rapidly generates cross-reactive arrays capable of sensing and differentiating gases and volatile organic compounds at part-per-million and part-per-thousand concentrations.

S Ramanathan - One of the best experts on this subject based on the ideXlab platform.

  • potassium bromate as an oxidizing agent in a titania based ru cmp slurry
    Electrochemical and Solid State Letters, 2010
    Co-Authors: Noyel S Victoria, Pranav P Sharma, Ian Ivar Suni, S Ramanathan
    Abstract:

    Ru chemical Mechanical planarization CMP was studied in slurries containing titania and potassium bromate at different pHvalues, showing that the Ru removal rate is enhanced at pH 2 or less. Potentiodynamic polarization studies indicate that thecorrosion current is enhanced in the presence of bromate, while the static etch rate experiments show that the etch rate is low.Potassium bromate increases Ru removal only at anodic potentials or during Mechanical Abrasion. Studies at different concentra-tions of abrasive and oxidizing agent reveal that the removal rate enhancement saturates at 0.75 mM bromate and 4 wt % titania.© 2010 The Electrochemical Society. DOI: 10.1149/1.3481948 All rights reserved.Manuscript submitted July 6, 2010; revised manuscript received July 27, 2010. Published August 31, 2010.

Chi Jiang - One of the best experts on this subject based on the ideXlab platform.

  • robust multifunctional superhydrophobic fabric with uv induced reversible wettability photocatalytic self cleaning property and oil water separation via thiol ene click chemistry
    Applied Surface Science, 2019
    Co-Authors: Chi Jiang, Weiqu Liu, Maiping Yang, Chunhua Liu, Yankun Xie, Zhengfang Wang
    Abstract:

    Abstract Robust superhydrophobic fabric (SF) was successfully achieved by surface modification with anatase TiO2 sol and mercapto silanes, subsequently followed by hydrophobization with perfluorooctyl methacrylate (PFOMA) via thiol-ene click reaction. The resultant SFs not only exhibited excellent superhydrophobicity with a water contact angle of 157.7° and a water shedding angle of 4°, but also showed the considerable photocatalytic activity by the degradation of oil red O under UV irradiation. Moreover, the SFs exhibited a wetting transition from a superhydrophobic state to a superhydrophilic state by the alternation of UV exposure and thermal treatment. The SF could be utilized to separate oil-water mixture owing to its superhydrophobicity and superoleophilicity. Importantly, the SFs were tolerant towards strong acidic or alkaline environments, corrosive organic solvents, laundering, and Mechanical Abrasion. In addition, this facile preparation process could impart the superhydrophobicity to other substrates (such as PET fabrics, nonwoven fabrics, and sponges). Therefore, superhydrophobic materials with multi-functionality of UV induced reversible wettability, photocatalytic self-cleaning property, and oil-water separation are regarded as promising candidates for a wide range of applications.

Flavia Vitale - One of the best experts on this subject based on the ideXlab platform.

  • time evolution of the skin electrode interface impedance under different skin treatments
    Sensors, 2021
    Co-Authors: Brendan B. Murphy, Quincy Hendricks, Nicholas V. Apollo, Brian Litt, Brittany Scheid, Flavia Vitale
    Abstract:

    A low and stable impedance at the skin-electrode interface is key to high-fidelity acquisition of biosignals, both acutely and in the long term. However, recording quality is highly variable due to the complex nature of human skin. Here, we present an experimental and modeling framework to investigate the interfacial impedance behavior, and describe how skin interventions affect its stability over time. To illustrate this approach, we report experimental measurements on the skin-electrode impedance using pre-gelled, clinical-grade electrodes in healthy human subjects recorded over 24 h following four skin treatments: (i) Mechanical Abrasion, (ii) chemical exfoliation, (iii) microporation, and (iv) no treatment. In the immediate post-treatment period, Mechanical Abrasion yields the lowest initial impedance, whereas the other treatments provide modest improvement compared to untreated skin. After 24 h, however, the impedance becomes more uniform across all groups (<20 kΩ at 10 Hz). The impedance data are fitted with an equivalent circuit model of the complete skin-electrode interface, clearly identifying skin-level versus electrode-level contributions to the overall impedance. Using this model, we systematically investigate how time and treatment affect the impedance response, and show that removal of the superficial epidermal layers is essential to achieving a low, long-term stable interface impedance.

  • Time Evolution of the Skin–Electrode Interface Impedance under Different Skin Treatments
    'MDPI AG', 2021
    Co-Authors: Brendan B. Murphy, Brittany H. Scheid, Quincy Hendricks, Nicholas V. Apollo, Brian Litt, Flavia Vitale
    Abstract:

    A low and stable impedance at the skin–electrode interface is key to high-fidelity acquisition of biosignals, both acutely and in the long term. However, recording quality is highly variable due to the complex nature of human skin. Here, we present an experimental and modeling framework to investigate the interfacial impedance behavior, and describe how skin interventions affect its stability over time. To illustrate this approach, we report experimental measurements on the skin–electrode impedance using pre-gelled, clinical-grade electrodes in healthy human subjects recorded over 24 h following four skin treatments: (i) Mechanical Abrasion, (ii) chemical exfoliation, (iii) microporation, and (iv) no treatment. In the immediate post-treatment period, Mechanical Abrasion yields the lowest initial impedance, whereas the other treatments provide modest improvement compared to untreated skin. After 24 h, however, the impedance becomes more uniform across all groups (