Nanoparticle‐Reinforced Silica Gels with Enhanced Mechanical Properties and Excellent pH‐Sensing Performance

ABSTRACTOrganically modified silica gels and dye-doped silica gels have been patterned into micrometer-scale structures on a substrate using micro molding in capillaries (MIMIC). This approach is from a class of elastomeric stamping and molding techniques collectively known as soft lithography. Soft lithography and sol-gel processing share attractive features in that they are relatively benign processes performed at ambient conditions, which makes both techniques compatible with a wide variety of organic molecules, molecular assemblies, and biomolecules. The combination of sol-gel and soft lithography, therefore, holds enormous promise as a tool for microfabrication of materials with optical, chemical, or biological functionality that are not readily patterned with conventional methods. This paper describes our investigation of micro-patterned organic-inorganic hybrid materials containing indicator dyes for microfluidic sensor applications. Reversible colorimetric pH sensing via entrapped reagents is demonstrated in a prototype microfluidic sensor element. Patterned structures range from one to tens of micrometers in cross-section and are up to centimeters in length. Fundamental chemical processing issues associated with mold filling, cracking and sensor stability are discussed.

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Low-temperature solution processing of palladium/palladium oxide films and their pH sensing performance

Talanta ◽

10.1016/j.talanta.2015.08.062 ◽

2016 ◽

Vol 146 ◽

pp. 517-524 ◽

Cited By ~ 16

Author(s):

Yiheng Qin ◽

Arif U. Alam ◽

Si Pan ◽

Matiar M.R. Howlader ◽

Raja Ghosh ◽

...

Keyword(s):

Low Temperature ◽

Oxide Films ◽

Palladium Oxide ◽

Solution Processing ◽

Ph Sensing ◽

Temperature Solution ◽

Sensing Performance

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Correlations between textural and mechanical properties in wet silica gels

Journal of Non-Crystalline Solids ◽

10.1016/0022-3093(86)90134-1 ◽

1986 ◽

Vol 82 (1-3) ◽

pp. 220-224 ◽

Cited By ~ 16

Author(s):

J. Dumas ◽

J.F. Quinson ◽

C. Bovier ◽

S. Baza ◽

J. Serughetti

Keyword(s):

Mechanical Properties ◽

Silica Gels

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Encapsulation of Mammalian Cells in Nanoporous Silica Gels: Interactions at the Biointerface

ASME 2012 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2012-80211 ◽

2012 ◽

Author(s):

Eduardo Reátegui ◽

Lisa Kasinkas ◽

Alptekin Aksan

Keyword(s):

Mechanical Properties ◽

Thermal Stability ◽

Energy Conversion ◽

Mammalian Cells ◽

Silica Gels ◽

Nanoporous Silica ◽

Energy Conversion Systems ◽

And Function ◽

Inorganic Matrix

Encapsulation of cells in nanoporous silica gels has shown great potential for the development of biotechnology applications such as biosensors, biocatalysis, bioremediation, energy conversion systems, and cellular therapies [1]. However, even though the inorganic matrix confers improved mechanical properties, chemical and thermal stability, and is resistant to microbial attacks, long-term viability and function after encapsulation remains as one of the principal setbacks of this technology [2].

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pH Sensing Performance and Electrical Characterization on Hafnium Oxide Gate ISFETs with Single and Dual Stack Insulator by RF Sputtering

10.7567/ssdm.2007.p-11-12l ◽

2007 ◽

Author(s):

Tseng-Fu Lu ◽

Yen-Chih Lin ◽

Chia-Ming Yang ◽

Chao-Sung Lai ◽

Dorota G. Pijanowska ◽

...

Keyword(s):

Hafnium Oxide ◽

Rf Sputtering ◽

Electrical Characterization ◽

Ph Sensing ◽

Sensing Performance ◽

Dual Stack

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Influence of Formation Parameters on the Mechanical Properties of Wet Gels

MRS Proceedings ◽

10.1557/proc-88-73 ◽

1986 ◽

Vol 88 ◽

Cited By ~ 5

Author(s):

S. A. Pardenek ◽

J. W. Fleming ◽

L. C. Klein

Keyword(s):

Mechanical Properties ◽

Mechanical Behavior ◽

Sol Gel ◽

Silica Gels ◽

Ambient Conditions ◽

Relaxation Measurements ◽

Beam Bending ◽

Gel Composition ◽

Processing Steps ◽

Made In

ABSTRACTThe mechanical behavior of wet silica gels formed by various sol-gel processes has been studied. Samples were analyzed with a beam-bending apparatus specifically designed for accurate measurements of very low strength solids. Breaking strength, viscosity and relaxation measurements were made on gelled bodies. Specimens were studied in an undried gel state, molded in shapes suitable for the particular experiments. Tests were made in several ambient conditions including immersion in a liquid bath. The mechanical properties of gels are dependent upon the gel composition, gel age and other formation parameters such as pH, temperature and pressure. An understanding of these properties is particularly important in determining the nature of subsequent processing steps. Models for the structures of the various gels are proposed which explain variation in mechanical behavior.

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EVALUATION ON THE EGFET PH SENSING PERFORMANCE OF SOL-GEL SPIN COATED TITANIUM DIOXIDE THIN FILM

Jurnal Teknologi ◽

10.11113/jurnalteknologi.v83.16313 ◽

2021 ◽

Vol 83 (4) ◽

pp. 119-125

Author(s):

Muhammad AlHadi Zulkefle ◽

Sukreen Hana Herman ◽

Rohanieza Abdul Rahman ◽

Khairul Aimi Yusof ◽

Aimi Bazilah Rosli ◽

...

Keyword(s):

Thin Film ◽

Tio2 Thin Film ◽

Drift Rate ◽

Sol Gel ◽

Ph Sensor ◽

Ph Sensing ◽

Coating Method ◽

Effect Transistor ◽

Sensing Membrane ◽

Sensing Performance

For this study, TiO2 thin film was fabricated using the sol-gel spin coating method. The fabricated film was then applied as a sensing membrane in an extended gate field effect transistor (EGFET) pH sensor system. The pH sensing performance of the sol-gel spin-coated TiO2 was evaluated in terms of sensitivity, linearity, and hysteresis where the value obtained was 58.70 mV/pH, 0.9922, and 86.17 mV respectively. The drift rate of the sample when being measured for 12 consecutive hours was also determined where measurement in pH 4, pH 7, and pH 10 yield drift rate of 1.72 mV/h, 4.14 mV/h, and 6.05 mV/h respectively. Besides that, the TiO2 was characterized for its thickness (24.32 nm) and surface roughness (5.129 nm). From the results obtained, it was found that sol-gel spin-coated TiO2 thin film with thickness between 20 - 29 nm will have high pH sensitivity (more than 50 mV/pH).

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Self-sensing performance of metakaolin geopolymer with carbon nanotubes subjected to repeated compressive loading

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1209/1/012043 ◽

2021 ◽

Vol 1209 (1) ◽

pp. 012043

Author(s):

C Mizerová ◽

P Rovnaník ◽

I Kusák ◽

P Schmid

Keyword(s):

Mechanical Properties ◽

Carbon Nanotubes ◽

Electrical Conductivity ◽

Continuous Monitoring ◽

Compressive Loading ◽

Conductive Filler ◽

Applied Loading ◽

Interest In Research ◽

Metakaolin Geopolymer ◽

Sensing Performance

Abstract Alkaline activated binders showing enhanced piezoresistive properties have recently attracted increased interest in research of their application in smart self-sensing components. This study is focused on metakaolin geopolymer mortar doped with 0.05 and 0.10% carbon nanotubes, a conductive filler that effectively increases electrical conductivity without considerable deterioration of mechanical properties. Self-sensing performance of composites incorporated with electrodes and attached strain gauge was tested during different regimes of compressive loading cycles with continuous monitoring of strain and resistivity. Although the differences in sensitivity and repeatability were observed, all samples including the reference material have shown good response to applied loading.

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Sensing Performance and Mechanical Properties of Buckypaper Impregnated with Epoxy Resin

Nanomaterials ◽

10.3390/nano10112258 ◽

2020 ◽

Vol 10 (11) ◽

pp. 2258

Author(s):

Shiuh-Chuan Her ◽

Wei-Chun Hsu

Keyword(s):

Mechanical Properties ◽

Epoxy Resin ◽

Epoxy Composite ◽

Strain Sensitivity ◽

Piezoresistive Effect ◽

Thermogravimetric Analyzer ◽

Structural Applications ◽

Overall Performance ◽

Sensing Performance ◽

Better Than

Buckypaper consisting of a carbon nanotube (CNT) sheet has a great potential for sensing and structural applications due to the exceptional piezoresistive and mechanical properties of CNTs. In this work, buckypaper was impregnated with the epoxy resin to improve the fragility and handling capability. The mechanical properties of the buckypaper/epoxy composite were determined by the tensile and nanoindentation tests. A thermogravimetric analyzer (TGA) was used to evaluate the thermal stability. Strain and temperature sensing performances of the buckypaper/epoxy composite based on the piezoresistive effect were investigated using a meter source. Experimental results indicated that the elastic modulus and ultimate strength of the buckypaper/epoxy composite were increased by 82% and 194%, respectively, in comparison with the pristine buckypaper, while the strain and temperature sensitivities were decreased by 33% and 0.2%, respectively. A significant increase of the tensile strength accompanied with a moderate decrease of the strain sensitivity demonstrates that the overall performance of buckypaper/epoxy composite is better than that of pristine buckypaper.

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