Will Gates

Frequency Dependent Silica Dissolution Rate Enhancement under Oscillating Pressure via an Electrochemical Pressure Solution-like, Surface Resonance Mechanism

Publisher: American Chemical Society (ACS)

Date: 28-02-2022

DOI: 10.1021/JACS.1C11545

Abstract: From atomic force microscopy (AFM) experiments, we report a new phenomenon in which the dissolution rate of fused silica is enhanced by more than 5 orders of magnitude by simply pressing a second, dissimilar surface against it and oscillating the contact pressure at low kHz frequencies in deionized water. The silica dissolution rate enhancement was found to exhibit a strong dependence on the pressure oscillation frequency consistent with a resonance effect. This harmonic enhancement of the silica dissolution rate was only observed at asymmetric material interfaces (e.g., diamond on silica) with no evidence of dissolution rate enhancement observed at symmetric material interfaces (i.e., silica on silica) within the experimental time scales. The apparent requirement for interface dissimilarity, the results of analogous experiments performed in anhydrous dodecane, and the observation that the silica "dissolution pits" continue to grow in size under contact stresses well below the silica yield stress refute a mechanical deformation or chemo-mechanical origin to the observed phenomenon. Instead, the silica dissolution rate enhancement exhibits characteristics consistent with a previously described 'electrochemical pressure solution' mechanism, albeit, with greatly lified kinetics. Using a framework of electrochemical pressure solution, an electrochemical model of mineral dissolution, and a recently proposed "surface resonance" theory, we present an electro-chemo-mechanical mechanism that explains how oscillating the contact pressure between dissimilar surfaces in water can lify surface dissolution rates by many orders of magnitude. This reaction rate enhancement mechanism has implications not only for dissolution but also for potentially other reactions occurring at the solid-liquid interface, e.g. catalysis.

Insights into the Rheological Behavior of Aqueous Dispersions of Synthetic Saponite: Effects of Saponite Composition and Sodium Polyacrylate

Publisher: American Chemical Society (ACS)

Date: 12-09-2019

DOI: 10.1021/ACS.LANGMUIR.9B01805

Abstract: Synthetic saponite (Sap) easily delaminates in water to form a transparent sol and hydrogel with excellent rheological performance and is thus widely used in paints, cosmetics, and nanomaterials. The thixotropic property of Sap hydrogels is heavily dependent on the nature of Sap and the external electrolyte and polyelectrolyte yet, details on the relationship between rheological behaviors of saponite hydrogels and Sap composition and polyelectrolyte remain unclear. In this work, thixotropic rheological behaviors of a series of synthetic Sap hydrogels, with and without added sodium polyacrylate polyelectrolyte (NaPA), were investigated. The Sap s les, with a Si/Al molar ratio from 5 to 25, were successfully synthesized using hydrothermal methods and characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. The rheological performances of aqueous Sap dispersions and particle sizes and ζ-potentials of Sap were measured. The results showed that the crystallinity of the Sap increased with an increasing Si/Al molar ratio. All Sap s les, with the exception of the Sap with a Si/Al molar ratio of 5, dispersed well in water (3 wt %) to form hydrogels. The rheological behaviors of the hydrogels were related to the chemical composition and the layer charge of the Sap. The Sap with a Si/Al molar ratio of 25 had higher viscosity due to improved delamination. The addition of the NaPA, an anionic polyelectrolyte, into the hydrogels decreased the viscosity and altered the thixotropic properties such that the hydrogel becomes a sol. The addition of NaPA facilitated the dispersion and delamination of Sap, because under the electric field of negatively charged Sap particles in the hydrogel, the anionic NaPA was instantaneously polarized and thereby entered the hydration layer of the Sap particles.

Assessing Diffusion Relaxation of Interlayer Water in Clay Minerals Using a Minimalist Three-Parameter Model

Publisher: American Chemical Society (ACS)

Date: 06-07-2021

DOI: 10.1021/ACS.JPCC.1C04322

Two Forms of Ice Identified in Mars-like Clay Using Neutron Spectroscopy

Publisher: American Chemical Society (ACS)

Date: 06-12-2022

DOI: 10.1021/ACS.JPCC.2C06470

Suitability of remediated heat-treated soil in concrete applications

Publisher: Elsevier BV

Date: 03-2023

DOI: 10.1016/J.JENVMAN.2022.117076

A novel transient gravimetric monitoring technique implemented to GCL osmotic suction control

Publisher: Elsevier BV

Date: 12-2020

DOI: 10.1016/J.GEOTEXMEM.2020.05.002

Brain delivery of intranasalin situgel of nanoparticulated polymeric carriers containing antidepressant drug: behavioral and biochemical assessment

Publisher: Informa UK Limited

Date: 24-12-2014

DOI: 10.3109/1061186X.2014.994097

A Generalized Water Retention Model for Geosynthetic Clay Liners

Publisher: American Society of Civil Engineers (ASCE)

Date: 12-2022

DOI: 10.1061/(ASCE)GT.1943-5606.0002933

Influence of polymer enhancement on water uptake, retention and barrier performance of geosynthetic clay liners

Publisher: Elsevier BV

Date: 08-2022

DOI: 10.1016/J.GEOTEXMEM.2022.02.006

Inhalational Drug Delivery in Pulmonary Aspergillosis

Publisher: Begell House

Date: 2019

DOI: 10.1615/CRITREVTHERDRUGCARRIERSYST.2018025781

Neutron scattering quantification of unfrozen pore water in frozen mud

Publisher: Elsevier BV

Date: 09-2021

DOI: 10.1016/J.MICROMESO.2021.111267

Electric Field Induced Polarization Effects Measured by in Situ Neutron Spectroscopy

Publisher: American Chemical Society (ACS)

Date: 13-10-2017

DOI: 10.1021/ACS.JPCC.7B08769

Unconfined Compressive Strength and Visualization of the Microstructure of Coarse Sand Subjected to Different Biocementation Levels

Publisher: American Society of Civil Engineers (ASCE)

Date: 08-2019

DOI: 10.1061/(ASCE)GT.1943-5606.0002066

A New Method of AFM‐Based Nanolithography Using Frequency Enhanced Electrochemical Pressure Solution Etching

Publisher: Wiley

Date: 03-2023

DOI: 10.1002/ADMT.202201297

Abstract: A new method of direct‐write nanolithography that is able to rapidly etch silica surfaces under a scanning atomic force microscopy (AFM) probe in tapping mode (TM) is reported. In this lithography technique, silica surfaces are etched using a recently described electro‐chemo‐mechanical phenomenon of frequency enhanced electrochemical pressure solution (FEEPS). In FEEPS, the tapping of the AFM tip generates oscillations of the Stern potential at the silica‐water interface that can accelerate the silica dissolution kinetics by more than 5–6 orders of magnitude when surface resonance states are achieved i.e., when the oscillation frequency is in phase with the dynamics of interfacial chemical reaction steps. By scanning silica surfaces in TM, silica is selectively dissolved below the tapping tip as it is scanned. The FEEPS accelerated silica dissolution rates can generate etched features with depths of more than 60 nm in a single AFM tip pass. The rate of etching can be controlled easily by varying the scanning rate or by modulating the tapping frequency. This fine control over the silica etching process and because material is removed (dissolved) rather than displaced as with nanoscratching, the FEEPS process lends itself to gray‐scale nanolithography which is demonstrated.

Water exchange across a subgrade-GCL interface as impacted by polymers and environmental conditions

Publisher: Elsevier BV

Date: 02-2022

DOI: 10.1016/J.GEOTEXMEM.2021.08.005

CSIRO Land And Water Adelaide

Location: Australia

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Montana State University Bozeman

Location: United States of America

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Deakin University

Location: Australia

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New Mexico State University

Location: United States of America

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Central University Of Rajasthan

Location: India

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Monash University

Location: Australia

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University Of Illinois Urbana-Champaign

Location: United States of America

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Linkage Projects - Grant ID: LP150100832

Start Date: 06-2016

End Date: 06-2020

Amount: $300,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP120102203

Start Date: 03-2012

End Date: 12-2017

Amount: $320,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0989390

Start Date: 04-2009

End Date: 12-2013

Amount: $500,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP220100218

Start Date: 07-2022

End Date: 07-2026

Amount: $554,500.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP0989415

Start Date: 05-2010

End Date: 12-2013

Amount: $156,840.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP190100919

Start Date: 06-2019

End Date: 12-2022

Amount: $335,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE130100006

Start Date: 2013

End Date: 12-2013

Amount: $500,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP1095129

Start Date: 02-2010

End Date: 12-2015

Amount: $435,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP140100516

Start Date: 01-2015

End Date: 12-2018

Amount: $151,213.00

Funder: Australian Research Council

Industrial Transformation Training Centres - Grant ID: IC190100034

Start Date: 12-2020

End Date: 12-2025

Amount: $3,574,272.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP180101178

Start Date: 08-2020

End Date: 06-2024

Amount: $422,000.00

Funder: Australian Research Council

Special Research Initiatives - Grant ID: SR180100009

Start Date: 03-2019

End Date: 03-2023

Amount: $999,082.00

Funder: Australian Research Council