Sample cell for studying liquid interfaces with anin situelectric field using X-ray reflectivity and application to clay particles at oil–oil interfaces
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2018-04-24 |
| Journal | Journal of Synchrotron Radiation |
| Authors | Simon R. Larsen, Marie Hansteen, Barbara Pacáková, Keld Theodor, Thomas Arnold |
| Institutions | Norwegian University of Science and Technology, Institute for Energy Technology |
| Citations | 2 |
| Analysis | Full AI Review Included |
6CCVD Technical Documentation & Analysis: In Situ Electric Field X-Ray Reflectivity
Section titled “6CCVD Technical Documentation & Analysis: In Situ Electric Field X-Ray Reflectivity”Reference: Larsen et al., J. Synchrotron Rad. (2018). 25, 915-917. Application Focus: High-Field Electrochemical Interfaces and Colloidal Self-Assembly using Synchrotron X-ray Reflectivity (XRR).
Executive Summary
Section titled “Executive Summary”This documentation analyzes the construction and commissioning of a sample cell designed for in situ application of high DC electric fields during X-ray Reflectivity (XRR) studies of liquid interfaces.
- Novel Methodology: Successful integration of a high-voltage setup within an XRR experiment environment, enabling real-time structural analysis of interfaces under electrical stress.
- Key Achievement: Demonstrated application of static electric fields up to 200 V mm<sup>-1</sup> across a 15 mm gap to organize colloidal Li-Fht clay particles at oil-oil interfaces.
- Dynamic Control: Applied fields induced dynamic phase changes in particle assembly, resulting in the formation of ordered clusters and aligned bead chains.
- Electrode Requirements: The setup utilized precise plate electrodes (Copper or ITO) requiring high conductivity, flatness, and custom dimensions (110 mm x 45 mm plates).
- Dual Modality: The incorporation of Indium Tin Oxide (ITO) electrodes validates the need for conductive components that are also optically transparent, a function where Boron-Doped Diamond (BDD) can provide significant performance enhancement.
- Scientific Impact: This technique provides critical insights into electro-hydrodynamic forces governing particle stability and ordering, crucial for applications in pharmaceutics and enhanced oil recovery (EOR).
Technical Specifications
Section titled “Technical Specifications”The following hard parameters were derived from the experimental setup and commissioning results:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Applied Voltage Range | 0 to 3 | kV | Nominal test range for DC field generation |
| Maximum Static Field | 200 | V mm<sup>-1</sup> | Achieved maximum field intensity (20 kV cm<sup>-1</sup>) |
| Electrode Separation Gap | 15 | mm | Distance across which the electric field was applied |
| X-ray Beam Energy | 24 | keV | Energy used at Diamond Light Source beamline I07 |
| Incident Angle | ~0.1 | ° | Angle chosen to utilize the flat part of the sample |
| Sample Cell Length | 110 | mm | Dimension parallel to the incident beam path |
| Electrode Materials Used | Cu, ITO | N/A | Tested for conductivity and optical studies (ITO) |
| Colloid Concentration | 0.125 | % (w/w) | Lithium fluorohectorite (Li-Fht) in silicone oil |
Key Methodologies
Section titled “Key Methodologies”The experiment centered on constructing a robust, high-precision sample cell capable of surviving high voltage application and compatible with Synchrotron XRR requirements.
- Cell Fabrication: A liquid sample cell was constructed from Plexiglas, featuring custom internal grooves designed to securely accept plate electrodes and maintain a precise 15 mm separation gap.
- Interface Configuration: The cell was fitted with lateral Kapton windows to allow the X-ray beam access to the critical air-liquid or liquid-liquid interface (castor oil/silicone oil suspension).
- Electrode Implementation: Plate electrodes (Copper for high conductivity, ITO for optical transparency) were inserted into the grooves parallel to the incoming beam path.
- Electric Field Application: A DC voltage (0-3 kV range) was applied in situ across the electrodes, generating fields up to 200 V mm<sup>-1</sup> in the illuminated area.
- Data Acquisition: XRR measurements were performed at 24 keV, recording the reflectivity profiles and monitoring the ordering of clay particles (clusters or bead chains) as a function of the applied electric field strength.
6CCVD Solutions & Capabilities
Section titled “6CCVD Solutions & Capabilities”This study highlights the need for advanced, high-performance electrode materials capable of precise dimensional control and chemical inertness under high-voltage, wet conditions. 6CCVD’s Chemical Vapor Deposition (CVD) diamond materials offer superior performance over conventional Cu or ITO for long-term, high-intensity electrochemical studies.
Applicable Materials
Section titled “Applicable Materials”To replicate or significantly advance this research, 6CCVD recommends transitioning from traditional materials (Cu, ITO) to customized conductive diamond:
| 6CCVD Material | Rationale & Performance Advantage |
|---|---|
| Heavy Boron-Doped Polycrystalline Diamond (BDD PCD) | Superior Electrode Performance: BDD is chemically inert, resistant to corrosion/fouling in complex oil/aqueous media, and maintains structural integrity under extreme electric fields and high current density, unlike ITO or soft metals. |
| Precision Polished SCD/PCD Plates | If required for optical transparency in the XRR path (using transparent BDD variants) or for extreme flatness (Ra < 5 nm) for interface experiments where parallelism is paramount. |
Customization Potential
Section titled “Customization Potential”The required electrode components in the study were custom, planar plates (e.g., 110 mm x 45 mm, 15 mm gap). 6CCVD is uniquely equipped to meet these stringent dimensional and structural needs:
- Custom Dimensions: We provide custom conductive BDD plates and wafers up to 125 mm in diameter or equivalent custom shapes, easily exceeding the 110 mm requirement used in this setup.
- Precision Thickness: BDD material can be engineered for optimal bulk conductivity at custom thicknesses (0.1 µm up to 500 µm BDD films or thicker substrates up to 10 mm).
- Integrated Metalization: 6CCVD offers in-house metalization services (Ti/Pt/Au, W/Cu, etc.) for creating highly stable, low-resistance ohmic contact pads directly onto the BDD electrodes. This ensures reliable lead connection for the high-voltage application (0-3 kV).
- Surface Finishing: We guarantee precision polishing (Ra < 5 nm for inch-size PCD) to ensure the electrode plates are perfectly planar, critical for generating a homogeneous electric field (200 V mm<sup>-1</sup>) across the 15 mm gap.
Engineering Support
Section titled “Engineering Support”The challenges involved in studying complex liquid interfaces under in situ high fields—specifically managing electrode materials, stability, and high-field homogeneity—are core areas of our expertise.
- 6CCVD’s in-house PhD team specializes in providing material selection and design consultation for advanced electrochemical, interfacial physics, and high-energy beamline projects.
- We offer support in optimizing the geometry and doping level of BDD electrodes for maximum efficiency and lifetime in similar projects concerning colloid self-assembly, electrokinetics, or high-voltage actuation.
- We facilitate global shipping (DDU or DDP) of highly sensitive, precision-machined BDD components directly to synchrotron facilities worldwide.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Commissioning results of a liquid sample cell for X-ray reflectivity studies with an in situ applied electrical field are presented. The cell consists of a Plexiglas container with lateral Kapton windows for air-liquid and liquid-liquid interface studies, and was constructed with grooves to accept plate electrodes on the walls parallel to the direction of the beam. Both copper and ITO plate electrodes have been used, the latter being useful for simultaneous optical studies. Commissioning tests were made at the I07 beamline of the Diamond Light Source.