Solvothermal Synthesis of MIL-96 and UiO-66-NH2 on Atomic Layer Deposited Metal Oxide Coatings on Fiber Mats
June 13th, 2018
Metal-organic frameworks are effective in gas storage and heterogeneous catalysis, but typical synthesis methods result in loose powders that are difficult to incorporate into smart materials. We demonstrate a method of first coating fabrics with ALD metal oxides, resulting in conformal films of MOF on the fabrics during solvothermal synthesis.
This method can help answer key questions in the field of metal organic frameworks such as the nature of surface nucleation and MOF adhesion. The main advantage of this technique is that it produces MOF films on fabric during the MOF synthesis rather than requiring additional processing steps to adhere MOF to the fiber. Demonstrating the procedure will be Dennis Lee, a grad student from my laboratory.
First, place a PA-6 fabric sample in a reactor boat. Open the pressure gauge of the ALD reactor and remove the clasp from the reactor cap. Next, turn on manual control in the lab view system.
Close the carrier nitrogen and gate valve on the ALD reactor. Then open the vent nitrogen. The reactor will open and the cap will fall off.
After removing the reactor cap, load the fabric sample into the ALD reactor. Replace the reactor cap. Then open the gate valve.
Following this, open the carrier nitrogen and close the vent. Then turn off manual control. Load the recipe for titanium oxide on fabrics.
Set the recipe to run 300 cycles. Next, set the mass flow controller to 20 cubic feet per minute and the furnace temperature to 90 degrees Celsius. Open the manual valve to the titanium tetrachloride and water.
Close the pressure gauge and replace the clasp on the reactor cap. Then press start on the interface. Upon completion of the recipe, open the pressure gauge.
Remove the clasp from the reactor cap. Then turn on manual control in the system. Following this, close the carrier nitrogen and gate valve on the ALD reactor.
Then open the vent nitrogen. The reactor will open and the cap will fall off. Remove the sample boat.
Reseal the reactor. Add 0.0878 grams of trimesic acid to an 80 milliliter glass beaker. Add 12 milliliters of water and 12 milliliters of ethanol to the beaker.
Then add a magnetic stir bar to the solution and stir until the trimesic acid is fully dissolved. Next, place the solution in a Teflon-lined pressure vessel. Add previously prepared aluminum oxide-coded polypropylene to the solution and prop the fabric on a mesh support so it does not lie flat against the bottom of the vessel.
Following this, seal the pressure vessel and place it in the furnace at 110 degrees Celsius for 24 hours. Add 0.08 grams of zirconium chloride to a 20 milliliter glass scintillation vial. Add 20 milliliters of DMF to the zirconium chloride in five milliliter increments.
Cap the vial between increments and allow the fumes to dissipate. Next, sonicate the solution for one minute. Add 0.062 grams of 2-aminoterephthalic acid and a magnetic stir to the vial.
Stir the solution for five minutes. After stirring, add 25 microliters of deionized water to the vial. Then add 1.33 milliliters of concentrated hydrochloric acid to the vial.
Now submerge the titanium dioxide ALD-coded fabric swatch in the solution and cap the vial. Finally, place the sample in the furnace at 85 degrees Celsius for 24 hours. Scanning electron microscopy showed conformal MOF crystal thin films on all fibers resembling a cobblestone pattern.
When the aluminum oxide was reduced, the film began to break apart as the MOF formed resulting in a patchy coding. A bare polypropylene sample was exposed to MIL-96 synthesis conditions, but XRD showed no detectable MOF on the fibers. Cross-sectional images revealed the 500 cycle aluminum oxide base layer completely reacted while a fraction of the aluminum oxide base layer remained for the 1, 000 and 2, 000 cycle samples.
Cross-sections of the aluminum oxide ALD-coded polypropylene are shown here. Electron dispersion spectroscopy images of the cross-section revealed the carbon-based polypropylene core and predominantly aluminum oxide shell. XRD patterns of the MOF-coded fabric matching the simulated PXRD pattern of MIL-96 are shown here.
Following solvothermal MOF synthesis, XRD patterns revealed UIO-66-amine was present on the fibers. SEM images showed flaky MOF codings on the 50 degree Celsius samples, dense MOF codings on the 90 degree Celsius samples, and sparse MOF codings on the 200 degree Celsius samples. An uncoded PA-6 sample was exposed to UIO-66-amine synthesis conditions resulting in a relatively sparse MOF coding.
After watching this video, you should have a good understanding of how to produce conformal MOF films on ALD-coded substrates.
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Overview
This study presents a novel method for synthesizing metal-organic frameworks (MOFs) on fabric, enhancing their integration into smart materials. By coating fabrics with atomic layer deposition (ALD) metal oxides, conformal MOF films are produced during solvothermal synthesis, eliminating the need for additional processing steps.
Key Study Components
Area of Science
- Material Science
- Nanotechnology
- Catalysis
Background
- Metal-organic frameworks are known for their applications in gas storage and catalysis.
- Traditional synthesis methods often yield loose powders that are challenging to work with.
- Understanding surface nucleation and MOF adhesion is crucial for advancing MOF applications.
- This study aims to simplify the synthesis process by integrating MOFs directly onto fabrics.
Purpose of Study
- To develop a method for synthesizing MOFs directly on fabric substrates.
- To investigate the nature of surface nucleation during MOF formation.
- To enhance the adhesion of MOFs to fabric without additional processing steps.
Methods Used
- Coating fabrics with ALD metal oxides.
- Solvothermal synthesis to produce MOF films.
- Utilizing a reactor setup for controlled synthesis conditions.
- Demonstration of the procedure by a graduate student.
Main Results
- Successful synthesis of conformal MOF films on fabric.
- Reduction in processing steps required for MOF adhesion.
- Insights into the mechanisms of surface nucleation and adhesion.
- Potential applications in smart materials and catalysis.
Conclusions
- The method provides a streamlined approach to integrating MOFs into textiles.
- It opens new avenues for research in material science and catalysis.
- Further studies could explore the scalability and versatility of this technique.
Frequently Asked Questions
Executive Industry Relevance
Direct synthesis of MOF films on ALD-coated fiber mats addresses integration challenges for functional materials in biopharma R&D, enabling robust, conformal coatings without pore-blocking adhesives. This approach enhances material performance for applications requiring high surface area and controlled reactivity, supporting innovation in filtration, separation, and catalysis platforms. The method positions MOF-functionalized fabrics as scalable, device-ready components for advanced bioprocessing and analytical workflows.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables interrogation of surface nucleation mechanisms and MOF adhesion on functional substrates.
- Supports development of robust, reproducible materials for downstream analytical and separation assays.
- Facilitates mechanistic de-risking by providing well-characterized, conformal MOF coatings for experimental platforms.
Screening & Assay Development
- Delivers standardized, high-surface-area substrates for quantitative adsorption and separation assays.
- Improves reproducibility and scalability by eliminating variable adhesive layers that can block MOF pores.
- Prepares device-ready materials for integration into filtration and analytical screening systems.
Translational & Preclinical Research
- Enables direct incorporation of MOF-functionalized fabrics into prototype devices for bioprocessing or protective applications.
- Supports continuity from material synthesis to device testing, reducing translation gaps.
- Provides a platform for evaluating MOF-based materials in disease-relevant or process-relevant environments.
Pipeline & Workflow Integration
This method bridges material synthesis and device integration, supporting workflows from early discovery through preclinical prototyping where functionalized substrates are required.
- Discovery Biology: Advances understanding of MOF nucleation and adhesion, informing material selection for biological assays.
- Screening: Supplies reproducible, quantitative substrates for adsorption and separation performance testing.
- Analytics: Enables direct measurement of MOF loading, uniformity, and functional surface area on device-ready fabrics.
- Translational Research: Facilitates rapid prototyping and evaluation of MOF-coated materials in relevant device formats.
- Enterprise Reuse: Establishes a scalable, adaptable platform for MOF integration across multiple R&D programs.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence in material performance and functional integration.
- Operational Value: Streamlines fabrication, reduces variability, and enhances reproducibility of functionalized substrates.
- Strategic Value: Accelerates go/no-go decisions for material selection and device development.
- Portfolio Impact: Supports risk-adjusted advancement of MOF-enabled technologies across filtration, separation, and analytical platforms.
Implementation Considerations
- Requires expertise in ALD, solvothermal synthesis, and material characterization (e.g., SEM, XRD).
- Needs access to ALD reactors, controlled furnaces, and analytical instrumentation for quality assessment.
- Demands cross-team standardization of substrate preparation and synthesis parameters.
- Adaptation may be needed for different fiber types or device geometries.
- MOF loading and uniformity depend on precise control of ALD film thickness and synthesis conditions.
Biopharma FAQs
Chapters in this video
0:04
Title
0:31
Atomic Layer Deposition (ALD) of TiO2 on Polyamide-6 (PA-6) Fiber Mats
2:12
Solvothermal Synthesis of MIL-96
3:04
Solvothermal Synthesis of UiO-66-NH2
4:05
Results: Characterization of MIL-96 and UiO-66-NH2 on Atomic Layer Deposited Metal Oxide Coatings on Fiber Mats
5:44
Conclusion
