Home > Press > Northwestern researchers achieve unprecedented control of polymer grids: Materials could find applications in water purification, solar energy storage, body armor
Covalent organic frameworks (COFs) offer a unique combination of properties that show promise for waterpurification, energy storage and electronic devices. |
Abstract:
Materials are called two-dimensional covalent organic frameworks
These materials fill a long-standing gap in polymer science
Precision of structure, plentiful pores give scientists design control
Hexagonal pores provide extremely high surface area
Synthetic polymers are ubiquitous -- nylon, polyester, Teflon and epoxy, to name just a few -- and these polymers are all long, linear structures that tangle into imprecise structures. Chemists have long dreamed of making polymers with two-dimensional, grid-like structures, but this goal has proven challenging.
The first examples of such structures, now known as covalent organic frameworks (COFs), were discovered in 2005, but their quality has been poor and preparation methods are uncontrolled. Now a Northwestern University research team is the first to produce high-quality versions of these materials, demonstrate their superior properties and control their growth.
The researchers developed a two-step growth process that produces organic polymers with crystalline, two-dimensional structures. The precision of the material’s structure and the empty space its hexagonal pores provide will allow scientists to design new materials with desirable properties.
Even low-quality COFs have shown preliminary promise for water purification, storing electricity, body armor and other tough composite materials. Once developed further, higher-quality samples of these materials will enable these applications to be explored more fully.
“These covalent-organic frameworks fill a century-long gap in polymer science,” said William Dichtel, an expert in organic and polymer chemistry who led the study. “Most plastics are long, linear structures that tangle up like spaghetti. We have made ordered two-dimensional polymers where the building blocks are arranged in a perfect grid of repeating hexagons. This gives us precise control of the structure and its properties.”
Dichtel is the Robert L. Letsinger Professor of Chemistry at Northwestern’s Weinberg College of Arts and Sciences.
The study, “Seeded Growth of Single-Crystal Two-Dimensional Covalent Organic Frameworks,” will be published on June 21 by the journal Science via First Release. (The paper will appear in print at a later date.)
The 2D COFs have permanent pores and extremely high surface area. Imagine the surface area of a football field contained in about two grams of material, or two paper clips, Dichtel said. Every little hole is the same size and shape and has exactly the same composition.
In the two-step process, the scientists first grow small particle “seeds” to which they slowly add more of the building blocks, under carefully controlled conditions. The slow addition causes the building blocks to add to the seeds instead of creating new seeds. The result is larger, high-quality particles made up of large, hexagonal sheets instead of a bunch of aggregated crystals.
“This is primarily a synthesis paper, but we also measured properties that emerge only in these high-quality samples,” Dichtel said. “For example, we show that energy can move throughout the structure after it absorbs light, which may be useful in solar energy conversion.”
Once the 2D COFs were grown, fellow chemists Nathan C. Gianneschi and Lucas R. Parent carefully studied the particles using an electron microscope. They confirmed the particles are individual and not aggregated and are perfectly uniform throughout the entire structure.
Gianneschi is the Jacob and Rosaline Cohn Professor in the department of chemistry in Weinberg College. He also is a professor in the departments of materials science and engineering and of biomedical engineering in the McCormick School of Engineering. Parent is a postdoctoral fellow in Gianneschi’s group. Both are co-authors of the paper.
Next, Lin X. Chen and Richard D. Schaller measured how one of the materials interacts with light. Their studies show that energy can move through these materials for much longer distances than the sizes available through old methods.
Chen is a professor of chemistry, and Schaller is an assistant professor of chemistry, both in Weinberg. Both are co-authors of the paper.
“This study has been very gratifying -- to successfully grow these materials and begin to see their promise,” Dichtel, who has been studying COFs for a decade. “We think this development will be enabling for the field of polymer science.”
An Army Research Office for a Multidisciplinary University Research Initiatives (MURI) award (grant number W911NF-15-1-0447) supported this research.
####
For more information, please click here
Contacts:
Source contact:
William Dichtel
MEDIA CONTACT:
Megan Fellman
847-491-3115
Copyright © Northwestern University
If you have a comment, please Contact us.Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
Related News Press |
News and information
Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024
NRL charters Navy’s quantum inertial navigation path to reduce drift April 5th, 2024
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
Good as gold - improving infectious disease testing with gold nanoparticles April 5th, 2024
Law enforcement/Anti-Counterfeiting/Security/Loss prevention
With VECSELs towards the quantum internet Fraunhofer: IAF achieves record output power with VECSEL for quantum frequency converters April 5th, 2024
Researchers’ approach may protect quantum computers from attacks March 8th, 2024
2 Dimensional Materials
NRL discovers two-dimensional waveguides February 16th, 2024
'Sudden death' of quantum fluctuations defies current theories of superconductivity: Study challenges the conventional wisdom of superconducting quantum transitions January 12th, 2024
Possible Futures
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
With VECSELs towards the quantum internet Fraunhofer: IAF achieves record output power with VECSEL for quantum frequency converters April 5th, 2024
Materials/Metamaterials/Magnetoresistance
Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024
Focused ion beam technology: A single tool for a wide range of applications January 12th, 2024
Announcements
NRL charters Navy’s quantum inertial navigation path to reduce drift April 5th, 2024
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters
Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
Homeland Security
The picture of health: Virginia Tech researchers enhance bioimaging and sensing with quantum photonics June 30th, 2023
Sensors developed at URI can identify threats at the molecular level: More sensitive than a dog's nose and the sensors don't get tired May 21st, 2021
Highly sensitive dopamine detector uses 2D materials August 7th, 2020
Military
NRL charters Navy’s quantum inertial navigation path to reduce drift April 5th, 2024
What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024
New chip opens door to AI computing at light speed February 16th, 2024
Energy
Development of zinc oxide nanopagoda array photoelectrode: photoelectrochemical water-splitting hydrogen production January 12th, 2024
Shedding light on unique conduction mechanisms in a new type of perovskite oxide November 17th, 2023
Inverted perovskite solar cell breaks 25% efficiency record: Researchers improve cell efficiency using a combination of molecules to address different November 17th, 2023
The efficient perovskite cells with a structured anti-reflective layer – another step towards commercialization on a wider scale October 6th, 2023
Water
Taking salt out of the water equation October 7th, 2022
Battery Technology/Capacitors/Generators/Piezoelectrics/Thermoelectrics/Energy storage
What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024
A battery’s hopping ions remember where they’ve been: Seen in atomic detail, the seemingly smooth flow of ions through a battery’s electrolyte is surprisingly complicated February 16th, 2024
Grants/Sponsored Research/Awards/Scholarships/Gifts/Contests/Honors/Records
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
Chemical reactions can scramble quantum information as well as black holes April 5th, 2024
Solar/Photovoltaic
Development of zinc oxide nanopagoda array photoelectrode: photoelectrochemical water-splitting hydrogen production January 12th, 2024
Shedding light on unique conduction mechanisms in a new type of perovskite oxide November 17th, 2023
Inverted perovskite solar cell breaks 25% efficiency record: Researchers improve cell efficiency using a combination of molecules to address different November 17th, 2023
Charged “molecular beasts” the basis for new compounds: Researchers at Leipzig University use “aggressive” fragments of molecular ions for chemical synthesis November 3rd, 2023
The latest news from around the world, FREE | ||
Premium Products | ||
Only the news you want to read!
Learn More |
||
Full-service, expert consulting
Learn More |
||