Related Experiment Video
Updated: May 27, 2026
08:02
Synthetic Condensates and Cell-Like Architectures from Amphiphilic DNA Nanostructures
Published on: May 31, 2024
Dynamic-covalent macromolecular stars with boronic ester linkages
Abhijeet P Bapat1, Debashish Roy, Jacob G Ray
1Department of Chemistry, Southern Methodist University, 3215 Daniel Avenue, Dallas, Texas 75275-0314, USA.
Journal of the American Chemical Society
|November 23, 2011
Summary
Researchers created dynamic star-shaped polymers using reversible boronic ester bonds. These macromolecular stars can be formed and broken apart repeatedly, offering potential for advanced materials.
Area of Science:
- Polymer Chemistry
- Materials Science
- Supramolecular Chemistry
Background:
- Dynamic covalent chemistry enables the creation of self-healing and adaptable materials.
- Boronic esters are key dynamic covalent linkages responsive to external stimuli.
- Macromolecular architectures like star polymers offer unique properties for advanced applications.
Purpose of the Study:
- To synthesize novel macromolecular stars utilizing reversible boronic ester linkages.
- To investigate the formation, assembly, and dissociation of these star polymers.
- To demonstrate the repeatable nature of the star formation-dissociation cycle.
Main Methods:
- Arm-first synthesis of block copolymers with boronic acid functionalities.
- Cross-linking of block copolymers with multifunctional diols to form star polymers.
- Utilizing competitive exchange reactions with monofunctional diols to induce star dissociation.
Main Results:
- Successful preparation of nanosized multiarm stars with boronic ester cores and poly(N,N-dimethylacrylamide) (PDMA) coronas.
- Demonstration that star formation and dissociation are controllable via dynamic-covalent boronic ester bonds.
- Confirmation of repeatable star formation and dissociation over multiple cycles.
Conclusions:
- Macromolecular stars with reversible boronic ester linkages can be controllably formed and dissociated.
- The dynamic nature of boronic esters allows for stimuli-responsive reconfiguration of polymer architecture.
- These findings open avenues for designing adaptable and recyclable polymeric materials.
Related Concept Videos
01:29Covalent Bonds
Overview
01:08Covalent Bonds
Overview
When two atoms share electrons to complete their valence shells, they create a covalent bond. An atom's electronegativity—the force with which shared electrons are pulled towards an atom—determines how the electrons are shared. Molecules formed with covalent bonds can be either polar or nonpolar. Atoms with similar electronegativities form nonpolar covalent bonds; the electrons are shared equally. Atoms with different electronegativities share electrons unequally, creating polar bonds.
When two atoms share electrons to complete their valence shells, they create a covalent bond. An atom's electronegativity—the force with which shared electrons are pulled towards an atom—determines how the electrons are shared. Molecules formed with covalent bonds can be either polar or nonpolar. Atoms with similar electronegativities form nonpolar covalent bonds; the electrons are shared equally. Atoms with different electronegativities share electrons unequally, creating polar bonds.
02:18Network Covalent Solids
Network covalent solids contain a three-dimensional network of covalently bonded atoms as found in the crystal structures of nonmetals like diamond, graphite, silicon, and some covalent compounds, such as silicon dioxide (sand) and silicon carbide (carborundum, the abrasive on sandpaper). Many minerals have networks of covalent bonds.
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
01:01Phosphodiester Linkages
Overview
Phosphodiester bond forms when a phosphoric acid molecule (H3PO4) links with two hydroxyl groups (–OH) of two other molecules, forming two ester bonds. Two water molecules are released in this process. The phosphodiester bond is commonly found in nucleic acids (DNA and RNA) and plays a critical role in their structure and function.
Phosphodiester Bonds Link Nucleotides Together
DNA and RNA are polynucleotides or long chains of nucleotides that are linked together. A nucleotide is...
Phosphodiester bond forms when a phosphoric acid molecule (H3PO4) links with two hydroxyl groups (–OH) of two other molecules, forming two ester bonds. Two water molecules are released in this process. The phosphodiester bond is commonly found in nucleic acids (DNA and RNA) and plays a critical role in their structure and function.
Phosphodiester Bonds Link Nucleotides Together
DNA and RNA are polynucleotides or long chains of nucleotides that are linked together. A nucleotide is...
03:24Hybridization of Atomic Orbitals I
The mathematical expression known as the wave function, ψ, contains information about each orbital and the wavelike properties of electrons in an isolated atom. When atoms are bound together in a molecule, the wave functions combine to produce new mathematical descriptions that have different shapes. This process of combining the wave functions for atomic orbitals is called hybridization and is mathematically accomplished by the linear combination of atomic orbitals. The new orbitals that...
02:35Noncovalent Attractions in Biomolecules
Noncovalent attractions are associations within and between molecules that influence the shape and structural stability of complexes. These interactions differ from covalent bonding in that they do not involve sharing of electrons.
Four types of noncovalent interactions are hydrogen bonds, van der Waals forces, ionic bonds, and hydrophobic interactions.
Hydrogen bonding results from the electrostatic attraction of a hydrogen atom covalently bonded to a strong-electronegative atom like oxygen,...
Four types of noncovalent interactions are hydrogen bonds, van der Waals forces, ionic bonds, and hydrophobic interactions.
Hydrogen bonding results from the electrostatic attraction of a hydrogen atom covalently bonded to a strong-electronegative atom like oxygen,...