Related Experiment Video
Updated: Jan 31, 2026
08:03
Advanced Self-Healing Asphalt Reinforced by Graphene Structures: An Atomistic Insight
Published on: May 31, 2022
5.6K
Atomistic mechanisms for chemical defects formation in polyethylene
Lihua Chen1, Huan Doan Tran1, Rampi Ramprasad1
1School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive NW, Atlanta, Georgia 30332, USA.
The Journal of Chemical Physics
|December 24, 2018
Summary
Researchers identified seven mechanisms for chemical defect formation in polyethylene, explaining experimental observations and advancing understanding of polymer degradation and breakdown.
Area of Science:
- Materials Science
- Computational Chemistry
- Polymer Science
Background:
- Chemical defects in polymer dielectrics degrade electronic structure, causing material failure.
- Polymer degradation and breakdown mechanisms are complex and poorly understood experimentally and computationally.
Purpose of the Study:
- To elucidate atomistic mechanisms of common chemical defect formation in polyethylene.
- To connect computational findings with experimental observations of polyethylene defects and aging.
Main Methods:
- Density functional theory (DFT) calculations.
- Classical molecular dynamics (MD) simulations.
Main Results:
- Proposed seven distinct atomistic mechanisms for chemical defect formation in polyethylene.
- Demonstrated how these mechanisms explain various defect-related experimental observations.
- Established a link between computational models and experimental data on polyethylene defects.
Conclusions:
- The proposed mechanisms provide a foundational understanding of polyethylene degradation.
- This work bridges the gap between theoretical modeling and experimental studies of polymer aging.
- Offers a pathway for predicting and mitigating polymer dielectric failure.
Related Concept Videos
01:31Mechanism of Lamellipodia Formation
3.7K
Cells migrating in response to external stimuli form lamellipodia, which are thin membrane protrusions supported by a mesh of linked, branched, or unbranched actin filaments. These actin filaments interact with myosin motor proteins, creating the dynamic actomyosin complex within the cytoskeleton. Contractility, or the ability to generate contractile stress, is inherent to the actomyosin complex. It helps cells detect the stiffness of the surrounding ECM and exert contractile force for...
3.7K
01:39Mechanism of Filopodia Formation
3.2K
Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles.
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
3.2K
01:30Mechanical and Chemical Digestion in the Small Intestine
3.3K
The small intestine plays a crucial role in our digestive system, performing both mechanical and chemical digestion.
Mechanical digestion in the small intestine involves movements such as segmentations and migrating motility complexes (MMCs), primarily controlled by the myenteric plexus. Segmentations are localized contractions occurring in areas of the intestine distended by chyme—a mixture of partially digested food. These contractions mix chyme with digestive juices, facilitating...
Mechanical digestion in the small intestine involves movements such as segmentations and migrating motility complexes (MMCs), primarily controlled by the myenteric plexus. Segmentations are localized contractions occurring in areas of the intestine distended by chyme—a mixture of partially digested food. These contractions mix chyme with digestive juices, facilitating...
3.3K
00:59Mechanisms of Membrane Domain Formation
3.9K
Different physical properties of lipids and proteins allow them to localize and form distinct islands or domains in the membrane. Some membrane domains are formed due to protein-protein interactions, whereas others are formed due to the presence of specific lipids such as sphingolipids and sterols—for example, large proteins, such as bacteriorhodopsin, aggregate and create distinct domains.
Another mechanism for membrane domain formation involves membrane proteins interacting with...
Another mechanism for membrane domain formation involves membrane proteins interacting with...
3.9K
01:14Aldehydes and Ketones with Amines: Enamine Formation Mechanism
7.5K
Enamine formation involves the addition of carbonyl compounds to a secondary amine through a series of reactions. The mechanism begins with the generation of carbinolamine, a nucleophilic attack followed by several proton transfer reactions. The hydroxyl group of the carbinolamine is converted into water to make a better leaving group that can push the reaction forward by eliminating a water molecule. In enamine formation, the last step involves the abstraction of a proton from the α carbon to...
7.5K
01:10Aldehydes and Ketones with HCN: Cyanohydrin Formation Mechanism
4.3K
Cyanohydrins are formed when cyanide nucleophiles and carbonyl compounds like aldehydes and ketones react. A strong base, the cyanide ion, catalyzes cyanohydrin formation. The ions are generated from HCN under aqueous conditions. Once the cyanide ions are generated, the first step involves the nucleophilic attack of the cyanide ions on the electrophilic carbonyl carbon. This attack shifts the π electrons from the C=O to the oxygen atom forming the alkoxide ion intermediate. The alkoxide anion...
4.3K