Electrostatic electrochemistry at insulators

Liu, Chongyang; Bard, Allen J.

doi:10.1038/nmat2160

Cited by 288 publications

(251 citation statements)

References 21 publications

Supporting

Mentioning

236

Contrasting

Unclassified

Order By: Relevance

“…32,33 The chemical reactions have been explained to be induced by a surplus of electrons at the polymer surface, produced by the rubbing. While weakly bound electrons may be capable of inducing redox reactions, ions are not.…”

Section: G Tribochemistry and The Nature Of The Triboelectric Chargementioning

confidence: 99%

Squeezing out hydrated protons: low-frictional-energy triboelectric insulator charging on a microscopic scale

Knorr¹

2011

AIP Advances

View full text Add to dashboard Cite

Though triboelectric charging of insulators is common, neither its mechanism nor the nature of the charge is well known. Most research has focused on the integral amount of charge transferred between two materials upon contact, establishing, e.g., a triboelectric series. Here, the charge distribution of tracks on insulating polymer films rubbed by polymer-covered pointed swabs is investigated in high resolution by Kelvin probe force microscopy. Pronounced bipolar charging was observed for all nine rubbing combinations of three different polymers, with absolute surface potentials of up to several volts distributed in streaks along the rubbing direction and varying in polarity on μm-length scales perpendicular to the rubbing direction. Charge densities increased considerably for rubbing in higher relative humidity, for higher rubbing loads, and for more hydrophilic polymers. The ends of rubbed tracks had positively charged rims. Surface potential decay with time was strongly accelerated in increased humidity, particularly for polymers with high water permeability. Based on these observations, a mechanism is proposed of triboelectrification by extrusions of prevalently hydrated protons, stemming from adsorbed and dissociated water, along pressure gradients on the surface by the mechanical action of the swab. The validity of this mechanism is supported by explanations given recently in the literature for positive streaming currents of water at polymer surfaces and by reports of negative charging of insulators tapped by accelerated water droplets and of potential built up between the front and the back of a rubbing piece, observations already made in the 19th century. For more brittle polymers, strongly negatively charged microscopic abrasive particles were frequently observed on the rubbed tracks. The negative charge of those particles is presumably due in part to triboemission of electrons by polymer chain scission, forming radicals and negatively charged ions

show abstract

Section: G Tribochemistry and The Nature Of The Triboelectric Chargementioning

confidence: 99%

Squeezing out hydrated protons: low-frictional-energy triboelectric insulator charging on a microscopic scale

Knorr¹

2011

AIP Advances

View full text Add to dashboard Cite

show abstract

“…As is known, the redox reactions are the signature for electron transfer because it leads to the valence change. Therefore, many experiments depend on the redox reactions to indicate the dominant charge transfer process [45,46]. In turn, dependent on these experiments, the electro-potential of the surface (compared to H+/H 2 (0 V versus NHE), which is not necessarily equal to the electro-potential energy) can be more quantitatively determined [46].…”

Section: Ionmentioning

confidence: 99%

Fundamental theories and basic principles of triboelectric effect: A review

2018

View full text Add to dashboard Cite

Long-term observation of the triboelectric effect has not only proved the feasibility of many novel and useful tribo-devices (e.g., triboelectric nanogenerators), but also constantly motivated the exploration of its mysterious nature. In the pursuit of a comprehensive understanding of how the triboelectric process works, a more accurate description of the triboelectric effect and its related parameters and factors is urgently required. This review critically goes through the fundamental theories and basic principles governing the triboelectric process. By investigating the difference between each charging media, the electron, ion, and material transfer is discussed and the theoretical deduction in the past decades is provided. With the information from the triboelectric series, interesting phenomena including cyclic triboelectric sequence and asymmetric triboelectrification are precisely analyzed. Then, the interaction between the tribo-system and its operational environment is analyzed, and a fundamental description of its effects on the triboelectric process and results is summarized. In brief, this review is expected to provide a strong understanding of the triboelectric effect in a more rigorous mathematical and physical sense.

show abstract

“…When two polymers like Teflon and Lucite were rubbed together vigorously, it was found by Liu and Bard [33][34][35] and by Otero 36 that the surface charges developed can carry out different chemical redox reactions such as metal deposition, ion reduction and chemiluminescence, reactions which can be induced by electrons but not by ions. This conclusion was later challenged by Piperno et al 37 because it was shown that rubbing of these polymers results in transfer of material containing polar active species so that the surfaces are charged by ions.…”

Section: The Case For Electron Exchangementioning

confidence: 99%

“…The term rubbing contacts has been used in many publications on contact charging without any further definition, and the term vigorous rubbing is sometimes used. [33][34][35][36] In this review, pressing is defined as applying pressure during contact with no intent of applying friction. For example, in the report by Baytekin et al,4 it states: "the pressure applied during contact.…”

Section: Effect Of the Nature Of The Contactsmentioning

confidence: 99%

Triboelectric charging of insulating polymers–some new perspectives

Williams¹

2012

AIP Advances

107

View full text Add to dashboard Cite

A nanowire based triboelectric nanogenerator for harvesting water wave energy and its applications APL Materials 5, 074104 (2017) Tribolectric charging results from contact between surfaces, but precisely what is meant by each is not defined or understood, as they relate to charging. The recent microscopic evidence that contact charging can result from material transfer provides incentive to examine how contact charging is affected by these two factors. It is suggested that vigorous rubbing or pressing of two polymers results in transfer of deeper layers than would result from light contacts. Different layers can have substantially different compositions because polymers are typically not homogeneous as a function of depth, so contact and surface are related in this way. This could account for charge transfer between identical polymers, especially in asymmetric contacts in which the frictional force on one polymer differs from that on the other, so that material from different depths is transferred. This review outlines the roles of physics, chemistry and surface analysis in sufficient detail to focus on these subjects. It also makes suggestions how these concepts could be applied to some of the current leading edge research in this area.

show abstract

Electrostatic electrochemistry at insulators

Cited by 288 publications

References 21 publications

Squeezing out hydrated protons: low-frictional-energy triboelectric insulator charging on a microscopic scale

Squeezing out hydrated protons: low-frictional-energy triboelectric insulator charging on a microscopic scale

Fundamental theories and basic principles of triboelectric effect: A review

Triboelectric charging of insulating polymers–some new perspectives

Contact Info

Product

Resources

About