Change search
ReferencesLink to record
Permanent link

Direct link
Electrically Induced Debonding of Adhesives
KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
2010 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Electrically induced adhesive debonding is a process where an adhesive can be debonded at command with help of an applied voltage. To make this process function, the adhesive is  bonded between two metal substrates. In this study an epoxy adhesive is adhered between two aluminium foils forming a laminate structure. The adhesive is made ionically conductive by an addition of an ionic liquid before the curing. This arrangement forms an electrochemical cell, where the metal substrates act as the electrodes while the ionically conductive adhesive acts as the electrolyte. When a voltage is applied over the laminate, a current passes due to electrochemical reactions at the electrode interfaces and ionic transport in the adhesive.

This type of material can potentially be used in a wide range of applications. This includes making adhesive joints in automotives to both reduce the total weight but also to simplify the disassembly after end-of-life, enabling an inexpensive recycling process. Another potenital use for debondable adhesives is within consumer packaging. Here it could be possible to pack and transport goods using less packaging material as well as making the handling easier.

 The aim of this study was to increase the understanding about the processes leading to debonding. This knowledge is important in the development of new types of debonding adhesives. In this study, the commercial laminate Sinuate® was used as a model system. The experiments were focused on the electrochemical behavior and were performed mainly using galvanostatic polarization and electrochemical impedance spectroscopy. Information about the chemistry of debonding was collected with techniques such as scanning electron microscopy (SEM), mass spectrometry (MS) and Raman spectroscopy. The debonding did always take place at the anodic interface, separating the adhesive and the anode aluminium foil. It was found that the total cell resistance increased drastically during polarization, and that essentially all of this increase originated within the anodic half of the laminate. Examining the resistance behavior with EIS, it was found that the increase in total resistance was reversible.

The anodic  electrochemical reaction during polarization was determined to consist mainly of an oxidation of aluminium, while the major reaction at the cathodic interface was reduction of water into hydrogen. The debonding process, which took place at the anodic interface, could be related to reaction products formed in the polarization process. These products grew out from the anodic aluminium surface into the adhesive. A debonding mechanism is proposed where these products induce an increase in the adhesive volume, causing stresses at the interface which ultimately result in debonding.




Abstract [sv]

Elektriskt framkallad delaminering är en process som gör att en limfog kan fås att släppa på kommando med hjälp av en pålagd elektrisk spänning. För att processen ska fungera måste limmet vara bundet till två metallytor. I den här studien används ett epoxylim, bundet mellan två folier av aluminium, vilket bildar en laminatstruktur. Limmet gjordes jonledande genom en tillsats av en jonvätska innan härdningen. Detta laminat bildar en elektrokemisk cell, där metallytorna agerar som elektroder och limmet som elektrolyt. När en elektrisk spänning läggs över laminatet, uppstår en elektrisk ström till följd av elektrokemiska reaktioner vid elektrodytorna och jontransport i limmet.

 Dessa material skulle kunna användas inom ett brett spektrum av användningsområden. Exempel på detta är användandet av limmade fogar i fordon, vilket skulle både minska fordonens vikt och underlätta demonteringen efter livscykelns slut. En förenklad demontering skulle resultera i en billig återvinningsprocess. Andra exempel på användningsområden för elektriskt släppbara limmer är konsumentförpackningar. Inom detta område skulle varor kunna packas med mindre mängd förpackningsmaterial och hanteringen under transport och uppackning skulle kunna förenklas.

 Målet med det här arbetet var att öka förståelsen kring processerna som leder till delaminering. Dessa kunskaper är viktiga för utvecklande av nya sorter av elektriskt släppande limmer. Det kommersiella laminatet Sinuate® användes som ett modellsystem. Experimenten fokuserades kring elektrokemin och utfördes främst med galvanostatisk polarisering och elektrokemisk impedansspektroskopi (EIS). Information om släpprocessens kemi inhämtades med tekniker som svepelektronmikroskopi (SEM), masspektrometri (MS) och Raman-spektroskopi. Det upptäcktes att delamineringen alltid skedde i det anodiska gränsskiktet, på så sätt att aluminiumfolien och limytan separerades. Polarisationsprocessen ledde till en drastisk ökning av den totala cellresistansen och större delen av denna härrörde sig från den anodiska delen av laminatet. Denna ökning i resistans fanns vara reversibel genom att använda EIS. Den elektrokemiska reaktionen vid anoden bestod till största delen av en oxidation av aluminium, medan den katodiska reaktionen bestod av en reduktion av vatten till vätgas. Processerna som ledde till släpp i det anodiska gränsskitet kunde härledas till SEM-resultaten, där reaktionsprodukter observerades. Dessa produkter växte ut från aluminiumytan och in i limmet. En släppmekanism föreslås, där de bildade produkterna orsakar en volymsökning i limmet, vilket leder till spänningar i gränsskiktet som i sin tur gör att limmet släpper.


Place, publisher, year, edition, pages
Stockholm: KTH , 2010. , viii, 23 p.
Trita-CHE-Report, ISSN 1654-1081 ; 2010:52
National Category
Chemical Engineering
URN: urn:nbn:se:kth:diva-27742ISBN: 978-91-7415-815-1OAI: diva2:380505
2010-12-12, D3, Lindstedtsvägen 5, Stockholm, 10:30
QC 20101222Available from: 2010-12-22 Created: 2010-12-21 Last updated: 2010-12-22Bibliographically approved
List of papers
1. Dielectric properties of water inside single-walled carbon nanotubes
Open this publication in new window or tab >>Dielectric properties of water inside single-walled carbon nanotubes
Show others...
(English)In: Journal of Applied Electrochemistry, ISSN 0021-891X, E-ISSN 1572-8838Article in journal (Other academic) Submitted
National Category
Chemical Engineering
urn:nbn:se:kth:diva-27757 (URN)

QS 20120327

Available from: 2010-12-22 Created: 2010-12-22 Last updated: 2016-09-28Bibliographically approved
2. Electrochemical characterization of electrically induced adhesive debonding
Open this publication in new window or tab >>Electrochemical characterization of electrically induced adhesive debonding
2011 (English)In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 158, no 10, P109-P114 p.Article in journal (Refereed) Published
Abstract [en]

This study concerns with controlled debonding of adhesive generated with electricity. This is a concept which could potentially be used in a wide range of applications, such as light-weight automotives, which can be easily recyclable at the touch of a button. The studied material is produced as a laminate with an epoxy adhesive bonded between aluminium foils. An electrochemical investigation of these debonding adhesives was performed. A three-electrode system with a circular quasi-reference electrode was validated and used together with electrical impedance spectroscopy and scanning electron microscope. It was found that the resistance at the debonding anodic interface of the laminate increased during polarization. This increase in resistance was shown to be reversible at open circuit. During the polarization, aluminium compounds were produced at the anode. These compounds grew to penetrate the adhesive. A debonding mechanism based on increasing mechanical stresses at the anodic interface is proposed.

adhesive bonding, aluminium, anodes, electric resistance, electrochemical impedance spectroscopy, internal stresses, laminates, resins, scanning electron microscopy
National Category
Chemical Engineering
urn:nbn:se:kth:diva-27758 (URN)10.1149/1.3622657 (DOI)000294063000082 ()2-s2.0-80052091897 (ScopusID)

QC 20160427

Available from: 2010-12-22 Created: 2010-12-22 Last updated: 2016-04-27Bibliographically approved

Open Access in DiVA

fulltext(2241 kB)1326 downloads
File information
File name FULLTEXT01.pdfFile size 2241 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Leijonmarck, Simon
By organisation
Applied Electrochemistry
Chemical Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 1326 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 227 hits
ReferencesLink to record
Permanent link

Direct link