Adhesive forces and time dependent behaviour (creep and loading rate effects) on nanomechanical properties of polydimethylsiloxane (PDMS) and PDMS nanocomposite

Charitidis, CA; Koumoulos, EP; Tsikourkitoudi, VP; Vasilakos, SP; Tarantili, PA

dc.contributor.author	Charitidis, CA	en
dc.contributor.author	Koumoulos, EP	en
dc.contributor.author	Tsikourkitoudi, VP	en
dc.contributor.author	Vasilakos, SP	en
dc.contributor.author	Tarantili, PA	en
dc.date.accessioned	2014-03-01T02:01:43Z
dc.date.available	2014-03-01T02:01:43Z
dc.date.issued	2011	en
dc.identifier.issn	17904439	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/29229
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-79958744056&partnerID=40&md5=8b541ef871a56698cb239752a4057340	en
dc.subject	Creep	en
dc.subject	Forces	en
dc.subject	Loading rate	en
dc.subject	Nanoindentation	en
dc.subject	Polysiloxane nanocomposites	en
dc.subject	Time- dependent properties	en
dc.subject.other	Adhesive contact	en
dc.subject.other	Adhesive force	en
dc.subject.other	Berkovich indenters	en
dc.subject.other	Creep behaviour	en
dc.subject.other	Forces	en
dc.subject.other	Hold time	en
dc.subject.other	Indenters	en
dc.subject.other	Loading rate	en
dc.subject.other	Loading rate effects	en
dc.subject.other	Nanoindentation techniques	en
dc.subject.other	Nanomechanical property	en
dc.subject.other	No load	en
dc.subject.other	Polydimethylsiloxane PDMS	en
dc.subject.other	Silicone elastomers	en
dc.subject.other	Soft material	en
dc.subject.other	Soft polymers	en
dc.subject.other	Surface process	en
dc.subject.other	Time- dependent properties	en
dc.subject.other	Time-dependent behaviour	en
dc.subject.other	Unloading curves	en
dc.subject.other	Atomic force microscopy	en
dc.subject.other	Creep	en
dc.subject.other	Indentation	en
dc.subject.other	Investments	en
dc.subject.other	Loading	en
dc.subject.other	Loads (forces)	en
dc.subject.other	Nanocomposites	en
dc.subject.other	Nanoindentation	en
dc.subject.other	Plastic deformation	en
dc.subject.other	Silicones	en
dc.subject.other	Unloading	en
dc.subject.other	Microchannels	en
dc.title	Adhesive forces and time dependent behaviour (creep and loading rate effects) on nanomechanical properties of polydimethylsiloxane (PDMS) and PDMS nanocomposite	en
heal.type	journalArticle	en
heal.publicationDate	2011	en
heal.abstract	In the present study, nanoindentation technique was used to investigate the nanomechanical and time dependent behaviour of silicone elastomers, namely polydimethylsiloxane (PDMS) and PDMS nanocomposite, through Oliver & Pharr model. Considerable uncertainties arise when applying the nanoindentation technique to very soft materials with elastic modulus (E) below 5 MPa or adhesive PDMS samples. Detailed observations for the initial and adhesive contact of PDMS indentations with Berkovich indenter were also investigated. Significant initial penetration displacements were created during the finding surface process. Moreover, the plastic deformation where no load had yet been applied to PDMS was investigated and compared with similar studies using Atomic Force Microscopy. It was found that when the indenter tip was pulled away from the sample, the adhesive attraction deformed the soft polymer along the direction of the tip motion and caused a negative indentation (zero- load plastic deformation). Furthermore, an analysis of nanoindentation creep behaviour of PDMS was performed. The results showed that the nanomechanical properties of PDMS, namely hardness (H) and E, depend on the hold time incorporated in the experiment. A hold time of 300 s should be used in order to avoid a deviation in the calculation of H and E due to a change in the unloading curve that results in the inaccurate determination of stiffness. The effect of loading rate values of PDMS on H and E was also studied. With the increase of loading rate, H and E were found to decrease until they reached constant values. Therefore, a loading rate of 3 μN/s is recommended in order to avoid a deviation in the calculation of H and E values.	en
heal.journalName	Journal of Nanostructured Polymers and Nanocomposites	en
dc.identifier.volume	7	en
dc.identifier.issue	1	en
dc.identifier.spage	32	en
dc.identifier.epage	42	en