Atomic force spectroscopy of thermoresponsive photo-cross-linked hydrogel films

Responsive hydrogel thin films are interesting materials as responsive adhesives or as an active matrix in actuators and sensing applications, and thus, knowledge about their structural and micromechanical properties is of high relevance. Using atomic force spectroscopy, temperature-induced structur...

Description complète

Détails bibliographiques
Publié dans:Langmuir : the ACS journal of surfaces and colloids. - 1985. - 26(2010), 10 vom: 18. Mai, Seite 7262-9
Auteur principal: Junk, Matthias J N (Auteur)
Autres auteurs: Berger, Rüdiger, Jonas, Ulrich
Format: Article en ligne
Langue:English
Publié: 2010
Accès à la collection:Langmuir : the ACS journal of surfaces and colloids
Sujets:Journal Article Research Support, Non-U.S. Gov't Hydrogels Membranes, Artificial
LEADER 01000caa a22002652c 4500
001 NLM195165896
003 DE-627
005 20250211070132.0
007 cr uuu---uuuuu
008 231223s2010 xx |||||o 00| ||eng c
024 7 |a 10.1021/la903396v  |2 doi 
028 5 2 |a pubmed25n0651.xml 
035 |a (DE-627)NLM195165896 
035 |a (NLM)20163151 
040 |a DE-627  |b ger  |c DE-627  |e rakwb 
041 |a eng 
100 1 |a Junk, Matthias J N  |e verfasserin  |4 aut 
245 1 0 |a Atomic force spectroscopy of thermoresponsive photo-cross-linked hydrogel films 
264 1 |c 2010 
336 |a Text  |b txt  |2 rdacontent 
337 |a ƒaComputermedien  |b c  |2 rdamedia 
338 |a ƒa Online-Ressource  |b cr  |2 rdacarrier 
500 |a Date Completed 17.08.2010 
500 |a Date Revised 12.05.2010 
500 |a published: Print 
500 |a Citation Status MEDLINE 
520 |a Responsive hydrogel thin films are interesting materials as responsive adhesives or as an active matrix in actuators and sensing applications, and thus, knowledge about their structural and micromechanical properties is of high relevance. Using atomic force spectroscopy, temperature-induced structural and adhesive changes of thermoresponsive hydrogel layers with micrometer thickness based on photo-cross-linked N-isopropylacrylamide (NiPAAm) were investigated in the temperature range of 18-50 degrees C. Grafted onto flat surfaces, these hydrogel layers are restricted to a highly anisotropic swelling and deswelling predominantly perpendicular to the substrate surface, which was monitored and evaluated by force spectroscopy during vertical tip approach and retraction. Analyses of the tip penetration depth yielded quantitative information about the degree of swelling. As a second feature, the critical temperature was found to decrease with increasing cross-linking density. Temperature-dependent measurements with hydrophobic and hydrophilic atomic force microscopy (AFM) tips revealed a strong adhesion to the hydrogel layer in the swollen state, which was reduced upon the layer volume collapse. These observations on the micrometer-thick gel network layers are in contrast to previous reports on ultrathin pNiPAAm brushes and monolayers, which show no adhesion in the swollen state but only in the collapsed state. Furthermore, it was found that the hydrophobicity of the hydrogel probed with a hydrophobic tip continuously increases with temperature over a broad range of at least 30 K 
650 4 |a Journal Article 
650 4 |a Research Support, Non-U.S. Gov't 
650 7 |a Hydrogels  |2 NLM 
650 7 |a Membranes, Artificial  |2 NLM 
700 1 |a Berger, Rüdiger  |e verfasserin  |4 aut 
700 1 |a Jonas, Ulrich  |e verfasserin  |4 aut 
773 0 8 |i Enthalten in  |t Langmuir : the ACS journal of surfaces and colloids  |d 1985  |g 26(2010), 10 vom: 18. Mai, Seite 7262-9  |w (DE-627)NLM098181009  |x 1520-5827  |7 nnas 
773 1 8 |g volume:26  |g year:2010  |g number:10  |g day:18  |g month:05  |g pages:7262-9 
856 4 0 |u http://dx.doi.org/10.1021/la903396v  |3 Volltext 
912 |a GBV_USEFLAG_A 
912 |a SYSFLAG_A 
912 |a GBV_NLM 
912 |a GBV_ILN_22 
912 |a GBV_ILN_350 
912 |a GBV_ILN_721 
951 |a AR 
952 |d 26  |j 2010  |e 10  |b 18  |c 05  |h 7262-9