Nanotribology of hydrogels with similar stiffness but different polymer and crosslinker concentrations

• Hypothesis: The stiffness has been found to regulate hydrogel performances and applications. However, the key interfacial properties of hydrogels, like friction and adhesion are not controlled by the stiffness, but are altered by the structure and composition of hydrogels, like polymer volume fraction and crosslinking degree. Experiments: Colloidal probe atomic force microscopy has been use to investigate the relationship between tribological properties (friction and adhesion) and composition of hydrogels with similar stiffness, but different polymer volume fractions and crosslinking degrees. Findings: The interfacial normal and lateral (friction) forces of hydrogels are not directly correlated to the stiffness, but altered by the hydrogel structure and composition. For normal force measurements, the adhesion increases with polymer volume fraction but decreases with crosslinking degree. For lateral force measurements, friction increases with polymer volume fraction, but decreases with crosslinking degree. In the low normal force regime, friction is mainly adhesion-controlled and increases significantly with the adhesion and polymer volume fraction. In the high normal force regime, friction is predominantly load-controlled and shows slow increase with normal force. 

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Kemiteknik -- Polymerteknologi (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Chemical Engineering -- Polymer Technologies (hsv//eng)

Nyckelord

Adhesion

Colloidal probe atomic force microscopy

Friction

Hydrogel

Atomic force microscopy

Force measurement

Hydrogels

Nanotribology

Polymers

Probes

Stiffness

Volume fraction

Colloidal probe atomic force microscopies

Cross-linking degree

Crosslinker concentration

Hydrogel structure

Interfacial property

Normal forces

Polymer volume fraction

Tribological properties

Crosslinking

n

n' methylenebisacrylamide

polyacrylamide gel

Article

chemical composition

chemical structure

colloid

concentration (parameter)

correlation coefficient

cross linking

force

nanotechnology

priority journal

rigidity

shear strength

volume

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)