title: Chemical oscillation induced periodic swelling and shrinking of a polymeric multilayer investigated with a quartz crystal microbalance.
abstract: Poly(acrylic acid- co-3-azidopropyl acrylate) and poly(acrylic acid- co-propargyl acrylate) have been alternately fabricated into a multilayer via the click reaction. The layer-by-layer deposition was monitored with a quartz crystal microbalance with dissipation (QCM-D) in real time. The response of the multilayer under continuous flow of a bromate-sulfite-ferrocyanide solution with pH oscillation has also been investigated by use of QCM-D. As the pH oscillates between 3.1 and 6.6, either the frequency shift (Delta f) or the dissipation shift (Delta D) periodically varies with a constant amplitude, clearly indicating that the multilayer swells and shrinks oscillatedly. The changes of thickness, shear viscosity, and elastic shear modulus further indicate the oscillation.
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, China.
authors.forename: Yecang
authors.initials: Y
authors.lastname: Tang
authors.forename: Guangming
authors.initials: G
authors.lastname: Liu
authors.forename: Changqian
authors.initials: C
authors.lastname: Yu
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Wei
authors.forename: Guangzhao
authors.initials: G
authors.lastname: Zhang
mesh_terms: D003460:Crystallization; D006863:Hydrogen-Ion Concentration; D011108:Polymers / Q000737:chemistry*; D011791:Quartz / Q000737:chemistry*; D013057:Spectrum Analysis
chemical_list: D011108:Polymers; D011791:Quartz