Frequency Response of Polymer Films Made from a Precursor Colloidal Monolayer on a Nanomechanical Cantilever

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• 作者：Ting Liu ; Sascha Pihan ; Marcel Roth ; Markus Retsch ; Ulrich Jonas ; Jochen Stefan Gutmann ; Kaloian Koynov ; Hans-J眉rgen Butt ; R眉diger Berger
• 刊名：Macromolecules
• 出版年：2012
• 出版时间：January 24, 2012
• 年：2012
• 卷：45
• 期：2
• 页码：862-871
• 全文大小：525K
• 年卷期：v.45,no.2(January 24, 2012)
• ISSN：1520-5835

文摘

Nanomechanical cantilevers (NMC) were used for the characterization of the film formation process and the mechanical properties of colloidal monolayers made from polystyrene (PS). Closely packed hexagonal monolayers of colloids with diameters ranging from 400 to 800 nm were prepared at the air鈥搘ater interface and then transferred in a controlled way on the surface of NMC. The film formation process upon annealing of the monolayer was investigated by measuring the resonance frequency of the NMC (鈮?2 kHz). Upon heating of non-cross-linked PS colloids, we could identify two transition temperatures. The first transition resulted from the merging of polymer colloids into a film. This transition temperature at 147 卤 3 掳C as measured at 鈮?2 kHz remained constant for subsequent heating cycles. We attributed this transition temperature to the glass transition temperature T_g of PS which was confirmed by dynamic mechanical thermal analysis (DMTA) and using the time temperature superposition principle. The second transition temperature (175 卤 3 掳C) was associated with the end of the film formation process and was measured only for the first heating cycle. Furthermore, the transition of the colloidal monolayer into a homogeneous film preserved the mass loading on the NMC which allowed determination of the Young鈥檚 modulus of PS (鈮? GPa) elegantly.