Falling film break-up and thermal performance of thin polymer film heat exchangers

The thermo-mechanical integration of polymer films requires a precise knowledge of material properties. Nanoindentation is a widely used testing method for the determination of material properties of thin films such as Young’s modulus and the hardness. An important assumption in the analysis of the indentation is that the indented medium is a semi-infinite plane or half space, i.e., it has an “infinite thickness.” In nanoindentation the analyzed material is often a thin film that is deposited on a substrate. If the modulus ratio is small, (soft film on hard substrate) and the penetration depth is small too, then the Hertzian assumption does not hold. We investigate this situation with spherical and conical indentation. Measurement results are shown using spherical indentation on a visco-elastic thin polymer film and a full visco-elastic characterization is presented.

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Ionically Conductive Thin Polymer Film Prepared by Plasma Polymerization: I . Hybrid Film of Plasma Polymer Formed from Octamethylcyclotetrasiloxane, Poly(propylene oxide), and Lithium Perchlorate

Journal of The Electrochemical Society ◽

10.1149/1.2096699 ◽

1989 ◽

Vol 136 (3) ◽

pp. 625-630 ◽

Cited By ~ 19

Author(s):

Z. Ogumi ◽

Y. Uchimoto ◽

Z. Takehara

Keyword(s):

Polymer Film ◽

Propylene Oxide ◽

Plasma Polymerization ◽

Hybrid Film ◽

Lithium Perchlorate ◽

Plasma Polymer ◽

Thin Polymer Film ◽

Thin Polymer ◽

Poly Propylene

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Functional patterned coatings by thin polymer film dewetting

Journal of Colloid and Interface Science ◽

10.1016/j.jcis.2017.07.004 ◽

2017 ◽

Vol 507 ◽

pp. 453-469 ◽

Cited By ~ 12

Author(s):

Andrew M. Telford ◽

Stuart C. Thickett ◽

Chiara Neto

Keyword(s):

Polymer Film ◽

Thin Polymer Film ◽

Thin Polymer

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Rubber-Assisted Hot Embossing for Structuring Thin Polymer Film Polymeric Films

Microelectromechanical Systems ◽

10.1115/imece2006-15297 ◽

2006 ◽

Cited By ~ 1

Author(s):

Pratapkumar Nagarajan ◽

Donggang Yao

Keyword(s):

Thin Films ◽

Film Thickness ◽

Polymer Film ◽

Hot Embossing ◽

Polymeric Films ◽

Thin Polymer Film ◽

Thin Polymer Films ◽

Process Variables ◽

Hard Materials ◽

Thin Polymer

Precision structured polymer thin films with microstructures comparable to or greater than the film thickness are highly desired in many applications. Such micro-patterned thin films, however, are difficult to fabricate using the standard hot embossing technology where both halves of the mold are made of hard materials. This study investigated a rubber-assisted embossing process for structuring thin polymer films. The advantages of the rubber backup instead of a hard support include but are not limited to 1) simplifying the embossing tool, 2) protecting the embossing master, 3) facilitating embossing pressure buildup, and 4) accommodating conformal forming of microscale shell patterns. Several design and process variables including rubber hardness, embossing temperature, embossing pressure and holding time were carefully studied. Thin polystyrene films in a thickness of 25 μm were accurately patterned with microgrooves of characteristic dimensions on the order of 100 μm.

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