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In Situ Probing the Relaxation Properties of Ultrathin Polystyrene Films by Using Electric Force Microscopy

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ABSTRACT

The rapid development of nanoscience and nanotechnology involves polymer films with thickness down to nanometer scale. However, the properties of ultrathin polymer films are extremely different from that of bulk matrix or thin films. It is challenging to distinguish the changes of physical properties in ultrathin films using conventional techniques especially when it locates near the glass transition temperature (Tg). In this work, we successfully evaluated a series of physical properties of ultrathin polystyrene (PS) films by in situ characterizing the discharging behavior of the patterned charges using electric force microscopy. By monitoring the surface potential in real time, we found that the Tg of ultrathin PS films is clearly independent of film thickness, which are greatly different from that of thin PS films (film thickness larger than 10 nm).

No MeSH data available.


AFM topography images and surface potential of ultrathin PS films obtained in a single measurement. a The scratched film for thickness measurement. b AFM morphology of charged ultrathin PS film. c Surface potential images of charged ultrathin PS film with positive charge and d negative charge
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Fig2: AFM topography images and surface potential of ultrathin PS films obtained in a single measurement. a The scratched film for thickness measurement. b AFM morphology of charged ultrathin PS film. c Surface potential images of charged ultrathin PS film with positive charge and d negative charge

Mentions: Charge patterns in accord with the electrode template are successfully fabricated as illustrated in Fig. 1b. The ultrathin PS film is scratched to create some grooves for the measurement of film thicknesses (Fig. 2a). As an excellent polymer electret, PS film is able to store electric charges for a long time. It should be noted that only the areas contacted by the stamp can be electrically injected. Charge patterns are successfully fabricated without any morphological deformation, as shown in Fig. 2b. Both positive and negative charges with uniform patterns could be successfully injected onto the ultrathin PS films, as shown in Fig. 2c, d. Unless otherwise specified, negative charge patterns are chosen in the following experiments, owing to their long life time, than positive charge patterns at a given temperature.Fig. 2


In Situ Probing the Relaxation Properties of Ultrathin Polystyrene Films by Using Electric Force Microscopy
AFM topography images and surface potential of ultrathin PS films obtained in a single measurement. a The scratched film for thickness measurement. b AFM morphology of charged ultrathin PS film. c Surface potential images of charged ultrathin PS film with positive charge and d negative charge
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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Fig2: AFM topography images and surface potential of ultrathin PS films obtained in a single measurement. a The scratched film for thickness measurement. b AFM morphology of charged ultrathin PS film. c Surface potential images of charged ultrathin PS film with positive charge and d negative charge
Mentions: Charge patterns in accord with the electrode template are successfully fabricated as illustrated in Fig. 1b. The ultrathin PS film is scratched to create some grooves for the measurement of film thicknesses (Fig. 2a). As an excellent polymer electret, PS film is able to store electric charges for a long time. It should be noted that only the areas contacted by the stamp can be electrically injected. Charge patterns are successfully fabricated without any morphological deformation, as shown in Fig. 2b. Both positive and negative charges with uniform patterns could be successfully injected onto the ultrathin PS films, as shown in Fig. 2c, d. Unless otherwise specified, negative charge patterns are chosen in the following experiments, owing to their long life time, than positive charge patterns at a given temperature.Fig. 2

View Article: PubMed Central - PubMed

ABSTRACT

The rapid development of nanoscience and nanotechnology involves polymer films with thickness down to nanometer scale. However, the properties of ultrathin polymer films are extremely different from that of bulk matrix or thin films. It is challenging to distinguish the changes of physical properties in ultrathin films using conventional techniques especially when it locates near the glass transition temperature (Tg). In this work, we successfully evaluated a series of physical properties of ultrathin polystyrene (PS) films by in situ characterizing the discharging behavior of the patterned charges using electric force microscopy. By monitoring the surface potential in real time, we found that the Tg of ultrathin PS films is clearly independent of film thickness, which are greatly different from that of thin PS films (film thickness larger than 10 nm).

No MeSH data available.