The advantages/limitations obtained by working in dynamic scanning force microscopy (DSFM) at different levels of tip/sample interaction forces (from the net attractive to the hard repulsive regime) are experimentally shown by imaging monolayers containing novel fibre-like supramolecular nanostructures wrapped up in spiral-like domains. The structures have been obtained by using the Langmuir-Blodgett technique and transferring onto mica monolayers of quercetin-3-O-palmitate molecules mixed with a fraction of about 25% of dimyristoylphosphatidylcholine. The measurements in the attractive regime allowed us to reveal morphological features of the supramolecular structures that cannot be demonstrated by the conventional repulsive regime. In particular, by attractive dynamic scanning force microscopy (DSFMA) the height of the fibre-like structures was a factor of two to three higher and peculiar nano-ruptures along the wrapped fibres have been observed. The influence of the tip/sample contact interaction was investigated by recording images in hard tapping and successively imaging the same region in DSFMA as well as by comparing the images in DSFMA with those obtained in negative lift mode force modulation microscopy, phase imaging and friction force microscopy.

Dynamic scanning force microscopy investigation of nanostructured spiral-like domains in Langmuir-Blodgett monolayers

MARLETTA, Giovanni
2003-01-01

Abstract

The advantages/limitations obtained by working in dynamic scanning force microscopy (DSFM) at different levels of tip/sample interaction forces (from the net attractive to the hard repulsive regime) are experimentally shown by imaging monolayers containing novel fibre-like supramolecular nanostructures wrapped up in spiral-like domains. The structures have been obtained by using the Langmuir-Blodgett technique and transferring onto mica monolayers of quercetin-3-O-palmitate molecules mixed with a fraction of about 25% of dimyristoylphosphatidylcholine. The measurements in the attractive regime allowed us to reveal morphological features of the supramolecular structures that cannot be demonstrated by the conventional repulsive regime. In particular, by attractive dynamic scanning force microscopy (DSFMA) the height of the fibre-like structures was a factor of two to three higher and peculiar nano-ruptures along the wrapped fibres have been observed. The influence of the tip/sample contact interaction was investigated by recording images in hard tapping and successively imaging the same region in DSFMA as well as by comparing the images in DSFMA with those obtained in negative lift mode force modulation microscopy, phase imaging and friction force microscopy.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11769/10791
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