Atomic Force Microscopy of Solution Grown Polyethylene Single Crystals

Abstract

Atomic force microscopy (AFM) was applied to the precise thickness measurements of thin lamellae about 10 nm thick of polyethylene single crystals which were grown from dilute solutions and precipitated on cleaved mica. The obtained values agree well with the thickness determined by small angle X-ray scattering. Moreover, AFM observation allowed determination of the thickness difference of several angstroms in the different growth sectors of small crystals about several µ m wide. From the measurements, it was concluded that the free energy of the fold surface in the 110 growth sector was 30% larger than the values in the 100 sector. The larger surface free energy in the 110 sector means higher fold energy in the growth sector.

Nanoscale calorimetry of isolated polyethylene single crystals

“…The number of crystals multiplied by the volume of a typical crystal yielded the total volume of material on the sensor. We followed the same method as Nakagawa et al24 to obtain images with the AFM 24. The samples were observed in contact mode with a V‐shaped silicon nitride cantilever with an integrated pyramidal tip.…”

Three-dimensional shape of polyethylene single crystals grown from dilute solutions and from the melt

“…8, the image of lenticular crystals clearly shows a thin band running through the middle along the b-axis. The band region is thicker than the surrounding regions and indicates the existence of the {110} growth sectors [20], which keep their width (w40 nm) in the lenticular crystals. Because of the narrow width, questions were raised in terms of the existence of this sector in the discussion of the regimes I-II transition [21], which is followed by the crossover of the lateral shape from the lenticular type to the truncated lozenge with curved edges in polyethylene [22].…”

AFM and SALS Characterization of Spherulitic Structure in Polyethylene

“…Recently, the AFM has been applied to image various polymeric systems. , Systems of oriented poly(tetrafluoroethylene) (PTFE) − stretched/oriented polyethylene, , solution-grown polyethylene crystals, − and various polymer networks , have been imaged with the AFM. However, all of these studies involved lengthy sample preparation and/or physically orienting the polymer and have focused primarily on structure at very small length scales, i.e., lamellae.…”