Modern Research and Educational Topics in Microscopy
authors Paiva AT , Sequeira SM, Evtuguin DV, Kholkin AL, Portugal I
editors Mendez-Vilas A, Dias J
chapter title Nanoscale Structure of Cellulosic Materials: Challenges and Opportunities for AFM
author keywords AFM; cellulose; paper; silica hybrids
abstract Atomic Force Microscopy (AFM) can profile surfaces at resolutions from microns to a nanometre scale.This is particularly advantageous for the studies of paper and related materials based on cellulose fibres that possess a complex structural hierarchy and constituted of major building blocks with highly dispersed dimensions, from few nanometres to tens of microns. The aim of this work was to study the morphology ofcellulosic fibres from bleached Eucalyptus globulus kraft pulp and corresponding paper materials employing AFM technique. The advantages and disadvantages of AFM as applied to this extremely soft material are discussed. A series of papers was coated also with in situ formed silica using a sol-gel synthesis and the surface of obtained hybrid material was characterised. The dimensions and shapes of elementary cellulose fibrils, microfibrils, and macrofibrils have been determined. The diameters of elementary cellulose fibrils (4-5 nm) were of the same order as determined by X-rays scattering. The thickness of primary and secondary cell wall layers was assessed as well as the diameter and macromorphological elements of fibres. The dimensions of silica domains in the pseudo continuous film on the paper surface evidenced the mode of silica deposition in the hybrid material. This study reveals AFM as indispensable instrumentation for the study of macro- and micro- and nano substructures in the cellulose fibres and related materials.
publisher Formatex
isbn 978-84-611-9419-3
year published 2007
volume 1
beginning page 726
ending page 733

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