Lignin: Functional Biomaterial with Potential in Surface Chemistry and Nanoscience - The Nanoscience and Technology of Renewable Biomaterials - page 173

7

Lignin: Functional Biomaterial
with Potential in Surface Chemistry
and Nanoscience

Shannon M. Notley and Magnus Norgren

7.1 Introduction

Lignin along with the carbohydrates cellulose or hemi-cellulose and other extractive
materials, are the major components of the wood cell wall (Sj ostr om 1993). Indeed the
term lignin is derived from the Latin word for wood ' lignum '. Lignin is considered to
be, after cellulose, the second most abundant natural polymer, found chiefly in the cell
wall of woody tree species however it is also found in all vascular plant materials includ-
ing herbs and grasses (Sarkanen and Ludwig 1971). It is estimated that approximately
30% of all carbon in the biosphere may be attributed to lignin and as such, provides
ample opportunity for the use of this material in future applications involving sustainable
resources (Guo et al . 2008). Currently, global production of lignin based materials and
chemicals, mostly as a by-product from the pulping of wood fibres, exceeds 50 million
tonnes per annum with the majority used in low technology and low value added appli-
cations such as fuel or simply discharged as waste (Gosselink et al . 2004a). Whilst
lignin is found in many sources, the pulp and paper industry provides the best oppor-
tunity for securing vast quantities of this important raw material at economically viable
rates and so the discussion in this chapter on the potential use of lignin and derivatives
in nanotechnological applications will be focussed on lignin derived mainly from wood
fibres. Furthermore, as with all aspects of nanoscience, molecular interactions are of
great importance, whether considering lignin as a polymer in solution or in the solid