Salix Viminalis as a Source of Nanomaterials and Bioactive Natural Substances - Natural Polymers, Biopolymers, Biomaterials, and Their Composites, Blends, and IPNs - page 96

Salix viminalis is also applied for purification of soil and water as an effective
phytoremediator, that is a plant which easily accumulates high quantities of heavy
metal ions through capillary action involving roots and transporting tissues in stem.
The absorbed metal ions are accumulated in the plant cells which were proved in sev-
eral studies analysing metal ion content in different parts of the plant (Lukaszewicz et
al, 2009; Mleczek et al, 2009a, 2009b). The use of Salix viminalis for other purposes,
beside energetic use and/or phytoremediation of waters and soil, is a unique case.
Besides the expected and proven high tolerance to heavy metal ions, Salix viminalis
grows very fast in the mild climate zone yielding hard wood in high quantities from
1 ha (Labrecque et al., 1997). In light of the above statements, Salix viminalis seems
to be a valuable but underestimated raw material for some fabrication processes. The
high agricultural yield of Salix viminalis (Labrecque et al., 1997) will reduce consid-
erably the cost of products obtained from this source if one would like to expand the
currently described methods to industrial scale.
Contemporary materials science puts in picture the on numerous materials of
unique properties potentially applicable in many areas of industry and science. How-
ever, most of them are materials which are hardly accessible in larger amount which
results either from complexity of processing and/or cost of material fabrication. For
example, template synthesis of porous carbons and silica (Ryoo et al., 2001; Schlot-
tig et al., 1999) yields adsorbents of steerable pore dimension (pore size distribution
function PSD) and volume but transfer of such a technology to mass scale seems to
be rather questionable. Similar limitations may be recalled in the case of carbon nano-
tubes (CNTs) which for nearly 20 years are named as “very promising” material re-
garding an impressive number of described possible applications (Bakshi et al., 2010;
Upadhyayula et al., 2009). However, a wide practical application has not materialized
yet since the cost of 1 g CNTs of high purity (essential demand in most applications)
and properly functionalized (tailoring of chemical and physical) is ranging from ca.
hundred to above thousand of dollars (http//www.cheaptubes.com, 2011; http//www.
sigmaaldrich.com, 2011). Therefore, despite discrete pore structure (very narrow
PSD) CNTs cannot be regarded as a practical adsorbent for large scale use despite of
numerous papers and patents (Hu and Ruckenstein, 2004; Pilatos et al., 2010) claiming
such a possibility.
Thus, there is an obvious need for functional materials fabricated in a low-cost
process from widely accessible raw materials. Renewable resources are preferred due
to environment protection. The current report should be seen in light of the above
statement that is it describes a multidirectional chemical exploitation of Salix viminalis
wood grown on agriculture plantations (Figure 1) with high economical efficiency.
This suits regional policy in the area of Torun (Poland) but can be easily expandable to
other regions of Poland and adopted by other countries, as well. The proposed elabo-
ration is practically waste-less since all main products (solid and liquid phase) of the
process are in fact valuable and functional materials. In summary, the proposed con-
cept of Salix viminalis wood elaboration is environmentally friendly being waste-free
and based on renewable resources.