Biotemplating: Complex Structures from Natural Materials
Simon R Hall
Language: English
Pages: 216
ISBN: 1848164033
Format: PDF / Kindle (mobi) / ePub
In terms of structural complexity, the natural world presents innumerable examples of stunning beauty and high functionality, usually with the minimum of material and energy expenditure. Materials chemists can harness these amazing structures as ready-made scaffolds on which to grow inorganic phases which replicate the underlying complexity, thereby producing materials with greatly enhanced physical properties. This book comprehensively describes the entire range of natural materials that have been used in this way and the inorganic phases which result from them. The book covers simple molecules such as cellulose and chitin, to large biological constructs such as bacterial proteins, viruses and pollen. Practically every inorganic material has been synthesized using biotemplating methods and the book reflects this, ranging from simple oxides and carbonates such as silica and calcite, to complex semi- and superconducting materials. The book also discusses the formation of these materials from a mechanistic point of view, thereby enabling the reader to better understand the processes involved in biotemplated mineralization.
- Simple Mono- and Oligosaccharides
- Complex Polysaccharides
- Hydrocolloids
- Chitin/Chitosan
- Proteins and Lipids
- Viruses and Bacteria
- Complex Biostructures as Templates
- Into the Future -- Genetic Engineering and Beyond
dextran, xanthan gum and pullulan. Storage polysaccharides are those which are exclusively composed of alpha-linkages and comprise a large family of starches. 3.2 Cellulose Cellulose is a polysaccharide found in plants, where it is used as the primary structural component of the cell walls. It is formed exclusively from beta-glucose units which are 1→4 linked, therefore giving rise to a straight-chained polymer. With extended straight chains, the possibility exists for extensive interchain
nanoparticles showed higher than average sizes, compared to λ- and κ- carrageenan. They attribute this to the stabilization of hydrolyzed iron species by the particular sulfate charge distribution of ί-carrageenan. Finally, they note that the addition of ferric ions to ί-carrageenan leads to the formation of a heterogeneous gel, whereas for both λ- and κ-carrageenan/iron gels are homogeneous. This is an indication that for this particular system, ί-carrageenan is not able to bind all of the
experienced difficulties in removing the organic template without subsequent loss of inorganic structural integrity. Calcination to remove the organic part of the system would invariably result in structural collapse as outgassing occurred. By synthesizing the silica inside the organic template, calcination should leave the inorganic part intact. The synthesis was carried out using Schizophyllan (SPG), which is a natural polysaccharide present in the fungus Schizophyllum commune.
with a significant proportion of irregular-shaped metallic structures formed by non- specific interactions between the lipid assembly and the copper. The group were able to optimize the preferential binding by increasing the charge density at the lipid seams. They achieved this by using a mixed lipid starting material, comprising DC8,9PC lipid doped with 2% by weight of a negatively charged lipid, 1,2-bis(tricosa-10,12-diynoyl)-sn-glycero-3-phosphohydroxyethanol (DC8,9PEOH). The increased
separation techniques and tailored drug delivery. The high surface area material is also more chemically reactive, owing to micro- and nanoscale features providing greater numbers of reactive sites and points of nucleation, enabling a high surface area material to outperform a chemically identical, low surface area material. Carrying this motif through all length scales, carbon replicas of wood have been used as a template on which a zeolite was grown. Zeolites are high surface area