Question

What is the Atomic/chemical bonding of the following materials:

1- Uranium (alpha phase)
2- Bombyx Mori Silk
3- Calicium Aluminate Cement - 1 (CAC-1)

And how this affects their properties ?

Answer 1

(a) Uranium exists in 3 different phases-alpha, beta and gamma. The alpha phase consists of corrugated sheets of atoms arranged asymmetrically in an orthorhombic structure. Since the alpha phase atoms are arranged asymmetrically, this anisotropy prevents the alloy formation with most metals (except Niobium and Molybdenum) as they can't occupy the spaces between the Uranium atoms.

(b) Bombyx Mori Silk is a twin fiber as it is composed of 2 proteins: fibroin and sericin. Proteins are macromolecules. The amino acid composition of fibroin is given by: Glycine (46%), Alanine (30%), Ser (12%) and Tyr (5.3%).Macromolecules in the silk are bonded using covalent bonds.

(c) They contain lime (CaO)-alumina (Al2O3) system. Calcium aluminate cement has been manufactured, for example, by heating until molten or sintering a mixture of limestone and bauxite with a small amount of SiO_2, FeO and TiO₂. These types of cement are extensively used for refractory purposes.

CAC-1 is biocompatible and has been used in several biomedical applications.CAC has great mechanical property.