Morphological and Compositional Changes on Sand Dollar Biomaterials Induced by Heat Treatments

Abstract

The microstructural characterization of Mellita Eduardobarrosoi sp. Nov, a marine skeleton, subjected to thermal treatments of 4008, 6008, 8008, and 9008C is presented. The results show that this species has pores with diameters ranging between 10 and 20 mm and is constituted mainly of O, Ca, C, and Mg as (Ca, Mg)CO 3 . This particular compound transforms into CaO when heated higher than 8008C. This change is observed in FTIR spectra as the disappearance of two absorption bands at 875 cm 21 and 878 cm 21 , which correspond to loss of CO 2 .

Synthesis of Hydroxylapatite from Sand Dollar and β-Tricalcium Phosphate by Solid-State Method

“…The sand dollar was collected on the Veracruz beach, Mexico, and it is mainly calcium carbonate. [7] Also, it has small amounts of Si and Mg. b-TCP reactive degree was employed. Samples with different molar ratios of b-TCP and sand dollar were prepared, as illustrated in Table 1.…”

“…This method can produce stoichiometric hydroxylapatite particles and keep the shape of the precursor phosphate particles. [6] In contrast, the sand dollar has a porous structure, [7] and it has been used to produce (by the hydrothermal method), synthetic hydroxylapatite fibers with high crystallinity and c-axis elongation. [8][9][10][11] Then, if the synthesis method preserves the shape of the precursor and the sand dollar can be used as one precursor, one may obtain a porous hydroxylapatite from the sand dollar structure.…”

Microstructure development in laser forming of zirconium coatings on AZ91D magnesium alloy substrates

“…Indeed, as early as 1907, magnesium was reported as having been used to secure a fracture in a human leg [2]; Mg is also an important element of biomaterials [3]. Although the attempt failed, as the metal corroded too rapidly, interest in using Mg for orthopaedic implants has not gone cold but remains strong.…”

Hydroxyapatite growth on cotton fibers modified chemically

“…However, its mechanical properties are poor. Basically, its fracture toughness is very low, severely restricting its field of application in orthopaedics [1][2][3]. For this reason many efforts have been made to develop composite materials based on HAP on polymers such as polylactic acid, collagen, chitosan, polyethylene, etc.…”