Ultrasonic-assisted conversion of limestone into needle-like hydroxyapatite nanoparticles

Abstract

Needle-like hydroxyapatite nanoparticles were successfully synthesized via a reaction between calcium oxide (CaO) that was obtained from calcined limestone and orthophosphoric acid (HPO) under ultrasonic irradiation at 25 °C. The reaction systems were exposed to ultrasonic waves of 20 kHz for various times ranging from 0 to 4 h. The initial and final pH values of the mixtures of CaO and HPO solution were continuously observed (pH < 4.0) after ultrasonic irradiation. The powder was then dried at 60 °C and calcined at 300 °C for 3 h (3 °C/min). The products were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The results showed that the formation of needle-like hydroxyapatite (HAp) nanoparticles was substantially accelerated compared with the reaction without ultrasonic irradiation. The HAp phase was increasingly visible with longer ultrasonic irradiation time compared with the monetite phase (CaHPO). This suggests that ultrasonic waved induced a phase transition from the monetite to HAp phase. A smaller needle-like structure of HAp (diameter ∼ 7.4 nm) with a lower contamination of monetite phase was obtained following sonication for 3 h. This study shows that Thai limestone can used as a starting material for synthesizing needle-like HAp nanoparticles with the aid of ultrasonic methods.

Effect of ultrasonication on physicochemical properties of apple based nanocellulose-calcium carbonate composites

“…For aragonite, this vibration appears at ca. 855 cm -1 , whereas for calcite and vaterite crystals, the positions of the corresponding m 2 vibrations are very similar and appear at about 875 cm -1 (Cizer et al 2012;Guo et al 2011;Klinkaewnarong and Utara 2018;Stoica-Guzun et al 2012;Vagenas et al 2003). In the present case, a sharp peaks at 873 and 852 cm -1 on all spectra as in Fig.…”

“…S1). All bands visible there can be associated with crystalline forms of calcium carbonate (Cizer et al 2012;Klinkaewnarong and Utara 2018;Vagenas et al 2003). The FTIR spectra can serve also as the indicator of the isolation performance and the proof that other polysaccharides were removed during the isolation (Szymańska-Chargot et al 2017).…”

Hydroxyapatite for bone related applications derived from sea shell waste by simpleprecipitation method

“…Increased solubility in polymer composites may be due to the formation of Ca 2 HPO 4 CO 3 and Ca 2 PO 4 CO 3 [49]. HAp particles exhibit much higher tendency to grow along c-axis leads to increase the possibility of nanorods formations than particles [50]. This could be confirmed by the presence of (002) face.…”

Síntese e caracterização de membranas biopoliméricas híbridas contendo apatitas e nanopartículas de prata

“…11,12 Materialmente, é constituído, em peso, 90% pela matriz extracelular e 10% água. 12,13 Essa matriz, conhecida como matriz óssea, é um material híbrido orgânico-inorgânico tridimensional, que consiste em cerca de 60% de componente inorgânico e 30 % de fase orgânica. 12,13 É reportado que a fase mineral, que está sob a forma de hidroxiapatita carbonatada, é nucleada seletivamente e depositada na superfícies e nos interstícios de uma rede altamente ordenada formada pela a auto-organização supramolecular das cadeias de macromoléculas.…”

“…12,13 Essa matriz, conhecida como matriz óssea, é um material híbrido orgânico-inorgânico tridimensional, que consiste em cerca de 60% de componente inorgânico e 30 % de fase orgânica. 12,13 É reportado que a fase mineral, que está sob a forma de hidroxiapatita carbonatada, é nucleada seletivamente e depositada na superfícies e nos interstícios de uma rede altamente ordenada formada pela a auto-organização supramolecular das cadeias de macromoléculas. 14 No caso, essa fase orgânica é composta por lipídeos, uma série de proteínas não-colagênicas, como glicosaminoglicanos sulfatados e não sulfatados, e, majoritariamente, colágeno tipo-I, organizadas tridimensionalmente em estruturas fibrosas.…”