X-ray Diffractometer Spectra Research Articles

Keratin hydrolysate as a chrome exhaust aid and keratin filler in leather processing: A cleaner technology approach for tannery solid waste management and leather manufacturing

Hair burning unhairing and dampening of tannery wastes during the hair-saving unhairing process are becoming significant problems in the tanning industry. Therefore, this research article focuses on the extraction of keratin hydrolysate (KH) and its application as a chrome exhaust aid and keratin filler in leather manufacturing process. The structure, morphology and functional groups of the extract were examined using X-Ray Diffractometer (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectrometer (FTIR), respectively. To study and contrast the degree of improvement in chromium uptake, the KH solution was applied both before tanning on the pickled pelt and after tanning during basification. The thermal stability, physical strength characteristics and organoleptic properties of the leathers obtained were characterized. Furthermore, the environmental impact of the tanning system was assessed through a comparative analysis of the spent liquors. Finally, experimental retanning process was conducted to replace the commercial protein filler (Celatan F: 50, 75, and 100 %) with KH solution, with concurrent processing of control leather using conventional chrome tanning agent at 6 % dosage of chromium. The FTIR analysis of the extract confirmed the presence of alkyl side chains of amino acids as well as carboxylic, amide, carboxyl group and aldehyde functional groups at 1400-1700 cm−1,3,303.46 cm−1,3270 cm−1 and 2752 cm−1, respectively. XRD spectrum showed two diffraction peaks at 2 theta values of 9.36° and 21.16°, respectively. Leathers with improved mechanical strength, organoleptic properties and thermal stability were obtained with 100 % substitution of Celatan F at pH 6 and 10 % chromium dosage. It was also discovered that the shrinkage temperature of the experimental leather was enhanced to more than 105 °C. Environmental impact evaluation on the spent liquor showed that the complete replacement of Celatan F with KH solution brought about a notable decrease in COD and TDS in the spent liquor. The extraction and application of tannery hair waste-based keratin hydrolysate as an efficient, environmentally friendly chrome exhaust aid and keratin filler has been attempted and established in this research article.

Comparative Study on Structural, Dielectric Behavior and AC Conductivity of PPY-PVA Incorporated with TiO2 Fine and Nano Particles

Abstract An in-situ oxidative chemical polymerization technique to prepare thin films of PPY, PVA, and PPY-PVA blend doped with variable concentrations of TiO2 fine- and nano-particles was further investigated by X-ray diffractometer (XRD) and impedance spectrometer to study structural, dielectric, and AC conducting behavior. XRD spectra established that sharp and high intense peaks of PPY-PVA- fine TiO2 films indicated more crystallinity, which might be due to higher compactness and modification in interplanar spacing. Dielectric plots revealed that PPY-PVA-nano TiO2 films exhibited higher dielectric constants and lower dielectric loss compared to films of PPY-PVA- fine TiO2 in shorter frequency region, suggesting that these films are more suitable for charge storage devices. Conductivity plots revealed that AC conductivity of pure PPY was low (4.8 x10-3 S/cm at 313 0K) and was increased to 5.3 x10-3 S/cm by addition of PVA. AC conductivities of PPY-PVA-nano TiO2 thin films are relatively higher (7.43x10-3 S/cm to 1.14x10-2 S/cm) than PPY-PVA-fine TiO2 films (6.35x10-3 to 9.78x10-3 S/cm) with increasing frequency and temperature, which could be due to large surface area to volume ratio of nano-size dopant. This suggests that PPY-PVA-nano TiO2 thin films may be used for sensing various gasses.

Facile Extraction and Characterization of Silica Nanopowder from Marine National Park beach sand via Alkali Fusion Route

The current study showed utilization of locally available beach sand from Marine National Park in facile extraction of highly amorphous silica via a simple alkali fusion method. The purification of the silica sand was done using 6 N HCl solution to increase its purity. The method entailed formation of sodium silicate (Na2SiO3) solution from silica sand, precipitation using HCl acid to form tetraortosilicate acid, Si(OH)4 (silica gel) which is then heated to form amorphous silica (SiO2). The percentage yield of the extracted silica was 35.0139±0.11%. The extracted silica was characterized using X-Ray Fluorescence Spectrometer (XRF), X-Ray Diffractometer (XRD) and Fourier Transform Infrared Spectrophotometer (FT-IR). The XRF characterization revealed that the extracted silica content was 94.16±0.47 % which increased from 81.32±0.81% (Silica sand). The XRD results revealed a highly crystalline quartz as the main component of silica sand. The XRD spectra of extracted silica showed a broad diffraction peak at 2θ = 21.76o revealing its amorphous nature. The average particle size of the extracted silica was 45.15nm. The FT-IR characterization of the extracted silica showed hydroxyl (-OH) in silanol (Si-OH) and siloxane (Si-O-Si) as important functional groups. The results showed a low cost technique for the production of highly pure amorphous nanosized silica as a potential mineral that can be employed in vast industrial fields.

Thoughtful investigation of ZnO doped Mg and co-doped Mg/Mn, Mg/Mn/F thin films: A first study

Pure ZnO, Zn0.97Mg0.03O, Zn0.96Mg0.03Mn0.01O and Zn0.90Mg0.03Mn0.01F0.06O nanocrystalline thin films were successfully elaborated on glass substrates using spray pyrolysis method. Structural proprieties were mainly investigated by X-ray diffractometer (XRD), Scanning electron microscopy (SEM), UV–Visible spectrophotometry and Hall effect measurement technique. The XRD spectra revealed the preferred orientation of the prepared polycrystalline along (002) reflection and showed the hexagonal wurtzite structure. A decrease in the crystallinity of Zn0.90Mg0.03Mn0.01F0.06O sample has been observed from 17.206 to 13.489 nm due to the change in its ionic size. SEM images highlighted the homogeneity of the prepared samples surface and proved their nanostructure morphology. For the doped 3%Mg, 1%Mn and 6%F polycrystalline, the obtained transmission spectra were higher than that of pure ZnO and a shift towards the lower wavelengths with a band gap of 3.31 eV has been observed for Zn0.97Mg0.03O film. A low electrical resistivity of about 1.33 × 10−3 Ω.cm was measured for Zn0.90Mg0.03Mn0.01F0.06O thin film. Also, its photoelectric performance was proven to be significantly higher than that of the previously reported ZnO doped and co-doped thin films, which makes it a remarkable candidate for several optoelectronic devices.

Block Copolymer-Assisted Synthesis of Iron Oxide Nanoparticles for Effective Removal of Congo Red.

Iron oxide nanoparticles (IONPs) were synthesized via a block copolymer-assisted hydrothermal method and the phase purity and the crystal structure were investigated by X-ray diffraction. The Rietveld analysis of X-ray diffractometer spectra shows the hexagonal phase symmetry of α-Fe2O3. Further, the vibrational study suggests Raman active modes: 2A1g + 5Eg associated with α-Fe2O3, which corroborates the Rietveld analysis and orbital analysis of 2PFe. The superparamagnetic behavior is confirmed by magnetic measurements performed by the physical properties measurement system. The systematic study of the Congo red (CR) interaction with IONPs using a UV-visible spectrophotometer and a liquid chromatography-tandem mass spectrometry system equipped with a triple quadrupole mass analyzer and an electrospray ionization interface shows effective adsorption. In visible light, the Fe2O3 nanoparticles get easily excited and generate electrons and holes. The photogenerated electrons reduce the Fe3+ ions to Fe2+ ions. The Fe2+/H2O2 oxidizes CR by the Fenton mechanism. The strong adsorption ability of prepared nanoparticles towards dyes attributes the potential candidates for wastewater treatment and other catalytic applications.

A Study of Nano-Tungsten Colloid Preparing by the Electrical Spark Discharge Method.

This study developed an energy-enhanced (ee)-micro-electric discharge machining (EDM) system for preparing nano-tungsten (nano-W) colloids. This system enables spark discharge using tungsten wires immersed in deionized water, to produce nano-W colloids. Compared with the chemical preparation method, the processing environment for preparing colloids in this study prevented nanoparticle escape. Among the nano-W colloids prepared using the ee-micro-EDM system and an industrial EDM system, the colloid prepared by the ee-micro-EDM system exhibited a more favorable absorbance, suspensibility, and particle size. The colloid prepared by the ee-micro-EDM system with a pulse on time and off time of 10-10 μs had an absorbance of 0.277 at a wavelength of 315 nm, ζ potential of -64.9 mV, and an average particle size of 164.9 nm. Transmission electron microscope imaging revealed a minimum particle size of approximately 11 nm, and the X-ray diffractometer spectrum verified that the colloid contained only W2.00 and W nanoparticles. Relative to industrial EDM applications for nano-W colloid preparation, the ee-micro-EDM system boasts a lower cost and smaller size, and produces nano-W colloids with superior performance. These advantages contribute to the competitiveness of the electrical spark discharge method in the preparation of high-quality nano-W colloids.

In vitro bioactivity of 3D microstructure hydroxyapatite/collagen based-egg white as an antibacterial agent.

The present study aims to design 3D scaffold hydroxyapatite (HA)/collagen (Coll) based egg-white (EW) as antibacterial properties. The calcium source in HA synthesis derived from the Pinctada maxima shell cultivated on Bali Island has proven biocompatibility, and the compressive strength exceeded human bone. HA synthesis by precipitation with heat treatment in oven-dried at 80°C (HA-80) and annealed at 900°C (HA-900), has crystallinity 48% and 85%, respectively, were used for scaffold design. The physicochemical properties of X-ray diffractometer spectra showed that increasing temperature affected the crystallinity and HA phase formed. Furthermore, the crystal structure of HA changed in nanocomposite due to the substitution of Coll and EW, and the Fourier transform infrared spectroscopy spectra confirmed that the absorption peak of the phosphate group (1027-1029 cm-1 ) decreased intensity, presumably by protein binding of EW and Coll. The cell viability of HA/Coll/EW in 24, 48, and 72 h incubation period was 112.34 ± 4.36, 104.89 ± 3.41, 72.88 ± 6.85, respectively. The decreases of cell viability due to high cell density and reduced nutrients in wells. Antibacterial activity of HA/Col/EW exhibited a strong zone of inhibition against bacteria causing periodontitis; Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Staphylococcus aureus.

Sample Preparation of the Natural Source Hydroxyapatite (HAp) derived from Black Tilapia Fish Scales

Hydroxyapatite (HAp) is a biomaterial with the chemical formula Ca10(PO4)6(OH)2. Normally, it was used and applied in biomedical applications, cooking recipes and healthy food products. Due to this, it has attracted the researcher to work on HAp synthesis and extraction. In this study, the hydroxyapatite was extracted from fresh water Black Tilapia Fish Scales (BTFS) was analysed. The crystallinity of the HAp was characterized by using an X-ray diffractometer (XRD) whereas the Fourier transform infrared (FTIR) analysis was used to characterize the presence of HAp from the samples. Scanning electron microscopy (SEM) provided with an Energy Dispersive Spectroscopy, (EDS) was used to investigate the morphology and element of the hydroxyapatite powders. The BTFS samples were heated at 100 °C to composed and eliminated the remaining meat and other impurities. A mechanical crusher was applied to make a miniscule and fine hydroxyapatite powder using a thermal calcination technique using a furnace. The BTFS samples powder were calcined at a temperature of 900 °C for 3 hours correspondingly. The XRD spectra findings, uncovered the existence of the obtained BTFS HAp are articulate with Joint Committee on Powder Diffraction Powder Standard data (JCPDS) from the library. From the SEM results, HAp powder presence in hexagonal shape. The findings show the potential of producing high-value products from fishing waste, such as HAp with Ca/P ratio 1.74, for biomedical applications.

Effect of dip-coating cycle on some physical properties of Cu2NiSnS4 thin films for photovoltaic applications

Quaternary semiconductor Cu2NiSnS4 thin film was made by the sol–gel method associated with dip-coating technique on ordinary glass substrates. In this paper, we have studied the impact of dip-coating cycle at different cycles: 4, 5 and 6 on the structural, compositional, morphological, optical and electrical characteristics. CNTS thin films have been analyzed by various characterization techniques including X-ray diffractometer (XRD), Raman measurements, scanning electron microscope (SEM), energy-dispersive X-ray spectroscope (EDS), UV–Visible spectroscopy and four-point probe method. XRD spectra demonstrated the formation of cubic Cu2NiSnS4 with privileged orientation at (111) plane. Crystallite size of cubic CNTS thin films increases from 6 to 9 with augmentation of dip-coating cycle. Raman scattering confirmed the existence of CNTS thin films by Raman vibrational mode positioned at 332 cm−1. EDS investigations showed near-stoichiometry of CNTS sample deposited at five cycles. Scanning electron microscope showed uniform surface morphologies without any crack. UV–Vis spectroscopy indicated that the optical absorption coefficient values are larger than 104 cm−1. Estimated band gap energy of CNTS absorber layers decreases from 1.64 to 1.5 eV as dip-coating cycle increased. The electrical conductivity of CNTS thin films increases from 0.19 to 4.16 \(\left( {{\Omega }\;{\text{cm}}} \right)^{ - 1}\). These characteristics are suitable for solar cells applications.

Investigation of structural, optical, antibacterial, and dielectric properties of V-doped copper oxide thin films: Comparison with undoped copper oxide thin films

Vanadium doped Copper oxide (CO) thin films were prepared by the sol-gel dip-coating method. The properties of thin films were examined by X-Ray Diffractometer (XRD), UV–Visible-NIR spectrophotometry, and dielectric properties analyzer. The antibacterial and photocatalytic properties were also determined. XRD spectra revealed the dual-phase of copper oxide (cuprite and tenorite) for all percentages of V with no other impurity peak. Tauc's relation is used to probe the optical band gap which is reduced from 1.96 to 1.64 eV with an increase in vanadium doping percentage. The impurity band coalesces with the conduction band of copper oxide to decrease the band gap. Dielectric constant measurements reveal that the Ac conductivity of thin films increases with an increase in V doping percentage.

The effect of temperature on the structural, dielectric and magnetic properties of cobalt ferrites synthesized via hydrothermal method

Abstract A series of cobalt ferrite nanoparticles were prepared using hydrothermal process by varying the reaction temperature. The structural, magnetic and dielectric properties have been studied with the help of X-ray diffractometer (XRD), vibrating sample magnetometer (VSM) and impedance analyzer respectively. XRD spectra of all samples confirmed the formation of cobalt ferrite (CoFe2O4) nanoparticles (NPs). The lattice constant ‘a’ for temperature series samples is averaged around 8.4023 Å. Crystallite size of temperature series is calculated by Debye–Scherer formula that lies in the range of 15.04–20.49 nm. Its values increase because the chance of coalescence increases by increasing temperature. The maximum packing factor is obtained for the sample with highest reaction temperature. From VSM data, we get the M–H hysteresis curves for complete temperature series which confirms the magnetic nature. The maximum saturation magnetization 150.67 emu/g is obtained for the sample prepared at highest temperature. Different magnetic parameter such as saturation magnetization, coercivity, retentivity, squareness ratio, anisotropy constant and magneton number has been calculated from VSM data. AC response of all prepared ferrites was studied with impedance analyzer of frequency range 20 Hz to 20 MHz. Ferrites are the insulating materials, so, eddy current does not induce in transformer cores made of ferrite materials. In the medical field cobalt ferrite is used for drug delivery, as a biosensor and in MRI.

Microstructural characteristics and mechanical behaviour of aluminium matrix composites reinforced with Si-based refractory compounds derived from rice husk

The microstructural characteristics and mechanical behaviour of aluminium matrix composites reinforced with Si-based refractory compounds (SRC) derived from rice husk were investigated. The reinforcement materials (SRC) were synthesized using a carbothermal processing technique. The reinforcement was used to prepare a 10 wt.% Al-Mg-Si alloy-based composite using a double stir casting process. The composites produced were characterized using microhardness, tensile properties, scanning electron microscopy (SEM), and X-ray diffractometer (XRD). From the results, A1650, C1650, and A1600 grades of the samples show more resistance to indentation due to the high proportion of hard SRC in the reinforced materials. Superior elongation values were observed for these composites A1650, C1650 and A1600 grades, respectively. The grades A1250, B1250, and C1250 series had the least toughness values within the range of 20–37% as compared to the control sample. For all composites under examination, the percent porosity was noted to be less than 4% and the strain to fracture was within 24–38%. Higher intensity of SiC was observed from the XRD spectrum and the formation of intermetallic materials. The tensile fracture surface morphologies of the composites produced were similar, showing a ductile dimple-like structure. The formation of a micro-crack and micro-void was also observed along the interphase.

Impedance analysis of zirconium-doped lithium manganese oxide

In recent days, portable electronic devices are indispensable to improve the standard of living, which led to the demand for energy storage devices with good performance. Among the storage devices, rechargeable lithium ion batteries play a vital role due to the good electrical conductivity. In this study, impedance and electrical performance were studied for zirconium-doped Li4Mn5O12 at different concentrations (0.1, 0.2, 0.3 and 0.4 mol). The structural and morphological properties of the material were studied by powder X-ray diffractometer spectra and scanning electron microscopy analysis. Morphological properties exhibit the combination of polyhedral and needle-shaped particles, which were in micron size. The Nyquist plot indicates the absence of grain boundary effect and explained the bulk property, i.e., the negative temperature co-efficient of resistance property of the material. Zirconium-doped lithium manganese oxide (0.2 mol) exhibits good electrical property than other concentrations. Maximum conductivity was (1.4 × 10−5 S cm−1) observed at 160°C for the same. These results suggested that 0.2 mol of zirconium will enhance the electrical property of lithium manganese oxide (Li4Mn5O12).

Persimmon tannin functionalized polyacrylonitrile fiber for highly efficient and selective recovery of Au(III) from aqueous solution

An efficient fibrous adsorbent (PANF-TETA-PT) was prepared via grafting triethylenetetramine (TETA) on polyacrylonitrile fiber (PANF), followed by persimmon tannin (PT) immobilizing. Detailed characterization certified that plenty amounts of amino and phenolic hydroxyl groups existed on the surface of PANF-TETA-PT, which would provide excellent active sites for Au(III) adsorption. The batch characteristic results found that the adsorption equilibrium data could be fitted well with Langmuir equation, while the obtained kinetic data were consistent with the Pseudo-second-order equation. The maximum equilibrium adsorption capacity of PANF-TETA-PT towards Au(III) (801.2 mg/g) was apparently superior than that of the reported adsorbents, and the competitive adsorption showed that PANF-TETA-PT had a good preference to adsorption Au(III) in spite of some coexisting pollutants. The characterization analysis of Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffractometer spectrum (XRD) revealed that the electrostatic attraction and chelation dominated the uptake of Au(III) on PANF-TETA-PT, in which a part of loaded Au(III) was reduced to Au particles with the help of reductive functional groups. Thus, this adsorbent could be as a promising candidate to separation and preconcentration of Au(III) from wastewater.

Effective removal of lead(II) migrated from kitchen faucets using multi-slice feathery γ-alumina

In this study, γ-Al2O3 was synthesized using a hydrothermal method and its morphology and chemical composition was characterized by transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and X-ray diffractometer (XRD). The TEM images, EDX and XRD spectrum highlight good crystallization and multi-slice feathery microstructure, involving relatively pure crystal sintering. The Pb(II) concentration analysed by inductively coupled plasma mass spectrometry (ICP-MS) after centrifuging is linked to the γ-Al2O3 adsorption, and a removal method for Pb(II) from water passing through kitchen faucets is proposed. The Pb(II) value below 0.06 mg g−1 relative to the γ-Al2O3 value reveals 94% adsorption. Further assessment of the alumina separation effect for faucets shows Pb(II) precipitation from the downstream of the valve spool is below 0.16 μg L−1. About 0.12 g adsorbent is mixed with 1.0 L tap water to produce a suspension for effective soaking. The proposed method produced satisfactory results, providing a theoretical basis for authorities to exploit on heavy metal removal from kitchen faucets.

Micro-Structural and Thermoelectric Characterization of Zinc-Doped In0.6Se0.4 Crystal Grown by Direct Vapour Transport Method

Crystal of zinc-doped In0.6Se0.4 was successfully grown by direct vapour transport (DVT) method. Grown In0.6Se0.4:Zn crystal has been characterized by energy dispersive X-ray (EDAX) and powder X-ray diffractometer (XRD) techniques for compositional and micro-structural analysis, respectively. The EDAX spectra represent the grown In0.6Se0.4:Zn crystal enriched with excess indium doped with Zn, which consecutively shows enhanced n-type conductivity. The powder XRD spectrum signified that the grown sample was crystalline and had hexagonal structure. The micro-structural parameters: average crystallite size, average lattice strain, dislocation density, and domain population were determined from powder XRD spectra. The thermoelectric properties such as Seebeck coefficient (S), electrical resistivity (σ), and thermal conductivity (κ) were measured in the temperature range of 313 to 368 K. Grown In0.6Se0.4:Zn crystal reported Seebeck coefficient (S) as high as –548 μV K–1 and figure of merit of 1.14 at 368 K.

Structure, morphology and optical parameters of spray deposited CZTS thin films for solar cell applications

Objectives: To develop simple method for Cu2ZnSnS4 (CZTS) thin film deposition suitable for solar cell device application. Method: Cu2ZnSnS4 (CZTS) thin film was deposited by using simple chemical spray pyrolysis technique for substrate temperature (270±5) ◦C. Analytical reagent Grade 0.025 M Copper chloride (CuCl2), 0.0125 M zinc chloride (ZnCl2), 0.0125 M Tin chloride (SnCl4.5H2O) and 0.05 M Thiourea (SC (NH2)2) were used as sources of copper (cu+ ), zinc (Zn+), tin (Sn+ ) and sulfur (S- ) ions respectively. The structure, morphology and optical band gap of the film were investigated by using X-ray Diffractometer (XRD), Scanning Electron Micrograph (SEM) and UV-Visible spectroscopy respectively. Energy dispersive X-ray Analysis (EDX) was used for elemental analysis of deposited CZTS film. Findings: The XRD spectra showed that CZTS film exhibit polycrystalline tetragonal crystal structure with preferential orientation along (112) plane. The crystallite size calculated using full width at half maximum (FWHM) of (112) peak was to be 36.82 nm. SEM image revealed that film composed of regular arrangement of spherical granules of average size 1.61 µm. The purity of the CZTS phase was confirmed by elemental analysis. The calculated energy band gap (Eg) by using Tauc\'s plot was about 1.62 eV. The dc resistvity estimated by using IV characteristics of the CZTS film was to be 2.3× 10-2 Ω-cm. It is concluded that CZTS film prepared using present deposition technique can be used for solar cell device applications. Keywords: Chemical spray technique; CZTS Thin Films; band gap; structure of CZTS; electrical resistivity; elemental analysis

Enhance photocatalytic of hydrogen production from water-glycerol solution over RuO2-loaded

Study of hydrogen production from aqueous glycerol solution on RuO2-loaded LaNaTaO3 has been studied. This research aim is to investigate the influence of co-catalyst RuO2 and glycerol as a sacrificial reagent on the photocatalytic process of hydrogen production. La-doped NaTaO3 was prepared via sol-gel route. The RuO2 was loaded onto the LaNaTaO3 surface by impregnation method. The sample was characterization by Scanning Electron microscopy (SEM) and X-ray Diffractometer (XRD). From XRD spectrum shows that the La-NaTaO3 photocatalyst has high crystallinity. The SEM analysis indicates that the size of La-NaTaO3 photocatalyst is ranging from 100 to 250 nm without agglomeration and RuO2 as a co-catalyst is well loaded into the La-NaTaO3 surface. The rate of hydrogen production increased significantly with a glycerol concentration. Loading RuO2 on La-NaTaO3 photocatalyst is proved to increase the rate of hydrogen production of 3.2 times with the addition of glycerol as a sacrificial reagent. The highest hydrogen production activity was obtained for 0.3 wt.% ruthenium loading. The role of co-catalyst RuO2 and glycerol as a sacrificial reagent has enhanced the performance of La-NaTaO3 photocatalyst since both play an active role in the separation efficiency of electrons and holes and the reaction of hydrogen formation.

Scylla Serrata Shells Calcination using Electric Furnace and Microwave Kiln

To accommodate the rising demands for artificial bone substitutes, the possibilities of extracting calcium oxide (CaO) as precursor of hydroxyapatite (HAP) from Scylla serrata (crab) shells via electric furnace and microwave kiln heating (calcination) were investigated. The crab shells were obtained from food wastes from local restaurants in Miri, Malaysia. They were treated by calcination with temperatures of 600°C, 800°C, and 1000°C for 3 and 4 hours in electric furnace. The shells were also calcined in microwave kiln at power levels of 60%, 80% and 100% for 1 hour. Characterization on the calcined shell samples were done using Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffractometer (XRD). Based on the FTIR and XRD spectra, it was found that calcium oxide was obtained through calcination at temperatures ≥ 800°C. The results also indicated that a higher calcination temperature and duration would yield Ca O with larger crystallite size. Through calcination in microwave kiln, Ca O was readily produced when calcination was done at 60% power.

Synthesis of Carbonated Hydroxyapatite Derived from Snail Shells (Pilla ampulacea): Effect of Carbonate Precursor to the Crystallographic Properties

This study aimed to investigate the effect of the amount of carbonate in synthesis to the crystallography properties of carbonated-hydroxyapatite (CHAp) using the snail shells as the calcium source. Snail shells were cleaned, milled, and sintered at 1000°C for 4 hours to get CaO powder. CHAp synthesized by co-precipitation method. The molar ratio CO32-/PO43- was varied 0/6, 2/6, 3/6, and 6/6. Meanwhile, the molar ratio of Ca/P was kept at 1.67. After synthesis, the solution was aged, centrifugally washed, dried, and sintered at 400°C for 2 h in the air atmosphere. A scanning electron microscope (SEM) was used to observe the morphology of CHAp. An energy dispersive spectroscopy (EDS) was used to determine the chemical composition of CHAp. An X-Ray Diffractometer (XRD) was conducted to analyze the crystallography of CHAp. Fourier transform infrared (FT-IR) was used to evaluate the chemical structure of the CHAp. The XRD spectra of CHAp of all variations show they have apatite phase. There is no secondary phase observed in XRD spectra. The results of FTIR and EDS supported the XRD results. The increasing of carbonate amount in synthesis decreased the crystallinity and crystallite size of CHAp. The lattice parameter a-axis was decreased, but the lattice parameter c-axis was increased as the amount of carbonate increased in the synthesis process. The increasing of carbonate amount in synthesis decreases the crystallite size of CHAp. The results demonstrate that the amount of carbonate in synthesis affects the crystallography properties of CHAp.