Investigation of a Collagen-Chitosan-Hydroxyapatite System for Novel Bone Substitutes

2007 ◽  
Vol 330-332 ◽  
pp. 415-418 ◽  
Author(s):  
Xiao Liang Wang ◽  
Xu Dong Li ◽  
Xiao Min Wang ◽  
Jian Lu ◽  
Hui Chuan Zhao ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Bone Substitutes ◽  
Nano Materials ◽  
Natural Polymers ◽  
Uniform Dispersion ◽  
Obvious Phase Separation ◽  
Ft Ir ◽  
Main Components

Collagen (Col) and chitosan (Chi) are both natural polymers and have received extensive investigation in recent years in the field of tissue engineering, but there are few reports on the introduction of hydroxyapatite (HA) into the Col-Ch system. In this study, based on the miscibility of these two polymers under proper condition, hydroxyapatite (HA) was synthesis in the Col-Chi system by in-situ co-precipitate method to give rise to a novel nanocomposite. The structural characterization of such Col-Ch-HA nano-materials was carried out by using FT-IR, XRD, SEM and TGA analyses with main components and Col-Chi samples used for comparison. It was found that there exist interactions between Col and Chi molecules. The nucleation and growth of inorganic phase occurs in the Col-Chi system and final products are uniform dispersion of nano-sized HA in the Col-Chi network without obvious phase separation. This novel nanocomposite would be a promising material for bone tissue engineering.

Diffuse Reflectance FT-IR Characterization of Active Sites under Reaction Conditions: The Production of Oxygenates in the CO/H2 Reaction

1994 ◽  
Vol 48 (10) ◽  
pp. 1208-1212 ◽  
Author(s):  
J. J. Benítez ◽  
I. Carrizosa ◽  
J. A. Odriozola
Keyword(s):  
Infrared Spectra ◽  
Active Sites ◽  
Diffuse Reflectance ◽  
Reaction Conditions ◽  
In Situ Drifts ◽  
Ft Ir

The reactivity of a Lu2O3-promoted Rh/Al2O3 catalyst in the CO/H2 reaction is reported. Methane, heavier hydrocarbons, methanol, and ethanol are obtained. In situ DRIFTS has been employed to record the infrared spectra under the actual reaction conditions. The structure of the observed COads DRIFTS bands has been resolved into its components. The production of oxygenates (methanol and ethanol) has been correlated with the results of the deconvolution calculation. Specific sites for the production of methanol and ethanol in the CO/H2 reaction over a Rh,Lu2O3/Al2O3 catalyst are proposed.

scholarly journals Characterization of the Physical, Chemical, and Adsorption Properties of Coal-Fly-Ash–Hydroxyapatite Composites

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 774
Author(s):  
Eleonora Sočo ◽  
Dorota Papciak ◽  
Magdalena M. Michel ◽  
Dariusz Pająk ◽  
Andżelika Domoń ◽  
...  
Keyword(s):  
Fly Ash ◽  
Coal Fly Ash ◽  
Thermal Power ◽  
Synthesis Conditions ◽  
High Calcium ◽  
Ft Ir ◽  
Ir Analysis ◽  
Wet Synthesis

(1) Hydroxyapatite (Hap), which can be obtained by several methods, is known to be a good adsorbent. Coal fly ash (CFA) is a commonly reused byproduct also used in environmental applications as an adsorbent. We sought to answer the following question: Can CFA be included in the method of Hap wet synthesis to produce a composite capable of adsorbing both heavy metals and dyes? (2) High calcium lignite CFA from the thermal power plant in Bełchatów (Poland) was used as the base to prepare CFA–Hap composites. Four types designated CFA–Hap1–4 were synthesized via the wet method of in situ precipitation. The synthesis conditions differed in terms of the calcium reactants used, pH, and temperature. We also investigated the equilibrium adsorption of Cu(II) and rhodamine B (RB) on CFA–Hap1–4. The data were fitted using the Langmuir, Freundlich, and Redlich–Peterson models and validated using R2 and χ2/DoF. Surface changes in CFA–Hap2 following Cu(II) and RB adsorption were assessed using SEM, SE, and FT-IR analysis. (3) The obtained composites contained hydroxyapatite (Ca/P 1.67) and aluminosilicates. The mode of Cu(II) and RB adsorption could be explained by the Redlich–Peterson model. The CFA–Hap2 obtained using CFA, Ca(NO3)2, and (NH4)2HPO4 at RT and pH 11 exhibited the highest maximal adsorption capacity: 73.6 mg Cu/g and 87.0 mg RB/g. (4) The clear advantage of chemisorption over physisorption was indicated by the Cu(II)–CFA–Hap system. The RB molecules present in the form of uncharged lactone were favorably adsorbed even on strongly deprotonated CFA–Hap surfaces.

scholarly journals Design and Biophysical Characterization of Poly (l-Lactic) Acid Microcarriers with and without Modification of Chitosan and Nanohydroxyapatite

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1061 ◽  
Author(s):  
Liying Li ◽  
Kedong Song ◽  
Yongzhi Chen ◽  
Yiwei Wang ◽  
Fangxin Shi ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Cell Culture ◽  
Lactic Acid ◽  
Average Diameter ◽  
Natural Polymers ◽  
Promoting Effect ◽  
Biophysical Characterization ◽  
Promising Tool ◽  
Cell Carrier

Nowadays, microcarriers are widely utilized in drug delivery, defect filling, and cell culture. Also, many researchers focus on the combination of synthetic and natural polymers and bioactive ceramics to prepare composite biomaterials for tissue engineering and regeneration. In this study, three kinds of microcarriers were prepared based on physical doping and surface modification, named Poly (l-lactic) acid (PLLA), PLLA/nanohydroxyapatite (PLLA/nHA), and PLLA/nHA/Chitosan (PLLA/nHA/Ch). The physicochemical properties of the microcarriers and their functional performances in MC3T3-E1 cell culture were compared. Statistical results showed that the average diameter of PLLA microcarriers was 291.9 ± 30.7 μm, and that of PLLA/nHA and PLLA/nHA/Ch microcarriers decreased to 275.7 ± 30.6 μm and 269.4 ± 26.3 μm, respectively. The surface roughness and protein adsorption of microcarriers were enhanced with the doping of nHA and coating of chitosan. The cell-carrier cultivation stated that the PLLA/nHA microcarriers had the greatest proliferation-promoting effect, while the PLLA/nHA/Ch microcarriers performed the strongest attachment with MC3T3-E1 cells. Besides, the cells on the PLLA/nHA/Ch microcarriers exhibited optimal osteogenic expression. Generally, chitosan was found to improve microcarriers with superior characteristics in cell adhesion and differentiation, and nanohydroxyapatite was beneficial for microcarriers regarding sphericity and cell proliferation. Overall, the modified microcarriers may be considered as a promising tool for bone tissue engineering.

scholarly journals Antibacterial Properties of Biofilm Schiff Base Derived from Dialdehyde Cellulose and Chitosan

2019 ◽  
Vol 19 (2) ◽  
pp. 405
Author(s):  
Agung Pratama ◽  
Firman Sebayang ◽  
Rumondang Bulan Nasution
Keyword(s):  
Tensile Strength ◽  
Antibacterial Activity ◽  
Schiff Base ◽  
Antibacterial Properties ◽  
Oxidized Cellulose ◽  
Natural Polymers ◽  
Dialdehyde Cellulose ◽  
Ft Ir ◽  
Ir Analysis

Cellulose and chitosan are natural polymers that have been used as biocomposite. The aim of this research is to obtain biofilms from chitosan and oxidized cellulose crosslinks. This research is divided into three steps, i.e., isolation of cellulose from oil palm trunk and oxidation of cellulose using NaIO4 (0.2; 0.4; 0.6; 0.8; 1.0 mg/mL) to obtain dialdehyde cellulose (DAC), crosslink of oxidized cellulose with chitosan (DD = 72.85%) to obtain biofilm of chitosan/DAC (CDAC), and characterization of biofilms. The crosslinked reaction was confirmed by FT-IR analysis that showed the spectrum of Schiff base C=N group at 1651 cm–1. Tensile strength increased gradually when the NaIO4 concentration used was 0.2–0.6 mg/mL, but after those concentrations, the tensile strength slightly decreased. The morphology analysis showed that CDAC had smoother morphology than DAC, which was shown rough and showed some particle indicated the presence of unreacted cellulose. CDAC biofilms that prepared with 1.0 mg/mL NaIO4 showed the greatest antibacterial activity.

Design and Fabrication of a Multi-Functional Nanomanipulator

2009 ◽  
Vol 419-420 ◽  
pp. 21-24
Author(s):  
Ming Chang ◽  
Chia Hung Lin ◽  
Chung Po Lin ◽  
Juti Rani Deka
Keyword(s):  
Degrees Of Freedom ◽  
Electrical Characterization ◽  
The Body ◽  
Rapid Expansion ◽  
Nano Materials ◽  
Nano Fabrication ◽  
Permissible Range ◽  
Manipulation System

With rapid expansion of nanotechnology, microminiaturization has become imperative in the field of micro/nano fabrication. A nanomanipulation system with high degrees of freedom that can perform nanomachining, nanofabrication and mechanical/electrical characterization of nanoscale objects inside a scanning electron microscope (SEM) is presented. The manipulation system consists of several individual operating units each having three linear stages and one rotational stage. The body of the manipulator is designed using the idea of superposition. Each operating unit can move in the permissible range of SEM’s vacuum chamber and can increase or decrease the number of units according to the requirement. Experiments were executed to investigate the in-situ electrical resistance of nano materials.

Characterization of Catalytic Supports by Infrared Spectroscopy and ESCA

1982 ◽  
Vol 36 (4) ◽  
pp. 361-368 ◽  
Author(s):  
Larry F. Wieserman ◽  
David M. Hercules
Keyword(s):  
Infrared Spectroscopy ◽  
Surface Area ◽  
Elevated Temperatures ◽  
Silica Alumina ◽  
Free Hydroxyl ◽  
Ft Ir ◽  
Catalytic Supports ◽  
Silica And Titania

This study compares the properties of γ-alumina, silica, and titania using ESCA and in situ FT-IR. The FWHM's of the O1s and metal 2p ESCA peaks increased systematically from titania to γ alumina; the O1s/metal 2p ESCA peak area ratios were nearly equal for γ-alumina and silica. For titania, however, the value was half that obtained for γ-alumina. In situ FT-IR showed hydroxyl bands with increasing frequencies from titania to silica. Alumina and titania form carbonate-type structures after exposure to CO at elevated temperatures. Silica exhibited no additional bands after CO treatment that could be assigned to physically adsorbed CO or carbonate-type structures. At 100°C, there is a direct correlation between the specific surface area and the intensity of infrared absorbance of the free-hydroxyl and the hydrogen-bonded hydroxyl bands for silica. The intensities of the infrared bands due to matrix modes were not affected by surface area.

Characterization of the Aniline.DBSA/Thermoplastic Polyurethane Blends for the Thermo-Mechanical and Electro-Mechanical Properties

2021 ◽  
Vol 875 ◽  
pp. 96-103
Author(s):  
Ayesha Afzal ◽  
Iqra Abdul Rashid ◽  
H.M. Faizan Shakir ◽  
Asra Tariq
Keyword(s):  
Mechanical Properties ◽  
Thermoplastic Polyurethane ◽  
Strain Sensors ◽  
Sem Images ◽  
Dynamic Mechanical Thermal Analyzer ◽  
Thermal Analyzer ◽  
Uniform Dispersion ◽  
Polymerization Method

Conducting polymer blends Polyaniline-Dodecylbenzene sulfonic acid (Pani.DBSA) and thermoplastic polyurethane (TPU) were prepared using in-situ emulsion polymerization method by dissolving both components in DMF. Ani.DBSA/TPU blends were prepared with different compositions 20/80, 30/70, 40/60 and 50/50 wt%. Theses blends have good conducting and mechanical properties. Blends were characterized by Potentiostate, Thermogravimetric analysis (TGA), Infrared spectroscopy (FTIR) and Dynamic mechanical thermal analyzer (DMTA). The electrical conductivity increases up to 30 wt% loading of aniline.DBSA after that it decreases gradually. The uniform dispersion of aniline.DBSA showed in SEM images which is the indication of a strong connection between aniline.DBSA and TPU which increase the conductivity. These blends can be used as strain sensors.

scholarly journals Hydrogenative Cyclization of Levulinic Acid to γ-Valerolactone with Methanol and Ni-Fe Bimetallic Catalysts

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1096
Author(s):  
Ligang Luo ◽  
Xiao Han ◽  
Qin Zeng
Keyword(s):  
Photoelectron Spectroscopy ◽  
Levulinic Acid ◽  
Hydrogen Donor ◽  
Effect Of Temperature ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir ◽  
Temperature Programmed

A series of Ni-Fe/SBA-15 catalysts was prepared and tested for the catalytic hydrogenation of levulinic acid to γ-valerolactone, adopting methanol as the only hydrogen donor, and investigating the synergism between Fe and Ni, both supported on SBA-15, towards this reaction. The characterization of the synthesized catalysts was carried out by XRD (X-ray powder diffraction), TEM (transmission electron microscopy), H2-TPD (hydrogen temperature-programmed desorption), XPS (X-ray photoelectron spectroscopy), and in situ FT-IR (Fourier transform–infrared spectroscopy) techniques. H2-TPD and XPS results have shown that electron transfer occurs from Fe to Ni, which is helpful both for the activation of the C=O bond and for the dissociative activation of H2 molecules, also in agreement with the results of the in situ FT-IR spectroscopy. The effect of temperature and reaction time on γ-valerolactone production was also investigated, identifying the best reaction conditions at 200 °C and 180 min, allowing for the complete conversion of levulinic acid and the complete selectivity to γ-valerolactone. Moreover, methanol was identified as an efficient hydrogen donor, if used in combination with the Ni-Fe/SBA-15 catalyst. The obtained results are promising, especially if compared with those obtained with the traditional and more expensive molecular hydrogen and noble-based catalysts.

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