scholarly journals Detonation nanodiamonds biofunctionalization and immobilization to titanium alloy surfaces as first steps towards medical application

2014 ◽  
Vol 10 ◽  
pp. 2765-2773 ◽  
Author(s):  
Juliana P L Gonçalves ◽  
Afnan Q Shaikh ◽  
Manuela Reitzig ◽  
Daria A Kovalenko ◽  
Jan Michael ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Functional Groups ◽  
Titanium Substrate ◽  
Medical Application ◽  
Carbon Surface ◽  
Detonation Synthesis ◽  
Implant Surface ◽  
Body Tissues ◽  
Biological Modification ◽  
Surface Modified

Due to their outstanding properties nanodiamonds are a promising nanoscale material in various applications such as microelectronics, polishing, optical monitoring, medicine and biotechnology. Beyond the typical diamond characteristics like extreme hardness or high thermal conductivity, they have additional benefits as intrinsic fluorescence due to lattice defects without photobleaching, obtained during the high pressure high temperature process. Further the carbon surface and its various functional groups in consequence of the synthesis, facilitate additional chemical and biological modification. In this work we present our recent results on chemical modification of the nanodiamond surface with phosphate groups and their electrochemically assisted immobilization on titanium-based materials to increase adhesion at biomaterial surfaces. The starting material is detonation nanodiamond, which exhibits a heterogeneous surface due to the functional groups resulting from the nitrogen-rich explosives and the subsequent purification steps after detonation synthesis. Nanodiamond surfaces are chemically homogenized before proceeding with further functionalization. Suspensions of resulting surface-modified nanodiamonds are applied to the titanium alloy surfaces and the nanodiamonds subsequently fixed by electrochemical immobilization. Titanium and its alloys have been widely used in bone and dental implants for being a metal that is biocompatible with body tissues and able to bind with adjacent bone during healing. In order to improve titanium material properties towards biomedical applications the authors aim to increase adhesion to bone material by incorporating nanodiamonds into the implant surface, namely the anodically grown titanium dioxide layer. Differently functionalized nanodiamonds are characterized by infrared spectroscopy and the modified titanium alloys surfaces by scanning and transmission electron microscopy. The process described shows an adsorption and immobilization of modified nanodiamonds on titanium; where aminosilanized nanodiamonds coupled with O-phosphorylethanolamine show a homogeneous interaction with the titanium substrate.

scholarly journals Ultrasound-Assisted Surface Modification of MWCNT Using Organic Acids

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 72
Author(s):  
Patricia A. de León-Martínez ◽  
Aidé Sáenz-Galindo ◽  
Carlos A. Ávila-Orta ◽  
Adalí O. Castañeda-Facio ◽  
Marlene L. Andrade-Guel ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Organic Acids ◽  
Functional Groups ◽  
Photoelectron Spectroscopy ◽  
Surface Defects ◽  
Low Frequency ◽  
Carbon Surface ◽  
X Ray ◽  
Different Types ◽  
Surface Modified

In the present work, multiple-wall carbon nanotubes (MWCNTs) were surface modified in an environmentally friendly way, using low-frequency ultrasonic energy. This type of modification was carried-out using two different types of organic acids, citric acid (CA) and oxalic acid (OA). The modification of the MWCNTs was confirmed by Fourier-transform infrared spectroscopy (FTIR), where functional groups such as OH, C=O, O–C=O and COOH were detected. By means of Raman spectroscopy, an increase in carbon surface defects was found. On the other hand, using X-ray photoelectron spectroscopy (XPS), oxidation was evidenced on the surface of the modified MWCNT. In both Raman spectroscopy and XPS, the results indicate a greater modification when CA is used, possibly due to the fact that CA has a larger number of functional groups. MWCNT-CA showed good dispersion in methanol, while MWCNT-OA showed good stability in methanol and ethanol. Finally, a 20% removal of creatinine efficiency improvement was found with respect to the unmodified MWCNTs, while no improvement was found in the case of urea and uric acid.

scholarly journals Electrochemical Evaluation of Surface Modified Free-Standing CNT Electrode for Li–O2 Battery Cathode

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4196
Author(s):  
Ji Hyeon Lee ◽  
Hyun Wook Jung ◽  
In Soo Kim ◽  
Min Park ◽  
Hyung-Seok Kim
Keyword(s):  
Functional Groups ◽  
Atomic Layer ◽  
Free Standing ◽  
Coating Technology ◽  
Oxygen Functional Groups ◽  
Layer Deposition ◽  
Discharge Product ◽  
Effect Of Oxygen ◽  
Surface Modified ◽  
Electrochemical Evaluation

In this study, carbon nanotubes (CNTs) were used as cathodes for lithium–oxygen (Li–O2) batteries to confirm the effect of oxygen functional groups present on the CNT surface on Li–O2 battery performance. A coating technology using atomic layer deposition was introduced to remove the oxygen functional groups present on the CNT surface, and ZnO without catalytic properties was adopted as a coating material to exclude the effect of catalytic reaction. An acid treatment process (H2SO4:HNO3 = 3:1) was conducted to increase the oxygen functional groups of the existing CNTs. Therefore, it was confirmed that ZnO@CNT with reduced oxygen functional groups lowered the charging overpotential by approximately 230 mV and increased the yield of Li2O2, a discharge product, by approximately 13%. Hence, we can conclude that the ZnO@CNT is suitable as a cathode material for Li–O2 batteries.

scholarly journals Effect of Air Oxidation on Texture, Surface Properties and Dye Adsorption of Wood-Derived Porous Carbon Materials

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1675 ◽  
Author(s):  
Suhong Ren ◽  
Liping Deng ◽  
Bo Zhang ◽  
Yafang Lei ◽  
Haiqing Ren ◽  
...  
Keyword(s):  
Surface Area ◽  
Functional Groups ◽  
Porous Carbon ◽  
Carbon Materials ◽  
Dye Adsorption ◽  
Carbon Surface ◽  
Air Oxidation ◽  
Activation Temperature ◽  
Porous Carbon Materials ◽  
Hierarchical Porous

Hierarchical porous carbon materials made from cork were fabricated using a facile and green method combined with air activation, without any templates and chemical agents. The influence of air activation on the texture and other surface characteristics of the carbon materials were evaluated by various characterization techniques. Results indicate that air oxidation can effectively improve the surface area and the hierarchical porous structure of carbon materials, as well as increase the number of oxygen-containing functional groups on the carbon surface. The specific surface area and the pore volume of the carbon material activated by air at 450 °C (C800-M450) can reach 580 m2/g and 0.379 cm3/g, respectively. These values are considerably higher than those for the non-activated material (C800, 376 m2/g, 0.201 cm3/g). The contents of the functional groups (C–O, C=O and O–H) increased with rising activation temperature. After air activation, the adsorption capacity of the carbon materials for methylene blue (MB) and methyl orange (MO) was increased from 7.7 and 6.4 mg/g for C800 to 312.5 and 97.1 mg/g for C800-M450, respectively. The excellent dye removal of the materials suggests that the porous carbon obtained from biomass can be potentially used for wastewater treatment.

Radiotracer Studies of Carbon Black Surface Interactions with Organic Systems. I. Experimental Approach and Initial Results from Chemisorption and Vinyl Polymerization Studies

1968 ◽  
Vol 41 (2) ◽  
pp. 382-399 ◽  
Author(s):  
Marvin L. Deviney ◽  
Lawrence E. Whittington
Keyword(s):  
Carbon Black ◽  
Functional Groups ◽  
Reaction Mechanisms ◽  
Hydrogen Abstraction ◽  
Surface Interactions ◽  
Carbon Surface ◽  
Organic Systems ◽  
Carbon Black Surface ◽  
Basic Reaction ◽  
Black Surface

Abstract Radiotracer techniques have been applied to the study of interactions of carbon black surface functional groups with two chosen organic systems. The basic reaction mechanisms demonstrated in this study may have implications in elastomer reinforcement. Direct radiochemical evidence supports the conclusions of Hallum and Drushel (based on less direct polarographic data) that surface quinonic groups exhibit hydrogen abstraction activity toward tertiary hydrogens in paraffinic hydrocarbons. Studies on the system carbon black and styrene using tritium radiotracer have provided direct evidence that phenolic hydrogens participate in the polymerization acceleration and graft polymer formation reaction and are transferred to the growing polystyrene chains as postulated by Donnet. Several methods have been developed for specifically labelling certain oxygenated functional groups on the carbon surface with tritium and for tritium labelling carbon black in aromatic hydrogen positions. The techniques developed in this work and the basic reaction mechanisms derived will permit this investigation to be extended into a radiochemical study of carbon black surface interactions with elastomer related systems of interest to the rubber industry.

scholarly journals Retraction: In vitro osteoinduction of human mesenchymal stem cells in biomimetic surface modified titanium alloy implants

2014 ◽  
Vol 33 (1) ◽  
pp. 148-148
Author(s):  
Sonia SANTANDER ◽  
Clara ALCAINE ◽  
Jaber LYAHYAI ◽  
Maria Angeles PÉREZ ◽  
Clementina RODELLAR ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Titanium Alloy ◽  
Human Mesenchymal Stem Cells ◽  
Biomimetic Surface ◽  
Surface Modified

Contact of Rough Surfaces in Ankle Implants Under Combined Normal and Twist Loading

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Mohammad Hodaei ◽  
Kambiz Farhang
Keyword(s):  
Medical Application ◽  
Roughness Effects ◽  
Implant Surface ◽  
Surface Separation ◽  
Lateral Contact ◽  
Medical Issues ◽  
The Mean ◽  
Scale Roughness ◽  
Approximate Equations ◽  
Comprehensive Study

The medical application of implant replacements to remedy the pain in joints has necessitated a comprehensive study of wear due to contact of implant surfaces. Excessive wear can lead to toxicity and other implant associated medical issues such as patient discomfort and decreased mobility. Since implant wear is the result of contact between surfaces of tibia and talus implant, it is important to establish a model that can address implant surface contact mechanics with roughness effects. In this research, a statistical contact model is developed for the interaction of tibia and talus including normal and lateral contact in which surface roughness effects are included. The model accounts for the elastic–plastic interaction of the implant surface with roughness. For this purpose, tibia and talus implants are considered as macroscopic surfaces containing micron-scale roughness. Approximate equations are obtained that relate the contact force to the mean surface separation explicitly. Closed-form equations are obtained for hysteretic energy loss in implant using the approximate equations. Such a function can serve as a very useful tool for implant designers and manufacturers. Natural frequencies of both adduction-abduction and planter-dorsiflexion rotations are obtained using nonlinear vibration analyses.

The effect of nitrogen-containing functional groups on SO2 adsorption on carbon surface: Enhanced physical adsorption interactions

2018 ◽  
Vol 677 ◽  
pp. 78-82 ◽  
Author(s):  
Zhibin Qu ◽  
Fei Sun ◽  
Xin Liu ◽  
Jihui Gao ◽  
Zhipeng Qie ◽  
...  
Keyword(s):  
Functional Groups ◽  
Physical Adsorption ◽  
Carbon Surface ◽  
So2 Adsorption ◽  
Surface Enhanced

Pebax-1657 mixed matrix membrane containing surface modified multi-walled carbon nanotubes for gas separation

RSC Advances ◽  
2016 ◽  
Vol 6 (83) ◽  
pp. 79563-79577 ◽  
Author(s):  
S. A. Habibiannejad ◽  
A. Aroujalian ◽  
A. Raisi
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Functional Groups ◽  
Gas Separation ◽  
Mixed Matrix Membrane ◽  
Mixed Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
Surface Modified ◽  
Walled Carbon Nanotubes

In this study different functional groups on the surface of carbon nanotube enhanced the performance of Pebax 1657/MWNTs.

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