Structural Changes in TiO2 Films Formed by Anodizing of Electro-Polished Titanium

Anodizing is a surface modification technique that is applied to growing oxide films on Ti to accelerate the osseointegration of an implant. Besides the surface roughness, the crystalline structure of these films can affect its performance as a biomaterial. For this reason, this technique has been refined to produce crystalline films without requiring heat treatments. For this purpose, TiO2 films were grown on Ti (grade 2) by anodizing with direct current at different potentials. Images obtained by optical microscopy with polarized light revealed a granular microstructure in various colors, as consequence of different crystalline orientations of the grains and films thickness. Raman spectroscopy showed that the films crystallinity is affected by variations in the applied potential and anodizing time.

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Surface modification as a technique to improve inter-layer bonding strength in 3D printed cementitious materials

RILEM Technical Letters ◽

10.21809/rilemtechlett.2019.84 ◽

2019 ◽

Vol 4 ◽

pp. 33-38 ◽

Cited By ~ 7

Author(s):

Jolien Van Der Putten ◽

Geert De Schutter ◽

Kim Van Tittelboom

Keyword(s):

Surface Roughness ◽

Surface Modification ◽

Bonding Strength ◽

Substrate Surface ◽

Cementitious Materials ◽

Degree Of Hydration ◽

Custom Made ◽

Wire Brushing ◽

Modification Technique ◽

3D Printed

The structural capacity of 3D printed components mainly depends on the inter-layer bonding strength between the different layers. This bond strength is affected by many parameters (e.g. moisture content of the substrate, time gap, surface roughness,..) and any mismatch in properties of the cementitious material may lead to early failure. A common technique to improve inter-layer bonding strength between a substrate and a newly added layer is modifying the substrate surface. For the purpose of this research, a custom-made 3D printing apparatus is used to simulate the printing process and layered specimens with a different delay time (0 and 30 minutes) are manufactured with different surface modification techniques (wire brushing, addition of sand or cement and moisturizing substrate layer). The surface roughness was measured and the effect of the modification technique on the inter-layer-bonding strength was investigated. Results showed that the most effective way to increase the inter-layer bonding is increasing the surface roughness by a comb. This creates a kind of interlock system that will provide a higher inter-layer strength. The compressive strength is most influenced by the addition of cement, where the changing W/C-ratio will create a higher degree of hydration and consequently a higher strength.

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Powder Mixed Electric Discharge Machining: An Innovative Surface Modification Technique to Enhance Fatigue Performance and Bioactivity of β-Ti Implant for Orthopedics Application

Journal of Computing and Information Science in Engineering ◽

10.1115/1.4033901 ◽

2016 ◽

Vol 16 (4) ◽

Cited By ~ 19

Author(s):

Chander Prakash ◽

H. K. Kansal ◽

B. S. Pabla ◽

Sanjeev Puri

Keyword(s):

Surface Roughness ◽

Surface Modification ◽

Electric Discharge ◽

Fatigue Behavior ◽

Research Work ◽

Fatigue Performance ◽

Electric Discharge Machining ◽

Local Factor ◽

Modification Technique ◽

Fatigue Endurance

The development of surface modification technique has been the subject of the studies regarding the fatigue performance and biological characterization of the modified layers. In the present research work, powder mixed electric discharge machining (PMEDM) a novel nonconventional machining technique has been proposed for surface modification of β-Ti implant for orthopedics application. The surface topography and morphology like roughness, surface cracks, and recast layer thickness of each of the machined specimens were investigated using Mitutoyo surface roughness tester and field-emission scanning electron microscopy (FE-SEM), respectively. This study aims to investigate the effect of surface characteristics of PMEDM process on the fatigue performance and bioactivity of β-Ti implants and moreover a comparative analysis is made on the fatigue performance and biological activity of specimens machined with presently used machining methods like electric discharge machining (EDM) and mechanical polishing. The high cycle fatigue (HCF) performance of polished specimens was superior and had no adverse effect of microstructure on fatigue endurance. As expected, the fatigue behavior of β-Ti implant-based alloy, after undergoing EDM treatment, is poorly observed due to the microrough surface. The fatigue performance is dependent on microstructure and surface roughness of the specimens. Subsequent PMEDM process significantly improves the fatigue endurance of β-Ti implant-based alloy specimens. PMEDMed surface with micro-, sub-micro-, and nano-structured topography exhibited excellent bioactivity and improved biocompatibility. PMEDMed surface enabled better adhesion and growth of MG-63 when compared with the polished and EDMed substrate. Furthermore, the differentiation results indicated that a combination of nanoscale featured submicrorough PMEDMed surface promotes various osteoblast differentiation activities like alkaline phosphatase (ALP) activity, osteocalcin production, the local factor osteoprotegerin, which inhibits osteoclastogenesis.

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Structural and Technological Approach to Reveal the Role of the Lipid Phase in the Formation of Soy Emulsion Gels with Chia Oil

Gels ◽

10.3390/gels7020048 ◽

2021 ◽

Vol 7 (2) ◽

pp. 48

Author(s):

Ana M. Herrero ◽

Claudia Ruiz-Capillas

Keyword(s):

Raman Spectroscopy ◽

Structural Properties ◽

Structural Changes ◽

Protein Secondary Structure ◽

Lipid Phase ◽

Α Helix ◽

Β Sheet ◽

Shed Light ◽

Chia Oil

Considerable attention has been paid to emulsion gels (EGs) in recent years due to their interesting applications in food. The aim of this work is to shed light on the role played by chia oil in the technological and structural properties of EGs made from soy protein isolates (SPI) and alginate. Two systems were studied: oil-free SPI gels (SPI/G) and the corresponding SPI EGs (SPI/EG) that contain chia oil. The proximate composition, technological properties (syneresis, pH, color and texture) and structural properties using Raman spectroscopy were determined for SPI/G and SPI/EG. No noticeable (p > 0.05) syneresis was observed in either sample. The pH values were similar (p > 0.05) for SPI/G and SPI/EG, but their texture and color differed significantly depending on the presence of chia oil. SPI/EG featured significantly lower redness and more lightness and yellowness and exhibited greater puncture and gel strengths than SPI/G. Raman spectroscopy revealed significant changes in the protein secondary structure, i.e., higher (p < 0.05) α-helix and lower (p < 0.05) β-sheet, turn and unordered structures, after the incorporation of chia oil to form the corresponding SPI/EG. Apparently, there is a correlation between these structural changes and the textural modifications observed.

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Study of structural changes of gluten proteins during bread dough mixing by Raman spectroscopy

Food Chemistry ◽

10.1016/j.foodchem.2021.129916 ◽

2021 ◽

Vol 358 ◽

pp. 129916

Author(s):

Eloïse Lancelot ◽

Joran Fontaine ◽

Joëlle Grua-Priol ◽

Ali Assaf ◽

Gérald Thouand ◽

...

Keyword(s):

Raman Spectroscopy ◽

Structural Changes ◽

Bread Dough ◽

Gluten Proteins ◽

Dough Mixing

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Overview of Popular Techniques of Raman Spectroscopy and Their Potential in the Study of Plant Tissues

Molecules ◽

10.3390/molecules26061537 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1537

Author(s):

Aneta Saletnik ◽

Bogdan Saletnik ◽

Czesław Puchalski

Keyword(s):

Raman Spectroscopy ◽

Cell Walls ◽

Structural Changes ◽

Spatial Information ◽

Technological Development ◽

Analytical Techniques ◽

High Sensitivity ◽

Plant Tissues ◽

Wide Range ◽

Identification Technique

Raman spectroscopy is one of the main analytical techniques used in optical metrology. It is a vibration, marker-free technique that provides insight into the structure and composition of tissues and cells at the molecular level. Raman spectroscopy is an outstanding material identification technique. It provides spatial information of vibrations from complex biological samples which renders it a very accurate tool for the analysis of highly complex plant tissues. Raman spectra can be used as a fingerprint tool for a very wide range of compounds. Raman spectroscopy enables all the polymers that build the cell walls of plants to be tracked simultaneously; it facilitates the analysis of both the molecular composition and the molecular structure of cell walls. Due to its high sensitivity to even minute structural changes, this method is used for comparative tests. The introduction of new and improved Raman techniques by scientists as well as the constant technological development of the apparatus has resulted in an increased importance of Raman spectroscopy in the discovery and defining of tissues and the processes taking place in them.

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