Nanoscale Surface Pretreatment of Biomedical Co–Cr Alloy

2015 ◽  
Vol 3 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Tarek M. Abdel-Fattah ◽  
Jon Derek Loftis ◽  
Anil Mahapatro
Keyword(s):  
Surface Pretreatment

scholarly journals Application of Commercial Surface Pretreatments on the Formation of Cerium Conversion Coating (CeCC) over High-Strength Aluminum Alloys 2024-T3 and 7075-T6

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 930
Author(s):  
Juan Jesús Alba-Galvín ◽  
Leandro González-Rovira ◽  
Francisco Javier Botana ◽  
Maria Lekka ◽  
Francesco Andreatta ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Salt Spray ◽  
Aluminum Matrix ◽  
Optical Emission ◽  
High Strength ◽  
Chemical Conversion ◽  
Conversion Coating ◽  
Neutral Salt ◽  
Corrosion Properties ◽  
Surface Pretreatment

The selection of appropriate surface pretreatments is one of the pending issues for the industrial application of cerium-based chemical conversion coatings (CeCC) as an alternative for toxic chromate conversion coating (CrCC). A two-step surface pretreatment based on commercial products has been successfully used here to obtain CeCC on AA2024-T3 and AA7075-T6. Specimens processed for 1 to 15 min in solutions containing CeCl3 and H2O2 have been studied by scanning electron microscopy coupled with energy-dispersive X-ray analysis (SEM-EDX), glow discharge optical emission spectroscopy (GDOES), potentiodynamic linear polarization (LP), electrochemical impedance spectroscopy (EIS), and neutral salt spray (NSS) tests. SEM-EDX showed that CeCC was firstly observed as deposits, followed by a general coverage of the surface with the formation of cracks where the coating was getting thicker. GDOES confirmed an increase of the CeCC thickness as the deposition proceed, the formation of CeCC over 7075 being faster than over 2024. There was a Ce-rich layer in both alloys and an aluminum oxide/hydroxide layer on 7075 between the upper Ce-rich layer and the aluminum matrix. According to LP and EIS, CeCC in all samples offered cathodic protection and comparable degradation in chloride-containing media. Finally, the NSS test corroborated the anti-corrosion properties of the CeCC obtained after the commercial pretreatments employed.

scholarly journals Biofilm Lithography enables high-resolution cell patterning via optogenetic adhesin expression

2018 ◽  
Vol 115 (14) ◽  
pp. 3698-3703 ◽  
Author(s):  
Xiaofan Jin ◽  
Ingmar H. Riedel-Kruse
Keyword(s):  
Escherichia Coli ◽  
Cell Patterning ◽  
Biophysical Model ◽  
Microbial Consortia ◽  
Bacterial Biofilms ◽  
Surface Pretreatment ◽  
Resolution Cell ◽  
Stimulation Of

Bacterial biofilms represent a promising opportunity for engineering of microbial communities. However, our ability to control spatial structure in biofilms remains limited. Here we engineerEscherichia coliwith a light-activated transcriptional promoter (pDawn) to optically regulate expression of an adhesin gene (Ag43). When illuminated with patterned blue light, long-term viable biofilms with spatial resolution down to 25 μm can be formed on a variety of substrates and inside enclosed culture chambers without the need for surface pretreatment. A biophysical model suggests that the patterning mechanism involves stimulation of transiently surface-adsorbed cells, lending evidence to a previously proposed role of adhesin expression during natural biofilm maturation. Overall, this tool—termed “Biofilm Lithography”—has distinct advantages over existing cell-depositing/patterning methods and provides the ability to grow structured biofilms, with applications toward an improved understanding of natural biofilm communities, as well as the engineering of living biomaterials and bottom–up approaches to microbial consortia design.

Electroless nickel bumping of aluminum bondpads. I. Surface pretreatment and activation

2002 ◽  
Vol 25 (1) ◽  
pp. 87-97 ◽  
Author(s):  
D.A. Hutt ◽  
C. Liu ◽  
P.P. Conway ◽  
D.C. Whalley ◽  
S.H. Mannan
Keyword(s):  
Electroless Nickel ◽  
Surface Pretreatment

scholarly journals The Effect of Different Disinfecting Agents on Bond Strength of Resin Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Ahmed Mohammed Hassan ◽  
Ahmed Ali Goda ◽  
Kusai Baroudi
Keyword(s):  
Bond Strength ◽  
Sodium Hypochlorite ◽  
Shear Bond Strength ◽  
Resin Composite ◽  
Testing Machine ◽  
Control Group ◽  
Posterior Teeth ◽  
Surface Pretreatment ◽  
Dentin Surface ◽  
Post Hoc

Objective. The aim of this study was to evaluate the effect of different disinfectant agents on bond strength of two types of resin composite materials.Methods. A total of 80 sound posterior teeth were used. They were divided into four groups(n=20)according to the dentin surface pretreatment (no treatment, chlorhexidine gluconate 2%, sodium hypochlorite 4%, and EDTA 19%). Each group was divided into two subgroups according to the type of adhesive (prime and bond 2.1 and Adper easy one). Each subgroup was further divided into two subgroups according to the type of resin composite (TPH spectrum and Tetric EvoCeram). Shear bond strength between dentin and resin composite was measured using Universal Testing Machine. Data collected were statistically analyzed byt-test and one-way ANOVA followed by Tukey’spost hoctest.Results. It was found that dentin treated with EDTA recorded the highest shear bond strength values followed by sodium hypochlorite and then chlorhexidine groups while the control group showed the lowest shear bond strength.Conclusions. The surface treatment of dentin before bonding application has a great effect on shear bond strength between resin composite and dentin surface.

Influence of surface pretreatment of titanium- and cobalt-based biomaterials on covalent immobilization of fibrillar collagen

Biomaterials ◽  
2006 ◽  
Vol 27 (22) ◽  
pp. 4059-4068 ◽  
Author(s):  
Rainer Müller ◽  
Jochen Abke ◽  
Edith Schnell ◽  
Dieter Scharnweber ◽  
Richard Kujat ◽  
...  
Keyword(s):  
Covalent Immobilization ◽  
Fibrillar Collagen ◽  
Surface Pretreatment

Effect of Fiber’s Surface Pretreatment on the Interfacial Bonding Strength between Steel Fiber and Resin

2014 ◽  
Vol 989-994 ◽  
pp. 177-180
Author(s):  
Hao Yang ◽  
Jian Hua Zhang ◽  
Guo Yan Sun ◽  
Yi Zhang
Keyword(s):  
Mechanical Properties ◽  
Cast Iron ◽  
Bonding Strength ◽  
Steel Fiber ◽  
Resin Composite ◽  
Interfacial Bonding ◽  
Steel Fibers ◽  
Surface Pretreatment ◽  
Interfacial Bonding Strength ◽  
Coupling Treatment

For the characteristic that the mechanical properties of resin composite are lower than cast iron, steel fibers are used to improve its properties in this paper. A weak interfacial bonding strength between steel fibers and resin indicates that steel fibers’ property cannot perform well in the polymer. In order to improve the interfacial bonding strength, four methods of surface treatment, phosphating, acid pickling, oxidation, and coupling are applied to steel fibers, and the corresponding pull-off tests are carried out to compare with untreated steel fibers. Research results show that the maximum interfacial bonding strength is increased by 45.1% after coupling treatment.

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