Influence of surface treatment on the fluorescence of composite resins subjected to in situ bleaching

2019 ◽  
Vol 32 (1) ◽  
pp. 51-56
Author(s):  
Lourdes M G García ◽  
Ana Paula T Godoi ◽  
Osvaldo A Serra ◽  
Juliana F Lima ◽  
Leonardo P A Almeida ◽  
...  
2015 ◽  
Vol 2 ◽  
pp. 12-16
Author(s):  
Andre Afif Elossais ◽  
Gleice Gomes dos Reis ◽  
Luis Fernando Benitez Macorini ◽  
Pedro Gregol da Silva ◽  
Anna Thereza Peroba Rezende Ramos ◽  
...  

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Selda Sert ◽  
Nilgün Kızılcan

Purpose Cyclohexanone-formaldehyde resin (CFR) was in situ modified with olive pomace (OP) in the presence of sodium hydroxide. The purpose of this study is to produce eco-friendly OP modified cyclohexanone composite resins (OPCFCR) with a one-step method that has higher condensation reaction temperature than CFR. The water absorption properties, gloss value and cross-cut adhesion properties of the product were investigated. Design/methodology/approach Cyclohexanone, formalin (37% aqueous solution) and tannin were mixed and 20% aqueous NaOH solution was added to produce the resin. OP has environmentally friendly bio-based lignin, cellulose and phenolic compounds and the OP structure has been incorporated into the structure of the CFR resin during the in situ modification, such as resole resin and polysaccharide. The weights of pomace were used as 5% and 10% of the weight of cyclohexanone in cyclohexanone-formaldehyde composite resins, respectively. Findings There is an improvement in the properties of the OPCFCR produced from an agricultural waste that is very abundant in Gulf of Edremit region of Balikesir. The OPCFCRs were soluble in common organic solvents. The product OPCFCR has a dark red-brown color. Research limitations/implications The reaction mixture must be stirred continuously. Subsequently, 37% formalin was added dropwise in total while refluxing. The amount of aqueous NaOH solution is limited as the formed resin may become insoluble in common organic solvents. At the end of the reaction, a water-insoluble resin is obtained. Practical implications This study provides the application of ketonic resins. The OPCFCR containing phenolic groups may also promote the adhesive strength of a coating. Social implications These resins may be used for the preparation of adhesive. OP, with a large amount of catechol groups, was considered for reducing the formaldehyde emission level on the adhesive system. Originality/value OPCFCR has been synthesized in the presence of a base catalyst. Environmental and ecological concerns have increased the attention paid by chemical industry to renewable raw materials.


2021 ◽  
Author(s):  
Hitoshi Moriyama ◽  
Ryo Sakura ◽  
Takashi Yamaguchi ◽  
Takai Toshikazu ◽  
Yuta Yamamoto

<p>Welded joints is adopted rather than bolted joints for megastructure’s connections because the former can carry large force. However, the former has several problems, such as quality control of welding in situ, which the latter can solve. By contrast, as the load transfer ratio of each bolt becomes uneven proportionally to the number of bolts, local slip around extreme bolts occurs before the whole slip. Extreme bolts to which a large shear force is applied will break before other bolts. For utilizing the strength of all bolts, the problem is solved by improving shear deformation capacity in faying surface with novel surface treatment. Here, the treatment concepts were explored, and the coating’s effectiveness was evaluated through friction tests. The deformation capacity can be twice or more than that of conventional treatment, and the slip coefficient doesn’t depend on contact pressure. These features have the advantage to give stable slip behaviour.</p>


2014 ◽  
Vol 25 (6) ◽  
pp. 519-523 ◽  
Author(s):  
Erica Moreno Zanconato-Carvalho ◽  
João Felipe Bruniera ◽  
Natália Spadini de Faria ◽  
Vivian Colucci ◽  
Danielle Cristine Messias

Surface treatment of dentin before the bleaching procedure may affect its permeability and influence the bond strength of restorative materials. This study evaluated the influence of surface treatment before the bleaching on shear bond strength (SBT) of restorative materials to intracoronal dentin. Dentin slabs were subjected to surface treatment: no bleaching (control - CON), no surface treatment + bleaching (HP), 37% phosphoric acid + bleaching (PA) and Er:YAG laser + bleaching (L). After the bleaching procedure, specimens (n=10) were restored with: microhybrid composite resin (MH), flowable composite resin (F), and resin-modified glass-ionomer cement (RMGIC). The shear test was carried out. ANOVA and Tukey's test (α=0.05) showed significant difference for surface treatment and restorative materials (p<0.05). CON presented higher STB and was statistically different from HP (p<0.05). PA and L showed intermediate values and were statistically similar to CON and HP (p>0.05). STB for MH and F were higher than RMGIC (p<0.05), and did not differ from each other (p>0.05). The surface treatments with phosphoric acid and Er:YAG laser before the bleaching procedure provided shear bond strength at the same level of unbleached dentin and the composite resins presented superior bond strength to the intracoronal dentin.


2003 ◽  
Vol 82 (5) ◽  
pp. 736-738 ◽  
Author(s):  
H. Tang ◽  
J. A. Bardwell ◽  
J. B. Webb ◽  
S. Rolfe ◽  
Y. Liu ◽  
...  

2011 ◽  
Vol 80-81 ◽  
pp. 70-75 ◽  
Author(s):  
Bin Du ◽  
Shi Sheng Zhou ◽  
Na Li Li ◽  
Nan Wang

As an important metallic powder, aluminum powders are used widely in coating, inks and plastic industry. However, it is necessary to treat the aluminum powders first to improve the properties of weather-resistance, anti-corrosion in acidic or basic media and compatibility with resin. The methods of surface treatment of aluminum powders including encapsulation and using corrosive inhibitors are summarized. The kinds of corrosive inhibitors used in the method of corrosion inhibition and their mechanisms are also reviewed. The processes and technologies of inorganic passivation, encapsulation by polymer absorption and by in situ polymerization are introduced. The research directions of aluminum powders are also presented.


2019 ◽  
Vol 35 (6) ◽  
pp. 928-936 ◽  
Author(s):  
Bruna Marin Fronza ◽  
Steven Lewis ◽  
Parag K. Shah ◽  
Matthew D. Barros ◽  
Marcelo Giannini ◽  
...  

2018 ◽  
Vol 26 (01) ◽  
pp. 1850010
Author(s):  
Joon Ahn ◽  
Seongil Jang

The effects of oil wettability on the performance of a cyclone-type oil separator was studied through in situ experimentation and in a real refrigeration system. Based on previous research, the geometry of the oil separator in the present study was designed with an oil recovery device installed at its bottom to mount it on the actual refrigerator. The performance of the oil separator without surface treatment was predicted by applying design correlations proposed in the open literature, which were then compared with the experimental data. Through surface treatment, oleophilic or oleophobic properties were given to the inner wall and helix of the oil separator, and its performance was measured in a real refrigeration system. Oil wettability had a great effect on the performance of the oil separator, and in order to obtain high separation efficiency, oleophilic properties were found to be advantageous not only in the inner wall but also in the helix.


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