scholarly journals The Quenching and Sonication Effect on the Mechanical Strength of Silver Nanowires Synthesized Using the Polyol Method

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2167
Author(s):  
Junaidi Junaidi ◽  
Muhamad Wahyudi Saputra ◽  
Roniyus Marjunus ◽  
Simon Sembiring ◽  
Sutopo Hadi

This study aims to determine the effect of fast cooling (quenching) on thermal properties, mechanical strength, morphology and size of the AgNWs. The synthesis of AgNWs was carried out at three different quenching-medium temperatures as follows: at 27 °C (ambient temperature), 0 °C (on ice), and −80 °C (in dry ice) using the polyol method at 130 °C. Furthermore, the AgNWs were sonified for 45 min to determine their mechanical strength. Scanning electron microscopy analysis showed that the quenched AgNWs had decreased significantly; at 27 °C, the AgNWs experienced a change in length from (40 ± 10) to (21 ± 6) µm, at 0 °C from (37 ± 8) to (24 ± 8) µm, and at −80 °C from (34 ± 9) to (29 ± 1) µm. The opposite occurred for their diameter with an increased quenching temperature: at 27 °C from (200 ± 10) to (210 ± 10) nm, at 0 °C from (224 ± 4) to (239 ± 8) nm, and at −80 °C from (253 ± 6) to (270 ± 10) nm. The lower the temperature of the quenching medium, the shorter the length and the higher the mechanical strength of AgNWs. The UV-Vis spectra of the AgNWs showed peak absorbances at 350 and 411 to 425 nm. Thermogravimetric analysis showed that AgNWs quenched at −80 °C have better thermal stability as their mass loss was only 2.88%, while at the quenching temperatures of 27 °C and 0 °C the mass loss was of 8.73% and 4.17%, respectively. The resulting AgNWs will then be applied to manufacture transparent conductive electrodes (TCEs) for optoelectronic applications.

2020 ◽  
Vol 12 (11) ◽  
pp. 4633
Author(s):  
Mohamad Hanafi ◽  
Abdullah Ekinci ◽  
Ertug Aydin

Marine clay deposits are commonly found worldwide. Considering the cost of dumping and related environmental concerns, an alternative solution involving the reuse of soils that have poor conditions is crucial. In this research, the authors examined the strength, microstructure, and wet–dry resistance of triple-binder composites of marine-deposited clays and compiled a corresponding database. In order to evaluate the wetting–drying resistance of the laboratory-produced samples, the accumulated mass loss (ALM) was calculated. The use of slag alone as a binder, at any percentage, increased the ALM up to 2%. However, the use of lime as the third binder seemed to accelerate the chemical reactions associated with the hydration of clay and cementitious material and to enhance the chemical stability, i.e., specimens that included both lime and slag experienced the same ALM as specimens treated with cement only. Scanning electron microscopy analysis confirmed the durability improvements of these clays. The proposed unconfined compressive strength–porosity and accumulated mass loss relationship yielded practical approximation for the fine- and coarse-grained soils blended with up to three binders until 60 days of curing. The laboratory-produced mixes showed reduction of embodied energy and embodied carbon dioxide (eCO2) emissions for the proposed models.


Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 330 ◽  
Author(s):  
Yue Shi ◽  
Liang He ◽  
Qian Deng ◽  
Quanxiao Liu ◽  
Luhai Li ◽  
...  

Flexible transparent conductive electrodes (TCEs) are widely applied in flexible electronic devices. Among these electrodes, silver (Ag) nanowires (NWs) have gained considerable interests due to their excellent electrical and optical performances. Ag NWs with a one-dimensional nanostructure have unique characteristics from those of bulk Ag. In past 10 years, researchers have proposed various synthesis methods of Ag NWs, such as ultraviolet irradiation, template method, polyol method, etc. These methods are discussed and summarized in this review, and we conclude that the advantages of the polyol method are the most obvious. This review also provides a more comprehensive description of the polyol method for the synthesis of Ag NWs, and the synthetic factors including AgNO3 concentration, addition of other metal salts and polyvinyl pyrrolidone are thoroughly elaborated. Furthermore, several problems in the fabrication of Ag NWs-based TCEs and related devices are reviewed. The prospects for applications of Ag NWs-based TCE in solar cells, electroluminescence, electrochromic devices, flexible energy storage equipment, thin-film heaters and stretchable devices are discussed and summarized in detail.


Author(s):  
Mohamad Hanafi ◽  
Abdullah Ekinci ◽  
Ertug Aydin

Marine clay deposits are commonly found worldwide. Considering the cost of dumping and the related environmental concerns, an alternative solution involving the reuse of soils that have poor conditions is crucial. In this research, the authors examined the durability of marine deposited clays and compiled a corresponding database. The use of slag alone as a binder, at any percentage, increased the accumulated mass loss (ALM) up to 2%. However, the use of lime as the third binder seemed to accelerate the chemical reactions associated with the hydration of clay and cementitious material and to enhance the chemical stability, i.e., samples that included both lime and slag experienced the same ALM as samples treated with cement only. Scanning electron microscopy analysis confirmed the durability improvements of these clays. The proposed unconfined compressive strength and accumulated mass loss relationship yielded practical approximation for the fine- and coarse-grained soils blended with up to three binders until 60 days of curing.


Author(s):  
J. P. Benedict ◽  
R. M. Anderson ◽  
S. J. Klepeis

Ion mills equipped with flood guns can perform two important functions in material analysis; they can either remove material or deposit material. The ion mill holder shown in Fig. 1 is used to remove material from the polished surface of a sample for further optical inspection or SEM ( Scanning Electron Microscopy ) analysis. The sample is attached to a pohshing stud type SEM mount and placed in the ion mill holder with the polished surface of the sample pointing straight up, as shown in Fig 2. As the holder is rotating in the ion mill, Argon ions from the flood gun are directed down at the top of the sample. The impact of Argon ions against the surface of the sample causes some of the surface material to leave the sample at a material dependent, nonuniform rate. As a result, the polished surface will begin to develop topography during milling as fast sputtering materials leave behind depressions in the polished surface.


2021 ◽  
pp. 232020682199798
Author(s):  
Beyza Unalan Degirmenci ◽  
Alperen Degirmenci ◽  
Emine Kara

Aim: Natural antioxidants were offered as the answer of dentin adhesion issue. The aim of this study is to investigate the effects of proanthocyanidin and lycopene as pretreatment agents on the sound and caries-affected dentin surface on microtensile bond strength and microleakage. Materials and Methods: This study was designed as in vitro because of that 84 mandibular molar teeth were collected. Forty-two of the included teeth were carious teeth, while the other 42 were without caries. Sixty of them were used for microleakage and 24 for microtensile bond strength testing and scanning electron microscopy analysis. The samples were divided into six subgroups randomly according to dentin pretreatments: 5% proanthocyanidin, 5% lycopene, and no antioxidant application. After the restorative procedures, samples were attached to the microtensile tester. Samples were subjected to tensile stress in the load cell until they broke at a speed of 0.5 mm per min. Microtensile bond strength (µTBS) and microleakage test data were analyzed with two-way analysis of variance, Bonferroni correction, and Tamhane’s T2 tests. Results: Two-way variance analysis showed that dentin pretreatment applications, dentin substrate, and the interaction between these two parameters had statistically significant effects on µTBS values ( P < .001). There was no difference between dentin pretreatment applications in terms of microleakage scores ( P > .05). Conclusion: The application of dentin pretreatment with proanthocyanidin is a successful procedure that increases the bond strength in both dentin substrate, while pretreatment with lycopene in caries-affected dentin reduces it.


2021 ◽  
Vol 14 (7) ◽  
pp. 686
Author(s):  
Raquel Porto ◽  
Ana C. Mengarda ◽  
Rayssa A. Cajas ◽  
Maria C. Salvadori ◽  
Fernanda S. Teixeira ◽  
...  

The intravascular parasitic worm Schistosoma mansoni is a causative agent of schistosomiasis, a disease of great global public health significance. Praziquantel is the only drug available to treat schistosomiasis and there is an urgent demand for new anthelmintic agents. Adopting a phenotypic drug screening strategy, here, we evaluated the antiparasitic properties of 46 commercially available cardiovascular drugs against S. mansoni. From these screenings, we found that amiodarone, telmisartan, propafenone, methyldopa, and doxazosin affected the viability of schistosomes in vitro, with effective concentrations of 50% (EC50) and 90% (EC90) values ranging from 8 to 50 µM. These results were further supported by scanning electron microscopy analysis. Subsequently, the most effective drug (amiodarone) was further tested in a murine model of schistosomiasis for both early and chronic S. mansoni infections using a single oral dose of 400 mg/kg or 100 mg/kg daily for five consecutive days. Amiodarone had a low efficacy in chronic infection, with the worm and egg burden reduction ranging from 10 to 30%. In contrast, amiodarone caused a significant reduction in worm and egg burden in early infection (>50%). Comparatively, treatment with amiodarone is more effective in early infection than praziquantel, demonstrating the potential role of this cardiovascular drug as an antischistosomal agent.


Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2264
Author(s):  
Raphael H. M. Reis ◽  
Fabio C. Garcia Filho ◽  
Larissa F. Nunes ◽  
Veronica S. Candido ◽  
Alisson C. R. Silva ◽  
...  

Fibers extracted from Amazonian plants that have traditionally been used by local communities to produce simple items such as ropes, nets, and rugs, are now recognized as promising composite reinforcements. This is the case for guaruman (Ischinosiphon körn) fiber, which was recently found to present potential mechanical and ballistic properties as 30 vol% reinforcement of epoxy composites. To complement these properties, Izod impact tests are now communicated in this brief report for similar composites with up to 30 vol% of guaruman fibers. A substantial increase in impact resistance, with over than 20 times the absorbed energy for the 30 vol% guaruman fiber composite, was obtained in comparison to neat epoxy. These results were statistically validated by Weibull analysis, ANOVA, and Tukey’s test. Scanning electron microscopy analysis disclosed the mechanisms responsible for the impact performance of the guaruman fiber composites.


2021 ◽  
Vol 27 (S1) ◽  
pp. 3168-3170
Author(s):  
Hazel Jaynelle Morales-Rodriguez ◽  
Javier Camarillo-Cisneros ◽  
María Alejandra Favila-Pérez ◽  
Alva Rocío Castillo-González ◽  
Celia María Quiñonez-Flores ◽  
...  

2006 ◽  
Vol 12 (S02) ◽  
pp. 1270-1271
Author(s):  
M Olszta ◽  
J Dougherty ◽  
M Horn ◽  
EC Dickey

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005


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