Monday, January 27, 2020

Solvothermal Preparation of CaTiO3 Prism and CaTi2O4(OH)2

Solvothermal Preparation of CaTiO3 Prism and CaTi2O4(OH)2 Solvothermal preparation of CaTiO3 prism and CaTi2O4(OH)2 nanosheet by a facile surfactantfree method Weixia Dong, Gaoling Zhao, Bao Qifu, Gu Xingyong, Gaorong Han Abstract: Calcium titanate (CaTiO3) with prism-like-shaped morphology were synthesized by a simple solvorthermal process without any surfactants. It is found that NaOH concentration plays an important role in the formation of CaTiO3 prisms. A rational mechanism is proposed to illustrate the growth of CaTiO3 prisms. And the CaTi2O4(OH)2 interlaminar structure is illustrated. Keywords: solvorthermal preparation, surfactant-free, CaTiO3 prism, CaTi2O4(OH)2 interlaminar structure Introduction Due to its widespread potential applications in a lot fields, calcium titanium oxides have been considered as one of the most important inorganic materials. The most classic model for shape control is the Wulff facets argument or Gibbs-Curie-Wulff theorem, which suggests that the shape of a crystal depends on the relative specific surface energy of each face or facet of the crystal 1. However, our experiment results show that this pure thermodynamic can not explain well. It can be the concentration of existing monomers by tuning NaOH concentration plays a key role for the evolution of the shapes and phases of the calcium titanium oxide crystals 2. If the pH values can be well-controlled, the growth of crystals with different morphologies should be possible. As a result, the concentration of the remaining monomers after the nucleation process is dependent on the number of nuclei formed. To maintain the correct pH of the solvorthermal system, it is necessary to use alkaline or acidity mineralizers (i.e. pH adjusting agents). NaOH or HNO3 are most convenient for this purpose. However, intermediates are often observed during the preparation of CaTiO3. The presence of this impurity phase significantly affects the material’s properties and, thus, it should be avoided. Therefore, it is worthwhile to compare NaOH concentration that are necessary to obtain phase-pure caltium oxides 3. In the present work, calcium tantium oxides was prepared by a solvorthermal method by tuning NaOH concentration. A rational mechanism is proposed to illustrate the growth of CaTiO3 prisms. And the CaTi2O4(OH)2 interlaminar structure is analysised by XRD, SEM and FT-IR . Experimental procedure Synthesis The CaTiO3 crystals were synthesized in an aqueous medium by a solvothermal route. In a typical synthesis, 0.01mol Ti(OC4H9)4 (Sigma Aldrich, 99%) were mixed with molar ratio of water/enthonal=10/10. In particular, pH value of deionized water was adjusted 1 by adding HNO3. Then added to 10 ml of a 1 M CaCl2 ·5H2O solution under vigorous stirring at room temperature. After the solution was stirred for 5 min, various NaOH concentration (0.005 M, 0.01 M, 1 M, 3 M, 5 M, 7 M) was added to adjust the pH. Subsequently, the autoclave was sealed and maintained at180  °C for 36 h, followed by natural cooling to room temperature. Afterward, the final products were centrifuged, washed with deionized water and absolute ethanol several times, and then dried at 80  °C for 15 h in air. Characterization The morphologies of the powders were investigated by field emission scanning electron microscopy (FESEM, Hitachi S-4800, Japan). The crystal phases of the products were characterized by X-ray diffraction (XRD, PANalytical X’Pert Pro, Holland), in a 2ÃŽ ¸ range from 100 to 800, using Cu-Ka radiation. UV–Vis absorption was measured by a TU-1901 spectrophotometer equipped with a reflectance attachment and BaSO4 was used as the reference material. Infrared spectra of the samples were obtained using a Nicolet Nexus 470 Fourier transform infrared (FT-IR) spectrometer in the 400-4000 cm1 region by KBr pellet. Results and discussion We have systematically investigated the system in various NaOH concentrations while keeping the other reaction conditions unchanged, as shown in Fig. 1 and Fig. 2. Fig. 1 XRD patterns of samples synthesized at different NaOH concentrations: (a) 0.005 M, (b) 0.01 M, (c) 1 M, (d) 3 M, (e) 5 M, (f) 7 M. Fig. 1 shows the XRD patterns of the samples synthesized in various NaOH concentrations. When NaOH concentrations is 0.005 M, the sample is CaTi2O5 (JCPDS card 25-1450) phase. When NaOH concentrations is 0.01 M, the sample is pure CaTi2O4(OH)2 (JCPDS card 39-0357) phase (Fig. 1(b)). When NaOH concentrations increases to 1 M, intensity of CaTi2O4(OH)2 phase increases. Further increasing NaOH concentration to 3 M, CaTi2O4(OH)2 phase disappears and CaTiO3 (JCPDS card 42-0423) appears with a little trace of Ti3O5 and Ti4O7. When NaOH concentrations is above 5 M, pure CaTiO3 is obtained and peak intenisity of CaTiO3 further increases, which indicates well crystallized. Fig. 2 FESEM images of the samples synthesized at different NaOH concentrations: (a) 0.005M, (b) 0.01M, (c) 1M, (d) 3M, (e) 5 M, (f) 7 M. When NaOH concentrations is 0.005 M, CaTi2O5 aggregated particles are obtained (Fig. 2(a)). When NaOH concentrations is 0.01 M, CaTi2O4(OH)2 porous needlelike and floating irregular clouds-like particles are obtained (Fig. 2(b)). When the NaOH concentrations are 1 M, CaTi2O4(OH)2 morpholgy is mainly composed of overlap leaves (Fig. 2(c)). When the NaOH concentrations are 3 M, nanosheets disspeared, and a lot of aggregated particles with a little trace of prisms(Fig. 2(d)). Whereas above 5 M, CaTiO3 rectangular prisms were formed (Fig. 2 (e)-(f)). On the basis of all the above observations, it is indicated that the presence of NaOH concentrtion in the solution is necessary for the formation of calcium titanium oxides. From the viewpoint of the chemical composition effect, the NaOH concentration may influence the combination of free Ca2+ and release Ti4+ ions of TiO2 in the solvothermal process [4]. Due to forming a lower amounts of active OH ions and small amounts of TiO2 soluble species in low NaOH concentration (0.005M, 0.01M), reactive Ca2+ and TiO2 causes the reaction to be controlled by the transport of TiO2 soluble species from hydroxide crystals to an interface bearing reactive Ca species. A shortage of TiO2 soluble species near Ca2+ will halt the reaction to form CaTiO3. Instead, owing to the small solubility of titanium dioxide in the acid conditions, CaTi2O5 forms. Increasing NaOH to 0.01M, the solvothermal processing accelerate the TiO2 formation and promote TiO2 to transform small amounts of Ti4+ ions [4-5], which are involved in a reaction with Ca2+à ¯Ã‚ ¼Ã…’leading to the formation of CaTi2O4(OH)2 crystallites. However, a large amount of Ti(OH)4 was formed when NaOH concentration was increased to 1M, O-H group of TiO6 octahedron free end decreases, the probability of Ca2+ into the lattice of the increase, the formation of tetragonal CaTiO3 particles. With the increase of NaOH concentration to 5 M, i. e. in the high OH ion concentration, because of solvothermal synthesis of CaTiO3 crystal defects and grain size effect, CaTiO3 particles are formed. For the cubic phase CaTiO3, (110) and (100) surfaces can exist at the same time, gamma (110) is slightly larger than the gamma (100) crystal[3-4], which makes the tetragonal CaTiO3 nanocrystals along (110) plane and (100) surface growth, so CaTiO3 particles will give priority to the relatively low surface energy (100) surface growth, resulting in the formation of prism. Further increasing NaOH concentration, prism further Ostwald ripening, formi ng distinct edges and corners of CaTiO3 prisms [3-4]. A detailed time study is obvious for the growth process of the CaTiO3 prism in the case of 7 M NaOH. Unfortunately the experiments show the CaTiO3 prism are quickly fromed due to the fast growth rate, which prevents the direct observations of its detailed growth process. Howerver, based on the morphology evolution (Fig. 2(a)-(f)) , the growth process of CaTiO3 prism by the solvothermal process with 7 M NaOH is simply illustrated in Fig. 3. Fig. 3 Schematic representation of the growing process of CaTiO3 prism-like structures. In previous researches, our work found that CaTi2O4(OH)2 may have photocatalytic and electrochemical properties [5-6]. On view of the potential application, the structure of CaTi2O4(OH)2 is what we want. Fig. 4 shows FT-IR spectra in the range of 400-4000 cm–1 of CaTi2O4(OH)2 sample. The peaks at 3425 cm1 can be attributed to the O-H stretching. Compared with free –OH ( 3600 cm-1 )à ¯Ã‚ ¼Ã…’the absorption peak shifts to low wavelength, which is due to the coordinated water molecules via hydrogen bonding interaction to the CO32- of the interlamination [5]. The broad absorption band observed at 3200 cm-1 is originated from the presence of hydroxyl groups of water 7. The absorption peak at 1538 cm-1 attributes to H-O-H bending of the lattice water 8. The sharp absorption peak at 1357 cm-1 attributes to C-O-C bending of carbonate ion. A band centered at 750 cm-1, which is attributed to isolated tetrahedron TiO4 stretching vibration. The absorption bands below 500 cm-1, i . e. bands centered at 495 and 425 cm-1 can be ascribed to Ca-Ti-O bending vibrations 8. From XRD and FT-IR results, the interlamination contains CO32-, H2O, isolated tetrahedron TiO4 and –OH ions, Fig. 5 shows diagrammatic sketch of CaTi2O4(OH) 2 sample. Fig. 4 FT-IR spectra in the range of 400-4000 cm–1 of CaTi2O4(OH)2 sample. Fig. 5 Diagrammatic sketch of CaTi2O4(OH)2 sample. Conclusion In summary, we report here a simple solvothermal process for the formation of pure calcium tantium oxides without any surfactants. It is also found that the appropriate concentration of NaOH is vital for the formation of CaTiO3 prism. A possible mechanism has been proposed to explain the formation of CaTiO3 prism. And the CaTi2O4(OH) 2 interlaminar structure is illustrated. Acknowledgement The present work was supported by the National Natural Science Foundation (Grant No. 51262014 and 51172201). References H. Hosono, Y. Mishima, H. Takezoe and K. J. D. MacKenzie. ‘Nanomaterials: From Research to Applications’ Elsevier Ltd., Oxford, 2006, pp. 206 W. Dong, B. Song, G. Zhao and G. Han. ‘Effects of pH on morphosynthesis and properties of calcium titanium oxides via a facile aqueous strategy’, Mater. Res. Bull., 2013,11, 4633-4640 Y. J. Huang, H. T. Chiu, C.Y. Lee, Growth of CaTiO3 dendrites and rectangular prisms through a wet chemical method, CrystEngComm, 11 (2009)1904–1909. W. Dong, G. Zhao, B. Song, G. Xu, J. Zhou and G. Han. ‘Surfactant-free fabrication of CaTiO3 butterfly-like dendrite via a simple one-step solvothermal route’, CrystEngComm, 2012, 14, 6990 6997. W. Dong, B. Song, G. Zhao, and G. Han. ‘Controllable synthesis of CaTi2O4(OH) 2 nanoflakes by a facile template-free process and its properties’, Ceram. Int., 2013, 39, 6795-6803. W. Dong, B. Song, G. Zhao, and G. Han. ‘Synthesis and Characterization of CaTi2O4(OH) 2 Nanosheets for Lithium-Ion Battery’. INT. J. ELECTR. SCI., 2013, 8, 4551-4559 G. M. Duffy, S. C. Pillai and D. E. McCormack, J. Mater. Chem. 2007, 17, 181-184. K. Nakamoto. ‘Infrared and Raman Spectra of Inorganic and Coordination Compounds’, Fifth edn, Wiley, Toronto, 1997, pp.67-78.

Saturday, January 18, 2020

Advertising Paragraph Tenth Essay

Advertising is one of the best ways to get consumers’ attention. When the ad is spiced up with handsome men and beautiful women enjoying the great outdoors, people are likely to take a look at the ad, thinking it may be for a nice vacation or possibly for something healthy, but to the consumers’ surprise, it’s an ad for â€Å"Newport† cigarettes. How does this affect the audience? By creating an environment on the ad that is bright, lively and colorful, along with attractive men and women, it really gets the consumer’s attention well. The cigarette companies have used this strategy for years to reach their audiences, and the â€Å"Newport† ad is no different. The advertisement for â€Å"Newport† brand cigarettes does a good job of getting the consumers’ attention and even selling cigarettes in general, but when it comes to the advertisement of its own brand, the ad really lacks effectiveness. Looking at the picture, the only par t of the ad that sells the â€Å"Newport† brand are the three small packs of cigarettes in the top right corner and the word â€Å"Newport.† Everything else in the picture is just for getting the consumers’ attention. The main target audiences for this product are most likely avid male smokers, however, the ad can be geared towards both sexes. By showing the man running in front of the woman with the boogie board, he becomes the focal point. When looking at the picture, with the three packs of cigarettes and the text â€Å"pleasure† sitting directly above the man’s head along with the phrase â€Å"fire it up† pointing directly to the male, really shows how much more attention they want on or even from males. Also, by matching the colors of the man’s bathing suit, boogie board and the text, shows that the ad is more interested in helping the consumer focus on the man rather than the woman. It is because of these points that the ad fails to sell the â€Å"Newport† brand to both sexes. Another reason this ad fails to sell its product well is because it seems they put more attention i nto the picture, its surroundings and exaggerations, rather than the actual product â€Å"Newport† cigarettes. It seems they are depicting that even when the consumer smokes cigarettes, he or she can have a sexy, toned, muscular body and feel great all the time. This obviously is not true, considering that cigarettes contribute to weight gain, loss of respiratory stamina and many forms of cancer. Along with these disadvantages come stained teeth and bad breath, which all accompany the true criteria of an  everyday smoker. One of the most interesting selling points in this picture are the words â€Å"fire it up† posted right above the surgeon general’s warning. Positioning these words above the warning is a gross example of how much the cigarette companies don’t care about the negative effects their cigarettes have on their customers. Knowing that their product kills hundreds of thousands of people a year and permanently disables thousands of others, their decision to place this phrase above such a serious warning tells me that they want to convince the consumer to completely disregard how unsafe cigarettes really are. Also, the fact that the phrase â€Å"fire it up† does not include any information about the â€Å"Newport† brand cigarette itself also shows that the company really failed to sell its own brand. For an avid male smoker such as my-self, this ad does what it is intended to do. It makes us think to ourselves, â€Å"man, I could really go for a cigarette.† The ad does this well by setting a trigger off inside the consumer’s head, to start thinking about cigarettes. Unfortunately, when it comes to the advertisement selling its own brand, the ad really falls short, since the company producing the ad put more money into making the advertisement visually appealing rather than focusing on selling their own brand. In the future, it would be more advantageous for the company, if they focused more on integrating the specific benefits of using their brand over others, rather than creating an â€Å"eye pleasing† advertisement.

Friday, January 10, 2020

Amy Chua Analysis Essay

Reader: Parents from the Western World, who are also readers of The Wall Street Journal. Language: Well written text, with an extensive vocabulary. It is written to some extent with formal jargon. Circumstances: The writer’s home. She lives with her daughters and husband. There is a flashback into Chua’s childhood as well. Intention: She is trying to clarify the differences between Chinese parents and Western parents, along with making us understand the Chinese parents’ mindset and approach. 2) â€Å"Why Chinese Mothers Are Superior† is an article written by Amy Chua. Chua is a professor at Yale, she is the mother of two daughters and she is married to a â€Å"western† man. They live in the USA, but what makes her different is her upbringing. She is from a Chinese family. Throughout her upbringing she has been raised by Chinese methods. Currently being an adult and a parent herself, she has written an article in which she supports and simultaneously explains the significance of Chinese parents. Throughout the text she uses the three modes of appeal. She starts out by using ethos: â€Å"Amy Chua is a professor at Yale Law School, USA.† and â€Å"Well, I can tell them, because I’ve done it.† By pointing out her job, education and being a Chinese parent herself in the introduction, she lets the readers know that she is a reliable source. Then (line 41-43) she uses pathos, and tries to make Western parents feel ashamed of their parenting ha bits. In addition to that, with displaying â€Å"†¦western kids are more likely to participate in sports teams.† she thinks that it is easier for Western parents to let their kids play sports, instead of spending time with them. Chua uses logos, but pathos as well in (line 50-53). Any person can relate to her statement, and bit by bit persuades the reader to understand her parenting approach. In the following passage (line 54-59) she creates and strengthens her ethos by using a harsh metaphor, and in that way exposes the reader to the way she was raised. In the passage (line 65-69) she creates pathos by using contrasts as a topological feature; Chua makes the reader aware of how honest and real Chinese parents are to their kids in contrast to Western parents. â€Å"In other words, Western parents are concerned about their children’s psyches. Chinese parents aren’t. They assume strength, not fragility, and as a result they behave very differently.† Chua proves this statement with the following passages (line 78-92), where she creates logos by using comparisons as a topological feature, and antithesis as a linguistic feature. Later in the text (line 99-105) she uses pathos, but the whole passage backfires on Chua, because of Chinese parentsà ¢â‚¬â„¢ very overwhelming and disturbing view on parenting. Afterwards (line 125-137) she creates pathos by being mean towards her daughter, and her behavior makes Chua distant from the reader. Subsequent (line 156-165) she straightens up the situation by creating pathos again. â€Å"After the rain, the rainbow appears†, this time she describes her daughter’s success and happiness as a result of the hard working days. At last in the final passage (line 176-181) she concludes her article by creating pathos. By doing that she makes the reader feel, as the writer has achieved her goal of making Western readers understand Chinese parenting. But also lets the reader know, even though Chinese and Western are very different types of parents, there are in spite of everything some resemblances. From line 75-77 Chua uses antithesis to explain what some of the differences are between the Chinese and Western parents and how their mindsets are the total opposite. In line 90 she uses the phrase â€Å"†¦ hair – tearing explosion.† By using a metaphor, she makes it clear to the reader, how horrible the parents’ reaction is going to be. In line 121, once again she uses a metaphor â€Å"†¦ drilling each of her hands.† Her intention with this is to exaggerate how long and hard they worked on her daughter’s piano skills. In line 91 she says: â€Å"†¦ maybe hundreds of practice tests†. In this example the hyperbole is used in order to demonstrate the reader how much time the Chinese mother will dedicate to her daughter’s grade.

Thursday, January 2, 2020

`` Rebel Music `` By Daniel Felsenfeld - 869 Words

Most humans want to learn things as they grow, because of the need to adapt and evolve as the landscape changes around them. As a person grows, the need to either learn a skill or perfect an ability to complete a task is increased. In Daniel Felsenfeld’s story, â€Å"Rebel Music†, he describes the music literacy he developed throughout his teenage years. This was due to him finding another genre of music that garnered his attention turning him to become a composer of classical music. In Shannon Nichols story, â€Å"Proficiency†, she mentions developing a nonchalant attitude toward reading and writing due to failing a proficiency test multiple times. In many ways, I can certainly relate to them in terms of Felsenfeld developing a new attitude towards classical music. As well as Nichols having a nonchalant attitude towards reading and writing. Compared to Felsenfeld, during a time in my life when I grew very weary of today’s southern mumble hip hop, I found myself becoming a huge fan of 90’s hip hop, and that has given me the urge to possibly purse a career in hip hop. Continuing, we both started to take interest in music that other’s in our communities didn’t listen to at the same age of 17. On the other hand, when comparing my literacy development to Nichols we both developed nonchalant attitudes after experiencing failure. She developed that trait after failing a test multiple times, but I developed a nonchalant attitude when trying to write out lyrics that contain complex rhymes andShow MoreRelatedArtifacts Essay1476 Words   |  6 PagesHow Gymnastics Influenced My Life In â€Å"Rebel Music†, Daniel Felsenfeld delves into the inspirations he has drawn from music in his childhood. He tells of the struggles he experienced and the lack of inspiration from mandatory piano lessons from Ms. Shimizu. Although he dazzled her every time, he never felt connected to the music. Felsenfeld reminisced, â€Å"I was experiencing a personal drought, an acrid lack of culture of all kinds, especially music† (Felsenfeld 624). After he heard Beethoven’s Ninth