2014年加拿大会议-国际会议口头报告讲稿

(虽然短短5页，这可是本主一个多月的工作结晶，往对大家有帮助，别忘了给赞)P1Greeting: Thanks for introduction. Hello everyone. Wellcome to my talk. Thank the organisers for giving me this opportunity.Self-introduction: My name is [your name] a phd student at group of Prof. [your advisor] who is sitting there. We come from [your University], China. As you know, nanjing is a city with a long history which locates in the south-east of China. Subject: Today, I’m going to talk about our recent work about [your title].P2Outline: My presentation is divided into four parts: Background; Morphology control; Catalysis & Drug-delivery; Summary.P3（Introduction of the background）In the past, numerous researches have been done focusing on micro- and macro-scale. But, there is a central issue, how the understanding at the micro-scale can enable predictions of functional behavior at the macro-scale. Then, a new awareness, also an open concept ‘mesoscale science’ has recently emerged to link the micro- to the macroscale.It is clear that porous materials have great potential due to their various composition, structure and morphology.（My theme）In this talk, we focus on controllable synthesis of morphology and use it as mesoscale to obtain the quantification and optimization of the relevant processes. P4（Catalysis VS your materials）As for heterogeneous catalysis, it is widely known that macroscopic parameters such as the yield, selectivity, products and rate of chemical reactions are related to the nano-structure of catalyst including morphology, size, pore and composition. Because nano-structure can produce various effects on chemical process such as….P5（Drug-delivery VS your materials）And when it comes to drug delivery, the morphology and size of porous materials are two main subjects.(you can refer to some references to support your idea)Prof. Mou found that rod-like particles have many 优势（pointing）compared to sphere morphology.Prof. Tang studied mesoporous silica nanoparticles with aspect ratio from 1 to 5 as drug-carrier. She found that the AR of MSNs affect greatly these aspects. vivobiodistribution, clearance, and biocompatibility and so on.In addition, she proposed that particles with a larger AR generally affect cells to a larger degree compared to MSNs with a smaller AR. Therefore, given this result, it is necessary to expand the shape effect studies to a wide range.P6Periodic mesoporous materials have been widely studied in many fields, such as catalysis, sensor, drug-delivery and separation. Because they have Large Surface Area, Adjustable Pore Size, High Thermal Stability and Flexible Framework. Especially, the Flexible Framework make the controllable synthesis of morphology possible.P7(emphasize the importance of your work)Thus, we use mesoporous silica as Good Carrier Or Support. Next, we try to obtain the controllable synthesis of morphology and size. After that, we can introduce a variety of organic or inorganic modification. Finally, the functioned mesoporous materials with controllable morphology and size can paly as a good meso-scale to expect the quantification and optimization of the relevant processes between micro-scale and macro-scale. However, compared to the synthesis of mesoporous silica, the two parts are more difficult, which not only need a flexible method, but also need fine control of synthesis conditions. Therefore, it is still a challenge for researchers.P8(introduction of synthesis process)Next, we are going to introduce our work about morphology control.B riefly,in the synthesis process, we use two surfactants. we put …and …into concentrated …. Until the solution became transparent,… were added into the solution, we add silicon source and heteroatom source under certain conditions.Afther the following treatments: Hydrothermal treatment, centrifugation, dryness and calcination. Finally, we get the product.Obviously, this process is simple, and the two-surfactants are cheap and easy-obtained. So, it has great potential for scale-up production.P9(my aims of my work)In order to get full control of length, diameter, and pore size of nanotube, we try to change synthesis conditions … and so on. However, in this dual-surfactant system, we found the morphology was affected greatly….P10(introduction of my detailed work)First of all, we test the effects of the amount of ... on morphology. We increase the amount of ... and keep ... constant. The SEM images from a to g show with the increasing of ..., the morphology starts by long particles, then, changes into short ones. The corresponding sizes are listed. Moreover, TEM image of A2 demonstrate twodimension hexagonal structure and the highly ordered honeycomb-like structure.P11In addition, we use XRD and N2 physisorption to get information of mesostructure. From XRD and pore size distribution patterns. we can see that with the increasing of ..., there are two sections in the patterns. From A0 to A2, the 100 peaks shift to lower angel, meanwhile, the corresponding pore size become big. And from A3 to A7, the 100 peaks move to high angel, however, the pore size are almost the same with A0. And, although the peaks of A6 and A7 become broad and weak, all samples give similar nitrogen sorption amount and TEM pattern of A7 show the channels remain intact which indicates that the mesopores are remained despite of the increasing amount of .... And, the broad peaks of A6 and A7 may attribute to the dereasing size of particles.P12Next, we study the effects of amount of ... on the morphology of materials. We keep the amount of ... constant, and decrease the amount of .... As shown here, We can see that the changing trend of morphology is the same with the effect of incerasing amount of .... TEM pattern of B1 synthesized with low amount of ... shows collapsed channels. P13In this slide, I will talk about the possible reason. As shown here, we can also found with the decrease of ..., the peaks become weak and broad. And, at the same time the Nitrogen sorption amounts decrease. Taken together, we conclude that the the decreasing amount of ... may no be benificial for producing good channel.P14Taking into consideration the effects of molar ratio of ... to ..., we propose that in the binary surfactants system the role of ... is as template to form mesopore structure, while ... as regulator to control the morphology.We think that at low amount of ..., ... and ... form coupled micelles. While at high amont of ..., separated micelles occur.The morphology transformation was refered to a ….P15-P16[on the basis of your work, you should propose a proper mechanism to rationalize your results ]In the present study,…. There exist two kinds of interactions ..between the positively charged … and …, and … between …. It is clear that .. can accelerate the condensation of silicate anion. On the contrary, …hinder this process. Thus, there exists a competitive relationship between E and H. And the competition between the two kinds of interactions are responsible for the competition between the Gibbs free energy of the mesophase formation (ΔG) and the surface free energy (F). At low amount of …, ΔG is dominant. The long nanotube will be formed. When we increase the amount of ..., the proportion of the hydrogen bonds increased. As a result, the morphology with bigcurvature will be formed in order to minimize the surface energy.And in this case the mesostructure is determined by …of ….In this case, we refered to a work of Hiroaki Imai. First of all, the assembly between …occur, while the …attach on the … the particles. In this case, the … come from the template …. while the wall thikness of pores was determined by the balance bwtween H and E. So, the morphology transformation happened from long to short nanotube, and finally sphere morphology.P17P18In addition, we found that the inner pore size of materials could also be regulated by using quaternary ammonium cationic changing surfactant with different length of carbon chain (TTAB: C14, OTAB: C18), but under optimum conditions. As shown here, the obtained C14 and C18 samples show nanotube-like morphology and narrow pore size. The most probable pore sizes of C14 and C18 are 2.17 and 3.25 nm, respectively. P19Moreover, we also found that the morphology and size of materials can be regulated by systematical changing of experimental conditions, such as .../..., ammonia concentration, amount of ..., stirring and temperature, we also obtain nanotubes with different size and morphology. For example, we obtain sample S1 by changing ammonia concentration and temperature.P20In a short summary, by using this dual-surfactant system, we are able to produce honeycomb-like silica nanotube with controllable morpholgy at three-dimension, with with length changing from 100nm to 5μm; diameter from 50 to 600nm; pore size from 2.17 to 3.15 nm. The AR of materials are found in the range of 1 to 100. Therefore, we offered a flexible and effective strtegy for the controllable synthesis of honeycomb-like silica nanotube.P20Next part, we test the application of materials as catalyst support. For this purpose,. We prepared copper-modified nanotube reactor .P21As shown here, we obtained different nanoreactors with similar outer diameter and increasing length. When they are used to catalyze direct hydroxylation of benzene. An interesting result was obtained that the catalytic activities increase with the length of nanotube reactor.P22Moreover, we also analyze the mesostructure by XRD and N2 physisorption and testthe copper content and state by ICP and UV. From the UV pattern, we can see that the copper states of copper in three samples are similar.P23And the catalytic results and mesostructure data are all listed in table 1.Moreover, the decreasing specific surface generally lead to the decreasing of catalytic performance.We conclude that the increasing catalytic activities may come from the …. To support that, we also prepared iron-containing nanotube reactor with different length. As shown here. When we use iron-doped nanotubes to catalyze phenol hydroxylation. The same conclusion was obtained that the catalytic activities linearly increase with …. This may be due to …. Still there are many factors such as…, a quantitative relationship between … and c… was obtained,P24When we use samples with different length 1μm and 300 nm as drug-carrier, we found that the long sample show increased release amount of DOX and longer duration time. Moreover, the multi-channel are also able to encapsulate two drugs into different pores. Thus, a dual-drug-delivery system can be constructed by using our materials. Now, we are still on this work. [this sentence is very useful, especially when someone asks you question ]P25To summarize.[Finally, we summarize my work in short not complex sentence]We succeed in controllable synthesis of HSNs in a wide range of size or AR.As for mechanism, we think ... is as template to form pore structure, while ... to control the morphology.As for the applications in Catalysis & Drug-delivery,This research may provide a novel approach to modulate the catalysis and drug-delivery performance and promote rational design of catalysts support and bio-carrier.Thank you for your attention!。