冷凍干燥法制氣凝膠

1、1. Introduction 2. Synthesis of UFA 3. Freeze-drying technique 4. Conclusion What is the lightest material in the world? Aerogel Mechanica Propertiesl Electrical Conducti vities Thermal Acoustic Large open pores and High internal surface area Low Density Synthesis by Freeze-drying technique Haiyan S

2、，Zhen X，Chao G. Advanced Materials. 2013, 25:2554-2560. CNTs aqueous dispersion 1.0mg/ml，28ml GGO aqueous dispersion 1.0mg/ml，28ml Mixing Stiring for 1.5 h Haiyan S，Zhen X，Chao G. Advanced Materials. 2013, 25:2554-2560. mixture mold freeze-drying for 2d chemically reduced by N2H4 vapor at 90 for 24

3、h vacuum-drying at 160 for 24 h Mechanism :water became ice， then vapored, left many voids mold decides the shape Haiyan S，Zhen X，Chao G. Advanced Materials. 2013, 25:2554-2560. Haiyan S，Zhen X，Chao G. Advanced Materials. 2013, 25:2554-2560. (d)(c) (e)(f) Haiyan S，Zhen X，Chao G. Advanced Materials.

4、2013, 25:2554-2560. 冷凍干燥（Freeze-drying）又稱真空冷凍干燥、凍結干燥、凍干（FD）。 1811年 誕生，用于生物體脫水 1890年 醫(yī)學上的首次應用，凍干了一批生物器官 1932年 引入真空設備，在生物制品、藥劑以及食品領域迅猛發(fā)展 1935年 干燥的過程采用主動加熱，開始應用到工業(yè)生產(chǎn) 1965年 首先采用凍干技術制備出金屬超細粉末 如今 在超導材料、超細金屬粉末、精細陶瓷、催化劑、高能電池以及 薄膜材料等領域都得到了廣泛的應用。 孫啟達,冷凍干燥超細粉體技術及應用M.化學工業(yè)出版社,2006. History of Freeze-drying Phase

5、 diagram of salt-water system Shibing Ye et al, J. Mater. Chem. A, 2013, 1, 34953502 SEM images of (a and b) GOA and (c and d) GEA-9 Multifunctional Graphene/Platinum/Nafion（全氟 磺酸） Hybrids Luis Estevez et al. J. Am. Chem. Soc. 2011, 133: 61226125 Justin E.Silpe, et al. Langmulr , 2013 , 29: 8782-878

6、7. Freeze-dryingFreeze-drying l The as-prepared material shows a uniform particle size distribution and the particle size is much smaller than 300 nm. l the composite delivered a reversible capacity of 125.2 mAhg-1 without obviously fading after 100 cycles. Qiao Y Q, Wang X L, Mai Y J, et al. Journa

7、l of Alloys and Compounds, 2012, 536: 132-137. 徐如人, 龐文琴, 霍啟升.無機合成與制備化學M.高等教育出版社,2009. Salt solution （or colloid ） Spray-freezingCongelation Metal salt ball Composite Oxides Oxides, Matel ultra-fine powders Vacuum drying Pyrolyzation or other treatment Prepare ultra-fine powder Adavantages： 1. Can be

8、 obtained in a homogeneous mixture of the components in solution, suitable for adding trace components, synthesize complex functional ceramic materials nanoparticles. 2. Size of nanoparticles range from 1 nm to 50 nm . 3. Easy to operate and good in the preparation of high purity ceramic material. D

9、isadvantages： Efficiency is relatively low, corrosive gas impact the life of the equipment. . uThe principle of Freeze-drying technique uSynthesis of Advanced Materials by Freeze- drying technique has many Advantages: template-free simple retain the original structure scalable fabrication uEnlighten

10、ment: new wine in an old bottle; new concepts in an old framework 1. 孫啟達,冷凍干燥超細粉體技術及應用M.化學工業(yè)出版社,2006 2. 徐如人, 龐文琴, 霍啟升.無機合成與制備化學M.高等教育出版社,2009. 3. Han Y, Xu Z, Gao C. Ultrathin graphene nanofiltration membrane for water purificationJ. Advanced Functional Materials, 2013. 4. Estevez L, Kelarakis A, Go

11、ng Q, et al. Multifunctional graphene/platinum/nafion hybrids via ice templatingJ. Journal of the American Chemical Society, 2011, 133(16): 6122-6125. 5. Mecklenburg M, Schuchardt A, Mishra Y K, et al. Aerographite: Ultra Lightweight, Flexible Nanowall, Carbon Microtube Material with Outstanding Mec

12、hanical PerformanceJ. Advanced Materials, 2012, 24(26): 3486-3490. 6. Schaedler T A, Jacobsen A J, Torrents A, et al. Ultralight metallic microlatticesJ. Science, 2011, 334(6058): 962-965. 1. Introduction 2. Synthesis of UFA 3. Freeze-drying technique 4. Conclusion Haiyan S，Zhen X，Chao G. Advanced M

13、aterials. 2013, 25:2554-2560. (d)(c) (e)(f) Haiyan S，Zhen X，Chao G. Advanced Materials. 2013, 25:2554-2560. Phase diagram of salt-water system 徐如人, 龐文琴, 霍啟升.無機合成與制備化學M.高等教育出版社,2009. Salt solution （or colloid ） Spray-freezingCongelation Metal salt ball Composite Oxides Oxides, Matel ultra-fine powders Vacuum drying Pyrolyzation or other treatment Prepare ultra-fine powder uThe principle of Freeze-drying technique uSynthesis of Adv