全部 标题 作者
关键词 摘要

OALib Journal期刊
ISSN: 2333-9721
费用:99美元

查看量下载量

相关文章

更多...

冷冻干燥技术制备非晶态粉体的机理研究

Keywords: 冷冻干燥,非晶态,晶化,偏析

Full-Text   Cite this paper   Add to My Lib

Abstract:

利用XRD,SEM研究了冷冻干燥技术制备非晶态粉体的形貌及其形成过程,建立了快速冷冻条件下溶质粒子偏聚模型,结果表明:冷冻干燥技术制备的粉体为表面光滑的无定形态,形貌主要为片状和条柱状,有少量六边形态,低温冷冻时,水以冰的形式冻结,溶质以盐的形式析出,形成冰盐两相;空气回温时,非晶冰向晶态冰转化,微晶粒盐偏析到冰相界面,冰晶大小和形态不同导致非晶态粉体呈现不同形貌,溶液浓度较高时,主要是片状和条柱状非晶态粉体;溶液浓度较低时,盐的偏聚与溶液浓度本身无关,易出现六边形态的非晶态粉体。

References

[1]  KENFACK F,LANGBEIN H.Synthesis and thermal decomposition of freeze-dried copper-iron formates[J].Thermochimica Acta,2005 426:61-72.
[2]  XI Xiao-li,NIE Zuo-ren,YANG Jian-can,et al.Preparation and characterization of nanopowder for electronic emission ma- terials by freeze-drying[J].International Journal of Refractory Metals and Hard Materials,2006,24(3):210-214.
[3]  SHIN Hyunho,JUNG Hyun-suk,HONG Kug-sun,et al.Crystal phase evolution of TiO_2 nanoparticles with reaction time in acidic solutions studied via freeze-drying method[J].Journal of Solid State Chemistry,2005,178:15-21.
[4]  MANCIC L,MARINKOVIC Z,MILOSEVIC O.Synthesis of Bi based superconducting powders through the freeze drying [J].Mater Chemistry and Physics,2001,67:288-290.
[5]  TAMON H,ISHIZAKA H,YAMAMOTO T,et al.Preparation of mesoporous carbon by freeze drying[J].Carbon, 1999,37:2049-2055.
[6]  YAMAMOTO T,ENDO A,OHMORI T,et al.Porous properties of carbon gel microspheres as adsorbents for gas separa- tion[J].Carbon,2004,42:1671-1676.
[7]  SUN HEE CHOIA,SHLYAKHTINB O A,JOOSUN KIMA,et al.Structural and electrochemical properties of Li1+ xNi0.5Mn0.5O_2+δ(0≤x≤0.7) cathode materials for lithium-ion hatteries[J].Journal of Power Sources,2005,140: 355-360.
[8]  MASCARENHES W J,AKAY H U,PIKAL M J.A computational model for finite element analysis of the freeze-drying process[J].Comput Methods Appl Mech Engrg,1997,148:105-124.
[9]  刘永忠,郭有仪,郁永章.冷冻干燥过程的计算模型及其应有[J].西安交通大学学报,1999,33(12):61-65. LIU Yong-zhong,GUO You-yi,YU Yong-zhang.Numerical simulation of freeze-drying[J].Journal of Xi'an Jiaotong Uni- versity,1999,33(12):61-65.(in Chinese)
[10]  XI Xiao-li,NIE Zuo-ren,YANG Jian-can,et al.Preparation and Characterization of Ce-W compose nanopowder[J].Ma- terials Science & Engineering A,2005,394:360-365.
[11]  BERMEJO E,DANTAS T,LACOUR C,et al.Mechanism of formation of nanocrystalline hematite prepared by freeze- drying[J].Materials Research Bulletin,1995,30(5):645-652.
[12]  OETJEN G W,HASELEY P.Freeze-Drying[M].北京:化学工业出版社,2005.
[13]  张立德.超微粉体制备与应用技术[M].北京:中国石化出版社,2001.
[14]  连进军,李先国,冯丽娟.等.溶胶凝胶冷冻干燥技术制备纳米二氧化锡及其表征[J].化学世界,2004,4:171-174.LIAN Jin-jun,LI Xian-guo,FENG Li-juan,et al.Nanometer-scale stannic oxide from sol-gel-freeze drying process and its characterization[J].Chemical World,2004,4:171-174.(in Chinese)

Full-Text

Contact Us

service@oalib.com

QQ:3279437679

WhatsApp +8615387084133