**Author details**

Malin Liu\*

Address all correspondence to: liumalin@tsinghua.edu.cn

Institute of Nuclear and New Energy Technology, Tsinghua Univerisity, Beijing, China

## **References**

**Appendix**

γ Cone included angle Do Inlet diameter, m

182 Modern Surface Engineering Treatments

Dc Column diameter, m Hc Height of conical part, m Ho Static bed height, m dp Particle diameter, m ρ<sup>p</sup> Particle density, kg/m3 ρ<sup>f</sup> Fluid density, kg/m3 ρ<sup>b</sup> Bed density, kg/m3

Di Diameter of the bed bottom, m

ΔP<sup>M</sup> Maximum pressure drop, Pa

Vp The volume of spout area, m3

Tp The single particle cycle time, s

g Gravity, m/s2

**Acknowledgements**

**Author details**

Malin Liu\*

ΔP<sup>s</sup> Pressure drop at the stable spouting state, Pa UM Spouting velocity at maximum pressure drop, m/s

Tc The oscillation cycle period of particle clusters, s

Ums Minimum spouting velocity at the stable spouting state, m/s

Ts The time period of particle in spout area in a particle cycle time, s

Address all correspondence to: liumalin@tsinghua.edu.cn

The author would like to thank the National S&T Major Project (Grant No. ZX06901), the Independent Research Projects of Tsinghua University (20111080971) and Research Fund for the Doctoral Program of Higher Education of China(20121010010) for the financial support provided. Also, thanks go to Bing Liu, Youlin Shao, Jing Wang, Junguo Zhu, Bing Yang, Bingzhong Zhang, as my best colleagues. All the results of this chapter are completed together

with them. The author himself is responsible for all of the errors of this chapter.

Institute of Nuclear and New Energy Technology, Tsinghua Univerisity, Beijing, China


[14] Liu M, Liu B, Shao Y. Optimization of the UO2 kernel coating process by 2D simula‐ tion of spouted bed dynamics in the coater. Nuclear Engineering and Design. 2012b; 251: 124-130.

**Chapter 8**

**Surface Modification of Nanoparticles Used in**

In the last two decades a lot of attention has been payed on the preparation of nanoscaled materials and recently, depending on the development of new fabrication and characterization techniques, materials composed of a few atoms up to hundreds of atoms can be synthesized and their properties determined easily. Nano sized materials, as compared to their bulk counterparts, exhibit new characteristic optical, electrical and magnetic properties due to the enhanced surface to volume ratio and quantum confinement effects emerging in these size ranges. These new features of nanoparticles offers them the possibility to be used in a wide range of technological (magnetic data storage, refrigeration), environmental (catalysts, hydrogen storage), energy (lithium-ion batteries, solar cells) and biomedical applications. In biomedical applications there are different kind of nanoparticles used like metallic [1], magnetic, fluorescent (quantum dot) [2,3], polymeric [4,5] and protein-based nanoparticles [6, 7], in which much of the research in this field is focused on the magnetic nanoparticles. In this review only magnetic nanoparticles, which are composed of a magnetic core surrounded by a functionalized biocompatible surface shell will be concerned, where several reviews on other type of nanoparticles are available in the literature. In the scope of the text particular attention will be payed on superparamagnetic iron oxide (SPIONs), which is beyond the most studied one among all types of magnetic nanoparticles. In the beginning of the article, the biomedical applications of magnetic nanoparticles are summarized together with the key factors effecting the nanoparticles' performance in these applications. Then the requirement for the surface treatment of the nanoparticles are discussed in the context of colloidal stability, toxicity (biocompatibility) and functionalization. Finally, the followed procedures for the surface coating of magnetic nanoparticles are briefly explained and the different materials used as

**Biomedical Applications**

http://dx.doi.org/10.5772/55746

Additional information is available at the end of the chapter

surface coatings are listed in detail with examples from literature.

© 2013 Umut; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

© 2013 Umut; licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

distribution, and reproduction in any medium, provided the original work is properly cited.

Evrim Umut

**1. Introduction**

