24小时热门版块排行榜    

北京石油化工学院2026年研究生招生接收调剂公告
查看: 177  |  回复: 2
当前主题已经存档。

xbg2080

铜虫 (正式写手)

[交流] How to synthesize nanocrystal in the range of 30~100nm.

i wanna synthesize nanocrystal of Fe304 with 30~100nm.
the majority of literatures have reported the preparation of Fe304 nanocrystal with ~5% of standard deviation in size. but their size is too small, basically ~10nm, at most 20nm.   

so i desire to prepare nanocrystal in size >30nm. this size range of nanocrystal with ~5% of standard deviation is very rare in literatures reported.
who can propose new methods to do it except the seed-mediate method in literature?
Hope to discusse it.

i hv ever consulted a Korean author. He replied as follows:
___________________________________________
Actually, we don't have tried much to synthesize nanocrystals larger than 20 nm. So we have little kowledge from our experiences to anwer your question.

Theoritically, the difference between the surface free energies of a highly curved surface and a flatter surface is the driving force to redistribute the crystal monomers to result spherical shape on which the surface curvature is identical at all points. This redistribution process proceeds via intra- or inter-particle ripening. When a nanocrystal gets larger, its surface curvature decreases and so does its surface free energy. As a result, the driving force which leads to spherical shape of the particles is reduced, too. In my opinion, this might be the reason for the difficulties in synthesizing large spherical particles.

Regards,
권순구 Hyeon.
回复此楼
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

taijun_2008

木虫 (著名写手)

Alchemist

这种由表面曲率差异导致的驱动力是不是就是Ostwald老化?
[url=http://weibo.com/1438083415?s=6uyXnP][img]http://service.t.sina.com.cn/widget/qmd/1438083415/006db0cc/5.png[/img][/url]
2楼2007-11-10 20:26:14
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

xbg2080

铜虫 (正式写手)

Ostwald ripenning means larger particle will grow at the expense of consumption of smaller particle. generally the higher solubility, the smaller particle. this is general explanation.
3楼2007-11-12 16:38:08
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
相关版块跳转 我要订阅楼主 xbg2080 的主题更新
普通表情 高级回复 (可上传附件)
最具人气热帖推荐 [查看全部] 作者 回/看 最后发表
[考研] 环境专硕调剂 +6 会说话的肘子 2026-04-06 6/300 2026-04-07 02:00 by Sealedwind
[考研] 277求调剂 数一104分 +9 瓶子PZ 2026-04-05 13/650 2026-04-06 23:48 by 蓝云思雨
[考研] 347材料专硕求调剂 +7 zj8215216 2026-04-06 7/350 2026-04-06 21:57 by dongzh2009
[考研] 312求调剂 +13 gtw1 2026-04-06 15/750 2026-04-06 20:25 by lijunpoly
[考研] 270分求调剂 +5 maxjxbsk 2026-04-01 5/250 2026-04-06 15:32 by lin-da
[考研] 307分材料专业求调剂 +7 Hll胡 2026-04-05 7/350 2026-04-05 18:47 by 无际的草原
[考研] 一志愿华中农业大学0710(A)初试329分 求调剂 +4 一名26考研生 2026-04-04 4/200 2026-04-05 10:01 by barlinike
[考研] 083200 333求调剂 +3 十二!! 2026-04-04 3/150 2026-04-05 08:28 by barlinike
[考研] 材料工程085601数二英一335求调剂 +6 双马尾痞老板2 2026-03-31 6/300 2026-04-04 22:29 by hemengdong
[考研] 341求调剂 +3 洛多罗 2026-04-02 4/200 2026-04-04 21:36 by 智能智慧
[考研] 321求调剂 +6 认真求上学 2026-04-03 6/300 2026-04-04 19:51 by dongzh2009
[考研] 求调剂:085600材料与化工,考材科基,总分319 +21 678lucky 2026-03-31 26/1300 2026-04-04 16:22 by dongzh2009
[考研] 305求调剂 +3 77Qi 2026-04-03 3/150 2026-04-03 23:01 by qzxyhcsy
[考研] 考研调剂 +3 15615482637 2026-04-03 3/150 2026-04-03 22:50 by ms629
[考研] 350一志愿北京航空航天大学08500材料科学与工程求调剂 +5 kjnasfss 2026-04-03 5/250 2026-04-03 22:29 by 无际的草原
[考研] 085600专硕材料与化工348分求调剂 +10 上学啦! 2026-04-01 11/550 2026-04-03 14:13 by 百灵童888
[考研] 数一英一285求调剂 +7 AZMK 2026-04-03 9/450 2026-04-03 13:03 by ms629
[考研] 260求调剂 +3 朱芷琳 2026-04-02 3/150 2026-04-03 08:44 by yulian1987
[考研] 310分求调剂 +4 成功上岸wang 2026-04-01 4/200 2026-04-01 20:35 by liu823948201
[考研] 调剂申请 +8 张张张张zy 2026-03-31 9/450 2026-04-01 08:29 by zjbkx
信息提示
请填处理意见