24小时热门版块排行榜    

Znn3bq.jpeg
汕头大学海洋科学接受调剂
查看: 1760  |  回复: 9
当前只显示满足指定条件的回帖,点击这里查看本话题的所有回帖

xiaoLifeiD

至尊木虫 (知名作家)

[求助] 天然纤维素的详细溶解步骤 已有1人参与

越详细越好,谢谢!

发自小木虫IOS客户端
回复此楼

» 猜你喜欢

提供GPC服务
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

celan

专家顾问 (知名作家)

从事NMR和有机化合物结构鉴定


【答案】应助回帖

★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★
感谢参与,应助指数 +1
xiaoLifeiD: 金币+50, ★★★很有帮助 2017-09-09 16:05:27
Macromol Biosci. 2005 Jun 24;5(6):539-48.

Rapid dissolution of cellulose in LiOH/urea and NaOH/urea aqueous solutions.

Cai J1, Zhang L.


Author information



Abstract


Rapid dissolution of cellulose in LiOH/urea and NaOH/urea aqueous solutions was studied systematically. The dissolution behavior and solubility of cellulose were evaluated by using (13)C NMR, optical microscopy, wide-angle X-ray diffraction (WAXD), FT-IR spectroscopy, DSC, and viscometry. The experiment results revealed that cellulose having viscosity-average molecular weight ((overline) M eta) of 11.4 x 104 and 37.2 x 104 could be dissolved, respectively, in 7% NaOH/12% urea and 4.2% LiOH/12% urea aqueous solutions pre-cooled to -10 degrees C within 2 min, whereas all of them could not be dissolved in KOH/urea aqueous solution. The dissolution power of the solvent systems was in the order of LiOH/urea > NaOH/urea >> KOH/urea aqueous solution. The results from DSC and (13)C NMR indicated that LiOH/urea and NaOH/urea aqueous solutions as non-derivatizing solvents broke the intra- and inter-molecular hydrogen bonding of cellulose and prevented the approach toward each other of the cellulose molecules, leading to the good dispersion of cellulose to form an actual solution.


PMID: 15954076DOI: 10.1002/mabi.200400222 按这个地址自己可以下载全文
4楼2017-08-25 09:34:04
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
查看全部 10 个回答
2楼2017-08-22 22:48:18
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

xmc_SUZ

新虫 (小有名气)

7%NaOH/12%尿素水溶液预冷至-10 oC后,将50g纤维素(粘均分子量Mη为11.4×104)分散于1000g该溶剂中,室温下剧烈搅拌5分钟即获得透明的纤维素溶液。

» 本帖已获得的红花(最新10朵)

3楼2017-08-23 14:11:25
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

xiaoLifeiD

至尊木虫 (知名作家)

送红花一朵
引用回帖:
3楼: Originally posted by xmc_SUZ at 2017-08-23 14:11:25
7%NaOH/12%尿素水溶液预冷至-10 oC后,将50g纤维素(粘均分子量Mη为11.4×104)分散于1000g该溶剂中,室温下剧烈搅拌5分钟即获得透明的纤维素溶液。

没选应助没法给金币,再请教下,水溶以后,是怎么测GPC的呢?

发自小木虫IOS客户端
提供GPC服务
5楼2017-09-09 16:06:22
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
最具人气热帖推荐 [查看全部] 作者 回/看 最后发表
[考研] 材料299专硕求调剂 +16 +21 2026-04-09 16/800 2026-04-14 17:06 by jiangguiquan11
[考研] 一志愿西南大学生物学学硕344 求生物学相关调剂/生物与医药 +8 超人不会飞@ 2026-04-08 8/400 2026-04-14 16:06 by zs92450
[考研] 一志愿085502,267分求调剂 +19 再忙也要吃饭啊 2026-04-08 20/1000 2026-04-14 16:03 by zs92450
[考研] 288求调剂,一志愿华南理工大学071005 +25 ioodiiij 2026-04-08 25/1250 2026-04-14 15:59 by zs92450
[考研] 327求调剂 +22 Xxjc1107. 2026-04-13 24/1200 2026-04-14 14:45 by zs92450
[考研] 22专硕求调剂 +8 haoyun上岸 2026-04-11 10/500 2026-04-13 22:15 by zhq0425
[考研] 272分材料子求调剂 +41 Loy0361 2026-04-10 53/2650 2026-04-13 14:20 by 张zhihao
[考研] 266调剂 +10 daya sun 2026-04-07 11/550 2026-04-13 10:12 by fenglj492
[考研] 求调剂288 +7 ioodiiij 2026-04-10 9/450 2026-04-13 08:33 by Hayaay
[考研] 药学专硕调剂 +8 ? 一路生?花? 2026-04-10 10/500 2026-04-11 21:21 by zhouxiaoyu
[考研] 070300化学279求调剂 +19 哈哈哈^_^ 2026-04-08 20/1000 2026-04-11 20:43 by stoner78
[考研] 343求调剂 +9 王国帅 2026-04-10 9/450 2026-04-11 20:31 by dongdian1
[考研] 本科211 工科085400 280分求调剂 可跨专业 +11 LZH(等待调剂中 2026-04-10 11/550 2026-04-11 08:39 by zhq0425
[考研] 342电子信息专硕求调剂 +9 你让我怎么荔枝 2026-04-10 10/500 2026-04-11 08:33 by zhq0425
[考研] 263能源动力专硕求调剂 +3 加大号饭盒袋 2026-04-10 3/150 2026-04-10 22:23 by 286640313
[考研] 调剂申请086000一志愿西北农林科技大学生物与医药320分-本科齐鲁工业大学 +3 美美女士 2026-04-09 3/150 2026-04-10 10:31 by liuhuiying09
[考研] 278求调剂 +27 范婷娜 2026-04-07 31/1550 2026-04-09 20:49 by zhouxiaoyu
[考研] 调剂 +19 2261744733 2026-04-08 19/950 2026-04-09 19:11 by vgtyfty
[考研] 083200 初试305分 求调剂 暂不考虑跨专业 +15 Claireyyyy 2026-04-09 15/750 2026-04-09 16:11 by zhuimr
[考研] 化学工程与技术专业一志愿哈工程 291分B区 国家级大创负责人 有一作论文 +13 Emmy~ 2026-04-09 13/650 2026-04-09 14:47 by only周
信息提示
请填处理意见