第 27 卷第 6 期 高 校 化 学 工 程 学 报 No.6
Vo l . 2 7
2013 年 12 月 Journal of Chemical Engineering of Chinese Universities Dec.
2013
文章编号:1003-9015(2013)06-0967-07
木质素磺酸钠在固体平板上的吸附特征
邓永红, 肖 亮, 庞煜霞, 吴 渊, 邱学青
(制浆造纸工程国家重点实验室(华南理工大学), 华南理工大学 化学与化工学院, 广东 广州 510640)
摘
要:为了探究木质素磺酸钠
(
木钠,
SL)
在固体平板上的吸附特征,利用层析分离和透析法得到不含无机盐的窄分
子量分布的
SL
,然后将
SL
与聚二烯丙基二甲基氯化铵
(PDAC)
在固体平板上逐层吸附得到多层膜,利用紫外
-
可见光
光谱仪、椭圆偏振仪、原子力显微镜、接触角仪表征了
SL
的吸附特征。结果表明,疏水作用在
SL
的吸附中起了关键
的作用。
SL
的吸附层较薄,
10
层
SL/PDAC
自组装膜的厚度不超过
18 nm
。
SL/PDAC
自组装膜的表面形貌较平整,其
亲水疏水性能随聚阴、阳离子交替而呈现链齿形变化,其中
SL
层的平均接触角为
50°
。
SL
在阳离子表面的吸附包含
单分子吸附和聚集体吸附两方面的贡献。低浓度条件下,
SL
的单分子吸附占主导地位,吸附速率较快,吸附速率随浓
度的增加没有明显的变化。高浓度时,
SL
的吸附行为是单分子吸附和聚集体吸附的共同结果,所以吸附速率较慢,吸
附速率随浓度的增加而降低。
关键词:木质素磺酸盐;自组装;吸附;聚集
中图分类号:
TQ423.11
;
TQ351
文献标识码:
A DOI
:
10.3969/j.issn.1003-9015.2013.06.008
Adsorption Characteristics of Lignosulfonate on Solid Plate
DENG Yong-hong, XIAO Liang, PANG Yu-xia, WU Yuan, QIU Xue-qing
(State Key Lab of Pulp&Paper Engineering, School of Chemistry and Chemical Engineering,
South China University of Technology, Guangzhou 510640, China)
Abstract: In order to explore the adsorption characteristics of lignin lignosulfonate on solid plate, sodium
lignosulfonate (SL) was used as polyanion to build up multilayer films at planar substrate by using
poly(diallyldimethylammonium chloride) (PDAC) as the polycation. The adsorption characteristics were
monitored by Uv-vis spectroscopy, ellipsometer, AFM, and contact angle measurements. Results show that the
self-assembly of SL microgels and PDAC is mainly driven by hydrophobic interaction. The SL/PDAC
self-assembly films are thin—the thickness of 10 bilayer SL/PDAC self-assembly film is no more than 18 nm.
The film surfaces are generally flat and the surface wettability of SL/PDAC multilayers shows a jagged profile
when the outmost layer varies between SL and PDAC, and the averaged contact angle of SL layer is about 50°.
The total adsorbed amount of SL on polycations comes from adsorption of single molecules and aggregates.
Under low concentration, SL adsorption is dominated by the adsorption of single molecules. The adsorption rate
is relatively fast, and the adsorption rate has little change with increasing concentrations. Under high
concentration, SL adsorption is controlled by the adsorption of both single molecules and SL aggregates. The
adsorption rate is relatively slow, and the adsorption rate decreases with increasing concentrations.
Key words: lignosulfonate; layer-by-layer self-assembly; adsorption; aggregation
1 前 言
木质素磺酸盐属于阴离子表面活性剂,但其结构特征和分子量分布决定它在许多方面不同于合成表
面活性剂。木质素磺酸钠(SL)在高分子分散剂领域有广阔的用途
[1~5]
,当用作高分子分散剂时,SL 一端
附着或吸附在颗粒表面,而其余部分环绕在颗粒周围并伸展于水中
[6,7]
。吸附了 SL 的固体颗粒之间具有
收稿日期:2012-07-09;修订日期:2012-11-26。
基金项目:国家重点基础研究发展计划(973 计划)(2012CB215302);国家杰出青年科学基金(20925622);国家自然科学基金(20976064)资助项目。
作者简介:邓永红(1969-),女,湖南娄底人,华南理工大学副教授,博士。通讯联系人:邱学青,E–mail:xueqingqiu66@163.com