Water dynamics in the hydration shell of hyper-branched poly-ethylenimine

被引：4

作者：

Zhang, Jiaqi ^{[1
,2
]}

Yan, Yuyue ^{[1
,2
]}

Wang, Bin ^{[3
]}

Liu, Liyuan ^{[1
,2
]}

Li, Shaoxian ^{[1
,2
]}

Tian, Zhen ^{[1
,2
]}

Ouyang, Chunmei ^{[1
,2
]}

Gu, Jianqiang ^{[1
,2
]}

Zhang, Xueqian ^{[1
,2
]}

Chen, Yu ^{[4
]}

Han, Jiaguang ^{[1
,2
]}

Zhang, Weili ^{[5
]}

机构：

[1] Tianjin Univ, Ctr Terahertz Waves, Tianjin 300072, Peoples R China

[2] Tianjin Univ, Coll Precis Instrument & Optoeletct Engn, Tianjin 300072, Peoples R China

[3] Tianjin Chengjian Univ, Sch Sci, Tianjin Engn Technol Ctr Chem Wastewater Source R, Tianjin 300072, Peoples R China

[4] Tianjin Univ, Sch Sci, Dept Chem, Tianjin Key Lab Mol Optoelect Sci, Tianjin 300354, Peoples R China

[5] Oklahoma State Univ, Sch Elect & Comp Engn, Stillwater, OK 74078 USA

来源：

PHYSICAL CHEMISTRY CHEMICAL PHYSICS | 2022年 / 24卷 / 30期

基金：

中国国家自然科学基金;

关键词：

BAND DIELECTRIC-SPECTROSCOPY; AQUEOUS-SOLUTIONS; RELAXATION SPECTROSCOPY; THZ SPECTROSCOPY; NONPOLAR SOLUTES; TMAO SOLUTIONS; LIQUID H2O; REORIENTATION; ORIGIN; TEMPERATURE;

D O I：

10.1039/d2cp01944b

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

We performed THz and GHz dielectric relaxation spectroscopy to investigate the reorientational dynamics of water molecules in the hydration shell of amphiphilic hyper-branched poly-ethylenimine (HPEI). Four Debye equations were employed to describe four types of water in the hydration shell, including bulk-like water, under-coordinated water, slow water (water molecules hydrating the hydrophobic groups and water molecules accepting hydrogen bonds from the NH2 groups) and super slow water (water molecules donating hydrogen bonds to and accepting hydrogen bonds from NH groups). The time scales of undercoordinated and bulk-like water show a slight decline from 0.4 to 0.1 ps and from 8 to 2 ps, respectively. Because of hydrophilic amino groups, HPEI molecules exhibit a strong retardation effect, where the time scales of slow and super slow water increase with concentration from 17 to 39.9 ps and from 88 to 225 ps, respectively.

引用

页码：18393 / 18400

页数：8