Modification of Spherical Polyelectrolyte Brushes by Layer-by-Layer Self-Assembly as Observed by Small Angle X-ray Scattering

Yuchuan Tian; Li Li; Haoya Han; Weihua Wang; Yunwei Wang; Zhishuang Ye; Xuhong Guo

doi:10.3390/polym8040145

Modification of Spherical Polyelectrolyte Brushes by Layer-by-Layer Self-Assembly as Observed by Small Angle X-ray Scattering

Polymers (Basel). 2016 Apr 15;8(4):145. doi: 10.3390/polym8040145.

Authors

Yuchuan Tian¹, Li Li², Haoya Han³, Weihua Wang⁴, Yunwei Wang⁵, Zhishuang Ye⁶, Xuhong Guo^{7

8}

Affiliations

¹ State-Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China. tianyuchuanecust@163.com.
² State-Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China. lili76131@ecust.edu.cn.
³ State-Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China. 020120096@mail.ecust.edu.cn.
⁴ State-Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China. wang88101500@163.com.
⁵ State-Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China. Y20140094@mail.ecust.edu.cn.
⁶ State-Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China. 18817507593@163.com.
⁷ State-Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China. guoxuhong@ecust.edu.cn.
⁸ Engineering Research Center of Xinjiang Bingtuan of Materials Chemical Engineering, Shihezi University, Xinjiang 832000, China. guoxuhong@ecust.edu.cn.

Abstract

Multilayer modified spherical polyelectrolyte brushes were prepared through alternate deposition of positively charged poly(allylamine hydrochloride) (PAH) and negatively charged poly-l-aspartic acid (PAsp) onto negatively charged spherical poly(acrylic acid) (PAA) brushes (SPBs) on a poly(styrene) core. The charge reversal determined by the zeta potential indicated the success of layer-by-layer (LBL) deposition. The change of the structure during the construction of multilayer modified SPBs was observed by small-angle X-ray scattering (SAXS). SAXS results indicated that some PAH chains were able to penetrate into the PAA brush for the PAA-PAH double-layer modified SPBs whereas part of the PAH moved towards the outer layer when the PAsp layer was loaded to form a PAA-PAH-PAsp triple-layer system. The multilayer modified SPBs were stable upon changing the pH (5 to 9) and ionic strength (1 to 100 mM). The triple-layer modified SPBs were more tolerated to high pH (even at 11) compared to the double-layer ones. SAXS is proved to be a powerful tool for studying the inner structure of multilayer modified SPBs, which can establish guidelines for the a range of potential applications of multilayer modified SPBs.

Keywords: layer-by-layer deposition; small X-ray scattering; spherical polyelectrolyte brushes.

Abstract

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