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Liu Q, Chen N, Yin X, Long L, Hou X, Zhao J, Yuan X. Preparation of cellulose nanospheres via combining ZnCl 2·3H 2O pretreatment and p-toluenesulfonic hydrolysis as a two-step method. Int J Biol Macromol 2021; 181:621-630. [PMID: 33798585 DOI: 10.1016/j.ijbiomac.2021.03.168] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 03/16/2021] [Accepted: 03/28/2021] [Indexed: 11/17/2022]
Abstract
Spherical nanocelluloses, also known as cellulose nanospheres (CNS), have controllable morphology and have shown advantages as green template material, emulsion stabilizer. Herein, CNS were prepared via a new two-step method, first pretreatment of microcrystalline cellulose (MCC) using ZnCl2·3H2O and then acid hydrolysis of regenerated cellulose (RC) via p-toluenesulfonic acid (p-TsOH). The shape, size, crystallinity of MCC were changed, and nubbly RC with smallest size (942 nm) was obtained after 2 h pretreatment by ZnCl2·3H2O. CNS with high 61.3% yield were produced after acid hydrolysis (67 wt% p-TsOH) of RC at 80 °C, 6 h. The analysis of Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM) showed that CNS had an average diameter of 347 nm. CNS were present in precipitate after high-speed centrifugation, due to the high Zeta potential of -12 mV and large size. The structure of CNS was tested by Fourier Transfer Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Nuclear Magnetic Resonance (NMR), CNS had high crystallinity (cellulose II) of 61%. Thermal Gravimetric Analysis (TGA) indicated that CNS had high thermal stability (Tonset 303.3 °C, Tmax 332 °C). CNS showed poor re-dispersibility in water/ethanol/THF, 1 wt% CNS could be dissolved in ZnCl2·3H2O. 7.37% rod-like CNC were obtained after 6 h hydrolysis. FTIR proved that p-TsOH was recovered by re-crystallization. This study provided a novel, sustainable two-step method for the preparation of spherical CNS.
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Affiliation(s)
- Qi Liu
- Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, PR China; School of Material Science and Engineering, Tianjin University, Tianjin 300072, PR China
| | - Ning Chen
- Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, PR China; School of Material Science and Engineering, Tianjin University, Tianjin 300072, PR China
| | - Xiangyun Yin
- Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, PR China; School of Material Science and Engineering, Tianjin University, Tianjin 300072, PR China
| | - Lixia Long
- Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, PR China; School of Material Science and Engineering, Tianjin University, Tianjin 300072, PR China
| | - Xin Hou
- Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, PR China; School of Material Science and Engineering, Tianjin University, Tianjin 300072, PR China.
| | - Jin Zhao
- Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, PR China; School of Material Science and Engineering, Tianjin University, Tianjin 300072, PR China.
| | - Xubo Yuan
- Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, PR China; School of Material Science and Engineering, Tianjin University, Tianjin 300072, PR China
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