The Study of HDDA/Water Pickering Emulsions Prepared by Poly (Methyl Methacrylate) Grafts through MPS on Graphene Oxide/Silica Hybrid

• Main Authors: Chia-Te Su, 蘇家德
• Other Authors: Jeng-Yue Wu
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/18165717230662762002

碩士 === 國立中興大學 === 化學工程學系所 === 104 === The aim of this research is polymethylmethacrylate (PMMA) grafts through 3-methacryloxypropyl trimethoxysilane (MPS) on graphene oxide (GO) /Silica hybrid as Pickering emulsion Study of Water and 1,6-Hexanediol diacrylate (HDDA). It was found that Pickering emulsion could be formed by simple self-assembly method using the modified GO/Silica hybrid as a stabilizer, which could be adsorbed at the oil(1,6-Hexanediol diacrylate, HDDA)–water interface to stabilize the emulsion effectively and observe the emulsion particle size. In this thesis, we assume that the cation exchange capacity (CEC) of graphene oxide is the same with montmorillonite. Graphene oxide was grafted with tetraethylorthosilicate (TEOS) hydrolysis condensation and MPS. Then, through the adsorption of cetyl trimethyl ammonium bromide (CTAB) and polymerization of MMA to obtain the PMMA graft modified GO on GO/Silica. Using modified GO to make Pickering emulsions, Pickering emulsion is divided into two systems. System (Ⅰ) is the change with different water / oil phase ratio, and System (Ⅱ) is change the ratio of different Pickering interface agent. Also, the Pickering interfacial agent is divided into : (1) reduced by hydrazine；(2) Without reduction by hydrazine. Through the analysis of G1S1M-4M by FTIR, the C-H stretching vibration can occur at 2964 cm-1. 1720 cm-1 for C=O stretching vibration, 1457 cm-1 for CH3 stretching vibration, and 1149 cm-1 for O-CH3 stretching vibration. These stretching vibration spectra indicate PMMA had successfully been polymerized on the surface of graphene oxide. Through the analysis of GO and G1S1M-4M by XRD, the diffraction peak of GO is at 2θ equals 10.88°, which corresponds to a d-spacing of 0.812 nm. The diffraction peak does not emerge for G1S1M-4M between 2θ= 1.5 o ~10 o , and the d-spacing is larger than 5.88 nm which indicates the delamination of GO. The sample of G1S1M-4M does not have the diffraction peaks because the stacking order was random, and exhibit an amorphous diffraction shoulder around 20 o. Similar to G1S1M-4M, the diffraction peak was not found for G1S1M-4M-e-r between 2θ = 1.5 o ~ 10 o. There are two possibilities that make this scenario successful. First, the exfoliation still exists after reduction of GO. Second, the stacking order of GO was random. Through static water contact angle measurements, the contact angles for G1S1M-4M-e was determined as 75.5 o. The contact angle increases as the grafting of PMMA increases. After reduction, the contact angles for G1S1M-4M-e-r increased to 87.5 o. The reason for the change in contact angle was due to removal of oxygen functional groups. Pickering emulsions were prepared by system (Ⅰ) and system (Ⅱ) containing modified graphene oxides, which were used as an emulsifier for HDDA and water. The emulsion type of G1S1M-4M-e is W/O. The samples of G1S1M-4M-e 1 wt% is for the volume ratio for water to HDDA 0.25, 0.5, and 1, emulsion average particle size is 172 μm, 267 μm and 321 μm respectively. The samples of G1S1M-4M-e 2 wt% with the volume ratio for water to HDDA 0.25, 0.5, and 1, emulsion average particle sizes are 167 μm, 256 μm and 321 μm. The samples of G1S1M-4M-e 3 wt% with the volume ratio for water to HDDA 0.25, 0.5, and 1, emulsion average particle sizes are 98 μm, 104 μm and 239 μm. The emulsion type of G1S1M-4M-e-r is W/O. The samples of G1S1M-4M-e-r 1 wt% is for the volume ratio for water to HDDA 0.25, 0.5, and 1, emulsion average particle size is 311 μm, 551 μm and 1088 μm respectively. The samples of G1S1M-4M-e-r 2 wt% with the volume ratio for water to HDDA 0.25, 0.5, and 1, emulsion average particle sizes are270 μm, 378 μm and 826 μm.The samples of G1S1M-4M-e-r 3 wt% with the volume ratio for water to HDDA 0.25, 0.5, and 1, emulsion average particle sizes are 201 μm, 279 μm and 759 μm. In the observation of these samples, the particle sizes were larger for samples after hydrazine reduction reactions. The reason is due to the aggregation of reduced graphene in the reduction procedure with the oily surface of graphene oxide in the continuous phase.