谭 蔚,朱皓楠,刘丽艳
AuthorsHTML:谭 蔚，朱皓楠，刘丽艳
AuthorsListE:Tan Wei,Zhu Haonan,Liu Liyan
AuthorsHTMLE:Tan Wei，Zhu Haonan，Liu Liyan
Unit:天津大学化工学院，天津 300350
Unit_EngLish:School of Chemical Engineering and Technology，Tianjin University，Tianjin 300350，China
Abstract_Chinese:氧化石墨在去除所含金属离子杂质和添加金属离子改性的过程中遇到的浆液发生逾渗转变现象会导致固液 分离过程终止，成为层状碳材料工业化生产及应用过程中亟待突破的瓶颈．为了调控氧化石墨浆液的状态，探究各 因素对浆液逾渗转变阈值的影响，本文选择电导率变化率作为监控逾渗转变是否发生的指标，在对各因素进行初步 筛选的基础上，采用正交试验法研究金属阳离子价态、溶液 pH 值和环境温度对氧化石墨浆液逾渗转变阈值的影响 以及各因素间的交互作用．采用 SEM、激光粒度仪、FT-IR 等手段表征了氧化石墨浆液发生逾渗转变前后的形貌、 尺寸及官能团种类数量等特征，进一步验证通过电导率变化率来描述结果的准确性．结果表明，金属阳离子价态、 溶液 pH 值和环境温度对逾渗转变过程均有影响，其中金属阳离子价态是影响逾渗转变现象发生的首要因素，溶液 pH 值次之，而环境温度的影响最不显著．离子价态和溶液 pH 值之间存在交互作用，随着金属阳离子化合价的升 高，氧化石墨逾渗转变过程受溶液 pH 值的影响逐渐减小．试验所得调控氧化石墨浆液最佳固液分离操作条件为三 价金属阳离子(N3)、pH 值 1.41(P1)和 35 ℃(T3)．相关结果可为氧化石墨纯化和改性过程中涉及的浆液状态调控提 供指导，利于后续的固液分离操作．
Abstract_English:The percolation transition process of graphite oxide(GO) slurry involving the removal of metal ion impurities and modification by adding metal ions disrupts the solid-liquid separation process. This has become an urgent problem in the industrialized production and application of layered carbon materials. To adjust the state of the GO slurry，the factors influencing the percolation transition process of the slurry were investigated. In this study，the conductivity change rate was selected as the indicator of percolation transition. On the basis of the preliminary screening of various factors， orthogonal experiments were conducted to analyze the influence of metal cation valence，solution pH，and ambient temperature on the percolation transition threshold of the GO slurry. Moreover，the interaction between factors was ana\u0002lyzed. Scanning electron microscopy，laser particle size analysis，Fourier transform infrared spectroscopy，and other methods were used to characterize the morphology，size，and functional groups of the GO slurry before and after percolation transition and verify the accuracy of the results obtained using the conductivity change rate. The results showed that metal cation valence，solution pH，and ambient temperature affect the percolation transition threshold. Among them， metal cation valence was the most important factor influencing the percolation transition process，followed by solution pH. The effect of ambient temperature was the least significant. Meanwhile，the interaction between metal cation valence and solution pH was observed. With the increase in metal cation valence，the effect of solution pH on the percolationtransition of GO gradually decreased. The optimal solid-liquid separation operating conditions for the controlled GO slurry obtained in the test were trivalent metal cations (N3)，pH value 1.41 (P1)，and 35 ℃(T3). The relevant results can provide guidance on how to control the state of the GO slurry during the purification and modification processes， which will improve the solid-liquid separation operations.
Keyword_Chinese:氧化石墨；逾渗转变阈值；金属阳离子；电导率；固液分离separation
Keywords_English:graphite oxide；percolation transition threshold；metal cation；electrical conductivity；solid-liquid separation

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