聚苯乙烯-石墨烯奈米複合材料：材料合成與其結構、電子、熱和機械性質之研究

Abstract

本文的工作是了解並促進生產石墨烯的研發和聚合物奈米複合材料石墨烯在材料科學領域的綜合性。一些研究表明，石墨烯是具有極端剛度超機械和電子性質的獨特的奈米材料，並且可能會強化聚合物表面和聚合物基質。然而，這是非常困難的插入均勻石墨至聚合物基質而不使用原位法，注射法，石墨烯或添加劑固定在石墨烯的官能化。因此，實驗設計是為了尋找另一種方式比那些方法。所作的實驗設計必須根據幾個參數，如混合的方法，所述的物理參數和在我們的實驗室中可用的材料是合理的。在這項研究中，我們採用重複測量表明適當的實驗方法。事實上，一些方法被開發，以提高在有機溶劑中和在聚合物基質中的石墨烯分散體中，通過物理吸附機理已經。刻劃已經取得看其分散體的改進根據聚合物，溶劑，所述聚合物的重量，時間，溫度和其插入的方法的類型。另外，所用的石墨烯在我們的實驗室，這是從等離子輔助電化學剝離獲得來自另一個團隊。正在開發的過程，但如在X射線衍射（XRD），原子力顯微鏡（AFM），掃描電子顯微鏡（SEM），透射電子顯微鏡（TEM），X射線光電子能譜法的實驗表徵技術（XPS），拉曼光譜和布魯諾爾，埃米特和Teller方法（BET）已取得。這些表徵已經證實，石墨，製作足夠數量與奈米片晶厚度特性。在本文中，我們研究了聚苯乙烯 - 石墨烯和聚（雙酚A碳酸酯）-graphene和其他奈米複合材料。第一聚合物奈米複合材料石墨烯用石墨烯溶液共混法隨後進行結構研究鑄造蒸發的方法進行。然後聚合物石墨烯的奈米複合材料薄膜，通過熔化方法的熱和機械的研究產生的。有聚合物的石墨烯的奈米複合材料薄膜用4點探針儀，通過熱重分析（TGA）和通過微力儀器。在加入石墨烯已經顯示出改進的奈米複合材料的選擇的特性如根據石墨加入或在聚合物的部分結構特性（形態學），熱特性（熱穩定性），電性能或機械性能。事實上，人們發現，從掃描型電子圖像，我們得到具有石墨烯的低含量更好的分散。然後，電研究表明，在低填料含量的導電性增加，然後達到臨界值。然後，將熱分析顯示該聚合物的熱穩定性有積極的影響。最後，機械的研究表明對機械性能顯著修改。我們還生產聚合物奈米複合材料石墨烯與石墨烯奈米片和收購石墨粉末買。事實上，聚合物的石墨烯購買和聚合物 - 石墨奈米複合材料製成，其特徵在於，然後用第一了對比。這些結果表明，使用和允許的準確判斷石墨烯的類型和我們的實驗設計的兼容性之間的差。一些前景被認為如使用1-8 Diiodooctane作為添加劑，使用共聚物（PSPI二嵌段共聚物）或不同的聚合物（聚氨酯，聚環氧乙烷）的。這些前景研究，已經制定了相同的實驗設計。考慮到製造過程中擬定新和靜止，這些研究已經開發了產生由石墨烯的質量分數加載高達7％的奈米複合材料薄膜。

The work of this thesis was to understand and to contribute to the development of production of graphene and the synthesis of polymer-graphene nanocomposites in the material science area. Several researches showed that graphene is a unique nanomaterial with an extreme rigidity super-mechanical and electronic properties, and that could reinforce the polymer surface and the polymer matrix. However, it is extremely difficult to insert uniformly graphene into the polymer matrix without using in-situ method, injection method, functionalization of the graphene or additives fixing the graphene. Thus, an experimental design was made to find another way than those methods. The experimental design made must be justified according to several parameters such as the mixing method, the physical parameters and the materials available in our lab. In this study, we employed repeated measures to suggest an appropriate experimental approach. Indeed, some approaches had been developed in order to increase the dispersion of the graphene in organic solvents and in the polymeric matrices, via physical adsorption mechanism. Characterizations had been made to see the improvement of its dispersion depending on the type of the polymer, the solvent, the weight of the polymer, the time, the temperature and its insertion’s method. Also, the graphene used came from another team in our lab, which is obtained from plasma-assisted electrochemical exfoliation. The process is being developed but experimental characterization techniques such as the X-ray diffraction (XRD), the atomic force microscope (AFM), the scanning electron microscope (SEM), the transmission electron microscope (TEM), the X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and Brunauer, Emmet and Teller method (BET) had been made. Those characterizations have confirmed that the graphene was produced in enough quantity with thickness characteristics of nano-platelets. In this thesis, we studied polystyrene-graphene and poly (Bisphenol A carbonate)-graphene and other nanocomposites. First polymer-graphene nanocomposites were made using graphene by solution blending method followed by casting-evaporation approach for structural study. Then polymer-graphene nanocomposites films were produced by melting method for thermal and mechanical studies. The polymer-graphene nanocomposites films were characterized by 4-point probe instrument, by thermo-gravimetric analysis (TGA) and by micro-force instruments. The addition of the graphene has shown improvements in selected properties of the nanocomposites such as structural properties (morphology), thermal properties (thermal stability), electrical properties or mechanical properties depending on the fraction of graphene added or the polymer. Indeed, it was found that from the scanning electron image, we obtained a better dispersion with low content of graphene. Then, the electrical study showed that at low filler content the conductivity increases and then reaches a critical value. Afterwards, the thermal analysis showed a positive influence on the thermal stability on the polymer. Finally, mechanical studies showed significant modifications on the mechanical properties. We also produce polymer-graphene nanocomposites with graphene-nanosheets bought and graphite powder bought. Indeed, polymer-graphene-bought and polymer-graphite nanocomposites were made, characterized and then compared with the first ones. These results showed a difference between the type of graphene used and allowed to judge the accuracy and the compatibility of our experimental design. Some prospects were considered such as the use of 1-8Diiodooctane as an additive, the use of copolymer (PSPI Diblock copolymer) or different polymers (Polyurethane, Polyethylene oxide). Those outlook studies have been developed with the same experimental design. Considering the fabrication process new and still in elaboration, these studies have been developed to produce nanocomposites films loaded by mass fractions of graphene up to 7%.