本文選題：電熱特性 + 石墨納米片��； 參考：《哈爾濱工業(yè)大學》2017年碩士論文

【摘要】：石墨烯產(chǎn)品的科學研究以及工程應(yīng)用成為科技工作者以及工程技術(shù)人員努力開發(fā)的熱點。而石墨烯電熱制品,是最接近市場應(yīng)用的一類產(chǎn)品,因此開展本文工作,勢在必行。電熱材料是通過焦耳效應(yīng)將電能轉(zhuǎn)化為熱能的材料,目前主要使用的電熱材料是由重金屬合金制成的電阻絲。但金屬電熱材料存在重量大,不耐腐蝕,冶煉污染嚴重等缺點,需要找到一種新的電熱材料來替代它。石墨納米片(GNS)不僅導電能力非常優(yōu)良,環(huán)境友好,而且具有價格低廉,熱轉(zhuǎn)換效率高的優(yōu)點;另外,石墨制品電熱紅外特性還具有保健理療的特殊效果,非常適合替代金屬成為新的電熱材料。但石墨納米片在水溶液中易團聚,不利于加工,需要對它進行一定程度的改性。本文以石墨納米片為原料制作一種電熱薄膜,分析這種電熱膜的各項性能,并嘗試對納米片進行一定的改性,研究改性對薄膜的影響,最后對產(chǎn)生影響的原理進行了探討。以膨脹石墨為原料,通過超聲剝離的方法制備石墨納米片。將這種石墨納米片作為導電填料,硅酸鈉溶液做為成膜基質(zhì),使用凹版印刷法制備了一種無機電熱膜。對這種電熱膜進行分析,發(fā)現(xiàn)其具有非常高的發(fā)熱效率和電導率,在無機材料的表面附著力非常強,加速壽命試驗證明它有超過20萬個小時(22年)的使用壽命。進一步研究發(fā)現(xiàn),薄膜的電導率與納米片的添加量成正比,這一結(jié)果與滲流閾值模型的預(yù)測相符合;薄膜的尺寸與納米片的大小也對導電能力有影響,其實質(zhì)是影響石墨納米片之間相互接觸的概率。使用硫酸氧鈦作為鈦源,利用水熱法對石墨納米片進行改性,并研究了水熱的溫度、預(yù)氧化和分散劑對改性的影響。分析測試結(jié)果表明,石墨納米片的表面生成了一層由大量二氧化鈦小顆粒組成的薄膜,并于石墨納米片之間存在化學鍵上的聯(lián)系。水熱溫度在140℃下有最好的結(jié)果,預(yù)氧化能增多二氧化鈦附著的位點,生成了大量的直徑50nm以上的大顆粒;六偏磷酸鈉對改性有著較強的促進作用,可以使改性產(chǎn)物有著更大的比表面積。將改性后的納米片制成電熱膜,與未改性的薄膜對比發(fā)現(xiàn),改性后制作的薄膜電阻由34Ω下降至19Ω,并有著更高的使用溫度。結(jié)合對改性納米片的分析,發(fā)現(xiàn)電導率的提升是三種因素的共同作用:二氧化鈦顆粒阻止納米片堆疊,納米片由疏水變?yōu)橛H水以及硅酸鈉對二氧化鈦的分散作用。
[Abstract]:The scientific research and engineering application of graphene products have become the focus of scientific and technical researchers and engineers. The graphene electrothermal products are the most close to the market application, so it is imperative to carry out the work in this paper. Electrothermal material is a kind of material which converts electric energy into heat energy by Joule effect. At present, the main electrothermal material used is resistance wire made of heavy metal alloy. However, metal electrothermal materials have many disadvantages, such as heavy weight, low corrosion resistance, serious smelting pollution and so on, so it is necessary to find a new electrothermal material to replace it. The graphite nanochip GNS not only has excellent electrical conductivity, friendly environment, but also has the advantages of low price and high efficiency of heat conversion. In addition, the electrothermal infrared characteristic of graphite products also has the special effect of health therapy. It is very suitable to replace metal as a new electrothermal material. However, graphite nanoparticles are easy to agglomerate in aqueous solution, which is not conducive to processing, so it needs to be modified to some extent. In this paper, a kind of electrothermal film was made from graphite nanosheet. The properties of the film were analyzed, and the influence of the modification on the film was studied. Finally, the principle of the influence was discussed. Graphite nanoparticles were prepared by ultrasonic stripping from expanded graphite. A kind of inorganic electrothermal film was prepared by gravure printing using the graphite nanochip as conductive filler and sodium silicate solution as film forming matrix. It is found that the electrothermal film has a very high heating efficiency and conductivity and strong adhesion on the surface of inorganic materials. The accelerated life test shows that it has a service life of more than 200,000 hours (22 years). Furthermore, it is found that the conductivity of the films is proportional to the amount of nanocrystalline films, which coincides with the prediction of the percolation threshold model, and the size of the films also have an effect on the conductivity. Its essence is to influence the probability of contact between graphite nanoparticles. Graphite nanoparticles were modified by hydrothermal method using titanium sulfate as titanium source, and the effects of hydrothermal temperature, preoxidation and dispersant on the modification were studied. The results show that a thin film composed of a large number of titanium dioxide particles is formed on the surface of graphite nanocrystalline and there is a chemical bond relationship between graphite nanocrystals. Hydrothermal temperature at 140 鈩，

本文編號：1947406