本文關(guān)鍵詞：石墨烯調(diào)控PEG相變材料的設(shè)計、制備及其構(gòu)效關(guān)系研究　出處：《西南科技大學》2017年碩士論文　論文類型：學位論文

  更多相關(guān)文章： 相變材料 聚乙二醇 石墨烯 構(gòu)效關(guān)系 調(diào)控

【摘要】：相變儲能材料是新型能源材料的重要組成部分,作為一種先進的儲能材料,材料發(fā)生相態(tài)變化時會吸收或釋放出相變潛熱。相變材料不僅可以將間歇性、不穩(wěn)定的能量儲存起來,解決能源使用在時間和空間的不匹配問題,而且是提高太陽能、風能、地熱能、工業(yè)余熱等能源方面儲存管理的最佳候選。在提高能源利用效率,緩解環(huán)境與能源壓力方面具有重要的意義。聚乙二醇(PEG)相變材料是新型有機相變材料研究領(lǐng)域的重要分支,PEG具有接近人體適宜的相變溫度,較高相變潛熱及耐腐蝕性,相變過程近似恒溫,PEG的相變材料適宜于低溫,其溫度可以通過分子量設(shè)計。但PEG作為相變材料目前面臨以下缺點:導熱率較低、相變過程易滲漏、熱穩(wěn)定性差的缺陷,嚴重阻礙了PEG相變材料的應用價值。但PEG作為相變材料目前面臨以下缺點:導熱率較低、相變過程易滲漏、熱穩(wěn)定性差的缺陷,嚴重阻礙了PEG相變材料的應用價值。本論文采用Hummers法制備氧化石墨烯(Graphene Oxide,GO),一步水熱法制備了三維石墨烯凝膠復合PEG相變材料,采用抗壞血酸(Vitamin C,Vc)作為還原劑。這種三維網(wǎng)絡(luò)結(jié)構(gòu)不僅為PEG傳熱提供導熱通道,而且還為解決PEG滲漏性提供了支撐載體,隨著還原程度的增加,氧化石墨烯片層缺陷降低,就能夠達到與石墨烯近似的熱物理化學性質(zhì)。與純PEG相比,三維石墨烯凝膠復合PEG相變材料相變焓損失率低于1%,導熱率提高了61.7%,PEG含量可達99.3%。材料在70℃恒溫30min后,沒有發(fā)生液體的滲漏現(xiàn)象。當還原程度最大時,熱穩(wěn)定性相比純PEG提高了約20℃。另外,氧化石墨烯的表面含氧官能團以及PEG分子的可設(shè)計性,具備采用化學法制備功能化PEG相變材料的優(yōu)勢。本文采用SOCl2將氧化石墨烯表面的羧基官能團酰氯化,酰氯化的氧化石墨烯表面就具有高的化學反應活性,含氧官能團的減少使得氧化石墨烯缺陷降低,既提高了氧化石墨烯表面化學活性,又對氧化石墨烯進行了還原。實驗選用溫敏性有機小分子三聚氰氯對酰氯化的氧化石墨烯改性,制備石墨烯無機-有機功能化載體,當載體完全氨基化之后,氨基活性位點為PEG的改性提供了支撐點,采用4-4’-二苯甲烷二異氰酸酯改性使得PEG端位帶有活性氰酸跟,活性氰酸跟與氨基化的載體聚合制備一體化的石墨烯功能化復合PEG相變材料。獲得材料的相變焓損失率低至5.3%,導熱率提高了69.5%,熱分解溫度提高了50℃,在70℃、90℃和110℃分別30min內(nèi)沒有滲漏現(xiàn)象發(fā)生。石墨烯凝膠復合PEG相變材料和石墨烯功能化復合PEG相變材料的制備,實現(xiàn)了高導熱率、抗?jié)B漏及熱穩(wěn)定性一體化的PEG復合相變材料。
[Abstract]:Phase change energy storage material is an important part of new energy materials. As an advanced energy storage material, phase change will absorb or release phase change latent heat. Unstable energy is stored to solve the problem of time and space mismatch of energy use, but also to improve solar, wind, geothermal energy. The best candidate for energy storage management, such as industrial waste heat, in improving energy efficiency. Polyethylene glycol (PEG) phase change material is an important branch of the research field of new organic phase change materials. PEG has close to the suitable phase transition temperature of human body. The phase change materials with high latent heat and corrosion resistance are suitable for low temperature. The temperature can be designed by molecular weight. However, as phase change material, PEG is faced with the following shortcomings: low thermal conductivity, easy leakage during phase transition, and poor thermal stability. The application value of PEG phase change material is seriously hindered, but PEG as phase change material is faced with the following shortcomings: low thermal conductivity, easy leakage of phase transition process and poor thermal stability. The application value of PEG phase change material has been seriously hindered. In this paper, graphene oxide graphene oxide oxide is prepared by Hummers method. Three-dimensional graphene gel composite PEG phase change material was prepared by one-step hydrothermal method. Vitamin C was used as ascorbic acid. As a reducing agent, this three-dimensional network structure not only provides a heat conduction channel for PEG heat transfer, but also provides a support carrier for solving the leakage of PEG, with the increase of reduction degree. With the reduction of graphene oxide lamellar defects, the thermal physicochemical properties of graphene can be achieved. Compared with pure PEG, the phase change enthalpy loss rate of PEG phase change material is less than 1%. The thermal conductivity was increased by 61.7% and the PEG content could reach 99.3.After 30 min of constant temperature at 70 鈩，

本文編號：1427023