發(fā)布時(shí)間：2018-06-30 19:42

  本文選題：納米金球 + 聚合物基體�。� 參考：《江蘇大學(xué)》2017年碩士論文

【摘要】：近十年來(lái),柔彈性導(dǎo)電復(fù)合材料因其高彈性、高導(dǎo)電性的優(yōu)越性能而備受關(guān)注,在開發(fā)可彎曲和可拉伸的電子和光電子產(chǎn)品中起著不可或缺的作用。以金屬橡皮為代表的柔彈性導(dǎo)電復(fù)合材料的出現(xiàn),將極大地促進(jìn)相關(guān)產(chǎn)業(yè)的技術(shù)革新與智能化發(fā)展。與傳統(tǒng)復(fù)合材料的連續(xù)界面不同,納米復(fù)合材料中第二相的納米尺度效應(yīng)使得納米第二相與基體間的范德華作用增大,形成了獨(dú)特的“納米第二相-基體”納觀界面。這一界面構(gòu)成了納米第二相與基體之外的“第三相”,其對(duì)材料的納觀結(jié)構(gòu)以及宏觀材料的整體力學(xué)行為和性能都具有顯著的影響,因此對(duì)于該納觀界面本構(gòu)關(guān)系的建立、力學(xué)行為及性能的研究是準(zhǔn)確表征該類納米復(fù)合材料力學(xué)行為的關(guān)鍵點(diǎn)。目前對(duì)納米金球-聚乙烯基體界面力學(xué)性能的理論分析,以及分子動(dòng)力學(xué)模擬尚未見文獻(xiàn)報(bào)道,對(duì)金屬橡皮這一新型材料的納觀界面的研究仍具有很大的挑戰(zhàn)性。本文采用多尺度模擬方法,一方面,基于連續(xù)力學(xué)方法和蒙特卡羅方法,建立“單個(gè)納米金球+聚乙烯基體”和納米金球復(fù)合材料兩種模型,研究納米復(fù)合材料中“納米第二相-基體”界面的力學(xué)行為及性能;另一方面,利用分子動(dòng)力學(xué)模擬,比較“純聚乙烯”和“納米金球-聚乙烯”這兩種模型,研究納觀界面和環(huán)境變量對(duì)納米復(fù)合材料整體性能的影響。主要研究成果如下:(1)基于Lennard-Jones勢(shì),首次推導(dǎo)出了“球形納米填料-基體”界面的內(nèi)聚能量和內(nèi)聚應(yīng)力的解析式。(2)基于上述解析式,研究發(fā)現(xiàn)隨著金球半徑的增大,界面的內(nèi)聚能量(每單位面積)和內(nèi)聚強(qiáng)度均提高。并且在較小半徑下,曲率效應(yīng)作用很強(qiáng),隨著半徑的增大作用逐漸減弱,最后可忽略不計(jì)。(3)以往的研究均基于稀溶液假設(shè),不考慮金球之間的相互作用。本文首次探討了周圍納米復(fù)合材料中的金球?qū)缑娴挠绊?并且提出了稀溶液假設(shè)的適用范圍。(4)基于分子動(dòng)力學(xué)模擬,研究金球半徑和體積分?jǐn)?shù)、溫度、應(yīng)變速率對(duì)材料力學(xué)性能參數(shù)(楊氏模量、屈服應(yīng)力/應(yīng)變、斷裂應(yīng)力/應(yīng)變)的影響,通過(guò)比較得出“納米金球-聚乙烯”體系區(qū)別于“純聚乙烯”體系的納觀特性。
[Abstract]:In recent ten years, flexible and elastic conductive composites have attracted much attention because of their excellent properties of high elasticity and high conductivity, which play an indispensable role in the development of flexible and extensible electronic and optoelectronic products. The appearance of flexible elastic conductive composites represented by metal erasers will greatly promote the technological innovation and intelligent development of related industries. Different from the continuous interface of the traditional composites, the nanoscale effect of the second phase in the nanocomposites increases the van der Waals interaction between the nano-second phase and the matrix, forming a unique "nano-second phase-matrix" nano interface. This interface constitutes the "third phase" outside the second phase and the matrix, which has a significant effect on the nano structure of the material, as well as on the overall mechanical behavior and properties of the macroscopic material. Therefore, the constitutive relationship of the nano interface is established. The study of mechanical behavior and properties is the key point to accurately characterize the mechanical behavior of this kind of nanocomposites. At present, the theoretical analysis of the interface mechanical properties of nano-gold ball and polyethylene matrix and the molecular dynamics simulation have not been reported in the literature, and the study of the nano interface of metal rubber, a new material, is still very challenging. On the one hand, based on the continuous mechanics method and Monte Carlo method, two kinds of models of "single gold ball polyethylene matrix" and nano-gold ball composite material are established by using multi-scale simulation method. The mechanical behavior and properties of the interface between "nano-second phase and matrix" in nanocomposites were studied. On the other hand, the two models of "pure polyethylene" and "nano-gold ball polyethylene" were compared by molecular dynamics simulation. The effects of nano interface and environmental variables on the overall properties of nanocomposites were studied. The main results are as follows: (1) based on Lennard-Jones potential, the analytical expressions of cohesive energy and cohesive stress of "spherical nano-filler matrix" interface are derived for the first time. (2) based on the above analytical formula, it is found that with the increase of the radius of gold sphere, The cohesive energy (per unit area) and cohesion strength of the interface are increased. Moreover, the curvature effect is very strong in a small radius, which weakens gradually with the increase of radius. (3) the previous studies are based on the assumption of dilute solution and do not consider the interaction between the gold spheres. In this paper, the influence of the gold ball in the surrounding nanocomposites on the interface is discussed for the first time, and the applicable range of the dilute solution hypothesis is proposed. (4) based on the molecular dynamics simulation, the radius, volume fraction and temperature of the gold sphere are studied. The effect of strain rate on the mechanical properties of materials (Young's modulus, yield stress / strain, fracture stress / strain) was studied.
【學(xué)位授予單位】：江蘇大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TB33;TB383.1

【參考文獻(xiàn)】

相關(guān)期刊論文 前6條

1 CHEN Ying;LU BingWei;OU DaPeng;FENG Xue;;Mechanics of flexible and stretchable piezoelectrics for energy harvesting[J];Science China(Physics,Mechanics & Astronomy);2015年09期

2 馮雪;陸炳衛(wèi);吳堅(jiān);林媛;宋吉舟;宋國(guó)鋒;黃永剛;;可延展柔性無(wú)機(jī)微納電子器件原理與研究進(jìn)展[J];物理學(xué)報(bào);2014年01期

3 孫偉峰;王暄;;聚酰亞胺/銅納米顆粒復(fù)合物的分子動(dòng)力學(xué)模擬研究[J];物理學(xué)報(bào);2013年18期

4 李琳;王暄;孫偉峰;雷清泉;;聚乙烯/銀納米顆粒復(fù)合物的分子動(dòng)力學(xué)模擬研究[J];物理學(xué)報(bào);2013年10期

5 周松;王靜怡;張?jiān)俨?王霞;易鋒;;納米SiO_2/竹纖維/環(huán)氧樹脂復(fù)合材料性能研究[J];塑料助劑;2009年02期

6 李海東,龐洪寶,程鳳梅,杜春龍;m-LLDPE/nano-SiO_2復(fù)合材料的性能和形態(tài)結(jié)構(gòu)研究[J];塑料科技;2005年05期

，

本文編號(hào)：2086626