Ailan QU
,
Xiufang WEN
,
Pihui PI
,
Jiang CHENG
,
Zhuoru YANG
材料科学技术（英文）
Fluoropolymer and different kinds of silica particles were used for controlling surface chemistry and morphology, respectively. A superhydrophobic surface originated from strawberry-like or quincunx-shaped composite silica particles was obtained. The dual size particles are obtained by utilizing the graft of different modified silica particles with epoxy functional group and amine functional group. This makes the surface of film form a composite interface to have irregular binary structure which plays an essential role in trapping air between the substrate surface and the liquid droplets to be necessary for high contact angle and low contact angle hysteresis. The maximum contact angle for water on the hybrid film is about 174±2° and the contact angle hysteresis is less than 2°. The surface morphologies, roughness and the wettability on the surface of films containing different structural silica particles were compared. It was shown that the hierarchical irregularly structure with a low roughness factor and high air-trapped ratio is indispensable for superhydrophobic surface. Although this structural surfaces based on composite silica particles play a vital role in governing the surface wettability, it is necessary to combine with a low surface energy to make the surface superhydrophobic.
关键词:
Superhydrophobicity
,
双微观结构
,
纳米复合粒子
,
含氟硅
李常清
,
袁姗
,
罗荣
,
郭雅明
,
徐樑华
高分子材料科学与工程
将聚酰亚胺(PI)加入丙烯腈-衣康酸-二甲基亚砜体系进行聚丙烯腈(PAN)溶液聚合,湿法纺丝制备了PAN/PI复合纤维.利用流变仪、红外光谱、X射线衍射仪、扫描电镜、差示扫描量热仪等研究了PAN/PI溶液的性质和复合纤维的结构特点.研究发现,加入PI后,聚合物溶液的稳态黏度降低,弹性和粘性模量在低剪切速率区降低;PI作为成核剂,引起初生纤维结晶度增大、晶粒尺寸减小;PI与PAN的溶解性差异导致凝固加快,初生纤维形成皮芯结构;引起原丝体密度减小.PAN/PI纤维在N2下放热量较少,在空气中由于结构疏松放热量较大.
关键词:
聚丙烯腈纤维
,
聚酰亚胺
,
原液改性
,
晶态结构
Journal of Physics-Condensed Matter
We carry out density matrix renormalization group (DMRG) calculations to study pi-topology and spin alignment of an organic pi-conjugated spin system in the Hubbard model. We discuss the spin correlation, the energy gap and the lattice configuration in half-filled and doped systems. It is confirmed that electronic doping can alter the spin state, and the spin alignment is influenced by the parity of the total site number N. The electron-electron interaction is in favour of the ferromagnetic stability of the system. For the hall-filled odd case and the hole-doped even case, there exist strong ferromagnetic correlation and large energy gap in pi-conjugated spin systems.
关键词:
model;ferromagnets
殷景华
,
杨红军
,
梅金硕
,
雷清泉
高分子材料科学与工程
利用Materials Studio 3.0分别模拟了聚酰亚胺(PI)/α-Al2O3和聚酰亚胺(PI)/SiO2材料体系的表面结合能,结果表明,在(012)晶面,6.0 nm×4.0 nm范围内,随着纳米颗粒超晶格尺寸增大,PI/α-Al2O3结合能增加,PI/SiO2体系结合能变小;悬挂在α-Al2O3和SiO2(012)晶面上的H原子对体系总能量及结合能有明显影响,α-Al2O3和SiO2纳米颗粒掺杂主要通过分子间作用力与PI相复合.
关键词:
分子模拟
,
结合能
,
聚酰亚胺
,
α-氧化铝
,
氧化硅
李卓
,
刘金刚
,
杨海霞
,
范琳
,
杨士勇
宇航材料工艺
doi:10.3969/j.issn.1007-2330.2011.01.011
采用含醚键的不对称二酐单体,2,3,3',4'-二苯醚四酸二酐(aODPA)与三种芳香族二胺单体分别聚合制备了一系列PI薄膜.研究了aODPA-PI的结构与耐热稳定性、溶解性、力学以及光学性能的关系.结果表明,aODPA的不对称结构赋予了PI良好的溶解性能与光学透明性,在450 nm波长下的透光率超过85%.同时,PI薄膜还保持了优良的耐热稳定性及良好的力学性能,其氮气中的T5d超过510℃,拉伸强度超过了80 MPa.
关键词:
聚酰亚胺
,
光学透明性
,
耐热稳定性
,
力学性能
寇玉洁
,
张盼盼
,
牛永安
,
刘俊凯
,
白瑞
,
李垚
表面技术
目的 拓宽碳化硅增强聚酰亚胺(SiC/PI)复合薄膜在耐磨涂层领域的应用.方法 利用流延成膜法制备SiC/PI复合薄膜,在氮气氛围中对复合薄膜进行600～1000℃的碳化处理,并对碳化后的薄膜进行SEM,XRD及FNR等测试,分析碳化过程中组织结构的变化.结果 由于SiC纳米颗粒起到物理交联点的作用,复合薄膜的热稳定性和残碳率得到提高,同时也具有了断裂塑性特征.随着碳化温度升高,复合薄膜六角碳层结构逐步完善.PI在碳化中,芳核自由基聚合成环数更多的分子,且SiC与PI的界面处产生Si-O键.结论 碳化过程中,SiC纳米粒子与PI作用形成微弱的化学键合,改善了碳膜的界面结合情况,使得其耐热性得到提高.
关键词:
SiC/PI复合薄膜
,
耐磨涂层
,
碳化
,
微观结构
Synthetic Metals
We study the spin configuration of pi electrons and the dimerization in a conjugated polymer chain with a bipartite lozenge structure. By unrestricted Hartree-Fock approximation, it is found that around the middle of the chain appears a a electron spin polarization cloud with alteration of sign and amplitude of the spin density extending over a certain distance. In the stable ferrimagnetic state, the antiferromagnetic exchange interaction between electrons will become very strong, and almost zero dimerization happens for the chain.
关键词:
organic ferromagnetic polymers;magnetic phase transitions;spin density;wave;hubbard chains
霍丽霞
,
周晖
,
桑瑞鹏
,
张凯锋
,
蒋钊
宇航材料工艺
doi:10.3969/j.issn.1007-2330.2015.01.013
对钛合金表面的PI/MoS2涂层进行了湿热老化试验,在70℃、98％ RH条件下存储长达27 d.采用衰减全反射红外光谱和透射红外光谱分别对涂层表面及涂层进行分析测试,利用X射线光电子能谱对涂层表面成分进行分析.通过球盘摩擦试验机考察了湿热老化对润滑涂层的真空及大气摩擦性能的影响.采用拉脱法测试了湿热老化前后涂层附着力.结果表明,湿热会导致PL/MoS2润滑涂层表面的胶黏剂聚酰亚胺被水解侵蚀,膜层表面深度在50 nm以内的部分MoS2被氧化.湿热试验前后涂层的真空耐磨寿命降低13％,大气耐磨寿命降低16％;真空摩擦因数略有增加且波动增大,而大气摩擦因数显著增加,涂层附着强度也略显降低.
关键词:
湿热老化
,
聚酰亚胺
,
润滑涂层
,
摩擦学性能
,
红外光谱
刘杨秋
,
梁彤祥
,
付志强
,
倪晓军
,
赵福群
稀有金属材料与工程
聚酰亚胺(PI)材料具有介电常数低,分解温度高及化学稳定性好等优点,是很有前途的电子封装材料.Cu具有低的电阻和高的抗电迁移能力,是PI基板金属化的首选材料.采用物理气相沉积(PVD)方法在PI基板上沉积Cu薄膜,利用TiN陶瓷薄膜阻挡Cu向PI基板内部扩散.研究热处理条件下TiN陶瓷薄膜阻挡层的阻挡效果、Cu膜电阻变化以及Cu膜的结合强度,俄歇谱图分析表明TiN可以有效地阻挡Cu向PI内的扩散.300℃热处理消除了Cu膜内应力,提高了Cu膜的结合强度.
关键词:
聚酰亚胺
,
铜薄膜
,
TiN
,
热处理
