The origin of wrinkles on transferred graphene

When two-dimensional graphene is exfoliated from three-dimensional highly oriented pyrolytic graphite (HOPG), ripples or corrugations always exist due to the intrinsic thermal fluctuations. Surface-grown graphenes also exhibit wrinkles, which are larger in dimension and are thought to be caused by the difference in thermal expansion coefficients between graphene and the underlying substrate in the cooling process after high temperature growth. For further characterization and applications, it is necessary to transfer the surface-grown graphenes onto dielectric substrates, and other wrinkles are generated during this process. Here, we focus on the wrinkles of transferred graphene and demonstrate that the surface morphology of the growth substrate is the origin of the new wrinkles which arise in the surface-to-surface transfer process; we call these morphology-induced wrinkles. Based on a careful statistical analysis of thousands of atomic force microscopy (AFM) topographic data, we have concluded that these wrinkles on transferred few-layer graphene (typically 1–3 layers) are determined by both the growth substrate morphology and the transfer process. Depending on the transfer medium and conditions, most of the wrinkles can be either erased or preserved. Our work suggests a new route for graphene engineering involving structuring the growth substrate and tailoring the transfer process.      

Non-lithographic patterning of phage-displayed peptides with wrinkled elastomers

The development of controlled patterning of phage (viruses) could expand opportunities for both fundamental studies and creating various materials platforms. Inducing the elastomeric instability of PDMS film provides a non-lithographic, tuneable, controlled method for generating micro/nanoscale wrinkle patterns. Phage display has emerged as a powerful method for selecting peptides that possess enhanced selectivity and binding affinity toward a variety of targets. In this report, we demonstrate the non-lithographic patterning of phage-displayed peptides with wrinkled elastomers. Our results show that the phage-displayed peptides can be patterned on specific locations in controlled and tuneable ways, be transferred to other substrates and induce the self-assembly of hybrid materials. We anticipate that these results could open up exciting opportunities in fundamental studies and in applications ranging from sensors, hybrid materials, self-assembly, surface and interface, to micro/nanoelectronics.     

基于屈诱多形态力学测试的织物外观平整度表征

针对现有基于图像或视觉原理的织物外观平整度的测试方法易受到织物复杂花型和纹理的影响,存在织物品类适应性差等不足,提出基于后屈曲诱导的织物多形态构建和力学性能原位检测原理的织物外观平整度表征手段.选取30块织物试样进行多重形变下的原位力学测试,分别提取力-位移测试曲线的5个特征指标,利用SPSS软件对提取的织物特征指标及...     

棉织物羟丙基-β-环糊精接枝整理工艺研究

以无甲醛树脂Arkofix NZF为交联剂,MgCl2·6H2O为催化剂,采用轧-烘-焙工艺,用羟丙基-β-环糊精(HP-β-CD)整理棉织物。研究了HP-β-CD的质量浓度、树脂质量浓度、MgCl2·6H2O质量浓度、pH值、焙烘温度和时间等因素对织物性能的影响,确定最佳接枝工艺为:HP-β-CD质量浓度50g/L,树脂质量浓度60g/L,MgCl2·6H2O质量浓度10g/L,pH值5.5,焙烘温度170℃,焙烘时间3min。结果表明,经HP-β-CD整理的织物折皱回复角和接枝率比经β-CD整理后的高。     

几种不同组织结构的衬衫面料保形性研究

根据常见的衬衫面料组织结构,使用JC9.7 tex纱线设计了6种不同组织结构的面料,研究不同组织结构对织物保形性的影响。对面料的保形性(尺寸稳定性、抗折皱性、外观平整度、抗起毛起球性、顶破性、悬垂性)及舒适性(透气、透湿性)进行了测试。结果表明:组织结构对织物的折皱回复角、外观平整度等级、顶破强力、透湿量与透气率有直接影响;织物紧度太大、太小都不利于织物的折皱回复,相同紧度下斜纹组织的抗皱性比平纹好;6种组织结构中2/2斜纹组织抗折皱性最好,2/2方平组织的顶破强力、抗起毛起球等级最高,2/2破斜纹透气、透湿性最好,2/2斜纹组织具有良好的保形性。     

纯棉织物折皱回复角与其组织结构参数的关系

为从织物自身组织结构方面优化纯棉织物的折皱性,首先设计织物组织结构参数并制备织物,利用数字式织物折皱弹性仪测得织物的折皱回复角。在此基础上,建立纯棉织物经、纬向和总折皱回复角与织物组织结构参数(包括经纬纱线密度、经纬纱捻度、经纬向密度)之间的线性回归方程;同时分析织物折皱回复角与各组织结构参数间的相关性。结果表明:回归方程的计算值与折皱回复角实测值绝对误差不超过0.61°,回归方程具有较高的实用性;经纬纱捻度、线密度对纯棉织物的折皱回复性影响最大,可通过提高经纬纱捻度、降低经纬纱线密度来改善纯棉织物的抗皱性。     

羊毛角蛋白溶液在毛织物定型中的应用

采用自制的羊毛角蛋白溶液整理毛织物,通过正交试验选择合理的整理工艺参数,得到最优工艺为:羊毛角蛋白溶液用量15%(o.w.f)、处理温度75℃、处理时间60 min、浴比1∶25。对比整理前后毛织物的性能发现:毛织物毡缩率由17.85%下降到4.1%;急弹性回复角从144.2°提高到215°;断裂强力小幅提高而断裂伸长下降。整理后织物的毡缩率显著下降,折痕回复性提高,断裂强力增加而伸长下降,毛织物定型效果得到改善。     

浅锥形刻度盘成形工艺

介绍了浅锥形件正反拉伸成形工艺特点及模具结构设计要点 ,分析刻度盘在成形过程中产生的缺陷 ,并提出了防止措施     

Analysis on membrane wrinkling using stress extremum method

A stress extremum method is developed based on Von Karman equations for analysis of membrane wrinkles in this paper.A mechanical model is also established for analyzing shear membrane wrinkles.Expressi...