弹性体

Abstract(#br)Field emission (FE) properties of double-walled carbon nanotubes (DWCNTs) treated by polydimethylsiloxane (PDMS) elastomer with different heating temperature have been systematically studied. The current density of treated DWCNT films decreases with the increase of heating temperature. The screen-printed DWCNTs treated by PDMS elastomer with drying temperature 150\u003cce:hsp sp=\"0.25\"/\u003e°C for 20\u003cce:hsp sp=\"0.25\"/\u003emin have the best FE performance with a marvelous field enhancement factor ( β \u003cce:hsp sp=\"0.25\"/\u003e=\u003cce:hsp sp=\"0.25\"/\u003e20194).

Abstract(#br)The use of soft, synthetic materials for the replacement of soft, load-bearing tissues has been largely unsuccessful due to a lack of materials with sufficient fatigue and wear properties, as well as a lack of fundamental understanding on the relationship between material structure and behavior under cyclic loads.

Abstract(#br)The coefficient of thermal expansion (CTE) is a critical material property that represents the dimensional stability of a material under thermal loading. For soft materials such as elastomers, accurate measurement of the CTE is challenging due to the severe local deformation of the specimen in contact with the measuring apparatus. In this paper, a contact-free CTE measurement method is introduced for soft polymers using three-dimensional digital image correlation. The accuracy of the method was validated using various reference materials.

Abstract(#br)Mechanics of the extracellular matrix (ECM) play a pivotal role in governing cell behavior, such as cell spreading and differentiation. ECM mechanics have been recapitulated primarily in elastic hydrogels, including with dynamic properties to mimic complex behaviors (e.g., fibrosis); however, these dynamic hydrogels fail to introduce the viscoelastic nature of many tissues.

Stimuli-responsive materials undergo physicochemical, and/or structural changes when a specific actuation is applied. They are heterogeneous composites, consisting of a non-responsive matrix where functionality is provided by the filler. Surprisingly, the synthesis of Polydimethylsiloxane (PDMS)-based stimuli-responsive elastomers (SRE) has seldomly been presented. Here we present the structural, biological, optical, magnetic and mechanical properties of several magnetic SRE (M-SRE) obtained by combining PDMS and isoparafin-based ferrofluid (FF).

We have developed a modified-creep experiment with nanoindenter to measure the viscoelastic properties of elastomer films. Load-controlled experiments on PDMS (polydimethylsiloxane) films were performed using the Nano Indenter\n\t\t\t\t\t\t® XP with a flat-ended tip. By adapting the force–depth relation obtained by Choi et al. [S.T. Choi, S.R. Lee, Y.Y. Earmme, Acta Mater. (submitted for publication)], the indentation results were analyzed to obtain the relaxation modulus of the PDMS film as a function of time.

We have developed a technique to create polymer film patterns on substrates with microstructures using an elastomeric polydimethylsiloxane (PDMS) pad, wherein either a continuous or a patterned film on flat PDMS was used for pattern creation. During patterning of the continuous film, a polymer film is first spin coated onto the elastomer pad, and the pad is then brought into contact with the patterned substrate of interest.

文摘( # br )在大应变下，金属纤维与弹性体之间的界面粘结性能对保持可拉伸互连复合材料的结构完整性起着关键作用，但其界面粘结性能的机理仍不清楚。为此，采用纤维拔出试验和数值模拟的方法，研究了一种刚性金属纤维与超弹性弹性体基体之间的界面脱粘行为和物理机制。采用改进的圆柱形试样从聚二甲基硅氧烷( PDMS )中抽出铜纤维。采用Yeoh超弹性模型和黏聚力损伤模型，建立了模拟界面开裂的数值模型。我们报道了一种刚性纤维从弹性体中拔出过程的首次实物实验观察。结果表明，纤维拔出过程存在弹性变形、界面脱粘和界面摩擦三个阶段。刚性纤维与PDMS的界面剪切强度与PDMS混合比的倒数成正比，界面摩擦应力随混合比的1.25次方成反比变化。提高PDMS的混合比，由于PDMS内部和PDMS与金属材料界面的化学交联程度降低，使得PDMS和PDMS与金属材料界面的强度均降低，极限拉伸量增大。由数值模型得到的结果与试验数据吻合较好。这项工作可以帮助设计先进的可拉伸互连复合材料。