scholarly journals Mechanical Properties of Ultralow Density Graphene Oxide/Polydimethylsiloxane Foams

MRS Advances ◽  
2018 ◽  
Vol 3 (1-2) ◽  
pp. 61-66
Author(s):  
Cristiano F. Woellner ◽  
Peter S. Owuor ◽  
Tong Li ◽  
Soumya Vinod ◽  
Sehmus Ozden ◽  
...  

ABSTRACTLow-density, highly porous graphene/graphene oxide (GO) based-foams have shown high performance in energy absorption applications, even under high compressive deformations. In general, foams are very effective as energy dissipative materials and have been widely used in many areas such as automotive, aerospace and biomedical industries. In the case of graphene-based foams, the good mechanical properties are mainly attributed to the intrinsic graphene and/or GO electronic and mechanical properties. Despite the attractive physical properties of graphene/GO based-foams, their structural and thermal stabilities are still a problem for some applications. For instance, they are easily degraded when placed in flowing solutions, either by the collapsing of their layers or just by structural disintegration into small pieces. Recently, a new and scalable synthetic approach to produce low-density 3D macroscopic GO structure interconnected with polydimethylsiloxane (PDMS) polymeric chains (pGO) was proposed. A controlled amount of PDMS is infused into the freeze-dried foam resulting into a very rigid structure with improved mechanical properties, such as tensile plasticity and toughness. The PDMS wets the graphene oxide sheets and acts like a glue bonding PDMS and GO sheets. In order to obtain further insights on mechanisms behind the enhanced mechanical pGO response we carried out fully atomistic molecular dynamics (MD) simulations. Based on MD results, we build up a structural model that can explain the experimentally observed mechanical behavior.

RSC Advances ◽  
2021 ◽  
Vol 11 (24) ◽  
pp. 14484-14494
Author(s):  
Yahao Liu ◽  
Jian Zheng ◽  
Xiao Zhang ◽  
Yongqiang Du ◽  
Guibo Yu ◽  
...  

We successfully modified graphene oxide with amino-terminated hyperbranched polyamide (HGO), and obtained a high-performance composite with enhanced strength and elongation at break via cross-linking hydroxyl-terminated polybutadiene chains with HGO.


2010 ◽  
Vol 63 ◽  
pp. 147-151 ◽  
Author(s):  
David A. Schiraldi ◽  
Matthew D. Gawryla ◽  
Saeed Alhassan

A simple, inexpensive, and environmentally-friendly process for converting mixtures of clays and polymers has been developed. Polymer and clay are combined in water, and the mixtures are freeze dried to produce materials which have bulk densities typically in the range of 0.03 – 0.15 g/cm3. These low density polymer/clay aerogel materials possess good mechanical properties similar to those of traditional polymer foams, can be reinforced with fibers, modified with nanoparticles, biomineralized, or converted into porous ceramics.


2019 ◽  
Vol 31 (5) ◽  
pp. 557-569 ◽  
Author(s):  
Tong Sun ◽  
Huawei Zou ◽  
Ya Zhou ◽  
Rui Li ◽  
Mei Liang ◽  
...  

In this article, two types of functional graphene oxide (GO) with amine-rich surface were synthesized through chemically grafting two different molecular chain length trifunctional poly(oxypropylene)amines T5000 and T403, which were named as T5000-GO and T403-GO, respectively. The functionalized GO was then added to epoxy (EP) resin. Fourier transform infrared spectra analysis confirmed successful chemical functionalization on GO. Both T403-GO and T5000-GO were tightly embedded in the EP, because the amine-rich surface of functionalized-GO could form covalent bonds with the EP matrix, thereby contributing to the enhancement of mechanical properties. Particularly, T5000-GO, which has longer grafting molecule chains, achieved better compatibility and dispersibility in the EP matrix, resulting in a better reinforcing efficiency in mechanical properties. For example, the T5000-GO/EP composites showed an incremental enhancement in tensile strength with increasing filler concentrations, whereas their T403-GO/EP counterparts failed to follow the same trend. Meanwhile, the T5000-GO/EP composites with only 0.1-wt% T5000-GO achieved a prominent increase in flexural strength (approximately 50%) and flexural modulus (approximately 26.8%), which were higher than those of T403-GO-filled counterparts. This work indicated that the compatibility and interphase between GO and EP could be designed by manipulating the length of grafting molecule chains, thereby providing a better understanding of the relationship between the structure and mechanical properties of the graphene/EP nanocomposites.


2020 ◽  
Vol 20 (11) ◽  
pp. 6760-6767
Author(s):  
Seong Hwang Kim ◽  
Soo-Jin Park

Multiscale hierarchy is a promising chemical approach that provides superior performance in syner-gistically integrated microstructured fibers and nanostructured materials in composite applications. The main purpose of this work was to introduce graphene oxide (GO) between an epoxy matrix and basalt fibers to improve mechanical properties by enhancing interfacial adhesion. The composites were reinforced with various concentrations of GO. For all of the fabricated composites, the optimum GO content was found to be 0.5 wt%, which improved the interlaminar shear strength and fracture toughness by 66.2% and 86.1%, respectively, compared with those of neat composites. We observed a direct linear relationship between fracture toughness and certain surface free energy. In addition, the fracture toughness mechanisms were illustrated using a crack theory based on morphology analyses of fracture surfaces. Such an effort could accelerate the conversion of multi-scale composites into high-performance materials and provide rational guidance and fundamental understanding toward realizing the theoretical limits of mechanical properties.


2014 ◽  
Vol 67 (1) ◽  
pp. 121 ◽  
Author(s):  
Chen Lin ◽  
Yi-Tao Liu ◽  
Xu-Ming Xie

A simple and cost-effective strategy to create a strong interfacial interaction of coordination bonds in graphene oxide/poly(ethylene oxide) (GO/PEO) nanocomposites by divalent metal ions are demonstrated in this study. The strong interfacial interaction realizes efficient load transfer during the tensile process to significantly improve the mechanical properties of PEO. In addition, the dynamic interfacial interaction of coordination bonds minimizes the elongation loss. This strategy is applicable to a variety of polymer matrices containing coordination atoms, thus opens up a new opportunity for high-performance GO/polymer nanocomposites with significantly improved mechanical properties.


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