Superior mechanical performance of in-situ nanofibrillar HDPE/PTFE composites with highly oriented and compacted nanohybrid shish-kebab structure

2021 ◽  
Vol 207 ◽  
pp. 108715
Author(s):  
Tong Liu ◽  
Jiajun Ju ◽  
Feng Chen ◽  
Bozhen Wu ◽  
Jintao Yang ◽  
...  
2021 ◽  
Vol 5 (7) ◽  
pp. 191
Author(s):  
Yanshuai Wang ◽  
Siyao Guo ◽  
Biqin Dong ◽  
Feng Xing

The functionalization of graphene has been reported widely, showing special physical and chemical properties. However, due to the lack of surface functional groups, the poor dispersibility of graphene in solvents strongly limits its engineering applications. This paper develops a novel green “in-situ titania intercalation” method to prepare a highly dispersed graphene, which is enabled by the generation of the titania precursor between the layer of graphene at room temperature to yield titania-graphene nanocomposites (TiO2-RGO). The precursor of titania will produce amounts of nano titania between the graphene interlayers, which can effectively resist the interfacial van der Waals force of the interlamination in graphene for improved dispersion state. Such highly dispersed TiO2-RGO nanocomposites were used to modify epoxy resin. Surprisingly, significant enhancement of the mechanical performance of epoxy resin was observed when incorporating the titania-graphene nanocomposites, especially the improvements in tensile strength and elongation at break, with 75.54% and 176.61% increases at optimal usage compared to the pure epoxy, respectively. The approach presented herein is easy and economical for industry production, which can be potentially applied to the research of high mechanical property graphene/epoxy composite system.


Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 446
Author(s):  
Ioannis Spanos ◽  
Zacharias Vangelatos ◽  
Costas Grigoropoulos ◽  
Maria Farsari

The need for control of the elastic properties of architected materials has been accentuated due to the advances in modelling and characterization. Among the plethora of unconventional mechanical responses, controlled anisotropy and auxeticity have been promulgated as a new avenue in bioengineering applications. This paper aims to delineate the mechanical performance of characteristic auxetic and anisotropic designs fabricated by multiphoton lithography. Through finite element analysis the distinct responses of representative topologies are conveyed. In addition, nanoindentation experiments observed in-situ through scanning electron microscopy enable the validation of the modeling and the observation of the anisotropic or auxetic phenomena. Our results herald how these categories of architected materials can be investigated at the microscale.


2021 ◽  
Vol 11 (23) ◽  
pp. 11286
Author(s):  
Marina Paula Secco ◽  
Débora Thaís Mesavilla ◽  
Márcio Felipe Floss ◽  
Nilo Cesar Consoli ◽  
Tiago Miranda ◽  
...  

The increasingly strong search for alternative materials to Portland cement has resulted in the development of alkali-activated cements (AAC) that are very effective at using industrial by-products as raw materials, which also contributes to the volume reduction in landfilled waste. Several studies targeting the development of AAC—based on wastes containing silicon and calcium—for chemical stabilization of soils have demonstrated their excellent performance in terms of durability and mechanical performance. However, most of these studies are confined to a laboratory characterization, ignoring the influence and viability of the in situ construction process and, also important, of the in situ curing conditions. The present work investigated the field application of an AAC based on carbide lime and glass wastes to stabilize fine sand acting as a superficial foundation. The assessment was supported on the unconfined compressive strength (UCS) and initial shear modulus (G0) of the developed material, and the field results were compared with those prepared in the laboratory, up to 120 days curing. In situ tests were also developed on the field layers (with diameters of 450 and 900 mm and thickness of 300 mm) after different curing times. To establish a reference, the mentioned precursors were either activated with a sodium hydroxide solution or hydrated with water (given the reactivity of the lime). The results showed that the AAC-based mixtures developed greater strength and stiffness at a faster rate than the water-based mixtures. Specimens cured under controlled laboratory conditions showed better results than the samples collected in the field. The inclusion of the stabilized layers clearly increased the load-bearing capacity of the natural soil, while the different diameters produced different failure mechanisms, similar to those found in Portland cement stabilization.


2020 ◽  
Vol 44 (10) ◽  
pp. 4092-4098 ◽  
Author(s):  
Yu-wei Liu ◽  
Ping Wang ◽  
Jun Wang ◽  
Bo Xu ◽  
Jin Xu ◽  
...  

A kind of transparent poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogels with superior mechanical performance is prepared by in situ free radical polymerization of HEMA in water/BmimCl mixtures followed by the exchange of BmimCl with water.


2020 ◽  
Vol 240 ◽  
pp. 116313 ◽  
Author(s):  
Da Bao ◽  
Lisha Liu ◽  
Ting Sun ◽  
Ying Han ◽  
Fanliang Meng ◽  
...  

RSC Advances ◽  
2016 ◽  
Vol 6 (4) ◽  
pp. 3176-3185 ◽  
Author(s):  
Xiang-Fang Peng ◽  
Kai-Can Li ◽  
Hao-Yang Mi ◽  
Xin Jing ◽  
Bin-Yi Chen

In this work, we compounded polystyrene (PS) and polytetrafluoroethylene (PTFE) with poly(propylene carbonate) (PPC) to prepare multiphase composites that possess special properties and to improve the extrusion foaming ability of PPC.


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