Exploring the diversity of elastic responses of crystalline cadmium(ii) coordination polymers: from elastic towards plastic and brittle responses

CrystEngComm ◽  
2021 ◽  
Author(s):  
Mateja Pisačić ◽  
Ivan Kodrin ◽  
Ivana Biljan ◽  
Marijana Đaković

Noticeable differences in mechanically induced elastic responses were observed for isostructural crystalline coordination polymers, and their mechanical properties were examined through a highly integrated approach, using both theory and experiment.

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 497
Author(s):  
Filippo Marchelli ◽  
Giorgio Rovero ◽  
Massimo Curti ◽  
Elisabetta Arato ◽  
Barbara Bosio ◽  
...  

Valorising biomass waste and producing renewable energy or materials is the aim of several conversion technologies. In this work, we consider two residues from different production chains: lignocellulosic residues from agriculture and wool residues from sheep husbandry. These materials are produced in large quantities, and their disposal is often costly and challenging for farmers. For their valorisation, we focus on slow pyrolysis for the former and water hydrolysis for the latter, concisely presenting the main literature related to these two processes. Pyrolysis produces the C-rich biochar, suitable for soil amending. Hydrolysis produces a N-rich fertiliser. We demonstrate how these two processes could be fruitfully integrated, as their products can be flexibly mixed to produce fertilisers. This solution would allow the achievement of balanced and tuneable ratios between C and N and the enhancement of the mechanical properties. We propose scenarios for this combined valorisation and for its coupling with other industries. As a result, biomass waste would be returned to the field, following the principles of circular economy.


Author(s):  
Salah Eddine Brika ◽  
Yaoyao Fiona Zhao ◽  
Mathieu Brochu ◽  
Justin Mezzetta

This paper proposes an integrated approach to determine optimal build orientation for powder bed fusion by laser (PBF-L), by simultaneously optimizing mechanical properties, surface roughness, the amount of support structure (SUPP), and build time and cost. Experimental data analysis has been used to establish the objective functions for different mechanical properties and surface roughness. Geometry analysis of the part has been used to estimate the needed SUPP and thus evaluate the build time and cost. Normalized weights are assigned to different objectives depending on their relative importance allowing solving the multi-objective optimization problem using a genetic optimization algorithm. A study case is presented to demonstrate the capabilities of the developed system. The major achievements of this work are the consideration of multiple objectives and the establishment of objective function considering different load direction and heat treatments. A user-friendly graphical user interface was developed allowing to control different optimization process factors and providing different visualization and evaluation tools.


2016 ◽  
Vol 40 (3) ◽  
pp. 1997-2006 ◽  
Author(s):  
Kaustuv Banerjee ◽  
Kumar Biradha

The ligands containing chelating as well as exodentate functional groups were shown to form functional coordination polymers and heterometallic gels.


Author(s):  
O. Glotka ◽  
V. Olshanetskii

Purpose. The aim of the work is to obtain predictive regression models, with the help of which, it is possible to adequately calculate the mechanical properties of nickel-based superalloys of equiaxial crystallization, without carrying out preliminary experiments. Research methods. To find regularities and calculate  the latest CALPHAD method was chosen, and modeling of thermodynamic processes of phase crystallization was performed. Results. As a result of experimental data processing, the ratio of alloying elements Kg¢ was proposed for the first time, which can be used to assess the mechanical properties, taking into account the complex effect of the main alloy components. The regularities of the influence of the composition on the properties of heat-resistant nickel alloys of equiaxial crystallization are established. The analysis of the received dependences in comparison with practical results is carried out. The relations well correlated with heat resistance, mismatch and strength of alloys are obtained. Scientific novelty. It is shown that for multicomponent nickel systems it is possible with a high probability to predict a mismatch, which significantly affects the strength characteristics of alloys of this class. The regularities of the influence of the chemical composition on the structure and properties of alloys are established. A promising and effective direction in solving the problem of predicting the main characteristics of heat-resistant materials based on nickel is shown Practical value. On the basis of an integrated approach for multicomponent heat-resistant nickel-based alloys, new regression models have been obtained that make it possible to adequately predict the properties of the chemical composition of the alloy, which made it possible to solve the problem of computational prediction of properties from the chemical composition of the alloy. This allows not only to design new nickel-based alloys, but also to optimize the composition of existing brands.


2021 ◽  
Author(s):  
Meng Li ◽  
Zuzhi Bai ◽  
Xiao Chen ◽  
Cong-Cong Liu ◽  
Jing-Kun Xu ◽  
...  

Abstract Poly(3,4-ethylenedioxythiophene) (PEDOT) has proved its quite competitive thermoelectric properties in flexible electronics with its excellent electrical and mechanical properties. Since the early discovery of PEDOT, considerable experimental progress has been achieved in optimizing and improving thermoelectric properties as a promising organic thermoelectric material (OTE). Among them, theoretical research has made significant contributions to its development. Here the basic physics of conductive PEDOT are reviewed based on the combination of theory and experiment. Its purpose is to provide a new insight into the development of PEDOT, so as to effectively design and preparation of advanced thermoelectric PEDOT material in the future.


e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Mahdi Abdollahi ◽  
Ali Rahmatpour ◽  
Jamal Aalaie ◽  
Homayon Hossein Khanli

AbstractStyrene- butadiene rubber (SBR)/ clay nanocomposites were prepared by mixing the SBR latex with aqueous clay dispersion and co-coagulating the mixture. Tapping mode AFM and XRD were applied to characterize the structure of nanocomposites. It was found that fully exfoliated structure could be obtained by this method only when the low loading of layered silicate (< 10 phr) is used. With increasing the clay content, both non-exfoliated (stacked layers) and exfoliated structures can be observed simultaneously in the nanocomposites. The results of mechanical tests on the vulcanized pure SBR and SBR/ clay nanocomposites showed that the nanocomposites presents better mechanical properties than clayfree SBR vulcanizate. Furthermore, initial modulus, tensile strength, tensile strain at break, hardness (shore A) and tear strength increased with increasing the clay content, indicating the nanoreinforcement effect of clay on the mechanical properties of SBR/ clay nanocomposites. Compared to the clay free SBR vulcanizate, the nanocomposite vulcanizates exhibit a lower tanδ peak value, higher storage modulus and higher tanδ value at the rubbery region (0-60 °C) which indicate that the elastic responses of pure SBR towards deformation are strongly influenced by the presence of nanodisperced natural sodium montmorillonite layers especially completely exfoliated silicate layers.


1999 ◽  
Vol 594 ◽  
Author(s):  
J. G. Swadener ◽  
G. M. Pharr

AbstractSpherical indentation with continuous load and depth measurement is a useful technique for characterizing thin film mechanical properties. With this technique, the initial loading is in the elastic range. Therefore the elastic-plastic transition can be observed. However, the calibration of spherical indenters presents special problems. First, the radius of the indenter at the point of contact must be determined, and any deviation from a spherical radius must be evaluated. The shape of the indenter also causes mounting difficulties that can create a relatively large and nonlinear compliance in the testing machine. The calibration of spherical indenters is further complicated, because asperities on the indenter and surface roughness add to the uncertainty in locating the surface of the sample. In addition, spherical indenters are generally made of anisotropic single crystals, and the calculation of their elastic responses must include this anisotropy. To address these issues, a methodology has been developed for the calibration of spherical indenters, whereby indentation experiments are conducted on multiple ceramic materials in the elastic range. The method was used to determine the local radius of synthetic sapphire spherical indenters. The accuracy of this measurement was verified using confocal microscopy. The method was successfully applied to an indenter with a nonlinear machine compliance. Further results involving indentation in the plastic regime are also presented.


RSC Advances ◽  
2016 ◽  
Vol 6 (111) ◽  
pp. 110171-110181 ◽  
Author(s):  
Richard F. D'Vries ◽  
German E. Gomez ◽  
Diego F. Lionello ◽  
M. Cecilia Fuertes ◽  
Galo J. A. A. Soler-Illia ◽  
...  

The relationship between the structural features with the mechanical, luminescent and sensing properties were studied in the compounds formed from lanthanide metals, 3-hydroxinaphthalene-2,7-disulfonate and 1,10-phenanthroline ligands.


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