Recent Trends in Chemical and Material Sciences Vol. 3

During the last ten years, a significant interest on Sustainability of Supply Chains has arises. The integration of the three dimensions of sustainability, economic, environmental, and social is no more an option but a necessity. Based on our previous research work on the field of SSC, we aim through this book chapter to give an updated look to practices and patterns of sustainability applied on supply chain during the last ten years starting from 2010 till 2020, providing analytical and critical insights through and extended version of the research work. Thanks to its investigation of more than 93 papers, this book chapter is a valuable paper for practitioners. A data analysis is led and provides an overview of trends of sustainable supply chains field. A time line of pertinent reviews is presented, pinpointing on methodologies adopted. Furthermore, a focus on practices and patterns adopted and those who needs to be developed is given with a highlight of the main issues of the field. A holistic framework is defined and the role of each stakeholder is precisely delimited. Lastly, results and future considerations are provided with a highlight on current issues.

Experimental values of densities (\(\rho\)), viscosities (\(\eta\)) and ultrasonic velocities for binary mixtures of benzene and carbon tetrachloride with cumene and pseudocumene have been measured at two different temperatures 303.15 and 293.15 K. Excess volume of mixing (\(\nu\)^E), deviation of excess volume (\(\Delta\)\(\nu\)^E) from ideal mole fraction law and parameter (d) as a measure of strength of interaction between components of binary mixtures have been calculated from data of densities and viscosities. These results were fitted to Redlich-Kister polynomial equations to estimate the binary coefficients and standard errors. Excess volumes have been found to be negative and positive in sign for binary mixture of carbon tetrachloride with cumene and pseudocumene and carbon tetrachloride with benzene at entire mole-fraction range and at both the temperatures 303.15 and 293.15 K. On the other hand \(\Delta\)\(\eta\) were found to be negative for binary mixtures of carbon tetrachloride with cumene and pseudocumene except the binary mixture of carbon tetrachloride with benzene at entire mole-fraction range at T = 293.15 K. Positive value of excess volumes for three mixtures (carbon tetrachloride with benzene, cumene and pseudocumene) show feeble molecular interactions among the components. However, the negative value of \(\Delta\)\(\eta\) for binary mixtures of carbon tetrachloride with cumene and pseudocumene show weak interactions among the components. The experimental values of excess volumes of mixing (\(\nu\)^E) have been analyzed in the light of Flory’s theory.

Solar cells based on new class of organic inorganic hybrid perovskite CH₃NH₃PbI₃ have sprung to prominence in recent years, due to their remarkable improvements of photovoltaic power conversion efficiencies (PCEs) over the last few years. Recently, it was observed that antisolvent engineering was an effective approach to improve the PCE and stability of perovskite solar cells. In this direction CH₃NH₃PbI₃ based thin film solar cells were prepared by Ethyl acetate (EA); antisolvent treatment for the first time. Our observations suggest that due to non-covalent weak interaction between the perovskite absorber and the high boiling point antisolvent, EA, a new micro structured morphology evolves in the CH₃NH₃PbI₃ thin film, which we report for the first time. FESEM image shows microrod type structures of CH₃NH₃PbI₃ after EA antisolvent treatment. Energy band diagram was constructed using photoluminescence and photoemission studies. A better power conversion efficiency was achieved in EA treated film compare to without EA treated film.

Using the ab-initio calculations based on density functional theory, we have investigated the structural, electronic, and magnetic properties of the Ti-substituted Zn₃P₂ compound. One/Two Ti atom replacements in the unit cell of Zn₃P₂ containing eight molecules per formula unit (40 atoms) are considered in the study. Our results show that the ferromagnetic phase is favored for the single Ti atom substitution. The total energy corresponding to the ferromagnetic phase is lower than that of the nonmagnetic phase. A considerable value of the magnetic moment at the Ti site is obtained from our calculations. These compounds may be useful to spintronic applications, and we hope this study motivates others to further investigate about these compounds.

Vanadium produces the hardest carbides and can influence wear properties positively [1,2]. However, due to the minerals’ price fluctuations as a result of the current economic climate, vanadium is currently expensive and seldom used in wear resistant materials despite its valuable properties. Nevertheless, it is still important to study the effects of vanadium carbides (VC) on wear properties and later compare the cost/durability ratio to the other currently used industrial alloys.

Vanadium has been used as a secondary alloying element in high chromium cast iron (HCWCI) and has produced positive results through the influence of orientation and morphology of the eutectic carbide M₇C₃ [3,4]. VC are known to be discontinuous [5,6], which is helpful with regards to impact properties. VC alone cannot maintain high macro-hardness values and for improved results carbon (C) is needed to increase the strength of the matrix [7]. For improved wear properties, the hardness of the surface must be between 0.5 and 1.3 times the hardness of the abrasive. In this paper, the influence of the soaking and tempering temperatures on hardness and wear properties in a high vanadium alloy, 1.91C-0.82Mn-0.96Si-0.90Ni-1.35Cr-0.25Mo-6.12V, were investigated. The soaking temperatures were 1150 and 1250°C while the tempering temperatures were varied at 100°C interval from 300°C to 600°C. It was found that soaking at 1250°C increased the amount of retained austenite, but at the same time also improved the wear resistance in as-quenched condition as well as after tempering up to 500°C.

The global awareness about health and environment is rapidly increasing in a quick pace in the view of health hazards related to toxic gases that are associated with industrial and automobile exhausts. Thus, there is a requirement of gas sensors to sense such harmful especially green house gases in order to maintain the ecological balance. The nanostructured architecture of semiconducting materials have unique and attractive properties like high surface-to-volume ratio, high bandgap, low particle size, etc. which are advantageous for developing sensitive & selective gas sensors. In the present work, we describe the design and synthesis of a novel p-n type semiconducting MoO₃: NiO nanocomposite functionalized by different noble metals (Ag, Au, Pt & Pd) among which Pd incorporated MoO₃: NiO (MNPd) showed better efficiency comparatively towards Carbon dioxide (CO₂) gas. The observed response of MoO₃: NiO (MN) sensor exhibited sensitivity of S=80% whereas the Pd-loaded MoO₃: NiO (MNPd) sensor exhibited excellent sensitivity of S=96% and selectivity towards CO₂ in comparison to other interfering gases. The results explicitly confirm the effectiveness of MNPd nanocomposite engineered for high performance CO₂ gas sensor.

In this paper, we propose a three-phase method for determining the effective properties of composite materials reinforced by whiskerized fibers. A modified composite consisting of two phases - a fiber and a whiskerized layer acting as a binder - is considered. For a modified composite loaded with longitudinal shear, calculations of the stress-strain state in each of the phases and calculations of effective properties are carried out. It is assumed that in the case of pure shear along the fiber, the strength of the composite is controlled by the binder; therefore, the deformed state in each of the phases of the modified composite is investigated and a comparative analysis with the deformed state in each of the phases of a similar classical composite is carried out. The calculated values of the effective longitudinal shear modulus and effective loss modulus are also subjected to comparative analysis. Two types of modified composites, whisked by rigid CNTs and less rigid ZnO nanotubes, are investigated.

These studies are aimed to investigate influences of Ga dopant and As dopant on the optical properties of silicene. Silicene, a silicon analog of graphene, is expected to be better suited than graphene for the electronics industry, which is currently still dominated by silicon. In order to expand its application, its properties must be controllable. The development of the properties can be done by doping or applying external electric fields and stress. Like carbon, silicon also belongs to group IV of the periodic table. Ga (elements from group III) and As (element from group V) can play the role of dopant donor or acceptor in silicene. Therefore, the Density Functional Theory (DFT) calculations were carried out using a general gradient approach in order to investigate the influence of Ga atoms and Al atoms on the optical properties of silicon dioxide. The optical properties studied include refraction, reflection, and absorption. The results show that Ga doping, As doping, and Ga-As codoping reduce the value of the linear optical properties.  The ability to control and exploit its optical properties shed light on designing silicene-based electronic and spintronics materials.

Nanostructure investigation on the post implantation by Fe-B and NiFe-B on CVD diamond/Si(111) film have been studied by means of STEM related to their Magnetoresistance(MR)  phenomena. Two samples were investigated carefully, firstly sample is post NiFe-B at E=70keV and dose= 10¹⁵ ions/cm² (denoted as A-E3D1). Secondly, is post FeB at E=20 keV and dose= 10¹⁵ ions/cm² (denoted as B-E1D1). Based on FPP measurement at room temperature (RT) and H_applied=8 kOe, A-E3D1 sample has MR ratio almost 80% and MR ratio in B-E1D1 sample is 45%. Based on STEM-EDX investigation, there are two aspects of how MR ratio of A-E3D1 more higher than those of B-E1D1. Firstly, surface nanostructure on the top of A- E3D1 film is more grazing than on the top of B-E1D1. Analysis with Scanning Transmission Electron Microscope (STEM) equipped with Electron Energy Loss Spectroscopy (EELS) the growth of amorphous carbon layer on top of the implanted diamond film with thickness around 100 nm and only 20 nm on the no implanted sample have observed. Boron atoms were found inside the carbon amorphous layer distributed homogenously. Secondly, oxygen content at the interface between diamond film and silicon substrate in sample A-E3D1 was lower than those in B-E1D1 sample. This condition gives the resistance value in A-E3D1 lower than value in B-E1D1. This result is close to the Raman Spectroscopy data measurement which obviously suggests changes on the Raman spectrum due to implantation related to Oxygen excitation from B-E1D1 sample and the properties of magnetic film, respectively.

The co-digestion technique, which uses anaerobic digestion to treat two or more organic biodegradable waste streams, has a lot of potential for proper solid waste disposal. Under mesophilic conditions, the anaerobic co-digestion of fruit and vegetable waste (FVW) and municipal sewage sludge (MSS) was explored and compared to separate digestion of the substrates. The continuous studies were performed at an organic loading rate of 1.5 g VS/l.day and at an HRT of 20 days. It was observed that FVW had better performance than the MSS. However, FVW addition led to improvement of the process stability, with low Volatile Fatty Acids (VFA) / Total Alkalinity (TA) ratio and improves the gas production yield with its co-substrates. Specific gas production values of three reactors were: (i) 0.49 l/g VS_in & 1.0 l/g VS_des for FVW, (ii) 0.261 l/g VS_in & 0.643 l/g VS_des for MSS and (iii) 0.613 l/g VS_in & 1.078 l/g VS_des for co- digestion of FVW and MSS. Co-digestion is proven to produce more biogas. Anaerobic co-digestion of FVW and MSS performed better in terms of gas production, reactor stability in co-digestion substrates and buffering capacity. It is concluded that anaerobic co-digestion of MSS and FVW is an attractive method for environmental protection and energy savings.