REVIEW | doi:10.20944/preprints202107.0576.v1
Subject: Engineering, Automotive Engineering Keywords: Glassy Polymers; Diffusion; Sorption; Physical Aging; Polymer Coatings; Gas Separation Membranes
Online: 26 July 2021 (13:52:57 CEST)
For the past few decades, researchers have been intrigued with glassy polymers, which have applications ranging from gas separations to corrosion protection to drug delivery systems. The techniques employed to examine the sorption and diffusion of small molecules in glassy polymers are the subject of this review. Diffusion models in glassy polymers are regulated by Fickian and non-Fickian diffusion, with non-Fickian diffusion being more prevalent. The characteristics of glassy polymers are determined by sorption isotherms, and different models have been proposed in the literature to explain sorption in glassy polymers during the last few years. This review also includes the applications of glassy polymer. Despite having so many applications, current researchers still have difficulty in implementing coating challenges due to issues like as physical ageing, which is briefly discussed in the review.
ARTICLE | doi:10.20944/preprints201801.0036.v5
Subject: Materials Science, General Materials Science Keywords: carbon; atomic structure; force-energy behaviors; atomic binding; structure evolution; glassy carbon
Online: 30 July 2018 (08:46:38 CEST)
Many studies deal synthesis of carbon because of its versatility but lack the arresting of understanding at convincing and compelling levels. A binding energy shape-like parabola is linked to state of handing over electron to state of taking over electron at each opposite side of the atom maintaining the equilibrium of resulting new state of the carbon atom. Through this mechanism of transferring electrons for the gas state carbon atom, it converts into graphitic state, nanotube state, fullerene state, diamond state, lonsdaleite state and graphene state carbon atom. Forces of relevant poles remain neutral at instant of transferring electrons to attain specific state of their carbon atom. Structure evolutions in graphitic, nanotube and fullerene state carbon atoms are remained one-dimensional, two-dimensional and four-dimensional, respectively, where energy shape-like parabola is also involved along the relevant quadrant executing electron-dynamics to engage neutral behavior of exerting relevant poles forces. A graphite structure when develops under attained dynamics of atoms and their binding is under a bit difference of involved opposite pole forces, it develops in two-dimensional also. Evolution of structure in diamond, lonsdaleite and graphene state carbon atoms is under involving potential energy of electrons dealing double clamping of energy knot where relevant poles forces exerted in the orientationally controlled manner. Growth of diamond is south to ground, but binding of atoms is ground to south, so, it is a tetra-electrons ground to south topological structure. Lonsdaleite is a bi-electrons ground to just-south topological structure. Growth of graphene is just-north to ground, but binding of atoms is ground to just-north, so, it is a tetra-electrons ground to just-north topological structure. Glassy carbon is related to a layered-topological structure where successive tri-layers of gas, graphitic and lonsdaleite state atoms bind in the repetition manner. In glassy carbon, pairs of orientated electrons of gas and lonsdaleite state carbon atoms deal double clamping of energy knot by entering from the rear-side and front-side, respectively, to bind to intermediate layers of graphitic state atoms. Different carbon atoms develop amorphous structures when they bind under frustrating amalgamation. Hardness of carbon-based materials is also sketched in the light of different force-energy behaviors of different state carbon atoms. Here, structure evolution in each carbon state atom explores its own science.
ARTICLE | doi:10.20944/preprints202101.0382.v1
Subject: Chemistry, Analytical Chemistry Keywords: Chromium (VI); thin gold film; glassy carbon electrode and differential pulse anodic stripping voltammetry
Online: 19 January 2021 (13:52:45 CET)
A gold nanostructured film modified glassy carbon electrode (Aufilm/GCE) was developed for the determination of chromium (VI) in water sample. GCE was immersed into HAuCl4 solution (10-3M) and electrodeposition of thin gold layer was conducted at –0.4 V (vs Ag/AgCl) for 10 min. The strong affinity between Au and Cr species resulted with increasing of Cr (VI) signal, compared with the bare glassy carbon electrode. The electrodepositing time, type of supporting electrolyte, pH, the scan rate, modulation amplitude, and modulation time were optimized using differential pulse anodic stripping voltammetry (DP-ASV). The calibration graph using accumulation time of 120 s was linear from 10 to 120 µgL-1 with a sensitivity 1.3 x 10-2 µA/µgL-1. Under optimum experimental conditions, a good correlation coefficient R2=0.9971, and a low detection limit 5.5 µg/L Cr (VI) was obtained. The signal was reproducible with a relative standard deviation ±4.5 %. The developed Aufilm/GCE sensor was applied for the Cr (VI) determination of in sewage water samples.