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The harmful effects of most synthetic corrosion inhibitors on the environment are the motivation for the study of environmentally friendly extracts. The main components of silkworm sand extract (SSE) were studied by infrared spectroscopy (FTIR) and ultraviolet visible spectroscopy (UV-vis). The scale inhibition effect of SSE as scale inhibitor in calcium chloride solution was studied by means of electrical conductivity, static scale inhibition and scanning electron microscopy (SEM). Electrochemical impedance (EIS) and potentiodynamic polarization curve (PDP) were used to study its corrosion inhibition performance in simulated cooling water. The results showed that chlorophyll was the main component of SSE. When the concentration of SSE was more than 30 mg/L, the scale inhibition efficiency of calcium carbonate and calcium sulfate was both more than 90%. SSE could inhibit the supersaturation of calcium carbonate, prolong the nucleation time, and change the crystal shape of calcium scale. SSE had a good corrosion inhibition effect on Q235 steel in salt solution, and its corrosion inhibition mechanism was that SSE formed a protective film on the surface of Q235 steel. SSE could play a dual role of scale inhibition and corrosion inhibition, which was a potential new, environmentally safe corrosion and scale inhibitor for cooling water system.

In order to adapt to the rapid development of green plant extract corrosion inhibitors, spinach extract (SPE) was selected as a corrosion inhibitor for Q235 steel in citric acid (CA) environment. SPE was extracted using a simple ethanol reflux method, and its main components, as well as their stability in CA, were confirmed through Fourier transform infrared spectroscopy (FTIR) and ultraviolet-visible spectroscopy (UV-Vis). The corrosion inhibition performance of SPE on Q235 steel in 0.5 mol/L CA solution was investigated using various methods including weight loss, dynamic potential polarization (PDP), linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and contact angle measurements. Effects of temperature on the activation parameters (Ea, were studied by calculation. Results showed that chlorophyll was the main component of SPE, which exhibited good stability in a 0.5 mol/L CA solution. Furthermore, SPE significantly reduced the corrosion rate of Q235 steel in the 0.5 mol/L CA medium, acting as a mixed corrosion inhibitor for both cathodic and anodic reactions. With the increase of SPE concentration, both cathodic and anodic currents were reduced, active corrosion sites were blocked, the corrosion rate was decreased, and the corrosion inhibition efficiency was enhanced. The corrosion inhibition efficiency of Q235 steel obtained by weight loss method, PDP, LPR and EIS was more than 80% with 2.134 g/L of SPE concentration at 303 K. With the increase of system temperature, the corrosion inhibition efficiency of SPE on Q235 steel decreased, but the change was smaller. Compared to the blank system, the activation energy (Ea) of the system significantly increased after the addition of SPE. The effective components of SPE adsorped to the surface of Q235 steel in accordance with the Langmuir isotherm, predominantly through physical adsorption, and were characterized as monolayer adsorption. SPE exhibited good corrosion inhibition performance for Q235 steel in a 0.5 mol/L CA solution system, which was a green corrosion inhibitor with good application prospects in the pickling field. It could provide certain guidance for the development of plant extract-based corrosion inhibitors.

The α-Fe2O3/MWCNTs (α-ferric oxide/multi walled carbon nanotubes) material was synthesized by a facile approach via the calcination of Fe-based metal-organic-framework (MIL-53(Fe)) with MWCNTs doped and was used to fabricate a modified glassy carbon electrode (GCE) for detection of ferulic acid (FA).The composition and morphology of α-Fe2O3/MWCNTs were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Meanwhile, the electrochemical performances were investigated by cyclic voltammetry and differential pulse voltammetry. Under the optimized conditions, the proposed sensor not only exhibited high selectivity, but also showed a wide linear range over FA concentration from 0 to 6.0 µM with a low detection limit of 1.75 × 10− 8 mol/L, a reproducibility with five different electrodes with the RSD 2.39%, the peak current retained 94.2% after scanning 20 laps which attributed to the advantage of good electron transfer efficiency. [ABSTRACT FROM AUTHOR]

The conformation of a helical type polymer chain in the crystalline phase prefers the state with lower energy. The molecular simulation of the melting behaviors of α and β isotactic poly(propylene) (iPP) crystals with ultrafast heating shows that the ratio of right-handed and left-handed helix stays at 50% in α-iPP and changes from 100% to 50% in β-iPP before and after melting. Till date, the formation of β form crystal in iPP has not been understood well together with the mechanism of the crystallization process. One of the approaches to produce β-iPP is to shear the melt. The influence of shear flow on the crystallization behavior of iPP was investigated via ex situ and in situ X-ray measurements. It was found that preceding or simultaneously initiated formation of β-iPP together with α-iPP occurs under proper shear conditions. The β-rich iPP sample could no longer form β crystal at 135 °C after heating to the β-melting temperature with the melting of β-iPP and the retaining of oriented α-iPP, which is contrary to the accepted formation process of β-iPP. A mechanism was proposed to understand the shear-induced β crystal in iPP, considering the mesophase and stereocomplex type helical conformation of the polymer chains. [ABSTRACT FROM AUTHOR]

Shearing is unavoidable during thepolymer process, and isotacticpolypropylene (iPP) is one of the most used commercial polymers. iPPmixed with β-nucleating agent TMB-5 was isothermally crystallizedat 135 °C from melts under various shear conditions and investigatedvia synchrotron radiation small-angle and wide-angle X-ray scattering(SAXS and WAXS) techniques with CCD detector. The shear-induced crystallinestructure and the orientation of the samples were studied accordingto the obtained WAXS and SAXS patterns. The results showed that boththe crystallinity of α-iPP and β-iPP are in direct proportionto the orientation degree rather than shear rate especially at highshear rate, which proves that wall slip should not be neglected whentaking shear effect or rheological behavior into consideration. [ABSTRACT FROM AUTHOR]