On Steel Surface Modification via Embedment of ZnNPs@polystyrene Composite as Anti-corrosive Template

Corrosion is one of the serious problems countered in different industries as it dramatically causes strong impacting on the infrastructures. As an attempt for sorting out such problem, this approach investigated an innovative strategy for synthesis of corrosion inhibitor for steel surfaces based on composite of polystyrene and zinc nanoparticles (ZnNPs@polystyrene composite). The successive immobilization of ZnNPs (size average of 4-50 nm) within polystyrene matrix (Mwt of 372.587 g/ mole and degree of polymerization equals 3582 repeat unit/ molecule) for clustering of the desirable ZnNPs@polystyrene composite (surface area of 33.62 m2/g, average pore diameter of 9 nm) was approved via several instrumental analyses of FT-IR, XRD, SEM, HRSEM, EDX, TEM and BET with estimation of total pore volume and average pore diameter for the prepared composite. Thermal stability of the prepared composite was affirmed via TGA analysis. Corrosion percentage via weight loss percent in three media of water, H2SO4 and diesel fuel was estimated to reach maximally to 25 % in case of H2SO4, while, corrosion inhibition efficiency (CIE) percentage estimated according to weight loss to reach 94.27, 88.18 and 85.05 % after 10 days of soaking the steel samples coated with the synthesized ZnNPs@polystyrene composite (800 ppm) at 25 ℃, while, elevation of temperature up to 45 ℃, resulted in non-significant effect on the estimated CIE to be diminished to 91.8, 85.2 and 81.1% after soaking in water, diesel fuel and sulfuric acid as corrosion media, respectively. CIE was estimated to be near 30% in case of coating steel samples with polystyrene polymer, to be significantly increased to near 80 % and formidably jumped to near 100% by coating with ZnNPs@polystyrene composite, with weight percent of 30 & 50% of ZnNPs, respectively. In addition to, Zeta potential was also detected to be - 9.67 in case of untreated steel samples, while, it became - 4.98 after coating of sample with ZnNPs@polystyrene composite. Eventually, from Arrhenius plots, activation energies and thermodynamic parameters of rate constant, enthalpy (ΔH) and entropy (ΔS) confirmed that the interaction is more taking place between the corrosion species and ZnNPs@polystyrene composite as corrosion inhibitor rather than with steel surface. Postulation of the reaction mechanism for the anticorrosive action of the synthesized ZnNPs@polystyrene composite was presented according to the illustrated instrumental analyses.

Структура и механические свойства пористой диатомитовой керамики после деформации сжатием

This work is devoted to the study of the mechanical properties of porous ceramics based on diatomite. Based on the morphological analysis of the studied samples, the porous structure of ceramics (morphology and average pore diameter) was analyzed and the numerical value of the porosity of the samples (35...50%) was determined. The values of the static (70...115 GPa) and dynamic elastic modulus of the samples (37...50 GPa) were measured experimentally. The dependence of the dynamic modulus of porous diatomite ceramics on porosity is studied: the elastic modulus decreases with increasing porosity of the material. A decrease in the porosity of the material after deformation was also found. The formation of diatomite filaments after deformation of samples by compression at a rate of no more than 8 * 10-4 s-1 was detected.

Structural Characterization and Adsorption Capability of Carbonaceous Matters Extracted from Carbonaceous Gold Concentrate

In this paper, the structures of element carbon and humic acid extracted from carbonaceous gold concentrate were characterized employing a variety of analytical methods. The extracted amounts of ECE (elemental carbon extract) and HAE (humic acid extract) were 14.84–38.50 and 11.55–28.05 mg g−1, respectively. SEM and porosity analysis indicated that ECE occurred mostly as irregular blocky particles with a mesoporous surface with the average pore diameter being 31.42 nm. The particle size of ECE was mainly ranged from 5.5 to 42 μm and the specific surface area was 20.35 m2 g−1. The physicochemical features and structure of ECE were close to activated carbon, and the crystallinity was slightly lower than graphite. The particle size distribution of HAE varied from 40 to 400 nm with the specific surface area of 42.84 m2 g−1, whereas the average pore diameter of HAE was 2.97 nm. FTIR and UV–VIS analyses indicated that HAE was a complex organic compound containing the enrichment of oxygen-containing structure. The results showed that the adsorption amounts of ECE and HAE under the acidic conditions were 470.46 and 357.60 mg g−1, respectively. In an alkaline environment, the amount of ECE was 449.02 mg g−1 and the value of HAE was 294.72 mg g−1. ECE mainly utilized the outer surface and mesoporous structure to adsorb gold, while the functional groups’ complexation or surface site adsorption was the leading approach for HAE to adsorb gold.

Hydrochloric Acid and/or Sodium Hydroxide-modified Zeolite Y for Catalytic Hydrotreating of α-Cellulose Bio-Oil

The zeolite Y had been successfully modified by HCl and/or NaOH treatment. The modification of zeolite Y was performed by leaching the protonated zeolite Y (HY) in HCl solution (0.1 and 0.5 M) at 70 °C for 3 h resulting in DY0.1 and DY0.5. Subsequently, HY, DY0.1, and DY0.5 zeolites were immersed in 0.1 M NaOH for 15 min at room temperature resulting in AHY, ADY0.1, and ADY0.5. All samples were analyzed for acidity, crystallinity, Si/Al ratio, morphology, and textural properties. The catalytic performance of all samples was investigated in hydrotreating of α-cellulose bio-oil with a catalyst/feed weight ratio of 1/30. The HCl and NaOH treatment led to the decrease of the zeolite Y crystallinity and the increase of the zeolite Y average pore diameter (i.e., the mesopore distribution). The ADY0.5 gave the highest mesopore distribution, which was 43.7%, with an average pore diameter of 4.59 nm. Moreover, both of the treatments were found to increase the Si/Al ratio that caused the decrease of zeolites Y acidity. All the zeolite Y samples gave better catalytic activity to produce liquid products after being treated by NaOH. The sample ADY0.5 managed to produce 6.12% of 1-isopropyl-2,4-dimethylbenzene that has good potential to be processed into fuel.

Relationship between the Shear Strength and Microscopic Pore Parameters of Saline Soil with Different Freeze-Thaw Cycles and Salinities

Saline soil is a widely distributed special soil with poor engineering properties. In seasonally frozen regions, the poor properties of saline soil will cause many types of engineering damage such as road boiling, melt sinking, and subgrade instability. These engineering failures are closely related to the shear strength of saline soil. However, there are relatively few studies on saline soil in cold regions. The strength of the soil is always determined by its microstructure; therefore, the study aims to investigate the relationship between the shear strength and microscopic pore structure of saline soil with different freeze–thaw cycles and salinities. The shear strength characteristics of saline soil with different salinities subjected to different freeze–thaw cycles were obtained by triaxial tests. In addition, the microstructure of the soil samples was investigated by scanning electron microscopy (SEM) tests, and the microscopic pore parameters of the soil samples, including porosity (N), average pore diameter (D¯), average shape coefficient (K), surface fluctuation fractal dimension (F), and orienting probability entropy (Hm), were obtained by image processing software quantitatively. Based on the experimental results, the influence of freeze–thaw cycles and salinity on the shear strength characteristics and microstructure of the soil samples were analyzed. Besides that, in order to effectively eliminate the collinearity between independent variables and obtain a stable and reasonable regression model, principal component regression (PCR) analysis was adopted to establish the relationship between the microscopic pore parameters and the failure strength of the soil samples. The fitting results demonstrated that the failure strength of saline soil is mainly related to the size and direction of the pores in the soil, and it has little correlation with pore shape. The failure strength of the soil was negatively correlated with the average pore diameter (D¯) and porosity (N), and it was positively correlated with the orienting probability entropy of the pores (Hm). This study may provide a quantitative basis for explaining the variation mechanism of the mechanical properties of saline soil from a microscopic perspective and provide references for the symmetry between the changes of the macroscopic properties and microscopic pore structure of the saline soil in cold regions.

Different controlling factors of pore features between marine shale and transitional shale in the Upper Yangtze region, South China

<p>Compared with marine shale with plentiful research and successful exploration, fewer studies on transitional shale reservoirs limit further exploitation of shale gas. In this paper, comparative analysis, between Lower Silurian marine shale and Upper Permian transitional shale in the Upper Yangtze region, is carried out to analysis pore features of both shales and the main controlling factors, which can provide theoretical guidance for further exploration. A combination of methods is ultilized in terms of organic-chemistry geology measurement, X-ray diffraction (XRD), high-pressure mercury injection, gas adsorption, and focused ion beam milling and scanning electron microscopy (FIB-SEM). The results show that Lower Silurian marine shale and Upper Permian transitional shale have similar organic matter (OM) abundance (2.72% and 2.31%) and thermal degree (2.56wt%Ro and 2.68wt%Ro). However, the kerogen of Lower Silurian shale is type I derived from algae and plankton, while that of Upper Permian shale is mainly type III from higher plant debris. As for mineral composition, Siliceous minerals (> 43wt%) account for the majority in Lower Silurian shale, while clay (> 57wt%) is the main mineral in Upper Permian shale. Variations in material basis trigger to differences in pore characteristics between the two shales. Firstly, the pores in Lower Silurian shale are mostly hosted by OM with an average pore diameter of 7.94 nm, while Upper Permian shale mainly develops pores associated with clay minerals with an average pore diameter of 28.60nm. Moreover, Lower Silurian shale presented relatively higher pore properties than Upper Permian in both average pore volume (0.020ml/g and 0.015ml/g) and average pore surface area (7.99 m<sup>2</sup>/g and 1.2 m<sup>2</sup>/g). Various factors lead to the differences in pore types and pore properties between the two shales. For marine shale, OM with thermal convertibility tend to be mobilizable and porous. OM-hosted pores are the dominated type which is controlled by OM abandauce and thermal degree. However, in transitional shale, OM is featured by phase stability without porous feature. Pores associated with clay flakes are the main type which is controlled by the specifc material composition. Hence, the discrepancies of pore properties may be attributed to material diversities between marine shale and transitional shale.</p>

Added-value porous materials for controlled thymol release obtained by supercritical CO2 impregnation process

This study explores utilization of biodegradable and biocompatible polymers for controlled release of natural bioactive substance. For that purpose, poly(ε-caprolactone) (PCL) beads, cellulose acetate (CA) film, and poly lactic- co-glycolic acid (PLGA) flakes were impregnated with thymol by employing environmentally friendly process of supercritical carbon dioxide (scCO2) impregnation. At selected pressure and temperature, prolongation of operating time increased thymol loading. Pure scCO2 did not affect CA film with average pore diameter of approximately 3 µm, while it enabled change of PCL beads and PLGA flakes into foams with average pore diameter approximately 175 µm and 87 µm, respectively. Additionally to scCO2, thymol acted as a plasticizer increasing pore size of polymers up to three times. Kinetic of thymol release from selected samples was tested using phosphate buffer saline at 37°C and successfully described with Korsmeyer–Peppas, zero-order, first-order, and Higuchi models. The suggested method of PCL, CA, and PLGA supercritical impregnation led to development of porous, solvent free, added-value materials that release thymol in a controlled manner from 5 h to several days.

Effects of Palm Oil Fuel Ash as Micro-Filler on Interfacial Porosity of Polymer Concrete

The effects of palm oil fuel ash (POFA) as micro-filler on interfacial porosity and pore size distribution of polymer concrete (PC) is the main aim of this chapter. Beginning with a brief introduction about the topic, the materials and method used in this study are explained. Two categories of fillers were involved in this study, fine-micro filler (ground POFA and is paired with calcium carbonate), and coarse micro-filler (unground POFA and is paired with silica sand). It is revealed that the replacement of overall types of micro-filler at different filler content decreased the average pore diameter of PC significantly, except for PC incorporating unground POFA. Additionally, incorporation of fine-micro filler with dispersion characteristic could significantly reduce the interfacial porosity of PC as compared to incorporation of coarse micro-filler in PC.