Influence of gamma irradiation on rosin properties and its antimicrobial activity.

The main component of rosin natural gum is abietic acid, which has an interesting chemical structure to be studied with the influence of gamma-ray and the antimicrobial activity on the properties of a cheap abundant solid state natural material of rosin. Rosin is exposed to a wide scale of gamma-ray ranges from 0 to 100 kGy. The changes in the properties are tracked by various techniques of FTIR, XRD, TGA, GPC, and SEM. The molecular weight of rosin changes from 370 g/mol to higher and the morphological properties were investigated. The irradiated rosin acid (IRA) at different irradiation doses exploited antimicrobial effect versus Gram-positive and Gram-negative as well. The inhibition zone enhanced from 15 to 33, 14 to 28, 14 to 20, and 9 to 14 mm for Gram-positive and Gram-negative, respectively. Moreover, bioactive behavior for irradiated rosin of 40 kGy recorded the highest antibacterial activity against both types of bacteria. The outcome data of antimicrobial activity are good and confirm that there is a significant effect of irradiation dose on the biocidal activity of rosin.

Investigation of palladium catalysts in mesoporous silica support for CO oxidation and CO2 adsorption.

The oxidation of Carbon monoxide (CO) to Carbon dioxide (CO2) is one of the most extensively investigated reactions in the field of heterogeneous catalysis, and it occurs via molecular rearrangements induced by catalytic metal atoms with oxygen intermediates. CO oxidation and CO2 capture are instrumental processes in the reduction of green-house gas emissions, both of which are used in low-temperature CO oxidation in the catalytic converters of vehicles. CO oxidation and CO2 adsorption at different temperatures are evaluated for palladium-supported silica aerogel (Pd/SiO2). The synthesized catalyst was active and stable for low-temperature CO oxidation. The catalytic activity was enhanced after the first cycle due to the reconditioning of the catalyst's pores. It was found that the presence of oxide forms of palladium in the SiO2 microstructure, influences the performance of the catalysts due to oxygen vacancies that increases the frequency of active sites. CO2 gas adsorption onto Pd/SiO2 was investigated at a wide-ranging temperature from 16 to 120 °C and pressures ∼1 MPa as determined from the isotherms that were evaluated, where CO2 showed the highest equilibrium adsorption capacity at 16 °C. The Langmuir model was employed to study the equilibrium adsorption behavior. Finally, the effect of moisture on CO oxidation and CO2 adsorption was considered to account for usage in real-world applications. Overall, mesoporous Pd/SiO2 aerogel shows potential as a material capable of removing CO from the environment and capturing CO2 at low temperatures.

Influence of Casting Solvents on CO2/CH4 Separation Using Polysulfone Membranes.

Polysulfone membranes exhibit resistance to high temperature with low manufacturing cost and high efficiency in the separation process. The composition of gases is an important step that estimates the efficiency of separation in membranes. As membrane types are currently becoming in demand for CO2/CH4 segregation, polysulfone will be an advantageous alternative to have in further studies. Therefore, research is undertaken in this study to evaluate two solvents: chloroform (CF) and tetrahydrofuran (THF). These solvents are tested for casting polymeric membranes from polysulfone (PSF) to separate every single component from a binary gas mixture of CO2/CH4. In addition, the effect of gas pressure was conducted from 1 to 10 bar on the behavior of the permeability and selectivity. The results refer to the fact that the maximum permeability of CO2 and CH4 for THF is 62.32 and 2.06 barrer at 1 and 2 bars, respectively. Further, the maximum permeability of CF is 57.59 and 2.12 barrer at 1 and 2 bars, respectively. The outcome selectivity values are 48 and 36 for THF and CF at 1 bar, accordingly. Furthermore, the study declares that with the increase in pressure, the permeability and selectivity values drop for CF and THF. The performance for polysulfone (PSF) membrane that is manufactured with THF is superior to that of CF relative to the Robeson upper bound. Therefore, through the results, it can be deduced that the solvent during in-situ synthesis has a significant influence on the gas separation of a binary mixture of CO2/CH4.

Carbon Nanoparticles-Decorated Carbon Nanotubes.

Multi walled carbon nanotubes (MWCNTs) were decorated by activated carbon nanoparticles of resorcinol-formaldehyde aerogels. Carbon nanospheres and MWCNTs were mixed by equal mass ratios for different durations. The products were characterized by Raman spectroscopy, thermal gravimetric analysis, nanoscanning electron microscopy, transmission electron microscopy and x-ray diffraction. The results indicated that a significant decoration with carbon nanoparticles occurred onto the MWCNTs.

The Effect of Chitosan's Addition to Resorcinol/Formaldehyde Xerogels on the Characteristics of Resultant Activated Carbon.

Hybrid chitosan-resorcinol/formaldehyde xerogels were synthesized, and the effect of including minor quantities of chitosan on the consequent activated carbon was investigated. The resulting activated carbon were characterized by different techniques. Clear changes were found in the structure of activated carbon as a result of including chitosan in the synthesis. The results showed that the disorder ratio of crystal lattice decreased from 0.750 to 0.628 when increasing the concentration of chitosan from 0 to 0.037 wt%. The micropores increased from ~0.3% to ~1.0%, mesopores increased from ~11.2% to ~32.9% and macropores decreased from ~88.4% to ~66.1%. The total pore volume decreased from 1.040 to 0.238 cm3/g and the total pore surface area decreased from 912.3 to 554.4 m2/g. On the other hand, the average pore width decreased from 2.3 to 0.8 nm and the average particle size decreased from 224 to 149 nm. Nano-scale Scanning Electron Microscope (NanoSEM) morphology indicated a critical composition of chitosan (0.022 wt%) that affects the structure and thermal stability of activated carbon produced.

Nano-gate opening pressures for the adsorption of isobutane, n-butane, propane, and propylene gases on bimetallic Co-Zn based zeolitic imidazolate frameworks.

In this article, zeolitic-imidazolate framework-8 (ZIF-8) and its mixed metal CoZn-ZIF-8 were synthesized via a rapid microwave method. The products were characterized by Raman spectroscopy, XPS, XRD, EDX, TEM, NanoSEM, TGA, and DSC. The gas adsorption properties of samples were determined using C3 and C4 hydrocarbons, including propane, propylene, isobutane and n-butane at a temperature of 25 °C. The adsorption equilibrium and kinetics of these gases on various ZIFs were studied. It was noted that ZIF-8 and mixed metal CoZn-ZIF-8 samples start to adsorb these gases after certain pressures which are believed to result in the opening of their nano-gates (i.e., 6-membered rings) to allow the entry of gas molecules. The nanogate opening pressure value (p0) for each ZIF towards different gases was determined by fitting adsorption equilibrium data against a modified form of the Langmuir adsorption isotherm model. It was observed that the value of p0 differs significantly for each gas and to various extents for various ZIFs. Therefore, it is possible that the distinct values of p0 afford a unique technique to separate and purify these gases at the industrial scale. The overall mass transfer coefficient values of the adsorption process were also investigated.

Dataset on the new recipe for the preparation of nanoporous carbon nanorods using resorcinol-formaldehyde xerogels.

The data presented in this article are related to the research article entitled "Novel controlled synthesis of nanoporous carbon nanorods from resorcinol-formaldehyde xerogels" (Awadallah-F and Al-Muhtaseb, 2017) [1]. This article describes the novel controlled approach of nanoporous carbon nanorods synthesis from resorcinol/formaldehyde xerogels. The field dataset is made publicly available to enable critical or extended analyzes.