Acta Chimica Asiana

Quantum Dynamic Approach of B2N(∓,0) and N2B (∓,0) Clusters Study: A Symmetry Breaking due to the Jahn-Teller Effect

Majid Monajjemi — 2024-04-17

BN compounds play an important role in the preparation of hyper- thin films, that have received signifcant attention in products. In this article, we investigated the electronic structures of and. Triatomic NBN and BNB have recently been studied using various experimental and calculation approaches, and it is totally agreed that both of them are linear in their ground electronic step. The six ions including B₂N^(-), B₂N⁽⁺⁾, B₂N⁽⁰⁾ , BN₂^(-), BN₂⁽⁺⁾ and BN₂⁽⁰⁾ have been studied and been also compared with one another in terms of several basis sets and predication of the symmetry breaking (SB) subject. Artifactual SB with the v₃ vibration is occurred in the trial wave functions of coupled-cluster level, even when Brueckner orbitals of all nitrogen and oxygen atoms are used. In the of and molecules, the unpaired electrons are delocalized, while in the asymmetric, they are localized on either one of the B atoms or N atoms of and , respectively. Structures with (SB),, can be stronger by interaction to the . Hereby, the second-order Jahn-Teller effect allows the unpaired electron to localize on boron atom, rather than being delocalized. Finally, from a statistical thermodynamical analysis, we calculated the thermodynamically stabilities of those six ions.

Study of inorganic based anti-blocks as migration control of slip additive on surface polyethylene monolayer film

Laily Aulia Agustina — 2024-04-18

Slip migration must be controlled to maintain the performance and quality of flexible packaging. Inorganic based anti-block materials can be used to control the slip migration. This paper reported the effect of anti-block type on the inhibition of slip migration on polyethylene monolayer film. A series of formulations were made with three different anti-block additives, namely talc, natural silica, and synthetic silica, along with erucamide. The optical properties (haze) and friction properties (COF) were measured to assess the film characteristics as the development of slip migration in the presence of anti-block additives. Characterization of the anti-block material was conducted by SEM-EDX, slip additive type was examined by GC-MS, while the slip content on the surface was analysed by FTIR. The result showed that after seven days, synthetic silica anti-block gives COF up to 0.095, with the trace erucamide content on the film surface of 394 ppm, the lowest amongst other types of the anti-block used. The smaller particle size and higher silica content on synthetic silica anti-block resulted in better friction properties which act as a good barrier to limit a migration of erucamide onto the film surface.

Gas Detecting Evaluation by Graphitic-based Silicon Carbide Nanosurface doped with Manganese: A Promising Device for Air Pollution Monitoring

Fatemeh Mollaamin — 2024-04-18

Silicon carbide (SiC) as a direct broad bandgap semiconducting material has the potential to bring a considerable developement into optoelectronic and electronic devices. This article aims to investigate

Physico-chemical properties of manganese (Mn)–doped graphene-like silicon carbide (SiC) monolayer sheet by the first-principles methods based on the density functional theory (DFT) for scavenging of CO, CO₂, NO, NO₂ gas molecules. The results recommend that the adsorption of these gas molecules on Mn-embedded SiC sheet monolayer is more energetically desired than that on the pristine ones. Gas molecules of CO, CO₂, NO, NO₂ have been adsorbed on the Mn site of doped SiC monolayer through the formation of covalent bonds. The assumption of chemical adsorptions has been approved by the projected density of states (PDOS) and charge density difference plots. Charge density difference calculations also indicate that the electronic densities were mainly accumulated on the adsorbate of CO, CO₂, NO, NO₂ gas molecules. The ability of SiC nanosheet for monitoring of CO, CO₂, NO and NO₂ is fluctuated by their selectivity and sensitivity through NMR, NQR, IR and HOMO/LUMO approaches which can represent the efficiency of Mn–doped SiC surface as the promising sensors toward air pollution detecting.

Effect of water-methanol binary solvent system in green synthesis of copper nanoparticles with tobacco leaf extract

Tomi Suharto — 2024-04-18

The increasing demand for environmentally friendly nanoparticle synthesis, as a viable strategy for pollution control, has prompted an exploration of green chemistry methods. This study meticulously investigates the synthesis of copper nanoparticles utilizing tobacco leaf extract obtained through both cold and hot extraction techniques. The primary focus lies in scrutinizing the impact of various solvents employed for plant extracts and metal ion solutions on reduction dynamics and particle size. The study employs UV-Vis and phytochemical analyses to discern differences in chemical composition and efficacy, particularly between the water and methanol-water systems, despite their resemblance in UV-Vis spectra. Intriguingly, the results unveil that the choice of solvent significantly influences the particle size distribution and stability of colloidal nanoparticles. The methanol-water system, in particular, yields smaller, more uniform particles compared to other solvent systems. This research sheds light on the pivotal role of solvent selection in nanoparticle synthesis, emphasizing its profound impact on both the reduction process and the resulting particle size distribution. The findings underscore the nuanced relationship between solvent choice and the characteristics of the synthesized nanoparticles, providing valuable insights for optimizing environmentally friendly synthesis methods. Ultimately, this study contributes to the growing body of knowledge on green chemistry approaches for nanoparticle synthesis with implications for pollution control and sustainable materials production.

Determining the preeminent plastic wastes in the production of petrol using pyrolysis method and its effectiveness as an alternative fuel

Nelson Jun Herrero — 2024-04-18

Abstract: This study aimed to determine which type of plastic – PET, HDPE, LDPE, PP, PS, and Others, produces most oil yield in terms of time of complete degradation, temperature and amount of plastics using a non-catalytic slow pyrolysis method; it also determined the physical characteristics of the oil yield in terms of its color and appearance; and it also aimed to determine which petroleum produced by different types of plastics are more efficient in terms of (a) production of oil and (b) combustion time. Production of oil and oil yield is presented in milliliters and percentage, respectively. Combustion time is expressed in seconds from the time of ignition to total disappearance of flame having 1ml of oil tested from each produced pyrolytic oil. Experimental-descriptive comparative method was used in determining the type of plastic that yields to most of pyrolytic oil. Based from gathered results, at constant temperature and amount of plastics, PS produced most petroleum at 29.5% oil yield followed by PP with 29%. While PET produced the least petroleum with 0.01% oil yield. Color varies at different types of plastics, given that PET and PP produces light brown color, LDPE produces light yellow while HDPE, PS and Others produces black color. PET, HDPE, PP, PS and Others produced liquefied petroleum while LDPE produces flammable wax product. PS produced most petroleum with 295ml (29.5%), and PET produced least oil with 1ml (0.01%). Combustion time varies at different types of plastics: PS at 145 seconds, PP at 141 seconds, HDPE at 115 seconds, Others at 78 seconds, LDPE at 77 seconds while PET produced non – flammable oil yield. Thus, PS is most efficient as an alternative fuel in terms of production and combustion time. For the betterment of similar study, future researchers are encouraged to test the pyrolytic oil yielded from different types of plastics in engine performance and machineries and the comparative performance to the available commercial fuels.

Specific and nonspecific characteristics of the leaf extract of Blumea balsamifera originated from East Java, Indonesia

I Made Wisnu Adhi Putra — 2024-04-18

Blumea balsamifera extract has been shown to have biological activities such as anti-fungal, anti-tumor, radical scavenger, anti-obesity, hepatoprotective, antioxidant, anti-microbial, anti-inflammatory, antiplasmodial, and wound healing. The quality and efficacy of B. balsamifera extract are determined by its specific and nonspecific characteristics. This study explored the characteristics of B. balsamifera extract through a series of standardization processes. The dried leaves of B. balsamifera were powdered and macerated with 70% ethanol. After the solvent evaporation, a thick extract was obtained and stored in a refrigerator. The specific characteristics tested were organoleptic evaluation, total phenolic content (Folin-Ciocalteu method), total flavonoid content (aluminium chloride colorimetric method), and phytochemical screening using thin layer chromatography. The nonspecific characteristics tested were extraction yield, moisture content, total ash content, and acid-insoluble ash. The results of the study showed that the extraction process resulted in a yield of 13.4%. The extract had a thick and sticky appearance, a dark brown colour, a characteristic aroma, and a bitter taste. The moisture content, total ash content, acid-insoluble ash content, total phenolic content, and total flavonoid content of the extract were found to be 8.33±0.57 %ml/g, 11.63±0.86 %g/g, 2.26±0.12 %g/g, 43.86±0.89 mg GAE/g extract and 25.48±0.42 mg QE/g extract, respectively. Analysis using thin layer chromatography demonstrated that the extract included phenolics, flavonoids, terpenoids, and steroids.

Assessment of the Ecological Impact of Pollution in the Damanganga River

Manoj Godhaniya — 2024-04-18

The Damanganga River faces severe pollution from industrial effluents and sewage, impacting its ecological health. The study aimed to analyze the current water quality status at the proposed conventional barrage site across the river between Silvassa, Vapi and Daman in India. Water samples were collected from three sites along the river during different seasons and analyzed for physicochemical parameters like TDS, COD, BOD, nutrients, fecal coliforms, heavy metals, etc. as per standard methods. Principal component analysis (PCA) was done. GCMS profiling of organics was also carried out. Several parameters exceeded the desired limits. TDS, BOD, fecal coliforms were very high indicating organic pollution and sewage contamination. Dissolved oxygen was deficient at some sites. Cadmium, copper and iron exceeded limits due to industrial releases containing these metals. PCA showed organic pollution as the major degrading factor for water quality followed by industrial contamination. GCMS analysis revealed hazardous organics like petrochemicals, fatty acids, solvents, pesticides and aromatic pollutants at varying levels along the river’s course demonstrating pollution from oil spillages, industrial effluents and agricultural runoff. The findings confirm severe deterioration in the Damanganga's water quality from inadequately treated sewage and industrial discharges posing environmental and health risks. Stringent regulations, proper wastewater treatment, runoff control and regular monitoring are vital to improve the river's condition

Antimicrobial of Ethanolic Extract from Marpuyan Stem Bark (Rhodamnia cinerea Jack)

Musyirna Rahmah Nasution — 2024-04-18

The Bark of Marpuyan Tree (Rhodamnia cinerea Jack) is a plant that has been empirically used by communities in Indonesia for the treatment of infectious diseases caused by bacteria and fungi. The bark of Marpuyan contains flavonoids, phenolics, and saponins. This study aimed to evaluate the antibacterial and antifungal activities of the ethanol extract of the bark of Marpuyan using the disc diffusion method at various extract concentrations, namely 30%, 25%, 15%, 10%, and 5%. The results of the antibacterial activity test against Gram-positive bacteria (Staphylococcus aureus, Staphylococcus epidermidis, and Bacillus subtilis) showed inhibitory zones with respective diameters of 11.67±0.21 mm, 12.29±0.43 mm, and 12.78±0.14 mm. These results indicate weak antibacterial activity. In the antibacterial activity test against Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Salmonella typhi), inhibitory zones were found with respective diameters of 13.05±0.05 mm, 12.58±1.78 mm, and 10.98±0.21 mm. These results also indicate weak antibacterial activity. However, in the antifungal activity test, no activity was found against Candida albicans and Malassezia furfur. Nevertheless, the ethanol extract of Marpuyan bark showed moderate antifungal activity against Trichophyton mentagrophytes, with an inhibitory zone diameter of 15.44±2.02 mm.

Fotocatalytic degradation of methylene blue by floating TiO2-coconut fiber

Didiek Sugandi — 2024-04-18

Indonesia's expanding industrial sector has resulted in an increase in the use of dyes. Methylene blue (MB), a dye used in the batik and textile industries, has the potential to be detrimental to people and the environment. Recent research indicates that the TiO₂ photocatalyst has the ability to reduce MB. TiO₂ transported in coconut fiber can improve illumination in the photocatalysis process. The purpose of this study is to examine the properties and activity of a TiO₂-coconut fiber photocatalyst. SEM-EDX was used to characterize the morphology and composition of floating catalysts, and Fourier transform infrared (FT-IR) was used to characterize the functional groups. At 120 minutes, TiO₂-coconut fiber photocatalysis with a mass ratio of 20:80 w/w demonstrated the maximum degradation of 62.72%. The SEM-EDX data demonstrate the morphology of TiO₂ distribution on the surface of coconut fiber, which is distinguished by the presence of the main elements O, Ti, and C. The FT-IR study results demonstrate a shift and decrease in Ti-O absorption intensity from 756,09 cm1 to 721,38 cm1, indicating the presence of Ti-O-C bonds. It is hoped that this research will be useful in the treatment of MB in textile industry waste or other organic waste.