Steam explosion is a useful method to soften and dimensionally stabilizing wood. A significant increase in air permeability and sound absorption capability of steam-exploded palmwood compared to ...untreated palmwood is observed due to changes in cell wall. Cell wall’s changes are characterized by instrumental techniques such as Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscope and gas permeability by capillary flow porometry and sound absorption coefficient by two-microphone transfer function method. The average increase in air permeability (259.3%) and sound absorption coefficient (52.33% at frequency range of 250–6400 Hz) of steam-exploded samples is higher than that of untreated samples. Color of steam-exploded woods become black due to chemical reactions in cell wall during steam explosion. The color change, air permeability and sound absorption coefficient of wood are correlated with the findings. These results suggest that low-pressure steam explosion could be considered as an effective technique for improving the air permeability and sound absorption capability of palmwood in the longitudinal direction. This approach could be useful to manufacture sound absorption board to control the acoustical housing environment.
This review article focuses on the potential of biopolymer-based nanocomposites incorporating nanoparticles, graphene oxide (GO), carbon nanotubes (CNTs), and nanoclays in adsorption and membrane ...filtration processes for water treatment. The aim is to explore the effectiveness of these innovative materials in addressing water scarcity and contamination issues. The review highlights the exceptional adsorption capacities and improved membrane performance offered by chitosan, GO, and CNTs, which make them effective in removing heavy metals, organic pollutants, and emerging contaminants from water. It also emphasizes the high surface area and ion exchange capacity of nanoclays, enabling the removal of heavy metals, organic contaminants, and dyes. Integrating magnetic (Fe2O4) adsorbents and membrane filtration technologies is highlighted to enhance adsorption and separation efficiency. The limitations and challenges associated are also discussed. The review concludes by emphasizing the importance of collaboration with industry stakeholders in advancing biopolymer-based nanocomposites for sustainable and comprehensive water treatment solutions.
This study delves into the critical issue of water pollution caused by the presence of metal oxides, synthetic dyes, and dissolved organic matter, shedding light on their potential ramifications for ...both the environment and human health. Metal oxides, ubiquitous in industrial processes and consumer products, are known to leach into water bodies, posing a significant threat to aquatic ecosystems. Additionally, synthetic dyes, extensively used in various industries, can persist in water systems and exhibit complex chemical behavior. This review provides a comprehensive examination of the toxicity associated with metal oxides, synthetic dyes, and dissolved organic matter in water systems. We delve into the sources and environmental fate of these contaminants, highlighting their prevalence in natural water bodies and wastewater effluents. The study highlights the multifaceted impacts of them on human health and aquatic ecosystems, encompassing effects on microbial communities, aquatic flora and fauna, and the overall ecological balance. The novelty of this review lies in its unique presentation, focusing on the toxicity of metal oxides, dyes, and dissolved organic matter. This approach aims to facilitate the accessibility of results for readers, providing a streamlined and clear understanding of the reported findings.
Nowadays, arsenic (III) contamination of drinking water is a global issue. Laboratory and instrument-based techniques are typically used to detect arsenic in water, with an accuracy of 1 ppb. ...However, such detection methods require a laboratory-based environment, skilled labor, and additional costs for setup. As a result, several metal-based nanoparticles have been studied to prepare a cost-effective and straightforward detector for arsenic (III) ions. Among the developed strategies, colorimetric detection is one of the simplest methods to detect arsenic (III) in water. Several portable digital detection technologies make nanoparticle-based colorimetric detectors useful for on-site arsenic detection. The present review showcases several metal-based nanoparticles that can detect arsenic (III) colorimetrically at a concentration of ~0.12 ppb or lower in water. A literature survey suggests that biomolecule-based metal nanoparticles could serve as low-cost, facile, susceptible, and eco-friendly alternatives for detecting arsenic (III). This review also describes future directions, perspectives and challenges in developing this alternative technology, which will help us reach a new milestone in designing an effective arsenic detector for commercial use.
Synthesis of sodium alginate-g-
poly
(acrylamide-co-
N
-methylacrylamide) S-III, sodium alginate-g-
poly
(
N
-methylacrylamide-co-
N,N
-dimethylacrylamide) S-II, sodium alginate-g-
poly
...(acrylamide-co-
N,N
-dimethylacrylamide) S-I. Sodium alginate-g-
poly
(
N,N
-dimethylacrylamide) SAG-g-PDMA and sodium alginate-g-
poly
(acrylamide) SAG-g-PAM were prepared by solution polymerization technique using potassium peroxydisulfate as the initiator at 70 °C in water medium. The graft copolymers were characterized by FTIR and NMR (
1
H and
13
C) spectroscopy, SEM and XRD studies. All the five graft copolymers were used to remove Pb(II) ions from the aqueous solution and also in flocculation studies of kaolin clay (1.0 wt%), silica (1.0 wt%) and iron ore slime (0.25 wt%) suspensions. A comparative studies of all the five graft copolymers were also made in both the two cases. The Pb(II) ion removal capacity of all the graft copolymers follows the order S-III > SAG-g-PAM > S-II > SAG-g-PDMA > S-I. But the flocculation performance of the graft copolymers follows the order S-II > S-I > S-III > SAG-g-PDMA > SAG-g-PAM. S-III was also used for the competitive metal ion removal with Hg(II), Cd(II), Cu(II) and Zn(II). Pb(II) adsorption of S-III (the best Pb(II) ion adsorber) follows pseudo second order rate equation and Langmuir adsorption isotherm.
Face masks have become an essential commodity during the COVID-19 pandemic, and their use rises daily. Excessive face mask use will likely continue to combat the virus and bacterial impacts in the ...long term. Afterward, used face masks are hazardous to the environment since most are made of nonbiodegradable porous polymeric fibrous materials. Thus, finding new ways to recycle waste face masks is urgently needed. Similarly, managing agricultural water for irrigation is a crucial challenge in saving water. This study demonstrates an approach for recycling face masks as bag- or small-sized pillows filled with superabsorbent polymers (SAPs) for the slow release of water near plant roots. Previous studies have reported that SAPs or hydrogel could boost soil’s water retention capacity, mixed with hydrogel/SAP. However, mixing SAPs into soil is improper because biodegradation generates low toxic organic molecules and contaminates soil and surface water. The objective of this research was to develop a face mask reuse approach, reduce irrigation water using polymers, and reduce toxic contamination in the soil. Here, swollen SAPs were taken inside the pillow and buried near plants, and the growth of the plants was studied. The moisture of the inner soil was constant for a long time, boosting plant growth. Afterward, the face mask pillows could be removed from the soil and maintained for further use. This new approach could be helpful in pot farming. This approach could contribute to the circular economy and the development of environmental sustainability.
Cancer is a genetic disorder and its treatment usually requires a long time and expensive diagnosis. While chemotherapy is the most conventional approach in treating most cancers, patients often ...suffer from undesired side effects due to various pharmacokinetic aspects. To address this issue, target-oriented drug-delivery systems (DDS) or pulsatile drug-delivery systems (PDDS) have recently been developed as an alternative tool that takes care of the entire pharmacodynamic activities of drug action. Hydroxyethyl starch (HES) has emerged as an effective clinical tool for delivering anticancer agents into target cells. These systems have demonstrated significant potential as anticancer drug carrier conjugates through their innate pharmacokinetic properties with their safety profile. This review focuses primarily on the structural aspect during the use of HES or HES-based polymers as carriers for delivering well-known anticancer drugs. This review also indicates a perspective on the long-term research needed for the sake of improving modern drug-delivery systems based on HES polymers and in the form of nanocarriers.
Loud noise has become a regular part of life due to growing urbanization and lifestyle changes, making noise pollution a severe health concern. However, eco-friendly materials for low-frequency sound ...absorption still need improvement. Wooden puzzle-assembled boards are being used to construct wooden buildings in South Korea, but they require better sound absorption performance. Therefore, we have developed a strategy to enhance the sound absorption capability of wooden puzzle-assembled boards by suggesting the installation of a single-frequency resonator on the board. The resonator contains nine pinholes with a 6 mm diameter perforation connected to a 30 mm diameter hole leading to the center hollowed cavity (CHC). We evaluated the sound absorption coefficient (SAC) of the control (i.e., cross-laminated timber (CLT)) and a resonator board. The SAC of the resonator with zero pinholes (i.e., CHC), one pinhole (PH-1), five pinholes (PH-5), and nine pinholes (PH-9) were estimated using a two-microphone transfer function method at low frequencies ranging from 100 to 1600 Hz. The average SAC of PH-9 showed significant improvement at the frequency of 450 Hz (0.637 ± 0.001; 818%) compared to the control samples. The noise reduction coefficient was improved by 239% (0.07 for the control and 0.23 for the PH-9). We compared the experimental results in this study with theoretical results and found that the orientation of the neck length significantly impacted the resonant frequency of the pinhole resonator. This finding provides valuable insights into the design and optimization of pinhole resonators for specific acoustic applications.
•A wooden puzzle board that can be used to construct wooden structures.•New low-frequency sound absorption strategy.•A nine-pinhole (6 mm) resonator exhibits excellent sound absorption at 450 Hz.•Impressive results could entice both the manufacturer and the customer.
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•Synthesis of HES-g-Poly-(DMA-co-AA).•Characterization using GPC, FTIR, NMR and SEM.•Biodegradation studies by enzyme.•Dye removal from aqueous solution.•Study of adsorption kinetics.
...Hydroxyethyl Starch-g-Poly-(N,N-dimethylacrylamide-co-acrylic acid) was synthesized by solution polymerization technique using potassium peroxydisulfate (K2S2O8) as the initiator at 90°C. The synthesized graft copolymer was characterized by FTIR, NMR (both 1H and 13C) Spectroscopy, molecular weight determination by GPC, TGA/DTG and SEM analysis. Biodegradation study was carried out by enzymatic hydrolysis. The number of carboxylic acid groups incorporated into the polymer was calculated by measuring neutralization equivalent (N.E) of the graft copolymer titrimetrically. The synthesized graft copolymer was used as the adsorbent for the removal of Malachite green, a cationic dye from its aqueous solution. The operating variables studied were the amount of adsorbent, solution pH, contact time, temperature and the initial dye concentration. The adsorption data were used to fit in the pseudo-first order and pseudo-second order rate equation in order to investigate the sorption mechanism. Equilibrium isotherm was analyzed using the Langmuir and the Freundlich isotherms. In the present investigation it was found that the adsorption kinetics followed a pseudo second order kinetics for the studied dye concentration range. The negative value of free energy change indicates the spontaneous nature of the adsorption and also suggesting a chemisorption process.
Synthesis of amylopectin grafted polyacrylamide (AP-g-PAM) and poly(N,N-dimethylacrylamide) (AP-g-PDMA) was carried out by Ce4+ in water medium. The reaction conditions for maximum grafting was ...optimized by varying the reaction variables, including the concentration of monomers, ceric ammonium nitrate (CAN), amylopectin, reaction time and temperature. The graft copolymers were characterized by FTIR spectroscopy, NMR (both 1H and 13C) spectroscopy, molecular weight determination and molecular weight distribution by using size exclusion chromatography (SEC), thermal analysis (TGA), SEM studies. Biodegradation of the graft copolymers was carried out by enzyme hydrolysis. Flocculation performances of the graft copolymers were evaluated in 1.0wt% coal and 1.0wt% silica suspensions. A comparative study of the flocculation performances of AP-g-PDMA and AP-g-PAM was also made. It shows that the flocculation performance of AP-g-PDMA was better than that of AP-g-PAM. AP-g-PDMA performed best when compared with other commercial flocculants in the same suspensions.
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