In this study, chitosan and alginate were selected to prepare alginate/chitosan nanoparticles to load the drug lovastatin by the ionic gelation method. The synthesized nanoparticles loaded with drug were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), laser scattering and differential scanning calorimetry (DSC) methods. The FTIR spectrum of the alginate/chitosan/lovastatin nanoparticles showed that chitosan and alginate interacted with lovastatin through hydrogen bonding and dipolar-dipolar interactions between the CO , C=O, and OH groups in lovastatin, the CO , NH, and OH groups in chitosan and the CO , C=O, and OH groups in alginate. The laser scattering results and SEM images indicated that the alginate/chitosan/lovastatin nanoparticles have a spherical shape with a particle size in the range of 50-80 nm. The DSC diagrams displayed that the melting temperature of the alginate/chitosan/lovastatin nanoparticles was higher than that of chitosan and lower than that of alginate. This result means that the alginate and chitosan interact together, so that the nanoparticles have a larger crystal degree when compared with alginate and chitosan individually. Investigations of the in vitro lovastatin release from the alginate/chitosan/ lovastatin nanoparticles under different conditions, including different alginate/chitosan ratios, different solution pH values and different lovastatin contents, were carried out by ultraviolet-visible spectroscopy. The rate of drug release from the nanoparticles is proportional to the increase in the solution pH and inversely proportional to the content of the loaded lovastatin. The drug release process is divided into two stages: a rapid stage over the first 10 hr, then the release becomes gradual and stable. The Korsmeyer-Peppas model is most suitable for the lovastatin release process from the alginate/chitosan/lovastatin nanoparticles in the first stage, and then the drug release complies with other models depending on solution pH in the slow release stage. In addition, the toxicity of alginate/ chitosan/lovastatin (abbreviated ACL) nanoparticles was sufficiently low in mice in the acute toxicity test. The LD 50 of the drug was higher than 5000 mg/kg, while in the subchronic toxicity test with treatments of 100 mg/kg and 300 mg/kg ACL nanoparticles, there were no abnormal signs, mortality, or toxicity in general to the function or structure of the crucial organs. The results show that the ACL nanoparticles are safe in mice and that these composite nanoparticles might be useful as a new drug carrier.
Polyurethane (PU) foam is known as the popular material for the applications in many fields of industry and life. To improve the mechanical and thermal properties of this material, in this research, PU foam was reinforced with aniline-modified multiwalled carbon nanotubes (MWCNTs). Fourier transform infrared FTIR spectrum of modified MWCNTs showed the aniline was grafted on the surface of MWCNTs through the appearance of –NH2 stretches. The effect of MWCNTs with and without modification on the density, porosity, compressive strength, and heat conductivity of PU/MWCNT foam nanocomposites was investigated. The dispersibility of MWCNTs in the PU matrix was enhanced after modification with aniline. Compressive strength of PU nanocomposite reached the highest value after adding 3 wt.% of modified MWCNTs into PU foam. Besides, the water uptake of PU nanocomposites using 3 wt.% of MWCNTs was decreased to 13.4% as compared to that using unmodified MWCNTs. The improvement in thermal conductivity of PU/aniline-modified MWCNT nanocomposite was observed due to the change in the cellular size of PU foam in the presence of MWCNTs as shown by SEM images.
This paper presents the effect of MDI/PPG ratio, polydimethylsilosane surfactant content and graphite content on the mechanical properties of the PU/graphite composites in order to finding the most suitable content of components to prepare the PU/graphite composite having good properties. The obtained results showed that the tensile strength and compressive strength of the PU/graphite composite reached the highest value at the MDI/PPG ratio of 1.15/1 and polydimethylsilosane content of 0.8%. The high graphite weight can cause the decrease in compressive strength and tensile properties of the PU/graphite composites. However, the increase in graphite content in the composites can lead to improve in the solar energy adsorption ability of the composites significantly. This confirmed that the potential using of graphite as filler for PU to prepare the porous materials having good solar energy adsorption ability.
This case study focused on zero emission via waste sludge treatment process from a brewery wastewater treatment plant. A perspective solution was based on three main processes by sludge digestion (40 m3/day), biogas recovery and purification for generation (20 kWh) and organic fertilizer production for green agriculture. The system is designed to integrated processes and operated autocompletively, except for the fertilization of crops. This work results showed that organic content decreased 55 - 70% after 20 days of sludge retention time (SRT) with 55 - 65% methane (CH4) yield. The contaminants in biogas was purified by high gravity rotating packed bed (HGRPB) device using aqueous solution (NaOH 0.01 M) and removal efficiency of CH4 concentration is 87%, this CH4 content met a demand of the standard for generator engines or boiler combustion. The digested sludge was combined with other by-products to produce organic fertilizer for green agricultural development, the quality of organic fertilizer was examined and met the regulations of Decree No. 84/2019/ND-CP of the Government: Regulations on fertilizer management. The achievements of this case study respond the harmonious combination among waste treatment, energy recovery and organic fertilizer production to contribute to the direction of the circular economy aspect and sustainable development.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.