Synthesis of mesoporous silica nanoparticles by variation of microwave power for the ibuprofen drug delivery

Mesoporous silica nanoparticles (MSN), which combine both unique properties of nanomaterials and mesostructured substances, have arouse special attention in biomedical research field due to its great advantages in many aspects such as well biocompatible, unique properties of tunable pore size and structure, large surface areas and pore volumes, controllable morphology and modifiable surfaces1-2. The traditional synthesis method of mesoporous materials is the hydrothermal route, which uses a certain amount of surfactants, as well as acid or alkali to compose a mixed aqueous preparation. Although finely ordered mesoporous materials are obtained, the process is time and energy consuming3. It is known that microwave (MW) heating promotes nucleation and can reduce the synthesis time and particle size significantly in comparison with the conventional convection heating method3. For the synthesis of periodic mesoporous organosilica, it was reported that the synthesis time was reduced from 72 h to 36 h when the self-assembly process was performed under MW irradiation. The resulting materials also exhibited a high surface area, large pore volume and large pore diameters4. Within this context, the microwave was utilized to synthesize the MSN under 100 W, 300 W and 450 W heating powers. Ammonia was chosen as the catalyst and ethylene glycol as the co-solvent because of their polarity, which is higher than that of NaOH and methanol or ethanol which are commonly used to synthesize mesoporous silica. All MSNs was tested for adsorption and release of an anti-inflammatory and anti-cancer drug, ibuprofen. The characterization revealed that the MSN prepared under 450 W (MSN450) produced the most crystallized and prominent mesoporous structure compared to lower power applied (Figure 1). MSN450 exhibited the highest ibuprofen adsorption, followed by MSN300 and MSN100, confirming that more crystallized MSN demonstrated higher adsorptivity toward ibuprofen. For the release study, MSN450 showed the slowest release rate of ibuprofen, followed by MSN300 and MSN100. All MSNs was found to exhibit good activity for the ibuprofen adsorption and release

Ecosystem health assessment of Sungai Pengkalan Chepa Basin: water quality and heavy metal analysis

This study was to determine the ecosystem health status at Sungai Pengkalan Chepa Basin based on Water Quality Index (WQI) and heavy metal concentration in the river water. Water samples were collected from 11 stations along the river and they were analyzed using YSI 556 MPS and laboratory analysis for in-situ test and ex-situ test, respectively. Meanwhile, heavy metal concentrations were analyzed using AAS. Water sampling was carried out starting from November 2018 until June 2019. The results for total median value of water quality parameters were as follows; DO (2.72 mg/L), BOD (6.42 mg/L), COD (33.5 mg/L), AN (1.02 mg/L), TSS (27 mg/L), and pH (6.97). According to WQI, Sungai Pengkalan Chepa Basin is classified under Class III, therefore, it is considered as slightly polluted. The order of concentration of heavy metals in water is Fe > Cr > Zn > Cu > Cd. Most of the heavy metals were found within the permitted level of National Drinking Water Quality Standard (NDWQS) except for Cd. Based on the Kruskal Walis test, there was a significant difference between parameters namely DO, BOD, COD, AN, pH, Zn, and Cd with sampling locations (ρ < 0.05). Based on this study, it can be concluded that the ecosystem health of Sungai Pengkalan Chepa Basin is not healthy from the aspects of DO, BOD, COD, AN, and Cd. The water quality status of Sungai Pengkalan Chepa Basin was mainly affected by the anthropogenic activities from urban development

Simultaneous removal of lead, cadmium, and arsenic Ions from bivalve species using adsorption method

Bivalve such as blood cockle (Tegillarca granosa) feeds by filtering the suspended particle in water including heavy metals and eventually accumulate in the fleshes. Bivalve contaminated with heavy metals might be consumed by human which later could have been exposed to heavy metals toxicity. Therefore, this study was conducted to investigate the effectiveness of adsorption process towards the removal of lead (Pb), cadmium (Cd), and arsenic (As) ions from T. granosa. The findings found that the initial concentration of Pb and As in T. granosa exceeded the permissible limits set by WHO. To remove heavy metals from T. granosa, an adsorption procedure was carried out using lemon and mango peels as natural waste adsorbents. The presence of hydroxyl and carboxylic functional groups in mango and lemon peels was shown in FTIR spectra, which aided in the enhancement of the adsorption process. A series of tests were performed using various parameters such as dosage adsorbents, contact of time, and temperature of reaction. The highest removal percentages of Pb, Cd, and As in T. granosa using lemon peels were 59.65%, 88.89%, and 67.54% respectively. Meanwhile, the maximum removal from T. granosa using mango peels were 70.18% for Pb, 100% for Cd, and 84.71% for As. In conclusion, the adsorption process was effective in removing Pb, Cd, and As in T. granosa. Whereas both lemon peels and mango peels have ability to become effective naturals waste adsorbent in the adsorption process

Removal of as and cd ions from aqueous solution using biosorption technique

Arsenic (As) and cadmium (Cd) are listed as heavy metals that have contaminated the environment, especially water supplies. Therefore, the goal of this study was to remove heavy metals, particularly As and Cd metal ions, from aqueous solutions by utilizing natural waste adsorbents and at the same time, help in the reduction of waste products. This study was designed to use low-cost and more widely available adsorbents material such as coconut husk and banana peel to remove As and Cd ions in an aqueous solution. The adsorption method was utilized to reduce and remove the As and Cd ions, and their concentrations in an aqueous solution were then determined by Atomic Absorption Spectroscopy (AAS). Various parameters such as types of adsorbents (banana peel and coconut husk), adsorbent dosages (0.1-0.3g), contact time (30-70 minutes), and temperature (25-45°C) were used to carry out the removal process. The FTIR analysis revealed that certain heavy metals were more likely to bind to these adsorbents due to the presence of important functional groups such as hydroxyl (-OH) and carbonyl (C=O). From this study, the optimum removal conditions were 0.1 g dose of adsorbent along with 70 minutes of contact time at a reaction temperature of 25°C. The results revealed that banana peel removed 0.948 mg/L of Cd ions and 0.148 mg/L of As ions from the aqueous solution, suggesting that it was more efficient at removing heavy metals than coconut husk. Meanwhile, Cd ions have a higher affinity (93.9% to 99.9% removal) than As ions (8.3% to 22.2% removal) to adsorb onto the active sites of banana peel and be removed from an aqueous solution. In conclusion, the adsorption technique using natural waste adsorbents can be applied to remove the As and Cd ions from the aqueous solutions. The reduction of these heavy metals' concentration by adsorbents can also help to preserve the quality of water sources under the permissible limit set by WHO

Adsorptive removal of methylene blue in aqueous solution onto mesostructured silica nanoparticles

Mesostructured Silica Nanoparticles (MSN) have become increasingly important owe to their high surface area, thermal and mechanical stability, highly uniform pore distribution, tunable pore size, and unique hosting properties. This special feat ure is crucial to be adopted as effective adsorbents to adsorb wide range of organic dye solution. In this work, MSN was prepared through a facile preparation method and characterized by X -Ray Diffraction (XRD), N2 Physisorption and Transmission Electron Microscopy (TEM). The adsorption behavior of methylene blue in aqueous solution onto synthesized MSN was studied in a batch system at different pH (2–11), MSN dosage (0.1–0.5 g L-1), initial MB concentration (5–100 mg L-1) and temperature. The equilibrium data were evaluated using Langmuir and Freundlich isotherms, while the adsorption kinetics was assessed by the pseudo-first and second order model, along with thermodynamic aspect. The MSN obtained was believed to optimize the adsorption process with shorte r time. The results indicate the potential of this material as an effective adsorbent for methylene blue dye

Utilization of Lapindo Volcanic Mud for Enhanced Sonosorption Removal of Acid Orange 52

This study applied ultrasonic irradiation technique to remove acid orange 52 (AO52) and in the meantime utilizing the potential adsorbent, Lapindo volcanic mud (LVM). LVM was collected from the erupted mud in Sidoarjo, Indonesia and calcined prior the adsorption process. Previously in another study, Lapindo was proven to be efficient for adsorption of dyes in single adsorption method. In this study, the combination of adsorption with ultrasound, or as known as sono-sorption shows that the adsorptivity increased from 95.54 mg/g to 129.5 mg/g. The isotherm study shows that this process obeyed Langmuir isotherm model with adsorption capacity of 833.33 mg/g. The enhancement of sono-sorption method as compared to conventional method is believed to be resulted from the facilitated mass transfer driven by the ultrasound, along with the adsorption ability of LVM. The kinetic study fit to the pseudo second order equation

Strategies for introducing titania onto mesostructured silica nanoparticles targeting enhanced photocatalytic activity of visible-light-responsive Ti-MSN catalysts

Titanium-mesostructured silica nanoparticles (Ti-MSN) catalysts which are excellent photocatalytic materials for the environment were prepared by supporting mesostructured silica nanoparticles (MSNs) with titanium species synthesized by three different approaches: microwave and in situ and ex situ electrochemical methods, denoted as Ti-MSN-M, Ti-MSN-I, and Ti-MSN-E, respectively. The physicochemical properties of the catalysts were investigated via XRD, 29Si NMR, N2 adsorption-desorption, FTIR, ESR, and UV-DRS analyses. Characterization results revealed that the introduction of mesoporous titania nanoparticles (MTNs) prepared by the microwave method onto MSNs (Ti-MSN-M) did not significantly affect the silica framework. However, the silica network in the Ti-MSN-I and Ti-MSN-E was rather disrupted, particularly for the former catalyst, due to the desilication accompanied by isomorphous substitution of Ti in the MSN framework to form Si[sbnd]O[sbnd]Ti bonds. Ti was also found to be exchanged with the terminal hydroxyl groups of all catalysts to form the Si[sbnd]O[sbnd]Ti bonds. The addition of Ti species onto MSNs also increased the number of oxygen vacancies (Vo) and metal defect sites. Photocatalytic testing on the decolorization of Congo red (CR) resulted in the following order: Ti-MSN-I (94%) > Ti-MSN-M (90%) > Ti-MSN-E (34%). The Vo and metal defect sites were responsible in lowering the band gap of catalysts and decreasing the electron–hole recombination, while the great numbers of Si[sbnd]O[sbnd]Ti bonds as well as large surface area and pore volume increased the active sites and offered a good surface contact with light to enhance the activity of catalysts. A kinetic study demonstrated that the photodegradation followed the pseudo-first-order Langmuir-Hinshelwood model. Ti-MSN-I and Ti-MSN-M maintained their activities for up to five runs without serious catalyst deactivation, indicating their potential for the degradation of dye in wastewater. Mineralization measurements of CR by TOC and BOD5 analyses after 3 h of contact time were 85.7% and 87.6% using Ti-MSN-M, while 83.7% and 80.3% using Ti-MSN-I, respectively. Optimization by response surface methodology showed that the catalyst dosage, pH, and TiO2 loading were the significant factors in the decolorization of CR. This study demonstrated that these two green technologies; electrochemical and MW have a great potential to be used in synthesis of various advanced materials for greener and more sustainable processes