Porous hydroxyapatite (HAp) granules have been successfully fabricated from a HAp powder precursor and polyvinyl alcohol (PVA) additive by a simple sintering process. The composition and microstructures of the HAp were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) equipped with an energy dispersive X-ray (EDX) spectrometer. The effects of sintering temperature and PVA/HAp mass ratios on color, water stability, morphology, and chemical composition of HAp are discussed. Optimum conditions for the fabrication of HAp granules were found to be a PVA/HAp mass ratio of 3/20 and a sintering temperature of 600°C for 4 h. Accordingly, the obtained HAp is white in color, is in the granular form with a size of about 2 × 10 mm, and has a specific surface area of 70.6 m2/g. The adsorption of Pb2+ onto the as-prepared HAp granules was carried out in aqueous solution by varying the pH, the adsorbent dose, the initial concentration of Pb2+, and the contact time. The results of adsorption stoichiometry of Pb2+ on the HAp granule adsorbent were fitted to the Langmuir adsorption isotherm model (R2 = 0.99). The adsorption capacity and removal efficiency of the HAp granule adsorbent for Pb2+ under optimal conditions were found to be 7.99 mg/g and 95.92%, respectively. The adsorption process obeyed a pseudo-second-order kinetic model with R2∼1. The porous HAp granules studied in this work showed potential for the removal of Pb2+ from industrial wastewater.

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Uranium, as an energy source and radioactive waste, is very important in the nuclear fuel cycle. Recovery of uranium from nuclear waste solution is essential for further treatment and disposal. Herein, an ionic liquid-functionalized porous aromatic framework material P–C4 (PPN-6-CH2P+(C4H9)3Cl–) for uranium adsorption from alkaline solution was synthesized by grafting PPN-6 with the quaternary phosphonium for the first time. The U-exchange kinetics perfectly conforms to the pseudo-second-order dynamic model, which reveals the chemical adsorption process. P–C4 exhibits a record high uranium exchange capacity of over 670 mg/g and can efficiently capture [UO2(CO3)3]4– ions in the presence of the high concentrations of HCO3 –, CO3 2–, F–, SO4 2–, Cl–, and NO3 –. In addition, the uranyl tricarbonate in the loaded material could be easily eluted with a diluted hydrochloric acid. These advantages make P–C4 a new potential material for separating uranium from alkaline solution.

Microfluidics has emerged in recent years as a technology that has advantages and is well suited for studying chemistry, biology, and physics at the microscale. A common material which has been widely use to fabricate the microfluidic system is thermoplastic materials. The method of fabricating microfluidic devices has been growing because of advantages such as high-quality feature replication, inexpensiveness, and ease of use. However, the major barrier to the utilization of thermoplastics is the lack of bonding methods for different plastic layers to close the microchannels. Therefore, this study focused on fabricating a microfluidic device on poly(methyl methacrylate) (PMMA) plates by laser engraving. The bonding technique for plastic layers has relied on the application of small amounts of ethanol with conditions of low temperatures (100 ⁰C), and relatively low pressures (5 tons) for 2 minutes. With this technique, the microfluidic device is created to operate stably, without leakage or cracking even under high pressure. The microfluidic device was applied to synthesize liposomes with a 5:1 ratio of syringe pump velocity between water and lipid solution. The size of liposomes after synthesis is 109.64 ± 4.62 nm (mean ± sd) and the PDI is in accordance with standard conditions (PDI < 0.200).

Climate change is increasingly clear and threatening to human life. One of the consequences of climate change is the increase of sea level leading to saline intrusion and serious shortage of fresh water. Today, some technologies are used to treat saline water such as Reverse Osmosis technology (RO), Multi-Effect Distillation (MED) technology, and Multi-Stage Discharge Technology (MSF), Electrodialysis (ED) and Capacitive Deionization (CDI). Among them, CDI technology is a technique for energy-saving and economical. The conductive composite electrode based on activated carbon from Tra Bac coconut shell charcoal were fabricated which were used as a electrode for CDI device. In this study, effect of adhesives and conductors on characterization and properties of the materials was investigated. The adhessive of PVDf and conductor of CNTs was chosen. With ratio of AC/CNTs = 9:1, the composite had a specific surface area of BET of about 517 m2/g and pore size of 1.71 nm.