Photo catalytic oxidation of endocrine disruptor bisphenol A (BPA) was carried out under solar exposure with two types of reactor, non-light concentrating cylindrical photoreactor and concentrating one. The non-concentrating cylindrical reactor exhibited a higher apparent quantum yield than the solar-light concentrating one. The low degradation efficiency of the concentrating system could be highly attributable to that the reactor can employ only direct solar radiation, conversely to the non-concentrating reactor which employs both direct and diffuse radiation. The photo-oxidation of BPA was depressed under the strong illumination condition provided by the concentrating system, due to an enhanced hole/e- recombination. The optimal conditions to decompose BPA (0.1mM, 15L) were pursued. The aromatic ring cleavage occurred in a 90 % yield and the TOC decrease proceeds in a 95% yield after 90 min of irradiation under the optimal conditions (cylindrical photo reactor, flow rate: 7.2L/min TiO2: 2g/L, initial pH: 6.8) to decompose BPA (0.1mmol/L, 15L).
The physico-chemical interaction between hydrophobic polyolefin materials and originally hydrophilic inorganic nano-particles like surface hydroxylated SiO2 has not been well understood up to now. In this study, the influences of particle size, content of hydrophilic SiO2 nanoparticles on the isothermal growth rate of polypropylene (PP) spherulites in various PP/SiO2 nanocomposites were investigated by polarized optical microscope equipped with temperature controlled hot stage. Moreover, photo-oxidative degradation behavior of the PP/ SiO2 nanocomposites were investigated. It is most interesting to note that the addition of smaller SiO2 nanoparticles effectively lowered the growth rate of PP spherulites in the composites and the spherulite growth rate became zero for the PP/16nm-SiO2 nanocomposites with the SiO2 content above 2.5 wt%. It was found that the sample without spherulite morphology is more stable to photo-degradation. Spherulite structure is considered to have the influence affect photo-oxidative degradation.
This paper describes the effects of polyethylene glycol (PEG) derivatives on copper electroplating. α, ω-Diphenylazophenoxy polyethylene glycol (PEG-Az) of the novel PEG derivative provides interesting results, suppressing copper deposition during copper electroplating. We found that PEG-Az suppresses copper deposition without the chlorideion (Cl-ion). To determine the reason for this action, we carried out linear sweep voltammetry (LSV), glow discharge optical emission spectroscopy (GDOES), and electrochemical quartz crystal microbalance (EQCM) measurements for the plating bath containing PEG-Az. PEG-Az was found to be a stronger suppression effect than the PEG even without the Cl-ion.