The Total Solubility of the Co-Solubilized PAHs with Similar Structures Indicated by NMR Chemical Shift

The synergism/inhibition level, solubilization sites and the total solubility (S_t) of co-solubilization systems of phenanthrene, anthracene and pyrene in Tween 80 and sodium dodecyl sulfate (SDS) are studied by ¹H-NMR, 2D nuclear overhauser effect spectroscopy (NOESY) and rotating frame overhauser effect spectroscopy (ROESY). In Tween 80, inhibition for phenanthrene, anthracene and pyrene is observed in most binary and ternary systems. However, in SDS, synergism is predominant. After analysis, we find that the different synergism or inhibition situation between Tween 80 and SDS is related to the different types of surfactants used and the resulting different co-solubilization mechanisms. In addition, we also find that three polycyclic aromatic hydrocarbons (PAHs) have similar solubilization sites in both Tween 80 and SDS, which are almost unchanged in co-solubilization systems. Due to the similar solubilization sites, the chemical shift changes of surfactant and PAH protons follow the same pattern in all solubilization systems, and the order of chemical shift changes is consistent with the order of changes in the St of PAHs. In this case, it is feasible to evaluate S_t of PAHs by chemical shift. In both Tween 80 and SDS solutions, the ternary solubilization system has relatively high S_t rankings. Therefore, in practical applications, a good overall solubilization effect can be expected.     

Kinetics of glass transition,crystallization and soft magnetic properties of the Fe76.5Nb3B20Cu0.5 glassy alloys

Journal of Thermal Analysis and Calorimetry - Differential scanning calorimetry was used to investigate the non-isothermal crystallization kinetics of the Fe76.5Nb3B20Cu0.5 glassy alloys. The...     

Thermal behaviors and kinetic analysis of two natural kaolinite samples selected from Qingshuihe region in Inner Mongolia in China

Journal of Thermal Analysis and Calorimetry - The thermal characteristic behaviors of two kaolinite samples selected from Qingshuihe region in Inner Mongolia in China were studied through...     

Real time microscopy, kinetics, and mechanism of giant fullerene evaporation

We report in situ high-resolution transmission electron microscopy observing the shrinkage of single-layer giant fullerenes (GF). At temperatures approximately 2000 degrees C, the GF volume reduces by greater than one 100-fold while the fullerene shell remains intact, evolving from a slightly polygonized to a nearly spherical shape with a smaller diameter. The number of carbon atoms in the GF decreases linearly with time until the small subbuckyball cage opens and rapidly disappears. Theoretical modeling indicates that carbon atoms are removed predominantly from the weakest binding energy sites, i.e., the pentagons, leading to the constant evaporation rate. The fullerene cage integrity is attributed to the collective behavior of interacting defects. These results constitute the first experimental evidence for the "shrink-wrapping" and "hot-giant" fullerene formation mechanisms.     

Quantitative Time-Resolved Fluorescence Spectrum of the Cortical Sarcoma and the Adjacent Normal Tissue

The difference in time-resolved fluorescence spectrum between the cortical sarcoma and the adjacent normal tissue was studied in both experimental and theoretical ways. The Clinical data were obtained in vivo using a time-resolved fluorescence spectrometer employing a single fiber-optic probe for excitation and detection. Tissue was modeled as s-180 sarcoma tumor surrounded with normal muscle and was mediated by the Palladium-porphyrin photosensitizer (Pd-TCPP). The emitted fluorescence was considered as arising from the tumor tissue or the normal muscle, due to the presence of the photosensitizer. A computational code which could simulating time-resolved fluorescence emission was presented and applied to comparing fluorescence decay of photosensitizer in different stages of tumor growth. In this code the different stages of the tumor was modeled through changing the time τ, the delay of the fluorescence photon emission and z _max, the thickness of the tumor. It was found in the in vivo experiment that the fluorescence from tumor tissue decayed more quickly than from the adjacent normal muscle. For the ten rats in the first experiment day, the mean decay constant of tumor T _s and normal tissue T _n were 554 and 526 μs, respectively. And T _s increased with the tumor growth, from 554 μs in the first day to 634 μs in the eighth day while T _s kept steady. It was believed that the more adequate oxygen supplied by the normal tissue can more effectively quench the fluorescence and in the normal tissue the photosensitizer lifetime is smaller. As a result the simulated time-resolved fluorescence spectrum of normal tissue showed more quickly decay. And the thickness of the tumor can also delay the fluorescence decay. Both the experimental and simulated results indicated that the germination of the tumor would increase the decay constant of the time-resolved fluorescence spectrum. So decay constant of the tumor tissue spectrum should be larger than that of adjacent normal tissue for the reason of hypoxia and overgrouth. This fact could be of use in the tumor diagnoses.     

Evaluation of Poly(glycidyl methacrylate)-Coated Column for Enantioseparation with Azithromycin Lactobionate and Clindamycin Phosphate as Chiral Selectors in Capillary Electrophoresis

Chromatographia - In this study, a poly(glycidyl methacrylate) nanoparticle (PGMA NP)-coated column system with two antibiotics as selector was constructed for enantioseparation. The PGMA NP...     

A cost-effective anionic flocculant prepared by grafting carboxymethyl cellulose and lignosulfonate with acrylamide

How to efficiently utilize most abundant biomass of cellulose, lignin and their derivatives has become an emerging challenge as the anticipative oil depletion. In this paper, the ternary anionic copolymer of carboxymethyl cellulose-acrylamide-lignosulfonate (CAL) was successfully prepared by hydrothermal polymerization. Based on the flocculation characteristics of cationic methylene blue, the optimal polymerization process was confirmed as the raw material ratio of 1:1:1, initiator dosage of 0.9 wt %, the reaction time was 5 h and the reaction temperature was 55 °C. The results showed that the decolorization ratio was 87.5% at the CAL dosage of 600 mg/L for the 500 mg/L methylene blue simulated wastewater. The CAL achieved fast flocculation kinetics and super color removal ratios in the wide ranges of environmental pH, temperature and salt concentration. The flocculation mechanism is single charge neutralization. Moreover, the estimated treatment cost of CAL is 68.3% lower than that of commercial anionic PAM. The prepared anionic CAL flocculant has the characteristics of environmental safety, excellent flocculation performance and cost-effectiveness, which shows great potential in the field of dye wastewater treatment, and also provides a feasible way for the effective utilization of biomass resources.