LANGMUIR
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2013
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IF 4.187
Yumin Leng,Yonglong,Li,An Gong,Zheyu Shen,Liang Chen,Aiguo Wu
A new kind of analytical reagent, hexadecyl trimethyl ammonium bromide (CTAB), and dithizone product-modified gold nanoparticle dispersion, is developed for colorimetric response to 10 types of heavy metal ions (Mn+), including Cr(VI), Cr3+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+, and Pb2+. The color change of the modified gold nanoparticle dispersion is instantaneous and distinct for Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+, and Pb2+. The color change results from the multiple reasons, such as electronic transitions, cation−π interactions, formation of coordination bonds, and Mn+-induced aggregation of gold nanoparticles (AuNPs). The different combining capacity of heavy metal ions to modifiers results in the different broadening and red-shifting of the plasmon peak of modified AuNPs. In addition, Cr(VI), Cu2+, Co2+, Ni2+, and Mn2+ cause the new UV–vis absorption peaks in the region of 360–460 nm. The interactions between the modifiers and AuNPs, and between the modifiers and Mn+, are investigated by using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The results confirm that AuNPs are modified by CTAB and dithizone products through electrostatic interactions and Au–S bonds, respectively, and the Mn+–N bonds form between Mn+ and dithizone products. Furthermore, the experimental and density functional theory calculated IR spectra prove that dithizone reacts with NaOH to produce C6H5O– and [SCH2N4]2-. The validation of this method is carried out by analysis of heavy metal ions in tap water.
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DOI
PubMed
高影响因子
APPLIED CLAY SCIENCE
·
2024
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IF 5.3
Jixing Fan,Qian Liu,Li,Li,Guanzheng Zhuang,Peng Yuan
Maya Blue, a hybrid pigment that can be synthesized by heating a mixture of palygorskite (or sepiolite) and indigo, has unclear relationships between the structural features of clay substrates, heating atmosphere, colors, and stability. This study investigates the color properties, stability, and clay-dye interactions of Maya Blue pigments based on palygorskite and sepiolite, heated under air and vacuum conditions (180 °C for 8 h). Reflectance spectra, CIE color parameters, surface properties, and Fourier-transform infrared spectroscopy were employed to evaluate these pigments. Results indicate that indigo monomers can penetrate the channels of both palygorskite and sepiolite, conferring a greenish-blue hue and high stability. However, the diffusion of indigo is determined by the size match between the channel and indigo monomers. In palygorskite, indigo monomers can diffuse only upon heating because the channel size is only a little bit larger than the indigo molecule, while in sepiolite, lager channels allow easy diffusion, even without heating. However, sepiolite's larger channels make indigo molecules more prone to chemical degradation or migration. Under vacuum conditions, indigo molecules more easily diffuse into the channels of both clay minerals, yielding pigments with higher saturation and enhanced stability. These findings highlight the size-matching between clay minerals' micropores and organic molecules and offer valuable guidance for optimizing the preparation process of clay-dye hybrid pigments.
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DOI
高影响因子
Journal of Biomedical Research
·
2018
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IF 0
Mei-qing Sun,Zhan-lin Ding,Hong Wang,Guang-ping Yu,Li,Ming-chun Li,Meng-meng Zhen
BiOBr nanosheets are important photocatalytic nanomaterials. However, their biological effects remain to be explored. In this study, we investigated the antifungal effect of BiOBr nanosheets on Candida albicans . Strikingly, the nanosheets strongly inhibited the growth of C. albicans [IC 50 =(96±4.7) mg/L], hyphal development and biofilm formation. Compareed to the antifungal effect of the cationic surfactant cetyltrimethylammonium bromide, the inhibitory effect of the nanosheets on fungal pathogen was attributed to cetyltrimethylammonium bromide adsorbed by the nanosheets. Thermal gravity analysis and cetyltrimethylammonium bromide release experiment indicated that only 0.42% cetyltrimethylammonium bromide on BiOBr nanosheets was released. Taken together, this study uncovers the contribution of surfactant released from the nanosheets to their antifungal activity.
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DOI
PubMed
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