Leveling effects of ammonium salts on thermal stabilities of polyethylene glycols

Xia, Juan; Song, Le Xin; Liu, Wei

doi:10.1039/c3sm51484f

Cited by 5 publications

(2 citation statements)

References 93 publications

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“…With these conditions, moreover, the highest quantum yields were achieved with values of 45%–50% (Supporting Information). Along with the observation of the polyol getting yellow to brown, all the above considerations can be correlated to the thermal decomposition of the polyol . This thermal decomposition of the polyols is obviously also in close correlation to the observed fluorescence.…”

Section: Verification Of Unexpected Fluorescence Of Polyols and Pegylsupporting

confidence: 62%

Unexpected Fluorescence of Polyols and PEGylated Nanoparticles Derived from Carbon Dot Formation

Dong

Roming

Feldmann

2014

Part. Part. Syst. Charact.

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Synthesis of nanoparticles in high‐boiling alcohols (so‐called polyol synthesis) and surface functionalization of nanoparticles with polyethylene glycol (so‐called PEGylation) in combination with certain heating are often accompanied with an intense fluorescence in the blue to green spectral range. Based on the polyol synthesis of Zn3(PO4)2 nanoparticles and a critical consideration of the relevant experimental conditions—including the presence of nanoparticles, the role of dissolved metal salts (ZnCl2, MgCl2, KCl), the type of the polyol (DEG, GLY, PEG400), the temperature and time of heating (150–230 °C, 1–6 h)—we can correlate the observed fluorescence to the formation of carbon dots (C‐dots) stemming from thermal decomposition (i.e., dehydration and carbonization) of the polyol. Thus, the thermal decomposition of polyols results in C‐dots with a diameter of 3–5 nm at narrow size distribution. The formation of C‐dots is confirmed by transmission electron microscopy (TEM), high‐resolution TEM (HRTEM), X‐ray powder diffraction (XRD), Fourier‐transform infrared spectroscopy (FT‐IR), and fluorescence spectra.

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Section: Verification Of Unexpected Fluorescence Of Polyols and Pegylsupporting

confidence: 62%

Unexpected Fluorescence of Polyols and PEGylated Nanoparticles Derived from Carbon Dot Formation

Dong

Roming

Feldmann

2014

Part. Part. Syst. Charact.

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“…[34] NH 4 þ adsorption on the surface is stronger than the other monovalent cations. [63] The introduction of those ions with relatively strong Hofmeister effects, such as ammonium and sulfate, can enhance the stabilities of the monolayers.…”

Section: àmentioning

confidence: 99%

Impact of anions on the surface organisation of lipid monolayers at the air–water interface

Wang

2017

Environ. Chem.

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Environmental context. Lipids released from lysis of phytoplankton cells are enriched in the sea surface microlayer. Such surface-active organics can be transferred through bursting bubbles to sea-spray aerosols where they can influence atmospheric chemistry. The results presented here suggest that phospholipids combine more readily with SO 4 2À than with Br À , leading to enrichment of organic-coated sulfate salts in marine aerosols.Abstract. Inorganic salts and organic matter are known to be present at higher levels in the sea surface microlayer and marine aerosols; however, the impact of common anions on their surface properties is not well understood. Here, a 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) monolayer was enriched with the sodium and ammonium salts of different anions (Br À , Cl À , NO 3 À , SO 4 2À , CH 3 COO À , and HCO 3 À ), and the effects on the surface properties of the monolayer were investigated. The monolayer phase behaviour and the structure of the lipid phases were studied by surface pressure-area (p-A) isotherms and infrared reflection-absorption spectroscopy (IRRAS). The presence of salts in the subphase was found to increase the surface pressure of the DPPC monolayer at a fixed area per molecule. The effect of the anions follows the order of the Hofmeister series. The higher concentration of salt solution caused the p-A isotherm to shift to larger area. The IRRAS spectra demonstrate that the ordering of the DPPC molecules in the liquid condensed phase remains essentially unaffected, even at higher electrolyte concentrations. DPPC molecules combined with SO 4 2À could be transferred from the ocean to sea spray aerosol. The present study finds that the anions have significant influence on the surface organisation and, consequently, the interfacial properties, of the surface-active species at the air-water interface, a finding that has further implications for atmospheric aerosol nucleation.

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Contribution of polytetrafluoroethylene to the atmosphere-dependent synthesis of Cu-based nanomaterials through ion–dipole interactions

Zhao¹,

Song²,

Xia³

et al. 2014

RSC Adv.

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A simple, but efficient, method for the preparation of a series of Cu-based nanomaterials including Cu, CuCl, CuO, Cu@CuCl and CuCl@CuO was developed. Initially, we prepared a novel precursor consisting of a Cu(II)-urea complex (CUC, a coordination compound) and polytetrafluoroethylene (PTFE, a waterinsoluble polymer) using the technique of solid-solid grinding. Subsequently, the Cu-based materials were synthesized by sintering the precursor at different atmospheres and temperatures. This approach provides an environmentally friendly and green alternative towards creating Cu-based materials by generating complex-polymer binary systems without the use of solvents. Our results indicated that the effect of PTFE played a crucial role in the formation of the materials. Further, the role of PTFE was found to be associated with sintering atmospheres: the reduction of CuCl to Cu in nitrogen was delayed;contrarily its oxidation to CuO in air was advanced. The nature of this role was ascribed to an ion-dipole interaction between the partial negative charges on the fluorine atoms (F dÀ ) on the PTFE chains and the Cu(II) ions in the coordination centers [Cu(II)-urea] induced by a solid-solid mixing process, leading to the CUC complex decomposing later in nitrogen and earlier in air. Also, the presence of CUC drastically affects the thermal pyrolysis pattern of PTFE, resulting in a remarkable decrease, and even disappearance of the etching signals of PTFE. Finally, our data suggested that the as-prepared Cu@CuCl nanomaterial induced a strong surface-enhanced Raman scattering effect for several model compounds, including rhodamine 6G and crystal violet. We believe that this study represents a significant step towards the development of practical synthesis of Cu-based nanomaterials and opens up exciting opportunities for the design and construction of a wide range of transition metal-based nanomaterials through the link between polymers and coordination compounds.

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Leveling effects of ammonium salts on thermal stabilities of polyethylene glycols

Cited by 5 publications

References 93 publications

Unexpected Fluorescence of Polyols and PEGylated Nanoparticles Derived from Carbon Dot Formation

Unexpected Fluorescence of Polyols and PEGylated Nanoparticles Derived from Carbon Dot Formation

Impact of anions on the surface organisation of lipid monolayers at the air–water interface

Contribution of polytetrafluoroethylene to the atmosphere-dependent synthesis of Cu-based nanomaterials through ion–dipole interactions

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