Supramolecular self-assembly of conjugated diacetylenic amphiphile-tethered ligands photopolymerize to afford polydiacetylene (PDA) functional liposomes. Upon specific interaction with a variety of biological analytes in aqueous solution, PDA exhibits rapid colorimetric transitions. The PDA nanoassemblies, which are excellent membrane mimics, include an ene-yne polymeric reporter responsible for the chromatic transitions and the molecular recognition elements that are responsible for selective and specific binding to the biological target. A bottleneck in the fabrication of these colorimetric biosensors is the preparation of the diacetylenic monomer embedded with the recognition element of choice. In the present work, we make use of copper-catalyzed azide-alkyne cycloaddition (CuAAC) as key step in the preparation of sugar-coated liposome biosensors. The regioselective click ligation of the triacetylenic N-(2-propynyl)pentacosa-10,12-diynamide (NPPCDAM) with a variety of mannose- and lactose-tethered azides afforded chemo- and regioselectively the corresponding 1,2,3-triazole. The obtained diacetylenic monomers were incorporated efficiently into vesicles to afford functional mannose- and lactose-coated glycoliposomes. The obtained PDA-based click glycoliposomes have been characterized by using transmission electronic microscopy (TEM), dynamic light scattering (DLS), and UV/Vis spectroscopy. The efficiency of the reported approach was demonstrated by the rapid optimization of the hydrophilic spacer between the lipidic matrix and the mannose head group for the colorimetric detection of Concavalin A. 相似文献
Vapor pressures of four pure pentaerythritol esters, PE, pentaerythritol tetrapentanoate, pentaerythritol tetraheptanoate, pentaerythritol tetranonanoate and pentaerythritol tetra 2-ethylhexanoate were measured between 334 and 476 K in a recently developed gas saturation apparatus. The experimental vapor pressure values for the four polyolesters range from 5.6 × 10−5 Pa to 0.94 Pa. These data together with density values were used to determined SAFT and PC-SAFT characteristic parameters. The linearity of molecular parameters for both models with the molecular weight permits to interpolate and extrapolate these parameters for pentaerythritol ester with linear chains. For pentaerythritol esters with ethyl-alkanoic chains, the parameters of SAFT and PC-SAFT have been estimated assuming that the slope of these straight lines is the same for PEs with linear chains that for PE with branched chains. This procedure was used to predict density of commercial POEs, estimating the molecular weight when it is not available from the viscosity at 313.15 K. PC-SAFT gives better performances than SAFT to predict density data for these four compounds at high pressures and for other PEs at atmospheric pressure. Furthermore, characteristic parameters for Soave-Redlich-Kwong and Peng Robinson EoSs were also estimated from the experimental vapor pressures and literature density values. 相似文献
Abstract Reaction of pentaerythritol 1 with 1, 2 or 3 equivalents of diethyl phosphorochloridate 2 yielded pentaerythritol tris(diethyl phosphate) 5. Treatment of pentaerythritol with 4 or more equivalents of 2 gave pentaerythritol tetrakis(diethyl phosphate) 6. Transesterification of 5 and 6 with trimethylsilyl chloride and sodium iodide in acetonitrile followed by treatment with water gave pentaerythritol tris (dihydrogen phosphate) 7 and pentaerythritol tetrakis(dihydrogen phosphate) 8 respectively. Pentaerythritol bis(dihydrogen phosphate) 9 was prepared by the hydrolysis of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro [5,5] undecane 3,9-dioxide 10. The compounds 7,8 and 9 were isolated as anilinium salts and characterized by 1H, 13C and 31P NMR spectra. 相似文献
Melamine salt of pentaerythritol phosphate kaolin (MPPK) was synthesized by the reaction of pentaerythritol phosphate with kaolin (K) and melamine. The structure of MPPK was confirmed by EDXS, 1H NMR, FTIR, and XRD. MPPK was blended with polypropylene (PP) at different loading levels. Thermogravimetric analysis (TGA) results showed that MPPK improved the thermal stability of PP at high temperatures in all PP composites. Vertical burning rate test manifested that PP composites can achieve V0 at 20% and 25% MPPK loading levels. Cone calorimeter data exhibited that addition of 25% MPPK to PP reduced peak of heat release rate (pHRR) and total heat release (THR) by 86% and 76% and increased the char residue after test to 67%. The results of PP/25% MPPK composite were compared with the data obtained from PP containing 25% K and 25% of traditional intumescent flame retardant composed of melamine phosphate (MP), pentaerythritol (PE), and K. The outcomes indicated that MPPK was more efficient in flame retardancy than the other systems. The digital photographs and SEM images for char residue demonstrated that MPPK succeeded in forming cellular and coherent char layer on the PP surface. The main advantage of adding 25% MPPK to PP was its ability to preserve nearly the inner half of the sample without burning after cone calorimeter test. 相似文献
An amorphous,colorless,and highly transparent star network polymer with a pentaerythritol core linking four PEG-block polymeric arms was synthesized from the poly(ethylene glycol)(PEG),pentaerythritol,and dichloromethane by Williamson reaction.FTIR and ~1H-NMR measurement demonstrated that the polymer repeating units were C[CH_2-OCH_2O-(CH_2CH_2O)_m-CH_2O-(CH_2CH_2O)_n-CH_2O]_4.The polymer host held well mechanical properties for pentaerythritol cross-linking.The gel polymer electrolytes based on Lithium... 相似文献
Halogen bonding (XB) has been used to assemble tetrakis(4-pyridyl)pentaerythritol (tetradentate XB acceptor) with different alpha,omega-diiodoperfluoroalkanes (bidentate XB donors) or tetrakis(4-iodotetrafluorophenyl)pentaerythritol (tetradentate XB donor). The remarkable linearity of the XB formed, the rodlike character of alpha,omega-diiodoperfluoroalkanes and the mutual complementarities of pentaerythritol partners, translate the three-dimensional character of the XB acceptor into open primary networks, which interpenetrate to avoid the presence of voids and to ensure segregation of the modules. Two-dimensional (2D) square 4(4) layers (sql) with fourfold and fivefold interpenetration, as well as an eightfold diamondoid network (dia) of class Ia and a remarkable tenfold dia network of class IIIa, have been obtained. 相似文献
The previously described method involving the use of transient DSC was applied to pharmaceutical powder compacts and to ceramic
powder compacts. The samples were prepared by compressing powders of pentaerythritol tetraacetate and two kinds of alumina
powder (differing in particle size distribution) up to a pressure of 20 MPa by using a jig. For pentaerythritol tetraacetate,
a linear relationship was obtained between the parameter obtained by DSC and the compaction pressure.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
Fatty acid-based alkyd resins prepared with different amounts of glycerol and pentaerythritol were characterized. Sacha inchi oil and linseed oil (comparative purposes) were used as fatty acids’ sources. FT-IR and 1H NMR spectroscopy were done for alkyd structural verification. Alkyd resins were evaluated through physico-chemical (colour, density, viscosity) and thermal characterization. Film coating performance (drying, hardness, chemical resistance) was also studied. The oxidative crosslinking time tendency was corroborated by the quartz crystal microbalance (QCM) technique. Alkyd resins obtained with fatty acids from sacha inchi and linseed oils had similar properties. Results indicated that lighter resins can be obtained from sacha inchi oil, whereas pentaerythritol increases viscosity and thermal stability, and retards drying time of fatty-acid based alkyd resins. 相似文献
A series of pentaerythritol diphosphites (PEDP) was used to study the effect of structure on the decomposition of 1-methyl-1-phenylethyl hydroperoxide (cumene hydroperoxide, CHP) in chlorobenzene under nitrogen at 75°C. Whilst pentaerythritol diphosphites with bonds: react in a strictly stoichiometric reaction with cumene hydroperoxide, forming phosphates, we propose that pentaerythritol diphosphites and thiophosphates with bonds: react with cumene hydroperoxide by a different mechanism. The active heteroatom is sulphur which, through the formation of a catalytically active species, causes rapid decomposition of the hydroperoxide which is studied by measuring infra-red spectra using FTIR techniques. 相似文献