Search results for "aqueous solution"
showing 10 items of 1610 documents
Polymere ester von säuren des Phosphors, 3. Polymerisation des 2-Äthoxy-2-oxo-1,3,2-dioxaphospholans
1975
2-Athoxy-2-oxo-1,3,2-dioxaphospholan (1) wird durch verschiedene Alkoholate sehr schnell und in hoher Ausbeute zu Poly[oxy(athoxyphosphoryl)oxyathylen] (3) polymerisiert. Die Produkte sind hochviskos und farbols. Sie losen sich in Wasser, Alkoholen, Tetrahydrofuran, Dioxan, Methylenchlorid, Chloroform und Dimethylsulfoxid; unloslich sind sie in Ather und in Kohlenwasserstoffen. Polymerisationsgrade bis 83 (M = 12600) wurden gemessen. In wasriger Losung bei Raumtemperatur erfolgte auch nach Tagen kein merklicher hydrolytischer Abbau. Der mutmaslich anionische Polymerisationsmechanismus und mogliche Nebenreaktionen werden kurz diskutiert. 2-Ethoxy-2-oxo-1,3,2-dioxaphospholane (1) is polymeriz…
Optical Gating of Photosensitive Synthetic Ion Channels
2011
4-oxo-4-(pyren-4-ylmethoxy) butanoic acid is used as a photolabile protecting group to show the optical gating of nanofluidic devices based on synthetic ion channels. The inner surface of the channels is decorated with monolayers of photolabile hydrophobic molecules that can be removed by irradiation, which leads to the generation of hydrophilic groups. This process can be exploited in the UV-light-triggered permselective transport of ionic species in aqueous solution through the channels. The optical gating of a single conical nanochannel and multichannel polymeric membranes is characterised experimentally and theoretically by means of current-voltage and selective permeation measurements,…
Interactions of tetradecyldimethylaminoxide with polyacrylic and polymethacrylic acids in aqueous solution
2001
Abstract The interactions between the zwitterionic surfactant tetradecyldimethylaminoxide (C14DMAO) and the polyelectrolytes polyacrylic (PAA-205 and PAA-250) or polymethacrylic (PMA-100) acids have been investigated in aqueous solution. The physico-chemical properties of these systems have been monitored by measuring the solution pH, electric birefringence, zero-shear viscosity and density for increasing surfactant concentrations. The experimental results have shown that significant change in the physico-chemical properties of the polyacid/surfactant system occurs only in a narrow pH range and when the amphiphile forms rod-like micelles. Moreover, they clearly reveal the important role pla…
Site-specific halloysite functionalization by polydopamine: A new synthetic route for potential near infrared-activated delivery system
2022
Abstract Halloysite nanotubes (HNTs) represent a versatile core structure for the design of functional nanosystems of biomedical interest. However, the development of selective methodologies for the site-controlled functionalization of the nanotubes at specific sites is not an easy task. This study aims to accomplish a procedure for the site-selective/specific, “pin-point”, functionalization of HNTs with polydopamine (HNTs@PDA). This goal was achieved, at pH 6.5, by exploiting the basicity of ZnO nanoparticles anchored on the HNTs external surface (HNTs@ZnO) to induce a punctual polydopamine polymerization and coating. The morphology and the chemical composition of the nanomaterial was demo…
Near-Infrared Light Responsive Folate Targeted Gold Nanorods for Combined Photothermal-Chemotherapy of Osteosarcoma.
2017
Folate-targeted gold nanorods (GNRs) are proposed as selective theranostic agents for osteosarcoma treatment. An amphiphilic polysaccharide based graft-copolymer (INU-LA-PEG-FA) and an amino derivative of the α,β-poly(N-2-hydroxyethyl)-d,l-aspartamide functionalized with folic acid (PHEA-EDA-FA), have been synthesized to act as coating agents for GNRs. The obtained polymer-coated GNRs were characterized in terms of size, shape, zeta potential, chemical composition, and aqueous stability. They protected the anticancer drug nutlin-3 and were able to deliver it efficiently in different physiological media. The ability of the proposed systems to selectively kill tumor cells was tested on U2OS…
Ceramic foam supported active materials for boron remediation in water
2015
Due to the narrowrange between boron necessities and toxicity in the environment, there is a high interest in the design of effective boron remediation procedures. We have previously reported a promising boron adsorptionmaterial based on the affinity of boron aqueous species for cis-diol groups that were anchored on differentmesoporous silica matrices.However, the small particle size of these systemsmakes themdifficult to be applied on real remediation situations. In this context we report herein a novel systemfor boron adsorption fromaqueous solutions inwhich the high boron affinity for functionalized mesoporousmaterials is combined with themechanical properties of ceramic foams as macrosc…
Off–on BODIPY-based chemosensors for selective detection of Al3+ and Cr3+versus Fe3+ in aqueous media
2014
[EN] Two new off-on BODIPY-based chemosensors that are highly sensitive for trivalent cations in aqueous solutions are described. Compound 2 exhibits selective sensing of Al3+ and Cr3+ versus Fe3+ through two different channels (UV-vis and fluorescence).
A Highly Luminescent Nitrogen-Doped Nanographene as an Acid- and Metal-Sensitive Fluorophore for Optical Imaging.
2021
Dibenzo[hi,st]ovalene (DBOV) has excellent photophysical properties, including strong fluorescence and high ambient stability. Moreover, the optical blinking properties of DBOV have enabled optical super-resolution single-molecule localization microscopy with an imaging resolution beyond the diffraction limit. Various organic and inorganic fluorescent probes have been developed for super-resolution imaging, but those sensitive to pH and/or metal ions have remained elusive. Here, we report a diaza-derivative of DBOV (N-DBOV), synthesized in eight steps with a total yield of 15%. Nitrogen (N)-bearing zigzag edges were formed through oxidative cyclization of amino groups in the last step. UV-v…
Designed biodegradable hydrogel structures prepared by stereolithography using poly(ethylene glycol)/poly(D,L-lactide)-based resins
2010
Designed three-dimensional biodegradable poly(ethylene glycol)/poly(D,L-lactide) hydrogel structures were prepared for the first time by stereolithography at high resolutions. A photo-polymerisable aqueous resin comprising PDLLA-PEG-PDLLA-based macromer, visible light photo-initiator, dye and inhibitor in DMSO/water was used to build the structures. Porous and non-porous hydrogels with well-defined architectures and good mechanical properties were prepared. Porous hydrogel structures with a gyroid pore network architecture showed narrow pore size distributions, excellent pore interconnectivity and good mechanical properties. The structures showed good cell seeding characteristics, and human…
Lead Nanowires for Microaccumulators Obtained Through Indirect Electrochemical Template Deposition
2010
Metallic lead nanowires were deposited within pores of commercial anodic alumina membranes having an average pore diameter of 210 nm. "Direct" electrodeposition was attempted from 0.1 M Pb(NO 3 ) 2 aqueous solution with a variable concentration of H 3 BO 3 as a chelating agent, but it gave unsatisfactory results. An "indirect" two-step deposition procedure was then adopted, consisting of the anodic electrodeposition of α-PbO 2 nanowires, followed by their in situ reduction to metallic lead. Both these processes occurred at a high rate so that the indirect method led to a complete template pore filling with pure polycrystalline Pb in short times and with a high current efficiency.