betadex and titanium-dioxide

Polylactic acid (PLA) and cellulose acetate (CA) as biodegradable polymers are being highly exploited in the development of innovative materials across several industrial sectors. PLA and CA composite films with TiO

Topics: Anti-Bacterial Agents; beta-Cyclodextrins; Cellulose; Escherichia coli; Food Packaging; Nanocomposites; Polyesters; Polymers; Staphylococcus aureus; Titanium

Polymeric materials, such as polyvinyl alcohol (PVA) and ethylene-PVA copolymers (EVOH) are widely used in the food sector as packaging materials because of their excellent properties. TiO

Topics: beta-Cyclodextrins; Food Packaging; Food Preservation; Nanoparticles; Polyvinyl Alcohol; Titanium; Ultraviolet Rays

With the use of engineered nano-materials (ENM) becoming more prevalent, it is essential to determine potential human health impacts. Specifically, the effects on biological lipid membranes will be important for determining molecular events that may contribute to both toxicity and suitable biomedical applications. To better understand the mechanisms of ENM-induced hemolysis and membrane permeability, fluorescence lifetime imaging microscopy (FLIM) was performed on human red blood cells (RBC) exposed to titanium dioxide ENM, zinc oxide ENM, or micron-sized crystalline silica. In the FLIM images, changes in the intensity-weighted fluorescence lifetime of the lipophilic fluorescence probe Di-4-ANEPPDHQ were used to identify localized changes to membrane. Time-resolved fluorescence anisotropy and FLIM of RBC treated with methyl-

Topics: beta-Cyclodextrins; Erythrocyte Membrane; Fluorescence Polarization; Fluorescent Dyes; Hemolysis; Humans; Microscopy, Fluorescence; Nanostructures; Particle Size; Pyridinium Compounds; Silicon Dioxide; Titanium; Zinc Oxide

TiO

Topics: Adsorption; beta-Cyclodextrins; Fluorides; Kinetics; Nanocomposites; Solutions; Temperature; Thermodynamics; Titanium; Water Pollutants, Chemical

Photocatalytic properties of titanium dioxide nanoparticles (TiO

Topics: alpha-Cyclodextrins; Anti-Infective Agents; Benzoic Acid; beta-Cyclodextrins; Diffusion; Food Packaging; Food Preservation; Food Preservatives; Kinetics; Metal Nanoparticles; Sorbic Acid; Surface Properties; Titanium

In this work, aspartic acid-β-cyclodextrin (ACD) was synthesized by the reaction of β-cyclodextrin with aspartic acid and epichlorohydrin, and graphene oxide-TiO

Topics: Aspartic Acid; beta-Cyclodextrins; Catalysis; Graphite; Lead; Titanium

An ultra-high sensitivity sensor with the function of chiral signal amplification has been proposed for the enantiomer discrimination of various amino acid enantiomers based on charge transfer (CT)-induced SERS spectroscopy. The introduced TiO

Topics: Aniline Compounds; beta-Cyclodextrins; Hydrogen Bonding; Metal Nanoparticles; Phenylalanine; Silver; Spectrum Analysis, Raman; Stereoisomerism; Sulfhydryl Compounds; Titanium; Tryptophan; Tyrosine

A high-performance and selective adsorbent was developed for simultaneous extraction of 6 chlorobenzenes residues in soil samples by using magnetic solid phase extraction (MSPE) combined with automated SPE followed by gas chromatography-mass spectrometry (GC-MS). The adsorbent was synthesized by grafting carboxymethyl-β-cyclodextrin (CM-β-CD) on the surface of porous core-shell magnetic Fe3O4@flower like TiO2 microspheres (Fe3O4@fTiO2-CMCD), used as a carrier. The main factors (adsorbent amount, adsorption time, elution solvent, elution volume, and elution flow rate) affecting the extraction efficiency were investigated in detail. The adsorbent exhibited high loading capacity (25.6 mg g(-1) for 1,3-dichlorobenzene). This maybe due to meso-/macroporous TiO2 having high specific surface area; as a carrier of the β-cyclodextrin film, it could obviously increase the number of recognition sites. The newly developed adsorbent also showed good selectivity towards chlorobenzenes based on host-guest interactions between β-cyclodextrin (on adsorbent's surface) and targets, which can minimize complex matrix interference in soil samples. The proposed method was successfully applied for the analysis of environmental soil samples with recovery ranging from 87.3 to 104.3%. All target compounds showed good linearities with correlation coefficients (r) higher than 0.996. The limits of quantitation for the 6 CBs were 0.03-0.09 μg kg(-1). These findings confirmed meso-/macroporous structure Fe3O4@fTiO2-CMCD as a highly effective extraction material for use in trace CB analyses in complex soil samples.

Topics: Adsorption; beta-Cyclodextrins; Chlorobenzenes; Environmental Monitoring; Gas Chromatography-Mass Spectrometry; Magnetic Phenomena; Soil; Soil Pollutants; Solid Phase Extraction; Titanium

Nanotubular titania film was prepared in situ on titanium wire and was used as the fiber substrate for solid-phase microextraction (SPME) because of its high surface-to-volume ratio, easy preparation, and mechanical stability. Three different functional coatings, β-cyclodextrin (β-CD), β-cyclodextrin-co-poly(ethylenepropylene glycol) (β-CD/PEG), and polyethylene glycol (PEG)-based sorbents were chemically bonded to the nanostructured wire surface via sol-gel technology to further enhance the absorbing capability and extraction selectivity. Coupled to gas chromatography-flame ionic detection (GC-FID), the prepared SPME fibers were investigated using diverse compounds. The results indicated that the fibers showed good mechanical strength, excellent thermal stability, and wonderful capacity and selectivity to polar compounds, including polar aromatic compounds, alcohols, and ketones. Combining the superior hydrophilic property of a bonded functional molecule and the highly porous structure of a fiber coating, the prepared PEG-coated SPME fiber showed much higher adsorption affinity to ephedrine and methylephedrine than β-CD and β-CD/PEG fibers. The as-established PEG-coated SPME-GC analytical method provided excellent sensitivity (LODs, 0.004 and 0.001 ng mL(-1) for ephedrine and methylephedrine, respectively) and better linear range (0.01-2 000 μg L(-1)). In addition, it has surprising repeatability and reproducibility. Finally, the present approach was used to analyze ephedrine and methylephedrine from real urine samples, and reliable results were obtained.

Topics: beta-Cyclodextrins; Chromatography, Gas; Ephedrine; Flame Ionization; Humans; Phase Transition; Polyethylene Glycols; Polymethyl Methacrylate; Solid Phase Microextraction; Titanium; Volatile Organic Compounds

Water-dispersible, photocatalytic Fe3O4@TiO2 core-shell magnetic nanoparticles have been prepared by anchoring cyclodextrin cavities to the TiO2 shell, and their ability to capture and photocatalytically destroy endocrine-disrupting chemicals, bisphenol A and dibutyl phthalate, present in water, has been demonstrated. The functionalized nanoparticles can be magnetically separated from the dispersion after photocatalysis and hence reused. Each component of the cyclodextrin-functionalized Fe3O4@TiO2 core-shell nanoparticle has a crucial role in its functioning. The tethered cyclodextrins are responsible for the aqueous dispersibility of the nanoparticles and their hydrophobic cavities for the capture of the organic pollutants that may be present in water samples. The amorphous TiO2 shell is the photocatalyst for the degradation and mineralization of the organics, bisphenol A and dibutyl phthalate, under UV illumination, and the magnetism associated with the 9 nm crystalline Fe3O4 core allows for the magnetic separation from the dispersion once photocatalytic degradation is complete. An attractive feature of these "capture and destroy" nanomaterials is that they may be completely removed from the dispersion and reused with little or no loss of catalytic activity.

Topics: Adsorption; Benzhydryl Compounds; beta-Cyclodextrins; Catalysis; Dibutyl Phthalate; Endocrine Disruptors; Magnetite Nanoparticles; Models, Molecular; Molecular Conformation; Particle Size; Phenols; Photolysis; Temperature; Titanium; Water Pollutants, Chemical; Water Supply

This work revealed that β-cyclodextrin was attached onto the surface of TiO(2) predominately by its secondary ring side, which caused paradoxical functions of β-cyclodextrin in the photodegradation of the four bisphenols. The equilibrium between the guest adsorbed through β-cyclodextrin onto TiO(2) and the one locked in β-CD in water could also change the role of β-cyclodextrin in the degradation of a certain guest.

Topics: Adsorption; Benzhydryl Compounds; beta-Cyclodextrins; Endocrine Disruptors; Models, Molecular; Photolysis; Titanium

Three magnetic resonance (MR)/fluorescence imaging probes were tested for visualization, cellular distribution, and survival of labeled pancreatic islets in vitro and following transplantation. As T(1) contrast agents (CAs), gadolinium(III) complexes linked to β-cyclodextrin (Gd-F-βCD) or bound to titanium dioxide (TiO2 @RhdGd) were tested. As a T(2) CA, perovskite manganite nanoparticles (LSMO@siF@si) were examined. Fluorescein or rhodamine was incorporated as a fluorescent marker in all probes. Islets labeled with gadolinium(III) CAs were visible as hyperintense spots on MR in vitro, but detection in vivo was inconclusive. Islets labeled with LSMO@siF@si CA were clearly visible as hypointense spots or areas on MR scans in vitro as well as in vivo. All CAs were detected inside the islet cells by fluorescence. Although the vitality and function of the labeled islets was not impaired by any of the tested CAs, results indicate that LSMO@siF@si CA is a superior marker for islet labeling, as it provides better contrast enhancement within a shorter scan time.

Topics: Animals; beta-Cyclodextrins; Cells, Cultured; Contrast Media; Fluorescent Dyes; Gadolinium; Islets of Langerhans; Magnetic Resonance Imaging; Male; Manganese Compounds; Metal Nanoparticles; Microscopy, Fluorescence; Radiography; Rats; Rats, Inbred Lew; Titanium

A novel approach for attaining reactive cotton/wool and viscose/wool prints with outstanding UV-protection functions was achieved via inclusion of certain UV-absorbers namely 4-hydroxybenzophenone and UV-SUN(®) or UV-blockers like ZnO-NPs and TiO(2)-NPs along with MCT-βCD, as a reactive additive, in the printing paste formulation using Na-alginate as a thickening agent. Experimental results reveal that the inorganic UV-blockers exhibit better UV-protection functions compared with the used UV-absorbers, and the improvement in the imparted UV-protection capacity follows the decreasing order: ZnO-NPs>TiO(2)-NPs>4-hyroxybenzopherone≥UV-SUN(®)>>none>untreated. The enhancement in UV-protection functionality is governed by the type of substrate, cotton/wool>viscose/wool, extent of modification and loading of the used nano-metal oxides or organic absorbers onto the fabric surface as well functionality and ability of the used reactive dyes to absorb the hazardous UV-B radiation. The obtained functional prints exhibited outstanding UV-protection efficiency even after 15 washing cycles.

Topics: Alginates; Animals; Benzophenones; beta-Cyclodextrins; Cellulose; Cotton Fiber; Feasibility Studies; Glucuronic Acid; Hexuronic Acids; Nanoparticles; Printing; Protective Clothing; Titanium; Ultraviolet Rays; Wool; Zinc Oxide

Sulfated β-cyclodextrin was synthesized from sulfonation of β-cyclodextrin and sulfated polymer was crosslinked with cotton fabric using ethylenediaminetetraacetic acid as crosslinker. ZnO, TiO(2) and Ag nanoparticles were prepared and characterized by XRD, UV, DLS, SEM and PSA. The prepared nanoparticles were coated on crosslinked cotton fabric. The crosslinking and nanoparticles coating effects of cotton fabrics were studied by FTIR and SEM analysis. The antibacterial test was done against gram positive Staphylococcus aureus and gram negative Escherichia coli bacterium.

Topics: Anti-Bacterial Agents; beta-Cyclodextrins; Cotton Fiber; Cross-Linking Reagents; Edetic Acid; Escherichia coli; Microscopy, Electron, Scanning; Nanoparticles; Silver Nitrate; Spectroscopy, Fourier Transform Infrared; Staphylococcus aureus; Sulfates; Titanium; Zinc Oxide

A novel β-cyclodextrin (β-CD) grafted titanium dioxide (TiO(2)/β-CD) was synthesized through photo-induced self assembly methods, and its structure was characterized. The TiO(2)/β-CD hybrid nanomaterial showed high photoactivity under visible light irradiation (λ ≥ 400 nm and/or λ ≥ 420 nm) and simulated solar irradiation (λ ≥ 365 nm). Photodegradation of Orange II followed the Langmuir-Hinshelwood kinetics model. The initial rate R(0) of Orange II degradation increased by 6.9, 2.6 and 1.9 times in the irradiation conditions of λ ≥ 420nm, λ ≥ 400nm and λ ≥ 365 nm, respectively. β-CD increased the lifetimes of the excited states of the unreactive guests and facilitated the electron transfer from the excited dye to the TiO(2) conduction band, which enhanced the dye pollutant degradation. Superoxide radicals were shown to be the main reactive species that caused the degradation of Orange II under visible irradiation.

Topics: Algorithms; beta-Cyclodextrins; Catalysis; Coloring Agents; Electrons; Hydrogen Peroxide; Hydroxyl Radical; Kinetics; Light; Microscopy, Electron, Transmission; Nanoparticles; Photolysis; Powders; Spectrophotometry, Ultraviolet; Spectroscopy, Fourier Transform Infrared; Sunlight; Superoxides; Titanium; Water Pollutants, Chemical; X-Ray Diffraction

The beta-cyclodextrin-modified Ag-TiO2 core-shell nanoparticles were prepared by sodium borohydrate reduction of AgNO3 and the subsequent hydrolysis of the tetraisopropyl orthotitanate in an aqueous medium. Inversely in the preparation of beta-cyclodextrin-modified TiO2-Ag core-shell nanoparticles, first hydrolysis and then following reduction were carried out. The synthesized spherical core-shell nanoparticles were highly water-dispersible and had an average diameter in the range of 9 to 12 nm. A significant shifting of surface plasmon band was observed for the synthesized Ag-TiO2 and TiO2-Ag core-shell nanoparticles. On a model reaction, namely, the photodegradation of phenol by the UV light irradiation, the photocatalytic property of TiO2 nanoparticles was enhanced, when the Ag nanoparticle was embedded in the core of TiO2 nanoparticles but TiO2 nanoparticles coated by Ag shell decreased the photocatalytic property of TiO2 nanoparticles. The mechanism is ascribed to the surface plasmon characteristics of Ag in the core of the TiO2 nanoparticles under the acceleration by host-guest inclusion characteristics.

Topics: beta-Cyclodextrins; Catalysis; Gold; Light; Materials Testing; Nanostructures; Solubility; Titanium; Water

A novel adsorbent of carboxymethyl-beta-cyclodextrin modified nanometer TiO(2) (CM-beta-CD/TiO(2)) was prepared and used as a solid-phase extraction (SPE) material coupled to fluorescence spectroscopy determination of l-tryptophan (l-Trp) in biological samples. The experimental conditions for modified nanometer TiO(2) separation/preconcentration of l-Trp were optimized. The adsorption capacity of CM-beta-CD/TiO(2) for l-Trp was 75.2 microg/g. The linear range, detection limit (DL), and the relative standard deviation (RSD) were 0.10-1.20 microg/mL, 18.8 ng/mL, and 0.67% (n=3, 1.0 microg/mL), respectively, with a preconcentration factor of 10. The developed method was applied to determination of l-Trp in real samples and the recoveries were found to be in the range of 99.2-100.3%. For validation, a comparison material of NIC-140686 sample was analyzed and the determined value was in good agreement with the certified value.

Topics: Adsorption; beta-Cyclodextrins; Limit of Detection; Solid Phase Extraction; Spectrometry, Fluorescence; Titanium; Triticum; Tryptophan

Hollow magnetic graphitic carbon microspheres (HMGSs) with/without a TiO(2) nanoparticle layer on their surfaces are designed and synthesized by combining the bubble-template method, assembly of beta-cyclodextrin and Fe(3)O(4) stabilized by oleic acid and ammonia, and consequent graphitization reaction. HMGSs have potential in adsorption, enrichment, magnetic-assisted separation and drug delivery.

Topics: Adsorption; Ammonia; beta-Cyclodextrins; Ferrosoferric Oxide; Graphite; Magnetics; Microspheres; Nanoparticles; Oleic Acid; Particle Size; Porosity; Surface Properties; Titanium

TiO(2) nanoparticles were synthesized by hydrolysis of tetraisopropyl orthotitanate in an aqueous solution of cyclodextrin. The β-cyclodextrin-modified spherical TiO(2) nanoparticles were water-dispersible and had an average particle diameter of 4.4 ± 1 nm. Pyrene fluorescence was enhanced by increasing the concentration of β-cyclodextrin-modified TiO(2) nanoparticle and the sensitization effect was triply stronger than the case of the β-cyclodextrin only. The increase in a concentration of host (β-cyclodextrin) changes its microenvironment for guest (pyrene), that is, the interaction of pyrene with apolar cavity of β-cyclodextrin increases, resulting in enhancement of fluorescence. The sensitization behavior of pyrene fluorescence in the presence of TiO(2) nanoparticles occurs from the increase in the extinction coefficient of pyrene, demonstrating the charge transfer between pyrene and metal oxide nanoparticle.

Topics: beta-Cyclodextrins; Fluorescence; Nanoparticles; Particle Size; Pyrenes; Solutions; Surface Properties; Titanium; Water

Enhancement of beta-cyclodextrin (beta-CD) on TiO(2) photocatalytic degradation of bisphenol E (BPE, bis(4-hydroxyphenyl)ethane) was investigated under a 250 W metal halide lamp (lambda> or =365 nm) in this work. In the system of photocatalytic degradation of BPE, the photodegradation rate of BPE in aqueous solutions containing beta-CD and TiO(2) was obviously faster than that in aqueous solutions containing only TiO(2). After 40 min of irradiation, beta-CD could increase the photodegradation efficiency by about 26% for 10 mg l(-1) BPE in the UV-vis/TiO(2) system and the photodegradation of 2.5-20.0 mg l(-1) BPE in aqueous solutions was found to follow pseudo-first-order law and the adsorption constant and the reaction rate constant of BPE in the system containing beta-CD and TiO(2) are obviously higher than those in the system containing only TiO(2), the influence factors on photodegradation of BPE were studied and described in details, such as beta-CD concentration, pH, BPE initial concentration and gas medium. The formation of CO(2) as a result of mineralization of BPE was observed during the photodegradation process. After 120 min of irradiation, the mineralization efficiency of BPE reached 61% in the presence of beta-CD, whereas mineralization efficiency was only 23% in the absence of beta-CD. The enhancement of photodegradation of BPE could be dependent on the enhancement of adsorption of BPE on TiO(2) surface and moderate inclusion-depth of BPE in the beta-CD cavity.

Topics: Adsorption; beta-Cyclodextrins; Catalysis; Chromatography, High Pressure Liquid; Hydrogen-Ion Concentration; Kinetics; Minerals; Models, Molecular; Molecular Structure; Oxidation-Reduction; Phenols; Photolysis; Solutions; Spectrum Analysis; Suspensions; Titanium

This work evaluates a process for the elimination of pentachlorophenol (PCP) from effluents provided by a cyclodextrin-assisted flushing of contaminated soils. The effectiveness of photocatalytic degradation of PCP in several cyclodextrin (CD) solutions was evaluated using TiO2 as a photocatalyst. Effects of CD type on PCP degradation rate were studied at two pH values. A similar effect was observed for all CDs used on degradation rate of PCP and the decay of PCP was found to be less extensive at pH 11 than at pH 7. The kinetic orders of the photocatalytic reactions of PCP for all of the solutions have been determined. The first-order rate constants were found to be 0.0884, 0.0362, 0.0197 and 0.0053 min(-1) in CD solutions, respectively, at 0, 1, 2 and 5 mmol l(-1) of CD. Batch experiments were performed in order to study the CD extraction enhancement of PCP previously adsorbed on soil. The results show that the removal capacity of PCP from soil increases with CD concentration (from 0 to 5 mmol l(-1)). When the CD concentration was 5 mmol l(-1), an extraction of about 70% of PCP adsorbed on soil was observed, whereas only 37% was removed when water was used as the flushing solution. The optimal conditions for such a coupled method depend on the nature and concentration of the extracting agent and also on the photocatalytic experimental conditions. This work revealed that the coupling of cyclodextrin-enhanced solubilization and photocatalytic treatment is a promising method for contaminated soil remediation.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; beta-Cyclodextrins; Catalysis; Hydrogen-Ion Concentration; Pentachlorophenol; Photochemistry; Soil; Soil Pollutants; Titanium; Ultraviolet Rays; Waste Management