共查询到20条相似文献,搜索用时 11 毫秒
1.
Xiaoming Pan Junsheng Wu Yuanzheng Ge Kui Xiao Hong Luo Shujun Gao Xiaogang Li 《Journal of Sol-Gel Science and Technology》2014,72(1):8-20
Organically modified silicate (Ormosil) coatings have been synthesized through the sol–gel method for corrosion protection of aluminum alloy. Silica-based unmodified coatings were also designed to investigate the effect of tetraethoxysilane (TEOS) content on the properties of the coatings. The surface morphology of the coatings was characterized by scanning electron microscopy. The corrosion resistance was evaluated by immersion test, electrochemical impedance spectroscopy and potentiodynamic polarization measurements. In addition, the surface potential differences of the coated samples were determined by scanning Kelvin probe. The results showed that a better corrosion resistance of unmodified coating was prepared by controlling the TEOS/EtOH/H2O molar ratio of 0.109/1/1.52. Ormosil coatings provided excellent barrier properties and corrosion resistance in comparison with the unmodified sol–gel coatings. The Ormosil coating modified with triethoxyoctylsilane exhibited corrosion resistance properties superior to the other Ormosil coatings after exposure to 3.5 wt% NaCl solution for 10 days. 相似文献
2.
Shumaila Islam Rosly Abdul Rahman Zulkafli Othaman Saira Riaz M. A. Saeed Shahzad Naseem 《Journal of Sol-Gel Science and Technology》2013,68(2):162-168
Owing to the diverse potential applications of hybrid silica–titania thin films, the synthesis and characterization of these films have been carried out with a special focus on application as a medium index layer for multilayered functional coatings. For synthesis, tetraethylorthosilicate and titanium tetraisopropoxide were chosen as precursors for the formation of silica-titania hybrid thin films/nano-composites through an in situ sol–gel process. These films were sequentially obtained on Cu substrate utilizing spin coating. The hybrids were characterized by field emission scanning electron microscope, energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction, atomic force microscopy and Fourier transform infrared spectroscopy (FTIR). Field emission scanning electron microscope morphology displayed a smooth, densified and crack- free layer of silica-titania hybrid nanoparticles in the range of 20–71 nm after calcinations at low temperature of 300ºC for 1 h. X-ray diffraction pattern confirms the phases of titania with higher crystallinity and phase transformation at low temperature. The prepared films were uniform with low 8.852 nm RMS value. The stoichiometry of films was confirmed by EDX results. The FTIR spectroscopy indicated the establishment of heterogeneous chemical bonding between the Ti and Si surfaces through oxygen. 相似文献
3.
Ling Zhou Yanyue Kong Shian Zhong Xiaorun Zhou 《Journal of Sol-Gel Science and Technology》2013,66(1):59-67
This work adopted semi-covalent imprinting to prepare molecularly imprinted polymers (MIP) with ibuprofen, a non-steroidal anti-inflammatory drug, as template by sol–gel processing, which is characterized by both the high affinity of covalent binding and the mild operation conditions of non-covalent rebinding. A functional monomer, which was used to synthesize the monomer-imprinted molecule complex, was prepared by multi-step synthesis for the first time. MIP was characterized by Fourier transform IR spectrum and nitrogen adsorption. Thin-layer chromatography separation was used to evaluate the specific molecular recognition ability of MIP. In addition, dynamic and thermodynamic studies on MIP imprinting ibuprofen were undertaken. The results of equilibrium rebinding experiments showed that MIP exhibited good adsorption capacity for ibuprofen. Scatchard analysis illustrated that the template-polymer system shows only one-site binding behavior with a dissociation constant of 1.84 mmol L?1. Dynamic adsorption exhibited pseudo-second-order kinetics. The positive value of ΔHθ and the negative values of ΔGθ demonstrated that the binding system for MIP is endothermic and spontaneous. 相似文献
4.
Mohammad Saraji Hamideh Yousefi Soraia Meghdadi 《International journal of environmental analytical chemistry》2013,93(5):305-317
An ion imprinted silica sorbent was prepared using a sol–gel process for selective extraction of Ni(II) ions from water samples. Bis(dibenzoylmethanto)nickel(II) complex was used as template; phenyltrimethoxysilane and 3-aminopropyltriethoxysilane as functional monomers and tetraethylorthosilicate as reticulating agent. The material was packed in solid-phase extraction (SPE) column. The effect of sampling volume, elution conditions, sample pH and sample flow rate on the extraction of Ni ions from water samples were studied. The relative selectivity coefficients of imprinted sorbent for Ni(II)/Co(II), Ni(II)/Cu(II) and Ni(II)/Cd(II) were 23.7, 30.3 and 24.4, times greater than non-imprinted sorbent, respectively. The relative standard deviation of the eight replicate determinations of Ni(II) was 4.2%. The detection limit was 0.9 µg L?1 using flame atomic absorption spectrometry. The developed method was successfully applied to the determination of trace nickel in water samples. 相似文献
5.
Highly selective and efficient chloramphenicol imprinted sol–gel silica based inorganic polymeric sorbent (sol–gel MIP) was synthesized via matrix imprinting approach for the extraction of chloramphenicol in milk. Chloramphenicol was used as the template molecule, 3-aminopropyltriethoxysilane (3-APTES) and triethoxyphenylsilane (TEPS) as the functional precursors, tetramethyl orthosilicate (TMOS) as the cross-linker, isopropanol as the solvent/porogen, and HCl as the sol–gel catalyst. Non-imprinted sol–gel polymer (sol–gel NIP) was synthesized under identical conditions in absence of template molecules for comparison purpose. Both synthesized materials were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and nitrogen adsorption porosimetry, which unambiguously confirmed their significant structural and morphological differences. 相似文献
6.
Dinesh Balgude Kiran Konge Anagha Sabnis 《Journal of Sol-Gel Science and Technology》2014,69(1):155-165
Thermally cured cashew nut shell liquid based hybrid coatings have been successfully developed using three step processes of malenization, silane modification and subsequent hydrolysis and condensation with tetra ethyl orthosilicate for corrosion protection of mild steel. The synthesized precursor was then characterized by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy (1H-NMR, 13C-NMR and 29Si-NMR) for structural elucidation. Four different coating formulations were developed on the basis of silane content (5, 10, 15 and 20 %) in the coating and cured with hexabutoxymethylmelamine at 120 °C for 1 h. The completely cured coatings were evaluated for mechanical properties, solvent resistance, chemical resistance, hydrolytic stability and accelerated weathering properties. Scanning electron microscope/energy dispersive spectroscopy was used to analyse the morphological behaviour and elemental distribution of the coating. Results revealed that 20 % silane modification showed better overall properties as compared to other formulations due to formation of more metal–oxygen–silicon covalent bond at metal-coating interface. 相似文献
7.
Pai Rajesh V. Pillai K. T. Pathak Sachin Mukerjee S. K. Vinogradov V. V. Agafonov A. V. Vinogradov A. V. Aggarwal S. K. 《Journal of Sol-Gel Science and Technology》2012,61(1):192-196
Mesoporous γ-alumina samples were prepared by the sol–gel process from the boehmite sol having different template solutions.
Copper doped material was also prepared from sol containing template solution along with copper nitrate. Studies were performed
to understand the influence of templates on the morphology of the synthesized samples particularly with respect to specific
surface area and porosity. Synthesized samples were used to study sorption of Pu(IV) from nitric acid–oxalic acid solutions.
Distribution ratios (D) for Pu(IV) were determined using the γ-alumina samples with an objective to employ these for the recovery
of Pu. 相似文献
8.
Geik Ling Teoh Kong Yong Liew Wan A. K. Mahmood 《Journal of Sol-Gel Science and Technology》2007,44(3):177-186
Abstract Alumina nanofibers of high aspect ratio with surface area of >300 m2 g−1 has been prepared successfully in bulk quantities by the sol–gel method. The synthesis parameters including the binary water–alcohol
solvent system to aluminium isopropoxide ratio, pH, type of solvent and aging temperature affect the uniformity and formation
of nanofibers. It is proposed that alumina nanofibers were formed by the curling of the nanosheets upon condensation after
the hydrolysis. The phase evolution of alumina nanofibers from pseudoboehmite to α phase has been shown by XRD and FTIR. 27Al NMR investigations show that the Al atoms are six and four coordinated. The morphology of the alumina nanofibers does not
change much as the calcination temperature was increased. In addition, the average pore size increases and the BET surface
area decreases as a function of calcination temperature. The thermal behavior of alumina nanofibers was investigated by TGA.
Graphical Abstract
相似文献
9.
Z. Serbetçi R. K. Gupta F. Yakuphanoglu 《Journal of Sol-Gel Science and Technology》2012,61(3):477-483
Pure and antimony (Sb) doped CdO films were grown using sol–gel spin coating technique. The structural properties of the films
were investigated using atomic force microscopy. The structure of CdO film is converted from microrods to nanorods with Sb
dopant. The analysis of optical absorption revealed that optical bandgap of the films changes with doping. The optical bandgap
for 0.1, 0.5, 1.0, and 2.0% Sb doped CdO was determined to be 2.28, 2.30, 2.56, and 2.42 eV, respectively. Other optical constants
such as refractive index, extinction coefficient, and dielectric constants were calculated using the optical data. The refractive
index dispersion of the films obeys the single oscillator model. The volume and surface energy loss functions were calculated
and observed to increase with increase in the photon energy. 相似文献
10.
Roberto Gustavo Furlan Wagner Raphael Correr Ana Flavia Costa Russi Mônica Rosas da Costa Iemma Eliane Trovatti Édison Pecoraro 《Journal of Sol-Gel Science and Technology》2018,88(1):181-191
45S5 bioglass has been widely studied in the last few decades because of its bioactivity and promising applications in the biomedical field. Boron, even few studied, represents a potential element to improve the properties of the 45S5 bioglass derivatives. The bioglasses are conventionally prepared by heat treatment of oxides and silicon. Here, the sol?gel method is proposed for the preparation of the boron-based 45S5 bioglass (45S5B) and the classical 45S5 bioglass (45S5), using water-soluble salts as raw materials. The bioglasses were characterized by FTIR, XRD, and SEM, indicating the success of the sol?gel method for preparation of the samples. The bioglasses were also tested in vitro for bioactivity in biological conditions and cytotoxicity against eukaryotic cells. The bioactivity of 45S5B was similar to the bioactivity of 45S5 bioglass, indicated by the deposition of hydroxyapatite crystals at the surface of the pristine bioglasses. The results of cytotoxicity tests revealed that the IC50 of 45S5B (IC50?=?7.56?mg?mL?1) was similar to the IC50 of 45S5 (IC50?=?8.15?mg?mL?1), indicating its safety for application in the biomedical field. 相似文献
11.
Mohammad Mizanur Rahman Aleya Hasneen Won-Ki Lee Kwon Taek Lim 《Journal of Sol-Gel Science and Technology》2013,67(3):473-479
Waterborne polyurethane (WBPU) sol–gel adhesives were prepared through a prepolymer process followed by a sol–gel reaction of (3-aminopropyl)triethoxysilane (APTES). The terminal amine group of APTES reacted with the NCO group of the prepolymer, and the ethoxy group created Si–O–Si branching by hydrolysis and condensation reactions in water at the dispersion step. Water swelling (%), tensile strength and Young’s modulus of the synthesized WBPU sol–gel adhesives were improved by increasing APTES content. Synthesized WBPU sol–gel adhesives were used for bonding nylon fabrics. A significant improvement in adhesive strength was recorded, and the potential for good adhesive strength under water at moderately high temperature (up to 75 °C) was observed with 6.84 mol% APTES in WBPU sol–gel adhesives. 相似文献
12.
《Journal of organometallic chemistry》2011,696(26):4281-4292
Cp-functionalized monotroticenes [(η7-C7H7)Ti(η5-C5H4E)] (2, E = Ph2SiCl; 3, E = tBu2SnCl; 12, E = I) and bitroticenes [(η7-C7H7)Ti(η5-C5H4)]2E′ (5, E′ = PPh; 6, E′ = BN(SiMe3)2; 7, E′ = Cp2Ti) were prepared by salt elimination metathesis between the monolithiated troticene [(η7-C7H7)Ti(η5-C5H4Li)]·pmdta (1b) (pmdta = N,N′,N′,N″,N″-pentamethyldiethylene-triamine) and the appropriate electrophile. The troticenyl-substituted zirconocene monochloride [(η7-C7H7)Ti(η5-C5H4ZrClCp*2)] (Cp* = η5-C5Me5) (8) and hafnocene ethoxide [(η7-C7H7)Ti{η5-C5H4Hf(OEt)Cp2}] (Cp = η5-C5H5) (11), and the heterobimetallic μ-oxo complexes [(η7-C7H7)Ti(η5-C5H4MCp2)]2O (9, M = Zr; 10, M = Hf) were obtained instead of the expected zircona- and hafna[1]troticenophanes by reaction of the dilithiated troticene [(η7-C7H6Li)Ti(η5-C5H4Li)]·pmdta (1a) with [Cp2MCl2] (M = Zr, Hf) or [Cp*2ZrCl2] in stoichiometric amounts. These compounds were characterized by single crystal X-ray diffraction analyses and, in the case of 2, 3, 5–7, 9, 10 and 12, also by elemental analyses and 1H, 13C and 119Sn NMR spectroscopy. Exposure of the troticenyl organotin chloride 3 to moisture resulted in its partial hydrolysis and formation of the organostannoxane-bridged bitroticene 4, while palladium-catalyzed Negishi C–C cross-coupling reaction between the troticenylzinc chloride [(η7-C7H7)Ti(η5-C5H4ZnCl)] (13) and the iodotroticene 12 or iodobenzene (PhI) led to the fulvalene complexes [(η7-C7H7)Ti(η5-C5H4)]2 (14) and [(η7-C7H7)Ti(η5-C5H4Ph)] (15). Compound 4 displays an unsymmetrical structure with the troticenyl fragments cis with respect to the Sn–O–Sn core, whereas compound 14 is centrosymmetrically trans oriented. 相似文献
13.
Alain C. Tagne Kuate Swagat K. Mohapatra Constantin G. Daniliuc Peter G. Jones Matthias Tamm 《Journal of organometallic chemistry》2012,696(26):4281-4292
Cp-functionalized monotroticenes [(η7-C7H7)Ti(η5-C5H4E)] (2, E = Ph2SiCl; 3, E = tBu2SnCl; 12, E = I) and bitroticenes [(η7-C7H7)Ti(η5-C5H4)]2E′ (5, E′ = PPh; 6, E′ = BN(SiMe3)2; 7, E′ = Cp2Ti) were prepared by salt elimination metathesis between the monolithiated troticene [(η7-C7H7)Ti(η5-C5H4Li)]·pmdta (1b) (pmdta = N,N′,N′,N″,N″-pentamethyldiethylene-triamine) and the appropriate electrophile. The troticenyl-substituted zirconocene monochloride [(η7-C7H7)Ti(η5-C5H4ZrClCp*2)] (Cp* = η5-C5Me5) (8) and hafnocene ethoxide [(η7-C7H7)Ti{η5-C5H4Hf(OEt)Cp2}] (Cp = η5-C5H5) (11), and the heterobimetallic μ-oxo complexes [(η7-C7H7)Ti(η5-C5H4MCp2)]2O (9, M = Zr; 10, M = Hf) were obtained instead of the expected zircona- and hafna[1]troticenophanes by reaction of the dilithiated troticene [(η7-C7H6Li)Ti(η5-C5H4Li)]·pmdta (1a) with [Cp2MCl2] (M = Zr, Hf) or [Cp*2ZrCl2] in stoichiometric amounts. These compounds were characterized by single crystal X-ray diffraction analyses and, in the case of 2, 3, 5–7, 9, 10 and 12, also by elemental analyses and 1H, 13C and 119Sn NMR spectroscopy. Exposure of the troticenyl organotin chloride 3 to moisture resulted in its partial hydrolysis and formation of the organostannoxane-bridged bitroticene 4, while palladium-catalyzed Negishi C–C cross-coupling reaction between the troticenylzinc chloride [(η7-C7H7)Ti(η5-C5H4ZnCl)] (13) and the iodotroticene 12 or iodobenzene (PhI) led to the fulvalene complexes [(η7-C7H7)Ti(η5-C5H4)]2 (14) and [(η7-C7H7)Ti(η5-C5H4Ph)] (15). Compound 4 displays an unsymmetrical structure with the troticenyl fragments cis with respect to the Sn–O–Sn core, whereas compound 14 is centrosymmetrically trans oriented. 相似文献
14.
A type of high visible-light active titanium oxinitride(TiO2-xNx) powder was prepared by a simple proc-ess:the calcination of the hydrated titanium dioxide at the atmosphere of ammonia-argon using a tu-bular electric furnace at high temperatures. The hydrated titanium dioxide was synthesized as the precursor of TiO2-xNx using titanic acid as raw material,which came from sulfate technique of produc-ing titanium white. The effects of temperature and reaction time on the nitrogen content,grain size and crystal structure were studied. The visible-light activity and photocatalysis capability of the powder were also investigated. 相似文献
15.
Marques Ana C. Rojas-Hernandez Rocío Estefanía Almeida Rui M. 《Journal of Sol-Gel Science and Technology》2021,99(1):1-12
Journal of Sol-Gel Science and Technology - In this paper, structural, optical, and electrical features of undoped and copper-incorporated nickel oxide (Cu/NiO) films with different mole ratios... 相似文献
16.
New hybrid gels were prepared from the gelation of glycol-modified tetraethoxysilane (TEOS) in the presence of O-2-hydroxy-3-(trimethylammonio)propyl guar gum (HTPG), and were then used for the in situ encapsulation of papain. Different from the sol–gel process based on commonly used TEOS, the biofriendly sol–gel process developed in this study could be conducted rapidly at ambient temperature without the addition of any organic solvent or acidic catalyst. In particular, the mechanical strength and microstructure of resultant hybrid gel matrix could be modulated by HTPG amount. In comparison with free papain, the encapsulated papain is characteristic of improved enzymatic activity, thermal and storage stability as well as good reusability. 相似文献
17.
Vidales-Hurtado M. A. Caudana-Campos A. I. Mauricio-Sánchez R. A. Méndez-Montealvo G. Caballero-Briones F. Mendoza-Galván A. 《Journal of Sol-Gel Science and Technology》2021,99(2):315-325
Journal of Sol-Gel Science and Technology - A thermo-reversible sol–gel transition in solutions made of titanium n-butoxide, ethanol, water, and nitric acid is studied by in situ... 相似文献
18.
Rajesh V. Pai Shovit Bhattacharya S. K. Mukerjee V. Venugopal 《Journal of Sol-Gel Science and Technology》2014,72(3):455-463
Varying amounts of Na and K doped lanthanum–titanium oxides were synthesized by gel entrapment technique. These ceramics were characterized by X-ray diffraction. Microstructural investigations revealed grain growth in the doped material compared to undoped sample. Dielectric relaxations of these compounds were investigated in the temperature range 250–900 °C. A high degree of dispersion of the permittivity of un-doped lanthanum–titanium oxide and K and Na doped lanthanum–titanium oxide was observed in the frequency range <100 kHz which was attributed to oxygen vacancies. An increase in the permittivity values were observed with 1 % Na and K doped samples. The permittivity values further deteriorated with the dopant concentration. Using the Cole–Cole model, an analysis of the dielectric loss with frequency was performed, assuming a distribution of relaxation time. The dielectric loss was found to decrease by doping K in lanthanum–titanium oxide matrix. The dc conductivity studies showed that a temperature dependent hopping type mechanism is responsible for electrical conduction in the system. 相似文献
19.
Z. Altıntaş E. Çakmakçı M. V. Kahraman N. K. Apohan A. Güngör 《Journal of Sol-Gel Science and Technology》2011,58(3):612-618
Photocurable silica-titania hybrid coatings were prepared through an anhydrous sol–gel process. Moreover, test samples were
prepared by the addition of definite ratios of fluoro acrylate oligomers into the formulations to manage the optical properties
of transmitted light. Formulations were applied to corona-treated polycarbonate substrates. Upon adding the inorganic component
to the coating material, thermal, mechanical, and other properties, such as hardness, gloss, contact angle, and flame resistance
were improved. The photocured hybrid films showed an increase in the refractive index with increasing the titanium tetraisopropoxide
content. As expected, a decrease was observed in the refractive index of the coatings with the incorporation of fluoro acrylate
resin. The surface morphology of the hybrid films was characterized by ESEM analysis. In addition the chemical composition
of the surface of the coatings was identified by ESEM–EDS technique. ESEM studies indicated that inorganic particles were
dispersed homogenously throughout the organic matrix. 相似文献
20.
Dominik L. Jürgen-Lohmann Christoph Nacke Raymond L. Legge Leonardo C. Simon 《Journal of Sol-Gel Science and Technology》2009,50(1):77-86
Sol–gels are seeing widespread interest as suitable materials for the immobilization of biomolecules in applications ranging
from optical coatings to specialty biocatalysts. Although there are numerous studies that have characterized these materials
in terms of their macroscopic properties, few studies have examined and correlated these properties at the microscopic level.
This study describes a spin-coating technique for the preparation of aluminum-supported sol–gel thin films containing immobilized
lysozyme [E.C. 3.2.1.17] that are suitable for chemical mapping using FTIR microscopy operating in reflectance mode. This
type of information can then be used to understand a variety of aspects of these materials which can be used for optimal engineering
of these materials, as well as insightful design and modeling. A data analysis method was developed to extract information
on chemical speciation and domain information on the materials from FTIR data matrices. Results from these studies indicated
that, contrary to what might be expected, these sol–gels are not homogeneous on the microscopic level. Instead, they are heterogeneous
in both the distribution of lysozyme and hydrophobic monomers at the scale investigated (20 μm resolution). The method described
here has promise in terms of providing a non-invasive approach of chemically mapping concentrations of proteinaceous and related
substances as well as chemical domains in situ in sol–gel thin films. 相似文献