共查询到20条相似文献,搜索用时 93 毫秒
1.
A G 4.0 dendrimer-like poly (amido amine) (PAMAM) based on silica nanoparticles was fabricated via a divergent approach.It was built from γ-aminopropyi silica nanoparfides (APSN) core via repetitive addition of acrylate (MA) and hexylenediamine (HDA). FT-IR and EA were used to monitor the progress of dendrimer during each step. The amino group content of the resulting product increased from 0.49 to 3.72 mmol/g after the 4th generation. In addition, the percentage of grafting increased with increasing generation and reached to 65.9% after 4th generation. It was found that the resulting silica nanoparticles could be dispersed in methanol with a mean hydrodynamic particle diameter of 152.7 nm although the silica nanoparticles had agglomerated during the storage period. 相似文献
2.
HongYUAN RuXiuCAI DaiWenPANG 《中国化学快报》2003,14(11):1163-1166
A simple method to prepare the non-spherical gold particles was developed. The result solution included trigonal, truncated trigonal, hexagonal layers, and a pseudo-pentagonal shaped gold nanocrystals. The key factor is to control the relative rates of nucleation and cluster growth in this method. These attributes make seeding growth method as a useful tool in the fabrication of colloidal metal materials. A longitudinal plasmon resonance of 866 nm was observed, which is in the near-IR spectral regions (600-1000 nm). The excellent optical properties as near-IR labels are used to develop highly sensitive analvsis method. 相似文献
3.
Gold nanoparticles were synthesized through the reduction of tetrachlorauric acid (HAuCh) by NaBH4, with polyethyleneimine(PEI) as stabilizer. The nanoparticles were characterized by UV-vis spectroscopy and atomic force microscopy(AFM). 相似文献
4.
Site-specific Deposition of Colloidal Pd Nanoparticles on Self-assembled Microtubules from Biolipid 总被引:3,自引:0,他引:3
Lipid microtubules with wound ribbon features were fabricated by self-assembling method, and the deposition patterns of colloidal Pd particles on tubular template were investigated. The result indicates that colloidal Pd nanoparticles are preferentially decorated on the helical markings in the interior and on the exterior of preformed tubule and to the edge of loosely helical ribbons to obtain helical deposition features. The multi-bilayer microstructure of tubules can be marked by fine Pd nanoparticles deposited at the edge of helical ribbon. There are the site-specific interactions between lipid tubular template and colloidal Pd particles at the helical edge. A new route was illustrated that colloidal Pd particles firstly attach at the edge of thin flat membranes, and then thin membranes roll up and reassemble into tubule together with particles to form helical deposition patterns. The site-specific deposition of Pd is unbeneficial to obtain the homogeneous metal film on tubules, but it can be utilized to reveal the different chemical nature of lipid molecular assembly. 相似文献
5.
本文对近几年有关纳米二氧化钛粉体及薄膜的制备研究进行综述。重点介绍及评述了以无机钛盐和有机钛盐为前驱体制备纳米二氧化钛粉体及利用自组装方法制备二氧钛薄膜的最新研究成果。对今后研究工作的趋势进行了探讨。 相似文献
6.
YAN Jing-hui ZHANG Ming LIAN Hong-zhou LIU Jie LI Zhong-tian CAO Jie SHI Chun-shan 《高等学校化学研究》2006,22(3):274-277
Introduction Nanomaterialsusuallyshowsomenoveloptical,electronic,magneticandchemicalpropertiessignifi cantlydifferentfromthoseofthebulkmaterialsbecause oftheirextremelysmallsize,largespecificsurfaceare asandpeculiarquantumsize.Thepotentialoftheirap plicat… 相似文献
7.
JuanZHANG ShengYiZHANG JingJuanXU HongYuanCHEN 《中国化学快报》2004,15(11):1345-1348
The well-distributed, stable selenium nanoparticles (10 nm) with good adhesive abilityand biocompatibility were successfully synthesized by using the template of chitosan cross-linkedwith glutaradehyde. The resulting selenium nanoparticles were used as a new carrier forhorseradish peroxidase to construct H2O2 biosensors with good performances. 相似文献
8.
Sulfur doped anatase TiO2 nanoparticles (3 nm−12 nm) were synthesized by the reaction of titanium tetrachloride, water and sulfuric acid
with addition of 3M NaOH at room temperature. The electro-optical and photocatalytic properties of the synthesized sulfur doped TiO2
nanoparticles were studied along with Degussa commercial TiO2 particles (24 nm). The results show that band gap of TiO2 particles decreases
from 3.31 to 3.25 eV and for that of commercial TiO2 to 3.2 eV when the particle sizes increased from 3 nm to 12 nm with increase in sulfur
doping. The results of the photocatalytic activity under UV and sun radiation show maximum phenol conversion at the particle size of 4 nm at
4.80% S-doping. Similar results are obtained using UV energy for both phenol conversion and conversion of CO2+H2O in which formation
of methanol, ethanol and proponal is observed. Production of methanol is also achieved on samples with a particle size of 8 and 12 nm and
sulfur doping of 4.80% and 5.26%. For TiO2 particle of 4 nm without S doping, the production of methanol, ethanol and proponal was lower
as compared to the S-doped particles. This is attributed to the combined electronic effect and band gap change, S dopant, specific surface area
and the light source used. 相似文献
9.
One linear template 13 and one cyclophane template 15, both incorporating two electron rich 1,4‐dialkoxybenzene units and one diamide unit, have been synthesized. By utilizing donor‐acceptor interaction and/or intermolecular hydrogen bonding assembling principles, one novel hetero[3]rotazane 22·4Cl, possessing one neutral and one tetracationic ring components, has been synthesized from 13, through neutral [2]rotaxane 21 as intermediate. With 15 as template, tetracationic [2]catenane 23·4PF6 was assembled by using donor‐acceptor interaction, but no neutral [2]rotaxane could be obtained under the typical conditions of hydrogen bonding assembling principle. The interlocked supramolecular compounds have been characterized and their spectral properties are investigated. 相似文献
10.
BIAN Guo-Qing ZHU Qin-Yu DAI Jie WANG Xin YANG Wei YAN Ze-Min SUN Zhen-Rong MUNAKATA Megumu MAEKAWA Masahiko 《中国化学》2003,21(5):537-543
A new coluster-cracking method to synthesize dithiolate metal complexes was reported and four unsymmetric complexes with formula(Me4N)2[M(Ln)(SPh)2](M=Cd and Zn,L1=dmit=1,3-dithiole-2-thione4-5,dithiolate,L2=dmid=1,3-dithiole-2-one-4,5-dithiolate,SPh=thiophenolate)(1-4)were characterized by elemental analysis,IR,UV NMR spectra and so on.The advantages of this method are summarized in two aspects:(1) the preparation is very convenient;(2) the reaction usually completed giving the product with high pruity.The crystal structure of 1 showed that the bond distances of Cd(Ⅱ)to the sulfur of the thiophenolate group are shorter than those of Cd(Ⅱ)to the sulfur of dmit,so that the thiophenolate group does not be replaced in the reaction and thmixed ligand complexes are the dominant produxts.The dmit complexes showed well third-order NLO properties,but not of the dmid complexes,although dmid is an analogue to dmit. 相似文献
11.
以纳米TiO2为基底,L-色氨酸(L-Trp)为模板分子,采用溶胶凝胶法合成L-Trp印迹的纳米TiO2。采用扫描电镜和红外光谱对印迹纳米TiO2和非印迹纳米TiO2进行表征,表明模板分子L-Trp成功地印迹到纳米TiO2中。采用1%的氨水溶液去除印迹的纳米TiO2中的模板分子L-Trp,纳米TiO2上留下与L-Trp相匹配的空穴。采用荧光分光光度法研究了具有L-Trp铸型的纳米TiO2对L-Trp和D-色氨酸(D-Trp)的分离效果。实验表明,模板分子L-Trp与钛前驱体的最佳投料摩尔比为1∶0.2,富集溶液pH值为6.0时,印迹纳米TiO2对L-Trp具有优异的选择吸附性,其分离选择系数为2.42,可实现对色氨酸对映体的识别。 相似文献
12.
二氧化钛纳米粒子催化合成Hantzsch酯和多氢喹啉衍生物(英文) 总被引:2,自引:0,他引:2
Mahmood TAJBAKHSH Ehsan ALAEE Heshmatollah ALINEZHAD Mohammad KHANIAN Fatemeh JAHANI Samad KHAKSAR Parizad REZAEE Mahgol TAJBAKHSH 《催化学报》2012,(9):1517-1522
1,4-Dihydropyridine and polyhydroquinoline derivatives have been prepared efficiently in a one-pot synthesis via Hantzsch condensation using nanosized titanium dioxide as a heterogeneous catalyst.The present methodology offers several advantages such as excellent yields,short reaction times (30-120 min),environmentally benign,and mild reaction conditions.The catalyst can be readily separated from the reaction products and recovered in excellent purity for direct reuse. 相似文献
13.
A. E. Raevskaya A. V. Korzhak A. L. Stroyuk S. Ya. Kuchmii 《Theoretical and Experimental Chemistry》2005,41(2):111-116
The spectro-optical properties of nanoparticles of ZnS have been studied and the structure of the long wavelength edge of the absorption bands of the semiconductor has been analyzed. The influence of the synthesis conditions on the size and optical properties of the nanoparticles of ZnS formed has been investigated. It has been established that oxidative photo-corrosion of zinc sulfide colloids is accompanied by a decrease in the average size of ZnS nanoparticles and an increase in the defectiveness of their surfaces.__________Translated from Teoreticheskaya i Eksperimental’naya Khimiya, Vol. 41, No. 2, pp. 105–109, March–April, 2005. 相似文献
14.
Bioinspired Hierarchical Nanotubular Titania Immobilized with Platinum Nanoparticles for Photocatalytic Hydrogen Production 下载免费PDF全文
Dr. Xiaoyan Liu Jiao Li Dr. Yiming Zhang Prof. Jianguo Huang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(20):7345-7349
A bioinspired nanocomposite composed of platinum nanoparticles and nanotubular titania was fabricated in which the titania matter was templated by natural cellulose substance. The composite possesses three‐ dimensional hierarchical structures, and ultrafine metallic platinum particles with sizes of ca. 2 nm were immobilized uniformly on the surfaces of the titania nanotubes. Such a nanocomposite with 1.06 wt % of platinum content shows the optimal photocatalytic hydrogen production activity from water splitting of 16.44 mmol h?1 g?1, and excessive loading of platinum results in poorer photocatalytic performance. The structural integrity of the nanocomposite upon cyclic water‐splitting processes results in its sufficient photocatalytic stability. 相似文献
15.
纳米四氧化三铁表面酸碱性质研究 总被引:17,自引:0,他引:17
制备了纳米Fe3O4, 并对其进行了表征和表面酸碱行为研究. 实验结果表明, Fe3O4表面在水溶液中有非常明显的酸碱性质. 随着纳米Fe3O4加入量的增多, 溶液pH缓冲能力增强, 二者之间成正比, 据此可定量地测定H+在纳米氧化铁表面的吸附量. 运用MEDUSA和WINSGW计算软件计算了表面组分在溶液中的分布, 并讨论了表面电荷对表面组分分布的影响. 相似文献
16.
Dr. Mari Vinoba Dr. Margandan Bhagiyalakshmi Dr. Soon Kwan Jeong Dr. Sung Chan Nam Dr. Yeoil Yoon 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(38):12028-12034
Bovine carbonic anhydrase (BCA) was covalently immobilized onto OAPS (octa(aminophenyl)silsesquioxane)‐functionalized Fe3O4/SiO2 nanoparticles by using glutaraldehyde as a spacer. The Fe3O4 nanoparticles were coated with SiO2, onto which was grafted OAPS, and the product was characterized using SEM, TEM, XRD, IR, X‐ray photoelectron spectroscopy (XPS), and magnetometer analysis. The enzymatic activities of the free and Fe3O4/SiO2/OAPS‐conjugated BCA (Fe? CA) were investigated by hydrolyzing p‐nitrophenylacetate (p‐NPA), and hydration and sequestration of CO2 to CaCO3. The CO2 conversion efficiency and reusability of the Fe? CA were studied before and after washing the recovered Fe? CA by applying a magnetic field and quantifying the unreacted Ca2+ ions by using ion chromatography. After 30 cycles, the Fe? CA displayed strong activity, and the CO2 capture efficiency was 26‐fold higher than that of the free enzyme. Storage stability studies suggested that Fe? CA retained nearly 82 % of its activity after 30 days. Nucleation of the precipitated CaCO3 was monitored by using polarized light microscopy, which revealed the formation of two phases, calcite and valerite, at pH 10 upon addition of serine. The magnetic nanobiocatalyst was shown to be an excellent reusable catalyst for the sequestration of CO2. 相似文献
17.
Andra Dinache Simona Nistorescu Tatiana Tozar Adriana Smarandache Mihai Boni Petronela Prepelita Angela Staicu 《Molecules (Basel, Switzerland)》2023,28(1)
This study presents the spectral characterization of TiO2 nanoparticles (NPs) functionalized with three porphyrin derivatives: 5,10,15,20-(Tetra-4-aminophenyl) porphyrin (TAPP), 5,10,15,20-(Tetra-4-methoxyphenyl) porphyrin (TMPP), and 5,10,15,20-(Tetra-4-carboxyphenyl) porphyrin (TCPP). UV-Vis absorption and Fourier transform infrared spectroscopy–attenuated total reflection (FTIR-ATR) spectroscopic studies of these porphyrins and their complexes with TiO2 NPs were performed. In addition, the efficiency of singlet oxygen generation, the key species in photodynamic therapy, was investigated. UV-Vis absorption spectra of the NPs complexes showed the characteristic bands of porphyrins. These allowed us to determine the loaded porphyrins on TiO2 NPs functionalized with porphyrins. FTIR-ATR revealed the formation of porphyrin-TiO2 complexes, suggesting that porphyrin adsorption on TiO2 may involve the pyrroles in the porphyrin ring, or the radicals of the porphyrin derivative. The quantum yield for singlet oxygen generation by the studied porphyrin complexes with TiO2 was higher compared to bare porphyrins for TAPP and TMPP, while for the TCPP-TiO2 NPs complex, a decrease was observed, but still maintained a good efficiency. The TiO2 NPs conjugates can be promising candidates to be tested in photodynamic therapy in vitro assays. 相似文献
18.
19.
《Electroanalysis》2017,29(11):2638-2645
A novel sensor architecture based on thin film of tapioca decorated within nitrogen‐doped titanium dioxide (N‐TiO2) nanoparticles is reported. The nanostructures were characterized by scanning electron microscope, transmission electron microscope, X‐rays diffraction and voltammetric techniques. The proposed electrode was used for detection of low concentrations of 17‐β estradiol in without purification step, which was investigated by using linear sweep adsorptive stripping voltammetry. Under optimal conditions, the analytical curve was linear over a 17β‐estradiol concentration range of 9.9×10−6 to 1.4×10−5 mol L−1, with a detection limit of 1.7×10−7 mol L−1. The tapioca and N‐TiO2 nanoparticles homogeneous film was applied for detection of 17‐β‐estradiol in tap water and synthetic urine samples, which presented satisfactory results. 相似文献
20.
Zaual A. Temerdashev Olga A. Galitskaya Mikhail A. Bolshov 《Molecules (Basel, Switzerland)》2022,27(22)
We discuss the features involved in determining the titanium dioxide nanoparticle (TiO2NP) sizes in cosmetic samples via single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) in the millisecond-time resolution mode, and methods for considering the background signal. In the SP-ICP-MS determination of TiO2NPs in cosmetics, the background signal was recorded in each dwell time interval due to the signal of the Ti dissolved form in deionized water, and the background signal of the cosmetic matrix was compensated by dilution. A correction procedure for the frequency and intensity of the background signal is proposed, which differs from the known procedures due to its correction by the standard deviation above the background signal. Background signals were removed from the sample signal distribution using the deionized water signal distribution. Data processing was carried out using Microsoft Office Excel and SPCal software. The distributions of NP signals in cosmetic product samples were studied in the dwell time range of 4–20 ms. The limit of detection of the NP size (LODsize) with the proposed background signal correction procedure was 71 nm. For the studied samples, the LODsize did not depend on the threshold of the background signal and was determined by the sensitivity of the mass spectrometer. 相似文献