In Situ Reducing Synthesis of (CTAB+C18NH2)-Modified Hydrophobic Gold Nanoparticles at Room Temperature

2014 ◽  
Vol 618 ◽  
pp. 203-207
Author(s):  
Li Ping Chen
Keyword(s):  
Gold Nanoparticles ◽  
Cetyltrimethylammonium Bromide ◽  
Room Temperature ◽  
Microemulsion System ◽  
Mixed Surfactant ◽  
Gold Particles ◽  
Alkali Promotion

The hydrophobic gold nanoparticles with monodispersity are synthesized by using n-butanol reduction in situ under the condition of alkali promotion in cetyltrimethylammonium bromide (CTAB)/n-butanol/n-heptane/HAuCl4/NaOH(aq) W/O microemulsion at 30°C. The CTAB-stabilized gold nanoparticles are characterized by UV-vis, TEM , XRD and so on. The replacement of simple surfactant (CTAB ) with mixed surfactant CTAB/ octadecylamine can weaken the direction of CTAB to the growth of gold nanopartices and increase the monodispersity of gold nanoparticles. The effects of components of the microemulsion system on the shape, size and monodispersity of gold nanoparticles are also explored. The results show that the size of gold particles is changed by the amount of CTAB and C18NH2.

Preparation of Straight and Orderly Polypyrrole Microrods through Soft Template Methods

2011 ◽  
Vol 306-307 ◽  
pp. 679-683
Author(s):  
Li Bo Sun ◽  
Yuan Chang Shi ◽  
Lin Ya Chu ◽  
Bing Chang Zhang ◽  
Jiu Rong Liu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cetyltrimethylammonium Bromide ◽  
Growth Process ◽  
Room Temperature ◽  
Oxidative Polymerization ◽  
Soft Template ◽  
Microemulsion System ◽  
Transmission Electron ◽  
The Impact

The straight and orderly microrods of polypyrrole(PPy) was synthesized in a microemulsion system consisted of cetyltrimethylammonium bromide(CTAB), n-pentanol, water and pyrrole by chemical oxidative polymerization, in which CTAB was used as soft templates and APS was used as the oxidant. Fourier-transform infrared spectroscopy (FTIR) was used to characterize the structure of the PPy microrods. Transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM) was used to characterize the morphology of the samples. We discussed the impact of temperature, the adding way of the oxidant, the amount of cosurfactant n-pentanol to the morphology of PPy microrods. The results showed that straight and orderly PPy microrods with a diameter about 300nm and a length up to 20μm were synthesized when the temperature was kept at room temperature (25°C), the dropping time of APS was more than 1.5h, the ratio of CTAB to n-pentanol was 0.6:1, and the polymerization time was about 24h. We studied the growth process of PPy microrods by HTEM analysis. HTEM images revealed that the growth process of PPy changed from hollow microrods, semi-hollow microrods, and finally solid microrods.

scholarly journals The synthesis of highly active carbon dot-coated gold nanoparticles via the room-temperature in situ carbonization of organic ligands for 4-nitrophenol reduction

RSC Advances ◽  
2020 ◽  
Vol 10 (33) ◽  
pp. 19419-19424
Author(s):  
Yue Zhu ◽  
Juan Du ◽  
Qianqian Peng ◽  
Fengyi Wang ◽  
Jing Hu ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Active Carbon ◽  
Room Temperature ◽  
Organic Ligands ◽  
Carbon Dot ◽  
Highly Active ◽  
Nitrophenol Reduction ◽  
In Situ Carbonization

Due to the serious pollution issue caused by 4-nitrophenol (4-NP), it is of great importance to design effective catalysts for its reduction.

Friction and Rheological Properties of Meso-Porous MCM-41/Unsaturated Polyester In Situ Composites

2014 ◽  
Vol 599-601 ◽  
pp. 18-21
Author(s):  
Shu Long Hu ◽  
Jian Lv ◽  
Feng Ying Lu ◽  
Hua Shan Liu ◽  
De Ming Zeng
Keyword(s):  
Wear Resistance ◽  
Rheological Properties ◽  
Cetyltrimethylammonium Bromide ◽  
Room Temperature ◽  
Polyester Resin ◽  
In Situ Polymerization ◽  
Unsaturated Polyester ◽  
Roller Milling ◽  
Mcm 41

In this paper, meso-porous MCM-41 was synthesized at room temperature using cationic surfactant cetyltrimethylammonium bromide (CTAB) as the template agent. Then MCM-41/unsatura-ted polyester resin (UPR) materials were prepared by in-situ polymerization with the meso-porous MCM-41. MCM-41/UPR in-situ composites were prepared by roller milling and molding processes. Effects of meso-porous MCM-41 on rheological properties and wear resistance of the MCM-41/UPR composites have been investigated. It is shown that MCM-41 has a diameter in range of 4-5 nm and the pores are highly ordered. MCM-41 can improve the rheological properties and wear resistance of the composites. When MCM-41 content is 2%, the mass abrasion loss is decreased by 37.4%.

scholarly journals Structural and Magnetic Properties of Nanosized Barium Hexaferrite Powders Obtained by Microemulsion Technique

2010 ◽  
Vol 159 ◽  
pp. 57-62 ◽  
Author(s):  
Tatyana Koutzarova ◽  
Svetoslav Kolev ◽  
Kornely Grigorov ◽  
Chavdar Ghelev ◽  
Andrzej Zaleski ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Cetyltrimethylammonium Bromide ◽  
Room Temperature ◽  
Average Particle Size ◽  
Barium Hexaferrite ◽  
Anisotropy Field ◽  
Microemulsion System ◽  
Average Particle ◽  
Crystalline Anisotropy ◽  
Magneto Crystalline Anisotropy

Thin hexagonal barium hexaferrite particles synthesized using the microemulsion technique were studied. A water-in-oil reverse microemulsion system with cetyltrimethylammonium bromide (CTAB) as a cationic surfactant, n-butanol as a co-surfactant, n-hexanol as a continuous oil phase, and an aqueous phase were used. The microstructural and magnetic properties were investigated. The particles obtained were mono-domain with average particle size 280 nm. The magnetic properties of the powder were investigated at 4.2 K and at room temperature. The saturation magnetization was 48.86 emu/g and the coercivity, 2.4 x 105 A/m at room temperature. The anisotropy field Ha and magneto-crystalline anisotropy K1 were 1.4 x 106 A/m and 2.37 x 105 J/m3, respectively.

scholarly journals Au-Decorated WS2 Microflakes Based Sensors for Selective Ammonia Detection at Room Temperature

Chemosensors ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 9
Author(s):  
Qiyilan Guang ◽  
Baoyu Huang ◽  
Xiaogan Li
Keyword(s):  
Gold Nanoparticles ◽  
Synergistic Effect ◽  
Room Temperature ◽  
Response Recovery ◽  
Ammonia Detection ◽  
Improved Performance ◽  
Excellent Selectivity

Gold nanoparticles decorated WS2 microflakes (Au/WS2) have been synthesized by an in situ chemical reducing process. A chemiresistive-type sensor using as-synthesized Au/WS2 heterostructures as sensing materials shows an improved response to different concentrations of ammonia compared to pure WS2 at room temperature. As the concentrations of gold nanoparticles increased in heterostructures, response/recovery speeds of the sensors became faster although the sensitivity of the sensor was compromised compared to the sensitivity of the sensor with lower concentrations of Au. In addition, the Au/WS2-based sensor indicated excellent selectivity to formaldehyde, ethanol, benzene and acetone at room temperature. The improved performance of the sensors was attributed to the synergistic effect of electronic sensitization and chemical sensitization between WS2 and Au.

Synthesis of core–shell Au–Pt nanodendrites with high catalytic performance via overgrowth of platinum on in situ gold nanoparticles

2015 ◽  
Vol 3 (1) ◽  
pp. 368-376 ◽  
Author(s):  
Yijing Li ◽  
Wenchao Ding ◽  
Mingrui Li ◽  
Haibing Xia ◽  
Dayang Wang ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Room Temperature ◽  
Catalytic Performance ◽  
Core Shell

Well-dispersed, core–shell Au–Pt nanodendrites were synthesized via overgrowth of platinum on in situ 5.5 nm gold nanoparticles at room temperature.

Ultrastructural analysis of the spatial distribution of MRNA

1992 ◽  
Vol 50 (1) ◽  
pp. 552-553
Author(s):  
Gary Bassell ◽  
Robert H. Singer
Keyword(s):  
Electron Microscopy ◽  
Spatial Distribution ◽  
In Situ Hybridization ◽  
High Resolution ◽  
Nucleic Acids ◽  
Colloidal Gold ◽  
Dna Probe ◽  
Nucleotide Analogs ◽  
Gold Particles

We have been investigating the spatial distribution of nucleic acids intracellularly using in situ hybridization. The use of non-isotopic nucleotide analogs incorporated into the DNA probe allows the detection of the probe at its site of hybridization within the cell. This approach therefore is compatible with the high resolution available by electron microscopy. Biotinated or digoxigenated probe can be detected by antibodies conjugated to colloidal gold. Because mRNA serves as a template for the probe fragments, the colloidal gold particles are detected as arrays which allow it to be unequivocally distinguished from background.

Otoconia perfect/imperfect crystals

1994 ◽  
Vol 52 ◽  
pp. 42-43
Author(s):  
César D. Fermin ◽  
Dale Martin
Keyword(s):  
Image Processing ◽  
Room Temperature ◽  
Phosphotungstic Acid ◽  
Gallus Domesticus ◽  
Crystal Matrix ◽  
Organic Templates ◽  
Image Processing Algorithms ◽  
Processing Algorithms ◽  
Diffraction Patterns

Otoconia of higher vertebrates are interesting biological crystals that display the diffraction patterns of perfect crystals (e.g., calcite for birds and mammal) when intact, but fail to produce a regular crystallographic pattern when fixed. Image processing of the fixed crystal matrix, which resembles the organic templates of teeth and bone, failed to clarify a paradox of biomineralization described by Mann. Recently, we suggested that inner ear otoconia crystals contain growth plates that run in different directions, and that the arrangement of the plates may contribute to the turning angles seen at the hexagonal faces of the crystals.Using image processing algorithms described earlier, and Fourier Transform function (2FFT) of BioScan Optimas®, we evaluated the patterns in the packing of the otoconia fibrils of newly hatched chicks (Gallus domesticus) inner ears. Animals were fixed in situ by perfusion of 1% phosphotungstic acid (PTA) at room temperature through the left ventricle, after intraperitoneal Nembutal (35mg/Kg) deep anesthesia. Negatives were made with a Hitachi H-7100 TEM at 50K-400K magnifications. The negatives were then placed on a light box, where images were filtered and transferred to a 35 mm camera as described.

In Situ Localization of PPAR Gamma and Uncoupling Protein in Mouse Embryo Sections Using Digoxigenin-Labeled Riboprobes

1996 ◽  
Vol 54 ◽  
pp. 32-33
Author(s):  
C. Jennermann ◽  
S. A. Kliewer ◽  
D. C. Morris
Keyword(s):  
Alkaline Phosphatase ◽  
Room Temperature ◽  
Uncoupling Protein ◽  
Ppar Gamma ◽  
Nuclear Hormone Receptor ◽  
Full Length ◽  
Northern Analysis ◽  
Peroxisome Proliferator

Peroxisome proliferator-activated receptor gamma (PPARg) is a member of the nuclear hormone receptor superfamily and has been shown in vitro to regulate genes involved in lipid metabolism and adipocyte differentiation. By Northern analysis, we and other researchers have shown that expression of this receptor predominates in adipose tissue in adult mice, and appears first in whole-embryo mRNA at 13.5 days postconception. In situ hybridization was used to find out in which developing tissues PPARg is specifically expressed.Digoxigenin-labeled riboprobes were generated using the Genius™ 4 RNA Labeling Kit from Boehringer Mannheim. Full length PPAR gamma, obtained by PCR from mouse liver cDNA, was inserted into pBluescript SK and used as template for the transcription reaction. Probes of average size 200 base pairs were made by partial alkaline hydrolysis of the full length transcripts. The in situ hybridization assays were performed as described previously with some modifications. Frozen sections (10 μm thick) of day 18 mouse embryos were cut, fixed with 4% paraformaldehyde and acetylated with 0.25% acetic anhydride in 1.0M triethanolamine buffer. The sections were incubated for 2 hours at room temperature in pre-hybridization buffer, and were then hybridized with a probe concentration of 200μg per ml at 70° C, overnight in a humidified chamber. Following stringent washes in SSC buffers, the immunological detection steps were performed at room temperature. The alkaline phosphatase labeled, anti-digoxigenin antibody and detection buffers were purchased from Boehringer Mannheim. The sections were treated with a blocking buffer for one hour and incubated with antibody solution at a 1:5000 dilution for 2 hours, both at room temperature. Colored precipitate was formed by exposure to the alkaline phosphatase substrate nitrobluetetrazoliumchloride/ bromo-chloroindlylphosphate.

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