One-step method for preparation of pH-responsive gold nanoparticles with block copolymer shell structures by UV irradiation

2011 ◽  
Vol 67 (6) ◽  
pp. 1059-1072 ◽  
Author(s):  
Xiaoning Fu ◽  
Hui Yang ◽  
Xiaokai Zhang ◽  
Xue Li ◽  
Limei Xu ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Block Copolymer ◽  
Uv Irradiation ◽  
Shell Structures ◽  
Ph Responsive ◽  
Step Method ◽  
One Step

One step method to attach gold nanoparticles onto the surface of an optical fiber used for refractive index sensing

2016 ◽  
Vol 51 ◽  
pp. 208-212 ◽  
Author(s):  
J.A. García ◽  
D. Monzón-Hernández ◽  
J. Manríquez ◽  
E. Bustos
Keyword(s):  
Gold Nanoparticles ◽  
Refractive Index ◽  
Optical Fiber ◽  
Step Method ◽  
Refractive Index Sensing ◽  
One Step

A Rapid One-Step Method for Gold Nanoparticles Synthesis with Polyethylene Glycol 200

2019 ◽  
Vol 11 (10) ◽  
pp. 1445-1450
Author(s):  
Xianbo Mou ◽  
Danni Sheng ◽  
Yabin Zhu ◽  
Ruixia Hou ◽  
Mi Zhou ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Average Particle Size ◽  
Stability Study ◽  
Synthesis Process ◽  
Average Particle ◽  
Uv Spectrum ◽  
Step Method ◽  
Transmission Electron ◽  
Polyethylene Glycol 200 ◽  
One Step

Because of their unique and excellent properties, gold nanoparticles (GNPs) have been widely used in biological monitoring, cosmetics and clinical fields. In this study, PEG200, as a component, and ascorbic acid, as a reducing agent, were used to develop a rapid one-step method for GNPs synthesis at room temperature. The effect of PEG200 on GNPs synthesis and tolerance of GNPs to some common solvents were also investigated. The whole synthesis process was completed within one hour, and transmission electron microscope (TEM), dynamic light scattering (DLS) and UV-Vis characterization showed that the GNPs synthesized by this method had mono dispersity, a strong absorption peak at 522 nm, with an average particle size of 20.38 nm. Stability study showed that the color and UV spectrum of GNPs solution did not change significantly within 90 days. Moreover, its strong tolerance to PB (0.1 M), NaCl (0.9%) and TE solutions was also observed. This method avoids high temperature process, reduces the difficulty of condition control, and can provide immediate PEG-GNPs synthesis for some special occasions, and the strong solution tolerance ensures its great potential application in many fields.

Synthesis of Gold Nanoparticles in Cyclodextrin-Tetrachloroaurate System

2020 ◽  
Vol 12 (7) ◽  
pp. 849-862
Author(s):  
Yuri S. Pestovsky ◽  
Teerapol Srichana
Keyword(s):  
Gold Nanoparticles ◽  
Hydrochloric Acid ◽  
Particle Growth ◽  
Drug Carriers ◽  
Chloride Ions ◽  
Step Method ◽  
Commercial Preparation ◽  
Previous Hypothesis ◽  
One Step ◽  
First Time

Tetrachloroaurate reduction with α-, β-, and γ-cyclodextrin at pH 10.56 was studied in this study by dual-angle dynamic light scattering and spectrophotometry. The nanoparticles were also characterized by scanning electron microscopy. In contrast with our previous study, the nanoparticles were purified by centrifugation prior to characterization. The reaction is considered to be a promising one-step method for preparation of gold nanoparticles with immobilized cyclodextrins without the need for seeding. Unlike in our previous study, the reaction mixture was boiled under reflux conditions instead of an open vial. This change sped up the reaction, and extensive aggregation was avoided. For the first time, this study demonstrated that all three cyclodextrins were able to reduce tetrachloroaurate at room temperature as well, but long incubation periods were necessary. This is the first publication discussing the mechanism of tetrachloroaurate reduction by cyclodextrins. The first stage of the reaction involved tetrachloroaurate hydrolysis despite presence of hydrochloric acid in the commercial preparation of tetrachloroauric acid (HAuCl4). Tetrachloroaurate was therefore the precursor but not the actual oxidant. The previous hypothesis on autocatalytic decarboxylation of cyclodextrins was therefore proven wrong. Particle growth was accompanied by nucleation, leading to coexistence of nanoparticles and nanoclusters. The resulting nanoparticles contained a small fraction of aggregates, probably because of sodium chloride generated from hydrochloric acid. However, besides playing this detrimental role, chloride ions facilitated nucleation by stabilizing gold intermediates. The nanoparticles solutions could be stored at least for three months, which contrasted with our previous work, where the nanoparticles were stable for only three days. For the first time, freeze-drying and reconstitution of the resulting nanoparticles were investigated, and they were shown to be free from aggregation. The synthesized gold nanoparticles are recommended for use as drug carriers.

Synthesis and application of smart gel material modified silica microspheres for pH-responsive hydrophilicity in liquid chromatography

The Analyst ◽  
2021 ◽  
Author(s):  
Fangbin Fan ◽  
Licheng Wang ◽  
Xiaofeng Lu ◽  
Xiaojing Liang ◽  
Yong Guo
Keyword(s):  
Liquid Chromatography ◽  
Chromatographic Separation ◽  
Mobile Phase ◽  
Separation Performance ◽  
Retention Behavior ◽  
Ph Responsive ◽  
Silica Microspheres ◽  
Modified Silica ◽  
Step Method ◽  
One Step

We prepared a pH-responsive stationary phase with different degrees of hydrophilicity under acidic and neutral mobile phase conditions by a one-step method, and discussed its chromatographic separation performance and retention behavior in detail.

Effect of Dynamic Crosslinking on Mechanical Properties of PP/EPDM Blends

1993 ◽  
Vol 58 (11) ◽  
pp. 2642-2650 ◽  
Author(s):  
Zdeněk Kruliš ◽  
Ivan Fortelný ◽  
Josef Kovář
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Shear Modulus ◽  
High Impact ◽  
Necessary Condition ◽  
Step Method ◽  
Melt Mixing ◽  
One Step ◽  
High Impact Strength ◽  
Dynamic Curing

The effect of dynamic curing of PP/EPDM blends with sulfur and thiuram disulfide systems on their mechanical properties was studied. The results were interpreted using the knowledge of the formation of phase structure in the blends during their melt mixing. It was shown, that a sufficiently slow curing reaction is necessary if a high impact strength is to be obtained. Only in such case, a fine and homogeneous dispersion of elastomer can be formed, which is the necessary condition for high impact strength of the blend. Using an inhibitor of curing in the system and a one-step method of dynamic curing leads to an increase in impact strength of blends. From the comparison of shear modulus and impact strength values, it follows that, at the stiffness, the dynamically cured blends have higher impact strength than the uncured ones.

Bismuth particles imbedded degradable nanohydrogel prepared by one-step method for tumor dual-mode imaging and chemo-photothermal combined therapy

2019 ◽  
Vol 375 ◽  
pp. 122000 ◽  
Author(s):  
Yang Xuan ◽  
Xian-Lin Song ◽  
Xiao-Quan Yang ◽  
Ruo-Yun Zhang ◽  
Zi-Yu Song ◽  
...  
Keyword(s):  
Combined Therapy ◽  
Dual Mode ◽  
Step Method ◽  
One Step

scholarly journals Bio-Based Polyurethane Networks Derived from Liquefied Sawdust

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3138
Author(s):  
Kamila Gosz ◽  
Agnieszka Tercjak ◽  
Adam Olszewski ◽  
Józef Haponiuk ◽  
Łukasz Piszczyk
Keyword(s):  
Biomass Conversion ◽  
Structural Features ◽  
Mechanical Analysis ◽  
Process Efficiency ◽  
Hydroxyl Number ◽  
Step Method ◽  
One Step ◽  
Liquefaction Process ◽  
The Fourier Transform ◽  
Liquefaction Temperature

The utilization of forestry waste resources in the production of polyurethane resins is a promising green alternative to the use of unsustainable resources. Liquefaction of wood-based biomass gives polyols with properties depending on the reagents used. In this article, the liquefaction of forestry wastes, including sawdust, in solvents such as glycerol and polyethylene glycol was investigated. The liquefaction process was carried out at temperatures of 120, 150, and 170 °C. The resulting bio-polyols were analyzed for process efficiency, hydroxyl number, water content, viscosity, and structural features using the Fourier transform infrared spectroscopy (FTIR). The optimum liquefaction temperature was 150 °C and the time of 6 h. Comprehensive analysis of polyol properties shows high biomass conversion and hydroxyl number in the range of 238–815 mg KOH/g. This may indicate that bio-polyols may be used as a potential substitute for petrochemical polyols. During polyurethane synthesis, materials with more than 80 wt% of bio-polyol were obtained. The materials were obtained by a one-step method by hot-pressing for 15 min at 100 °C and a pressure of 5 MPa with an NCO:OH ratio of 1:1 and 1.2:1. Dynamical-mechanical analysis (DMA) showed a high modulus of elasticity in the range of 62–839 MPa which depends on the reaction conditions.

scholarly journals Analysis and applicability of a new quartic polynomial one-step method for solving COVID-19 model

2021 ◽  
Vol 1734 ◽  
pp. 012019
Author(s):  
S E Fadugba ◽  
V J Shaalini ◽  
A A Ibrahim
Keyword(s):  
Step Method ◽  
Quartic Polynomial ◽  
One Step
Sign in / Sign up

Export Citation Format

Share Document