Effect of UV irradiation during synthesis of polypyrrole by a one-step deposition/polymerization process

Author(s):  
Sunyoung Chang ◽  
Jaehong Park ◽  
Jiyoung Jang ◽  
Jungwoo Lee ◽  
Jaeseung Lee ◽  
...  
2011 ◽  
Vol 64 (12) ◽  
pp. 2404-2409 ◽  
Author(s):  
A. Akbari ◽  
M. Homayoonfal ◽  
V. Jabbari

A composite nanofiltration membrane was developed by a poly(acrylic acid) in situ ultraviolet (UV) graft polymerization process using an ultrafiltration polysulfone membrane as a porous support, by a phase inversion method. SEM images showed that the PSf membranes had numerous finger-like pores. Atomic force microscopy (AFM) showed that the roughness of the surface was reduced by an increase in UV irradiation times. The rejections of sodium chloride and sodium sulfate were moderate and declined with the increase of concentration. We observed that by increasing UV irradiation time and nanofiltration pressure applied, retention of dyes was enhanced and in the most irradiated membrane (M-4 membrane) at 4 bars, color removal with a high rejection of about 99.80% was achieved. It was found that the separation efficiency of dyes in the mixture of salt and dyes decreased with the salt concentration due to a decrease in the Donnan effect. It was also found that by varying the pH, the membrane surface and the dyes' charges are changed, which meant that the membrane surface and dyes had different interactions at various pHs.


2007 ◽  
Vol 121-123 ◽  
pp. 251-254 ◽  
Author(s):  
Zhi Rui Guo ◽  
Y. DuanMu ◽  
Ning Gu

Nanoscaled fibrous aggregates of gold nanoparticles have been synthesized by a simultaneous reduction-oxidation polymerization process using aniline as reducing agent as well as monomer in an ethanol medium. Time-dependent UV-Vis absorption spectroscopy was used to track the formation process of gold nanoparticles. The transmission electron microscopy (TEM) images and Fourier transform infrared (FT-IR) spectrum of the as-preapred products indicate these gold nanoparticles were binded by the oxidation polymerization resultant of aniline.


CrystEngComm ◽  
2014 ◽  
Vol 16 (48) ◽  
pp. 10943-10948 ◽  
Author(s):  
Juan Li ◽  
Jian Yan ◽  
Chengzhan Liu ◽  
Lihong Dong ◽  
Hui Lv ◽  
...  

A ternary composite ZnO–Ag–polypyrrole was synthesized through a fast reaction between zinc acetate and hexamethylenetetramine followed by an in situ surface polymerization process. The sample exhibited a superior catalytic performance in the degradation of methylene blue under both UV irradiation and visible light.


Author(s):  
Boris S. Tanaseichuk ◽  
Margarita K. Pryanichnikova ◽  
Alexey A. Burtasov

Asymmetric conjugate diynes are of considerable interest because of their ability to solid state polymerization to form polymers with an ordered tough polyene structure. The capacity of conjugated diynes to such polymerization is determined by the presence and nature of the substituents in the side chain diynes and the degree of their distance from the diacetylenic fragment. To evaluate the effect of the distance a bulky substituent of conjugate diyne′s fragment for ability of asymmetric diacetylenes ordered solid state polymerization were prepared 4 alkildiinil′s ether of p-hydroxybenzaldehyde with varying degrees of distance diyne′s fragment from the benzene ring.Synthesis of alkildiinil′s esters of p-hydroxybenzaldehyde was carried out in two stages. At the first stage by alkylation of p-hydroxybenzaldehyde of corresponding of toluenesulfonate′s terminal alkynol or ω-bromalkines in the presence of sodium ethoxide was prepared monoalkinil′s ether of p-hydroxybenzaldehyde, in which the terminal triple bond is separated from the phenoxyl′s fragment 1, 2, 3 and 4 methylene′s groups. Use as a alkylating agent of toluenesulfonate′s terminal alkynols, which differ in low volatility compared ω-bromalkines, gives a fairly high (~ 60%) the yield of desired products. At the second stage according to the method of Kadio-Chodkiewich the condensation-3-brompropin-2-ol with the corresponding monoalkinil′s esters of p-hydroxybenzaldehyde were alkildiynil′s ethers of p-hydroxybenzaldehyde, which have a terminal triple bond is separated from the benzene′s ring 1, 2, 3 and 4 methylene′s groups. The effect of the degree of remoteness of the conjugate diyne′s fragment from the bulk p-formilfenoksil′s substituents on these compounds ability to solid state polymerization under UV irradiation was studied by the asymmetric diynes. About the polymerization rate was judged visually by a color change. All investigated diynes exhibited the ability to solid state polymerization. The rate of it was largely dependent of the number of methylene′s fragments, separating p-formilfenoksil′s ring from diyne′s fragment. If the irradiation of diynes containing 3 or 4 methylene′s fragments, color change of almost colorless to dark brown occurred within 5-6 h, then diynes containing 1 or 2 of the methylene′s fragments was required for 24 h. It goes to show that the increase the length of the methylene′s chain, postpones surround p-formilfenoksil′s fragment from a paired diyne′s fragment, eases  the solid state polymerization. However, the absence of the bright color of the polymer characteristic polydiacetylene′s ordered structures indicates that, polymerization was not well-ordered in out case.Thus, the results showed that administration of methylene′s fragments, causing varying degrees of remoteness of the conjugate diyne′s fragment from the bulk p-formilfenoksil′s fragment, has a significant impact on the ability of asymmetric conjugate diynes to solid state polymerization under UV irradiation. The increase in the degree of remoteness promotes their solid state polymerization, those namely the structure of asymmetric diynes determines their behavior in the polymerization process.


2016 ◽  
Vol 18 (3) ◽  
pp. 695-699 ◽  
Author(s):  
Jingyu Wang ◽  
Yonghong Deng ◽  
Yong Qian ◽  
Xueqing Qiu ◽  
Yuan Ren ◽  
...  
Keyword(s):  

One-step irradiation in a mild solvent caused lignin to be partially depolymerized and π–π disaggregated and thus lignin was largely whitened.


2013 ◽  
Vol 34 (8) ◽  
pp. 2451-2454 ◽  
Author(s):  
Hongzhou Lian ◽  
Lianshe Fu ◽  
Paulo S. Andre ◽  
Jun Lin

RSC Advances ◽  
2018 ◽  
Vol 8 (26) ◽  
pp. 14713-14721 ◽  
Author(s):  
K. Nagel ◽  
L. Kaßner ◽  
A. Seifert ◽  
R.-E. Grützner ◽  
G. Cox ◽  
...  

Polyamide 6/silica/polysiloxane composites have been prepared in a one-step process using lactam-substituted silicon monomers.


2018 ◽  
Vol 273 ◽  
pp. 1508-1518 ◽  
Author(s):  
Chao Liang ◽  
Yuanchang Liu ◽  
Chong Liu ◽  
Xia Li ◽  
Li Chen ◽  
...  

2017 ◽  
Vol 726 ◽  
pp. 365-369
Author(s):  
Xia Kong ◽  
Ya Wei Hu ◽  
Wei Pan

Abstract. ZnO nanoparticles with different morphology were synthesized through a one-step and low temperature hydrothermal method with different reaction time. The prepared ZnO nanoparticles have been used as photocatalysts for the degradation of methylene blue (MB) aqueous solution under UV irradiation to study the relationship between the morphology and photocatalytic performance. The phase, crystallographic structure and morphology of synthesised ZnO nanoparticles were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The photocatalytic activity of ZnO nanoparticles were carried out by UV-visible spectroscopy (UV-vis). SEM results showed that different particle sizes and morphologies of flower-like, elliptical-shape and rod-shapes were obtained at 60 °C for 1 h, 4 h, 8 h and 12 h, which promoted photodegradation of methylene blue (MB) aqueous solution under UV light irradiation. Especially, elliptical-shape ZnOnanoparticles with reaction time of 4 h were most efficient, and the degradation rate was up to 98.2% after 20 min UV irradiation.


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