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GMP-quadruplex-based hydrogels stabilized by lanthanide ions

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Science China chemistry 2018年第5期61卷 604-612页

作者： Jin Zhang Xiaoyang Li Xiuping Sun Aixin Song Yebang Tan Jingcheng Hao key laboratory of colloid and interface chemistry Ministry of Education Shandong University

This work describes the gelation behaviors and properties of a biological molecule, guanosine 5′-monophosphate disodium salt(GMP), in the presence of trivalent lanthanide ions. Hydrogels composed of GMP-quadruplexes were prepared by adjusting p H,through which the protonation of phosphate group was controlled to tune the interactions between lanthanide ions and *** the p H region of 2–6, the electrostatic interaction between lanthanide ions and phosphate group is hindered and the cation-dipole interaction acts as the main driving force for the formation of G-quadruplexes. All the hydrogels were found consisting of three-dimensional network of the intertwining one-dimensional nanofibers formed by the stacking G-quartets induced by lanthanide ions. A significant fluorescence enhancement of thioflavin T(Th T), a fluorescent molecule, was found to be triggered by the G-quadruplex structures, for which the rotation of chromophoric groups on Th T molecules were prohibited due to the implant into the G-quadruplex structures.

关键词： G-quadruplex hydrogel hydrogen bonding electrostatic interaction ion-dipole interaction fluorescence enhancement

Phase Behavior and Dielectric Spectroscopy of the Sodium Dodecyl Trioxyethylene Sulfate/n-Butanol/Water System

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Chinese Journal of chemistry 2003年第10期21卷 1290-1296页

作者：魏素香牟建海赵孔双雷建平李干佐 Department of chemistry key laboratory for colloid & interface chemistry of State Education Ministry

The phase diagram of the ternary system of sodium dodecyl trioxyethylene sulfate (SDES)/ n butanol/water is obtained at (30 0±0 1) ℃. There exists a clear, isotropic, and low viscosity L phase, which could be divided into W/O micelle, bi continuous (B.C.) phase and O/W micelle by conductivity measurements. Dielectric Relaxation Spectroscopy (DRS) measurements are applied to investigate microstructure changes of this system. For samples with a fixed weight ratio, SDES/ n butanol=3/7, DRS indicates a structure transition from W/O to O/W micelles via B.C. phase with the increase of water content. For the samples with a fixed weight ratio, SDES/H 2O=4/6, DRS can presents that there exist changes of onefold structure size of W/O micelles as n butanol content increases. The results obtained from DRS and their analyses are in good agreement with those from phase diagram and conductivity measurements.

关键词： phase behavior conductivity dielectric relaxation spectroscopy micelle

Promoted porous Co_3O_4-Al_2O_3 catalysts for ammonia decomposition

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Science China chemistry 2018年第11期61卷 1389-1398页

作者： Zhe-Shan Zhang Xin-Pu Fu Wei-Wei Wang Zhao Jin Qi-Sheng Song Chun-Jiang Jia key laboratory for colloid and interface chemistry Key Laboratory of Special Aggregated Materials School of Chemistry and Chemical Engineering Shandong University

Transition metal catalysts have been considerably used for NH3 decomposition because of the potential application in COx-free H2 generation for fuel cells. However, most transition metal catalysts prepared via traditional synthetic approaches performed the inferior stability due to the agglomeration of active components. Here, we adopted an efficient method, aerosol-assisted self- assembly approach （AASA）, to prepare the optimized cobalt-alumina （C0304-A1203） catalysts. The C0304-A1203 catalysts exhibited excellent catalytic performance in the NH3 decomposition reaction, which can reach 100% conversion at 600 ℃and maintain stable for 72 h at a gaseous hourly space velocity （GHSV） of 18000 cm3 gcat-1 h-1. The catalysts were characterized by various techniques including transmission electron microscope （TEM）, scanning electron microscope （SEM）, nitrogen sorption, temperature-programmed reduction by hydrogen （H2-TPR）, ex-situ/in-situ Raman and ex-situ/in-situ X-ray diffraction （XRD） to obtain the information about the structure and property of the catalysts. H2-TPR and in-situ XRD results show that there is strong interaction between the cobalt and alumina species, which influences the redox properties of the catalysts. It is found that even a low content of alumina （10 at%） is able to stabilize the catalysts due to the adequate dispersion and rational interaction between different components, which ensures the high activity and superior stability of the cobalt-alumina catalysts.

关键词： cobalt-alumina catalyst aerosol-assisted self-assembly approach ammonia decomposition anti-sintering redox prop-erties

Hydrogels formed by L-histidine derivatives with highly selective release for charged dyes

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Chinese Chemical Letters 2018年第8期29卷 1219-1222页

作者： Xiaoyang Li Fanjun Zhang Xiuping Sun Yuanyuan Hu Aixin Song Jingcheng Hao key laboratory of colloid and interface chemistry (Ministry of Education) Shandong University

The amphiphilic derivatives of L-histidine with different alkyl chains, NIPCA, UIPCA, and TIPCA, have been designed and their self-assembly behaviors with citric acid were investigated. All L-histidine derivatives can form hydrogels with citric acid, and exhibit the increasing gelation ability and mechanical strength with the increasing chain length. The gelation ability is considered to be affected by the synergistic effect of electrostatic interaction, hydrogen bonding and hydrophobic interaction. The hydrogels exhibit excellent releasing selectivity for charged dyes in aqueous solution, enlightening people to utilize this kind of hydrogels as intelligent carriers to separate the mixtures of charged dyes.

关键词： Gelation Electrostatic interaction Hydrogen bonding Hydrophobic interaction

Aggregation Behaviour of Cationic Diblock Copolymer （MTAC）10（BA）16： MesoDyn Simulation Study

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Chinese Physics Letters 2007年第2期24卷 411-413页

作者：曹晓荣谭业邦徐桂英 key laboratory of colloid and interface chemistry (Ministry of Education) Shandong University Jinan 250100

The aggregation behaviour of an amphiphilic cationic block copolymer （MTAC）10（BA）16 in aqueous solution is investigated by MesoDyn simulation. Simulation results show that （MTAC）10 （BA）16 can form spherical, irregular and network aggregates with the increasing volume fraction. The time evolution of order parameter shows that the process of aggregate formation can be divided into diffusion control stage and hydrophobic interaction control stage, while the time evolution of energy indicates that the aggregate formation is driven by enthalpy but not entropy. The order parameter of the hydrophobic blocks BA increases with the increasing （MTAC）10（BA）16 concentration, while the time needed for system balance has the contrary trend.

关键词： PHASE-SEPARATION AQUEOUS-SOLUTION SURFACTANTS DYNAMICS DERIVATIVES MIXTURES

CeO_(2-x) modified Ru/γ-Al_(2)O_(3) catalysts for ammonia decomposition reaction

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Journal of Rare Earths 2023年第6期41卷 801-809,I0001页

作者： Qinglu Meng Haoxin Liu Kai Xu Weiwei Wang Chunjiang Jia key laboratory for colloid and interface chemistry Key Laboratory of Special Aggregated MaterialsSchool of Chemistry and Chemical EngineeringShandong UniversityJinan 250100China

Developing high-performance ammonia decomposition catalysts for preparing COx-free hydrogen shows great practical ***,CeO_(2) is used as a promoter to modulate the metal-support interaction to enhance the catalytic performance of Ru/Al_(2)O_(3) catalysts.A series of 1Ru/xCe-10AI(x=0.5,1,or 3)catalysts was prepared by a facile colloidal deposition *** find that the optimized 1 Ru/1Ce-10Al catalyst exhibits excellent activity for the decomposition of ammonia with a very high hydrogen yield of7097 mmolH2/(gRu·min)at 450℃.It is confirmed that Ru species are highly dispersed on the support surface as stable small clusters(~1.3 nm).More importantly,due to the interaction between Ru species and partially reduced CeO_(2-x),the electron density of Ru species is increased,which is beneficial to the high activity of the 1 Ru/xCe-10Al *** work paves a way to construct high-efficiency ammonia decomposition catalysts modified by CeO_(2).

关键词： Ammonia decomposition Ru clusters CeO_(2-x)promoter Metal-support interaction Rare earths

Au/La-CeO_(x) catalyst for CO oxidation:Effect of different atmospheres pretreatment on gold state—Commemorating the 100th anniversary of the birth of Academician Guangxian Xu

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Journal of Rare Earths 2021年第4期39卷 364-373页

作者： Lulu Zhou Shuai Wei Weiwei Wang Zhao Jin Chunjiang Jia key laboratory for colloid and interface chemistry Key Laboratory of Special Aggregated MaterialsSchool of Chemistry and Chemical EngineeringShandong UniversityJinan 250100China

So far,it is still a controversial issue which status of gold species is a better active site for catalyzing CO ***,the influence of the different atmospheres pretreatment(oxidative and reductive)on gold state of Au/La-CeOx(1 wt%gold loading)catalyst during CO oxidation was *** changes of Au species were monitored by combined in situ diffuse reflectance infrared Fourier transform spectroscopy(in situ DRIFTS)and X-ray photoelectron spectroscopy(XPS).For the sample pretreated with oxidative atmosphere,the data show that the initial Au^(3+)is transformed to Au^(δ+)(0key step to lead to higher *** the sample after reductive atmosphere pretreatment,Au^(δ+)is mixed with a small amount of Au^(0)which can be converted to Au^(δ+)with the increase of temperature in ***,the sample always maintains high activity during the ***,the Au®+obtained by reductive pretreatment is more active than the Au^(3+)obtained by oxidative treatment in catalyzing CO oxidation.

关键词： Au/La-CeO_(x)catalyst Pretreatment atmospheres CO oxidation Au^(δ+) Au^(3+) Rare earths

Sequential protocol for C(sp)-H carboxylation with CO_2:KO^tBu-catalyzed C(sp)-H silylation and KO^tBu-mediated carboxylation

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Science China chemistry 2018年第4期61卷 449-456页

作者： Bo Yu Peng Yang Xiang Gao Zhenzhen Yang Yanfei Zhao Hongye Zhang Zhimin Liu Beijing National laboratory for Molecular Sciences Key Laboratory of Colloid Interface and Thermodynamics Institute of ChemistryChinese Academy of Sciences

CO_2 incorporation into C-H bonds is an important and interesting topic. Herein a sequential protocol for C(sp)-H carboxylation by employing a metal-free C-H activation/catalytic silylation reaction in conjunction with KO^tBu-mediated carboxylation with CO_2 was established, in which KO^t Bu catalyzes silylation of terminal alkynes to form alkynylsilanes at low temperature, and simultaneously mediates carboxylation of the alkynesilanes with atmospheric CO_2. Importantly, the carboxylation further promotes the silylation, which makes the whole reaction proceed very rapidly. Moreover, this methodology is simple and scalable, which is characterized by short reaction time, wide substrate scope, excellent functional-group tolerance and mild reaction conditions,affording a range of corresponding propiolic acid products in excellent yields in most cases. In addition, it also allows for a convenient ^(13)C-labeling through the use of ^(13)CO_2.

关键词： CO2 incorporation carboxylation propiolic acid KO^tBu C(sp)-H silylation

Fe- and Co-doped lanthanum oxides catalysts for ammonia decomposition:Structure and catalytic performances

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Journal of Rare Earths 2017年第1期35卷 15-23页

作者： XUN Yanran HE Xinxin YAN Han GAO Ziwang JIN Zhao JIA Chunjiang key laboratory for colloid and interface chemistry Key Laboratory of Special Aggregated Materials School of Chemistry and Chemical Engineering Shan- dong University Jinan 250100 China

In this paper, a series of Fe- and Co-doped lanthanum（hydr）oxides catalysts were prepared by a simple coprecipitationhydrothermal method. The as-prepared catalysts were characterized with various techniques including powder X-ray diffraction（XRD）, N2 adsorption/desorption, inductively coupled plasma（ICP） and transmission electron microscopy（TEM）. The Fe-based catalysts exhibited consecutive phase changes of amorphous Fe Ox→FeLaO3→Fe2N under different stages（as-prepared→calcination→ammonia decomposition reaction）; as for Co-based catalysts, the phase transformation followed a sequence of Co（OH）2→Co3O4→metallic Co. It was revealed that Fe2N and metallic Co were most probably the active crystalline phase respectively for Feand Co-based catalysts in the decomposition of ammonia.

关键词： transitional metal rare earth lanthanum(hydr)oxides composite catalysts ammonia decomposition