检索结果-南通市图书馆

Frontiers of Environmental Science & Engineering 2021年第4期15卷 273-285页

作者： Chenchen Li Lijie Yan Yiming Li Dan Zhang Mutai Bao Limei Dong Key Laboratory of Marine Chemistry Theory and Technology Ministry of EducationOcean University of ChinaQingdao266100China

Removing spilled oil from the water surface is critically important given that oil spill accidents are a common occurrence.In this study,TiO_(2)@palygorskite composite prepared by a simple coprecipitation method was used for oil spill remediation via a dispersion-photodegradation synergy.Diesel could be efficiently dispersed into small oil droplets by TiO_(2)@palygorskite.These dispersed droplets had an average diameter of 20-30µm and exhibited good time stability.The tight adsorption of TiO_(2)@palygorskite on the surface of the droplets was observed in fluorescence and SEM images.As a particulate dispersant,the direct contact of TiO_(2)@palygorskite with oil pollutants effectively enhanced the photodegradation efficiency of TiO_(2)for oil.During the photodegradation process,·O_(2)^(−)and•OH were detected by ESR and radical trapping experiments.The photodegradation efficiency of diesel by TiO_(2)@palygorskite was enhanced by about 5 times compared with pure TiO_(2)under simulated sunlight irradiation.The establishment of this new dispersion-photodegradation synergistic remediation system provides a new direction for the development of marine oil spill remediation.

关键词： palygorskite TiO_(2) Pickering emulsion Oil spill Dispersion Photodegradation

Suspension Polymerization of Methyl Methacrylate Stabilized Solely by palygorskite Nano Fibers

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2014年第2期32卷 123-123,124-129页

作者：黎白钰 Yin-ping Wang Xiao-bin Niu Zai-man Liu The School of Chemical & Biological Engineering Lanzhou Jiaotong University

A kind of fibrous clay, palygorskite （PAL）, was used as the sole stabilizer in suspension polymerization without the using of any other stabilizer usually used, especially polymeric stabilizers. In order to improve the compatibility with the organic monomer, PAL nano fibers were organically modified with silane coupling agent methacryloxypropyltrimethoxysilane （MPS）. Transmission electron microscopy （TEM） and Fourier-transform infrared （FTIR） spectroscopy results show that the hydrolyzed MPS was attached onto PAL surface through Si--O--Si bonds formation without morphology change of PAL. At a loading amount of PAL to monomer as low as 0.36 wt%, effective stabilization could be achieved. After suspension polymerization, spherical poly（methyl methacrylate）（PMMA） particles were obtained. Scanning electron microscopy （SEM） analysis on both the outer surface and the inner cracked surface of the spherical PMMA particles indicates that the PAL particles reside on the surface of the PMMA spheres. The densely stacked PAL together with attached silane coupling agent stabilized the droplets throughout the suspension polymerization.

关键词： palygorskite Attapulgite Clay Poly（methyl methacrylate） Suspension polymerization.

Enhanced adsorptive removal of Cr(VI)in aqueous solution by polyethyleneimine modified palygorskite

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2020年第10期28卷 2650-2657页

作者： Jiahong Wang Tongtong Sun Atif Saleem Yao Chen School of Environmental Science and Engineering Shaanxi University of Science and TechnologyXi'an 710021China Shaanxi Key Laboratory of Green Preparation and Functionalization of Inorganic Materials Xi'an 710021China

Polyethyleneimine(PEI)modified palygorskite(Pal)was used for the adsorption of Cr(VI)in aqueous solution.The absorbent was characterized by Fourier transform infrared spectroscopy(FT-IR)and thermogravimetric analysis(TGA).Characterized results confirmed that the Pal has been successfully modified by PEI.The modification of PEI increased the Cr(VI)adsorption performance of the Pal by the adsorption combined reduction mechanism,and amino groups of the adsorbent play the main role in the enhanced Cr(VI)adsorption.The maximum adsorption capacity was 51.10 mg·g^-1 at pH4.0 and 25°C.The adsorption kinetics of Cr(VI)on the adsorbent conforms to the Langmuir isotherm model.The maximum adsorption occurs at pH3,and then the adsorption capacity of PEI-Pal was decreased with the increase of p H values.The adsorption kinetics of Cr(VI)on PEI-Pal was modeled with pseudo-second-order model.The addition of Cl^-,SO4^2-and PO4^3-reduced the Cr(VI)adsorption by competition with Cr(VI)for the active sites of PEI-Pal.The Cr(VI)saturated PEI-Pal can be regenerated in alkaline solution,and the adsorption capacity can still be maintained at 30.44 mg·g^-1 after 4 cycles.The results demonstrate that PEI-Pal can be used as a potential adsorbent of Cr(VI)in aqueous solutions.

关键词： palygorskite Polyethyleneimine Adsorption Cr(VI)

Preparation of palygorskite-based Phase Change Composites for Thermal Energy Storage and Their Applications in Trombe Walls

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2017年第6期32卷 1306-1317页

作者：施韬 LI Shanshan 张豪 LI Zexin ZHU Min College of Civil Engineering and Architecture Zhejiang University of Technology Hangzhou 310014 China Key Laboratory ofCivil Engineering Structures & Disaster Prevention and Mitigation Technology of Zhejiang Province College of Civil Engineering and Architecture Zhejiang University of Technology Hangzhou 310014 China

palygorskite/paraffin phase-change composites were prepared by the combination of purified palygorskite clay and sliced paraffin. Then, this composite was used in the Trombe wall to improve its energy storage ability. Further, its energy storage ability was compared to that of ordinary concrete wall through contrastive test. The experiments show that palygorskite clay is a type of clay mineral with strong adsorption ability, and the purity of natural palygorskite clay can reach up to 97.1% after certain purification processes. Paraffin is well adsorbed by palygorskite, and the test results show that the optimal adsorption ratio is palygorskite： paraffin = 2：1（mass ratio）. palygorskite/paraffin phase change composites can be obtained by using palygorskite as the adsorbing medium to adsorb paraffin. The composite materials exhibit good heat storage（release） performance, which can store heat with increasing environment temperature and release heat with decreasing temperature. This property not only increases the inertia to environment temperature change, but also promotes the energy migration in different time and space, thus achieving a certain energy-saving effect. The application of palygorskite/paraffin phase change composite materials to the Trombe wall can significantly reduce the fluctuation of indoor temperature and enhance the thermal inertia of indoor environment. From the aspect of energy storage effect, the Trombe wall fabricated using PCMs is significantly superior to the concrete wall with the same thickness.

关键词： phase change materials palygorskite attapulgite trombe wall thermal energy storage paraffin

SAED and HRTEM Investigation of palygorskite

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2008年第2期82卷 385-391页

作者： CHEN Tao WANG Hejing ZHANG Xiaoping ZHENG Nan Institute of Gemology China University of Geosciences Wuhan 430074 Hubei China Key Laboratory of Orogenic Belts and Crustal Evolution （Peking University） Ministry ofEducation of China School of Earth and Space Sciences Peking University Beijing 100871 Electron Microscopy Laboratory School of Physics Peking University Beijing 100871

The microstructure of palygorskite from Longwang Mountain of Xuyu County, Jiangsu Province, was studied by energy dispersive X-ray analysis （EDX）, selected-area electron diffraction （SAED） and high-resolution transmission electron microscopy （HRTEM）. The average composition of the palygorskite studied is （Si7.38A10.62）（A10.96Fe^3＋ 0.62Mg2.86 0.56）Ca0.03K0.06O20（OH）2（OH2）4, which is rich in Mg. Several SAED patterns from a single crystal of palygorskite were obtained with different zone axes. The polymorphs （monoclinic and orthorhombic） are unequivocally distinguished by distant interplanar angles, even though they possess similar sets of d-values. High-resolution images of three principal zones （[010], [100] and [110]） were obtained. The lattice fringes on HRTEM images along [010] have spacings of 0.319 nm. These fringes are interpreted as periodic alterations of two tetrahedral （T） sheets and one octahedral （O） sheet （-TT-O-TT-O-）. We have directly observed trioctahedral and dioctahedral individual palygorskite particles along [100]. They are all presented as dark lines along [001], but the width of dark lines corresponding to trioctahedral crystals （0.913 nm） is twice that of the dioctahedral ones （0.456 nm）. This is because the trans.sites are occupied by cations in trioctahedral palygorskite. The width of dark lines along [110] is 1.024 nm, a bit thinner than the theoretical spacing （1.044 nm）. This is because water molecules quickly leave the structure upon the irradiation by the electron beam.

关键词： HRTEM microstructure palygorskite polymorph SAED

Structures and Properties Characterization of Acrylonitrile-butadiene-styrene /Organo-palygorskite Clay Composites

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2012年第6期27卷 1068-1071页

作者：张哲 CHANG Ying XU Jian WU Zhancui MA Hengchang 雷自强 Key Laboratory of Eco-Environment-Related Polymer Materials Ministry of EducationKey Laboratory of Polymer Materials of Gansu ProvinceCollege of Chemistry and Chemical EngineeringNorthwest Normal University

palygorskite （PGS） and vinyl tris-（2-methoxyethoxy） silane （KH-172） modified palygorskite （OPGS） were used to prepare acrylonitrile-butadiene-styrene （ABS）/clay composites. Thermal stability of the composites was evaluated by using thermogravimetric analysis （TGA）. The morphology of the fractured surface and the degree of dispersion of the clay in the ABS matrix were observed by scanning electron microscopy （SEM）. X-ray diffraction （XRD） analysis results showed the variation of the crystal structure. Measurements of the tensile properties of the ABS/clay composites proved that the ABS/OPGS composited material represented the most excellent tensile property, because of good compatibility and dispersion of ABS with OPGS.

关键词： palygorskite acrylonitrile-butadiene-styrene modification silane coupling agents composites

Solar Photocatalysis of TiO₂ Supported Natural palygorskite Nanofibers Elaborated by a One_Pot Mechanochemical Route

在线全文

学校读者我要写书评

暂无评论

Journal of Minerals and Materials Characterization and Engineering 2022年第3期10卷 254-274页

作者： Lakbita Omar Rhouta Benaissa Goetz Vincent Maury Francis Plantard Gaël Daoudi Lahcen Mohammed VI Polytechnic University (UM6P) Marrakech Morocco IMED_Lab Faculty of Sciences and Technologies Cadi Ayyad University Marrakech Morocco PROcédés Matériaux et Energie Solaire Rambla de la Thermodynamique PROMES_CNRS UPR 8521 Perpignan France CIRIMAT Université de Toulouse Toulouse France Laboratoire de Geoscience et Géoenvironnement Faculté des Sciences et Techniques Guéliz Université Cadi Ayyad Marrakech Morocco

This study reports the successful synthesis of supported TiO2_palygorskite nanocomposites by a one-pot dry mechanochemical route. Indeed, the elaboration procedure involved an in-situ reaction between accessories carbonates present in raw fibrous palygorskite clay and titanyl sulfate (TiOSO4) precursor under variable grinding conditions, essentially ball/solid matter mass ratio and rotation velocity. This yielded after air annealing at 600%C for 1 h to the immobilization of anatase TiO2 nanoparticles (≈8 nm of average size) as evidenced by XRD and TEM analyses. Once the conditions of elaboration were optimized, the photocatalytic properties were evaluated under 3 conditions: artificial UV radiation, artificial solar radiation (UV + visible range) and under dynamic solar illumination taking into account the discontinuities of the solar resource. The results allowed the estimation and comparison of the catalyst’s capabilities and showed its ability to work under natural irradiation. The so developed supported photocatalysts TiO2/palygorskite exhibited a good activity towards the removal of Orange G (OG) dye from aqueous media under artificial UV and natural solar radiations.

关键词： TiO2 palygorskite Mechanochemical Synthesis Nanocomposite Solar Photocatalysis Wastewater Treatment

Distribution of palygorskite in the Lingtai Profile of Chinese Loess Plateau:Its Paleoclimatic Implications

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2008年第5期82卷 967-974页

作者： XIE Qiaoqin CHEN Tianhu CHEN Jun JI Junfeng XU Huifang XU Xiaochun School of Resources and Environment Engineering Hefei University of Technology Hefei Anhui 230009 China Department ofGeoscience Nanjing University Nanjing Jiangsu 210093 China Department of Geology and Geophysics University of Wisconsin Madison W153706 USA

palygorskite is a typical indicator mineral of the arid and strong evaporation environment. Distribution of palygorskite in loess-red clay sequences may act as an important indicator for reconstruction of the paleoenvironment and paleoclimate. In this paper, field emission scanning electron microscope and high-resolution transmission electron microscope observations on the red clay-loess-paleosol of the Renjiapo profile at Lingtai, Gansu Province indicate that palygorskite occurs widely in red clay sequences formed before 3.6 Ma, but no occurrence has been found in eolian sediments since 3.2 Ma. Micromorphological features and microstructure of palygorskite show that it is an autogenic mineral formed during pedogenesis, and transformed from iilite-montmorilionite under the pore water action. In the Lingtai profile, the disappearance horizon of palygorskite is consistent with those of increasing magnetic susceptibility, dust flux and depositional rate. The distribution of palygorskite in the profile indicates that the interval of around 3.6 Ma was an important transformation period of the East Asian paleomonsoon, when changes took place in the East Asia paleoclimate pattern, i.e. a high-frequency strong fluctuation alternative evolution of the environment. Therefore, palygorskite is a key indicator mineral of the East Asian paleomonsoon evolution of that time.

关键词： palygorskite paleoclimate Lingtai loess-red clay sequence

Dissolution behavior and dissolution mechanism of palygorskite in HCl solution

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2004年第3期 43-48页

作者： CAI Yuanfeng and XUE Jiyue*(Department of Earth Sciences, Nanjing University, Nanjing 210093, China)

The 1 mol/L, 3 mol/L and 5 mol/L HCl solutions were employed to leach two palygorskites with different trioctahedral contents in their crystal structure for different period of time. The results of the dissolution experiments show that the dissolution process could be divided into three steps, and that this dissolution behavior can be attributed to its higher Mg 2+ content, and is restricted by the extraction behavior of Si 4+ . The preferential extraction for Mg 2+ promotes the extraction behavior of Si 4+ from Si O framework. Because the Si 4+ in the form of amorphous SiO 2 is adsorbed onto the surface of palygorskite fibre, the reaction between palygorskite and acid is obstructed. With the elapsing of time, or the increasing of the acid concentration, the amorphous SiO 2 flocculates, and then the channels of chemical reaction are reopened. The ratio value of Mg 2+ /(Fe 3+ +Al 3+ ) in leaching solution tends to a fixed value, showing that the acid attacks not only the surface but also the structural channels. There are no obvious three steps observed during the acid attack on the palygorskite with a lower trioctahedral content. The differential behavior for two palygorskites is discussed.

关键词： palygorskite acid leaching dissolution mechanism Anhui Mingguang Guanshan.

Iron-rich palygorskite: A potential clay material for contaminated environment remediation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Geochimica 2006年第S1期 109-110页

作者： Zhen LI1, Lin YIN1,2, Kun HE1 1 Department of Earth Sciences, Nanjing University, Nanjing 210093, China 2 Research Center of Engineering Technical of Attapulgite, Jiangsu Province