for Journals by Title or ISSN
for Articles by Keywords
help
  Subjects -> EARTH SCIENCES (Total: 603 journals)
    - EARTH SCIENCES (447 journals)
    - GEOLOGY (67 journals)
    - GEOPHYSICS (27 journals)
    - HYDROLOGY (17 journals)
    - OCEANOGRAPHY (45 journals)

EARTH SCIENCES (447 journals)                  1 2 3 4 5 | Last

Acta Geodaetica et Geophysica     Hybrid Journal   (Followers: 1)
Acta Geodaetica et Geophysica Hungarica     Full-text available via subscription   (Followers: 2)
Acta Geophysica     Hybrid Journal   (Followers: 7)
Acta Geotechnica     Hybrid Journal   (Followers: 8)
Acta Meteorologica Sinica     Hybrid Journal   (Followers: 2)
Advances in High Energy Physics     Open Access   (Followers: 11)
Advances In Physics     Hybrid Journal   (Followers: 7)
Aeolian Research     Hybrid Journal   (Followers: 2)
African Journal of Aquatic Science     Hybrid Journal   (Followers: 13)
Algological Studies     Full-text available via subscription   (Followers: 2)
Alpine Botany     Hybrid Journal   (Followers: 4)
AMBIO     Hybrid Journal   (Followers: 12)
Anales del Instituto de la Patagonia     Open Access   (Followers: 2)
Andean geology     Open Access   (Followers: 5)
Annales Henri Poincaré     Hybrid Journal   (Followers: 1)
Annales UMCS, Geographia, Geologia, Mineralogia et Petrographia     Open Access   (Followers: 1)
Annals of Geophysics     Full-text available via subscription   (Followers: 9)
Annals of GIS     Hybrid Journal   (Followers: 16)
Annals of Glaciology     Full-text available via subscription  
Annual Review of Marine Science     Full-text available via subscription   (Followers: 9)
Anthropocene Review     Hybrid Journal   (Followers: 1)
Applied Clay Science     Hybrid Journal   (Followers: 2)
Applied Geochemistry     Hybrid Journal   (Followers: 6)
Applied Geomatics     Hybrid Journal   (Followers: 7)
Applied Geophysics     Hybrid Journal   (Followers: 6)
Applied Ocean Research     Hybrid Journal   (Followers: 6)
Applied Petrochemical Research     Open Access   (Followers: 3)
Applied Remote Sensing Journal     Open Access   (Followers: 9)
Aquatic Conservation Marine and Freshwater Ecosystems     Hybrid Journal   (Followers: 21)
Arctic, Antarctic, and Alpine Research     Full-text available via subscription   (Followers: 7)
Artificial Satellites     Open Access   (Followers: 15)
Asia-Pacific Journal of Atmospheric Sciences     Hybrid Journal   (Followers: 2)
Asian Journal of Earth Sciences     Open Access   (Followers: 17)
Atlantic Geology : Journal of the Atlantic Geoscience Society / Atlantic Geology : revue de la Société Géoscientifique de l'Atlantique     Full-text available via subscription   (Followers: 3)
Atmosphere-Ocean     Full-text available via subscription   (Followers: 5)
Atmospheric and Climate Sciences     Open Access   (Followers: 15)
Australian Journal of Earth Sciences: An International Geoscience Journal of the Geological Society of Australia     Hybrid Journal   (Followers: 11)
Boletim de Ciências Geodésicas     Open Access  
Boreas: An International Journal of Quaternary Research     Hybrid Journal   (Followers: 9)
Bragantia     Open Access   (Followers: 2)
Bulletin of Earthquake Engineering     Hybrid Journal   (Followers: 10)
Bulletin of Geosciences     Open Access   (Followers: 8)
Bulletin of Marine Science     Full-text available via subscription   (Followers: 13)
Bulletin of the Lebedev Physics Institute     Hybrid Journal   (Followers: 1)
Bulletin of the Seismological Society of America     Full-text available via subscription   (Followers: 17)
Bulletin of Volcanology     Hybrid Journal   (Followers: 13)
Canadian Journal of Plant Science     Full-text available via subscription   (Followers: 12)
Canadian Mineralogist     Full-text available via subscription   (Followers: 1)
Canadian Water Resources Journal     Hybrid Journal   (Followers: 20)
Carbonates and Evaporites     Hybrid Journal   (Followers: 4)
CATENA     Hybrid Journal   (Followers: 3)
Central European Journal of Geosciences     Hybrid Journal   (Followers: 5)
Central European Journal of Physics     Hybrid Journal   (Followers: 1)
Chemical Geology     Hybrid Journal   (Followers: 9)
Chemie der Erde - Geochemistry     Hybrid Journal   (Followers: 3)
Chinese Geographical Science     Hybrid Journal   (Followers: 3)
Chinese Journal of Geochemistry     Hybrid Journal   (Followers: 2)
Chinese Journal of Oceanology and Limnology     Hybrid Journal   (Followers: 3)
Ciencia del suelo     Open Access  
Climate and Development     Hybrid Journal   (Followers: 11)
Coastal Management     Hybrid Journal   (Followers: 18)
Comptes Rendus Geoscience     Full-text available via subscription   (Followers: 5)
Computational Geosciences     Hybrid Journal   (Followers: 11)
Computational Mathematics and Mathematical Physics     Hybrid Journal   (Followers: 1)
Computers and Geotechnics     Hybrid Journal   (Followers: 5)
Contemporary Trends in Geoscience     Open Access  
Continental Journal of Earth Sciences     Open Access   (Followers: 2)
Continental Shelf Research     Hybrid Journal   (Followers: 8)
Contributions to Mineralogy and Petrology     Hybrid Journal   (Followers: 7)
Contributions to Plasma Physics     Hybrid Journal   (Followers: 2)
Coral Reefs     Hybrid Journal   (Followers: 18)
Cretaceous Research     Hybrid Journal   (Followers: 4)
Cybergeo : European Journal of Geography     Open Access   (Followers: 4)
Developments in Geotectonics     Full-text available via subscription   (Followers: 2)
Developments in Quaternary Science     Full-text available via subscription   (Followers: 3)
Développement durable et territoires     Open Access   (Followers: 2)
Diatom Research     Hybrid Journal  
Doklady Physics     Hybrid Journal   (Followers: 1)
Dynamics of Atmospheres and Oceans     Hybrid Journal   (Followers: 3)
E3S Web of Conferences     Open Access  
Earth and Planetary Science Letters     Hybrid Journal   (Followers: 195)
Earth Interactions     Full-text available via subscription   (Followers: 8)
Earth Science Research     Open Access   (Followers: 7)
Earth Surface Dynamics (ESurf)     Open Access   (Followers: 1)
Earth Surface Processes and Landforms     Hybrid Journal   (Followers: 11)
Earth System Dynamics     Open Access   (Followers: 5)
Earth System Dynamics Discussions     Open Access   (Followers: 4)
Earth's Future     Open Access   (Followers: 1)
Earth, Planets and Space     Open Access   (Followers: 1)
Earthquake Engineering and Engineering Vibration     Hybrid Journal   (Followers: 7)
Earthquake Science     Hybrid Journal   (Followers: 9)
Earthquake Spectra     Full-text available via subscription   (Followers: 12)
Ecohydrology     Hybrid Journal   (Followers: 11)
Electromagnetics     Hybrid Journal   (Followers: 1)
Energy Efficiency     Hybrid Journal   (Followers: 11)
Energy Exploration & Exploitation     Full-text available via subscription   (Followers: 4)
Environmental Earth Sciences     Hybrid Journal   (Followers: 10)
Environmental Geology     Hybrid Journal   (Followers: 11)
Environmental Geosciences     Full-text available via subscription   (Followers: 4)
Environmental Geotechnics     Open Access  

        1 2 3 4 5 | Last

Journal Cover Applied Clay Science
   [4 followers]  Follow    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 0169-1317
     Published by Elsevier Homepage  [2575 journals]   [SJR: 0.999]   [H-I: 63]
  • In-situ FTIR analyses of bentonite under high-pressure
    • Abstract: Publication date: January 2011
      Source:Applied Clay Science, Volume 51, Issues 1–2
      Author(s): Frederico Gil Alabarse , Rommulo Vieira Conceição , Naira Maria Balzaretti , Flávia Schenato , Ana Maria Xavier
      The stability of bentonite is of particular interest for containment barriers in nuclear waste disposal facilities. However, very little is known about the stability of montmorillonite (the major component of bentonite) under high-pressure (HP) conditions. The objective of this work is to investigate the stability of montmorillonite under HP conditions, using a sample of bentonite in which the major component is a dioctahedral calcium montmorillonite. This montmorillonite was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray fluorescence (XRF), specific surface area (SA), thermogravimetric analysis (TGA) and differential thermal analysis (DTA). HP experiments up to 7.7GPa at room temperature (RT) were performed using toroidal chambers (TC). The samples were characterized by XRD after the HP processing. In-situ FTIR analyses were performed in the samples inside a diamond anvil cell (DAC) up to 8GPa (dispersed in KBr) and up to 13GPa (pure bentonite). In-situ FTIR measurements inside the DAC showed that montmorillonite was stable despite a reversible deformation in the Si–O bond and did not lose water up to 13GPa. XRD analysis of the samples processed at 8GPa at RT inside the TC showed no marked modification in the (001) reflections and b-parameter (060) reflections of montmorillonite induced by high pressure. The obtained results indicated that montmorillonite remained stable under high pressure conditions.
      Highlights ► The montmorillonite structure is stable up to 8GPa. ► The interlayer H2O of the montmorillonite transforms into ice under high pressure. ► The montmorillonite structure does not loose H2O under high pressure. ► The energy of the Si-O bonding changes reversibly under high pressure.

      PubDate: 2014-12-17T17:45:09Z
       
  • Cobalt-modified Brazilian bentonites: Preparation, characterisation, and
           thermal stability
    • Abstract: Publication date: January 2011
      Source:Applied Clay Science, Volume 51, Issues 1–2
      Author(s): L.F. Cótica , V.F. Freitas , I.A. Santos , M. Barabach , F.J. Anaissi , R.Y. Miyahara , P.W.C. Sarvezuk
      The thermal effect on the phase evolution and crystallinity of raw and cobalt-modified Brazilian bentonites was investigated. The modified bentonites were prepared dispersing the bentonite particles in Co2+ hydroxide gels. The samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, thermal analyses and energy dispersive X-ray spectroscopy. An endothermic peak around 900°C indicated the formation of olivine. A test with benzyl alcohol confirmed the catalytic activity as acidic catalyst for alcohol oxidation.
      Highlights ► A modification of Brazilian bentonites through the addition of a cobalt gel, was proposed. ► Modified-bentonites are thermal stables until 600°C. ► Cobalt-bentonites presented catalytic activity as acid catalyst in alcohol oxidation reactions.

      PubDate: 2014-12-17T17:45:09Z
       
  • Raw halloysite as reusable heterogeneous catalyst for esterification of
           lauric acid
    • Abstract: Publication date: January 2011
      Source:Applied Clay Science, Volume 51, Issues 1–2
      Author(s): Leandro Zatta , José Eduardo Ferreira da Costa Gardolinski , Fernando Wypych
      The methylic and ethylic esterifications of lauric acid were investigated using raw halloysite as a catalyst, in heterogeneous media. The reactions were conducted with different molar ratios (alcohol:lauric acid) and proportions of catalyst, at 160°C for 2h in a pressurized steel reactor. Halloysite produced lauric acid conversion of 95.02% and 87.11% for the methylic and ethylic esterifications, respectively. These results were better than those obtained from thermal conversion (75.61% and 59.86% for methanol and ethanol, respectively). After four consecutive reaction cycles, halloysite was recovered and could be reused after washing and drying. The results showed that halloysite is a promising inexpensive and reusable material for esterification reactions involving fatty acids.
      Graphical abstract image Highlights Methylic esterification of lauric acid using raw halloysite as catalyst. a, b and c represent different molar ratios (methanol:lauric acid) and zero catalyst content represent the thermal conversion. Reactions conditions: 160°C for 2h. ►Raw halloysite was used on the (m)ethanolic esterification reactions of lauric acid. ►The catalytic activity was demonstrated by the higher reaction yields. ►The catalyst recovery and reuse was attested with four consecutive reaction cycles. ►These results show the use of inexpensive catalysts to produce fatty acid esters.

      PubDate: 2014-12-17T17:45:09Z
       
  • Catalysts based on clay and iron oxide for oxidation of toluene
    • Abstract: Publication date: February 2011
      Source:Applied Clay Science, Volume 51, Issue 3
      Author(s): Francisco G.E. Nogueira , João H. Lopes , Adilson C. Silva , Rochel M. Lago , Jose D. Fabris , Luiz C.A. Oliveira
      Two samples of heterogeneous catalysts were prepared by impregnating a raw-clay, a montmorillonite-rich material, with iron oxides, in order to be used in oxidative reactions of toluene. The starting clay-sample was collected from a pedon in the region of San Juan, Argentina. All catalysts were characterized with X-ray powder diffraction (XRD), infrared spectroscopy, temperature programmed reduction (TPR), scanning electron microscopy with energy dispersive X-ray analysis (SEM/EDS), and specific surface area measurements. After impregnating the raw clay material with iron oxides, there was a collapse of basal plane spacing and an increase in surface area, from 17 to 62m2 g−1 of montmorillonite. The TPR, EDS, and XRD results evidenced that the dispersion of iron-containing species depended on how the impregnation was made. The catalyst with higher exposure to iron oxides on sample preparation presented a higher catalytic activity on toluene oxidation.


      PubDate: 2014-12-17T17:45:09Z
       
  • Measuring the plasticity of clays: A review
    • Abstract: Publication date: January 2011
      Source:Applied Clay Science, Volume 51, Issues 1–2
      Author(s): F.A. Andrade , H.A. Al-Qureshi , D. Hotza
      Plasticity is the outstanding property of clay–water systems. It is the property a substance has when deformed continuously under a finite force. When the force is removed or reduced, the shape is maintained. Mineralogical composition, particle size distribution, organic substances and additives can affect the plasticity of clays. Several measuring techniques and devices were proposed to determine the optimal water content in a clay body required to allow this body to be plastically deformed by shaping. In this review, methods of evaluating the plasticity of clay–water systems are presented. Despite the advance in the theory of the plasticity and the methods of measurement, a common procedure for all types of materials does not exist. The most important methods are those that simulate the conditions of real processing.
      Highlights ► Plasticity is related to deforming a substance continuously under a finite force. ► Composition, particle size, organic matter and additives may affect clay plasticity. ► Several techniques are used to determine the optimal water content of clays. ► Methods for evaluating the plasticity of water-clay systems were reviewed. ► A consolidated method for measuring clay plasticity still does not exist.

      PubDate: 2014-12-17T17:45:09Z
       
  • Comparative study between catalysts for esterification prepared from
           kaolins
    • Abstract: Publication date: February 2011
      Source:Applied Clay Science, Volume 51, Issue 3
      Author(s): Luís Adriano S. do Nascimento , Rômulo S. Angélica , Carlos E.F. da Costa , José R. Zamian , Geraldo N. da Rocha Filho
      The esterification of free fatty acids (FFA) is an alternative for the production of biodiesel from oils with high concentrations of FFA. In this paper, catalysts for the esterification of oleic acid with methanol were prepared from two Amazon kaolins (Century and flint) and two standard kaolins (KGa-1b and KGa-2) that were thermally treated at 950°C and leached with 4M sulfuric acid solutions. The activated metakaolin samples were characterized by X-ray diffraction, scanning electron microscopy, N2 adsorption–desorption and pyridine adsorption studies using TG/DTG and FTIR analysis. The leached metakaolin prepared from Century showed the lowest Al content, the highest number of acidic sites (250.5μmolPy/g) and offered larger conversion values. The influences of reaction parameters, such as temperature and time, were also investigated. Based on the catalytic results, kaolin was found to be a promising raw material for the production of new solid acid catalysts for the esterification of FFA. In particular, Amazonian flint kaolin, previously considered unusable for biofuel, was found to be amenable to production.
      Graphical abstract image Highlights ► The well-ordered kaolins were more effectively leached. ► Activated metakaolins presented a considerable increase in surface area. ► A correlation with Al content and acidity for each prepared sample. ► Leached metakaolins studied showed catalytic activity for the esterification. ► Kaolin can be a raw material for the production of catalysts for the esterification.

      PubDate: 2014-12-17T17:45:09Z
       
  • Bentonite functionalized with propyl sulfonic acid groups used as catalyst
           in esterification reactions
    • Abstract: Publication date: February 2011
      Source:Applied Clay Science, Volume 51, Issue 3
      Author(s): D.S. Moraes , R.S. Angélica , C.E.F. Costa , G.N. Rocha Filho , J.R. Zamian
      The main objective of this work is the functionalization of bentonite from the Amazon (region) by the grafting of propyl sulfonic acid groups to catalyze the esterification reaction of acetic acid and 1-propanol. Functionalization was accomplished by anchoring, oxidation and acid activation of (3-mercaptopropyl)trimethoxysilane, (MTPS). The procedure gave acid properties to the raw bentonite. This material, acting as a catalyst, increased the reaction speed and improved the yield by about 12% compared to the uncatalyzed reaction. The functionalized bentonite was characterized by XRD, TG/DTA, FTIR, N2 adsorption/desorption at 77K and XRF, and the surface acidity was determined by titration.
      Highlights ► Bentonite used as catalyst in esterification reactions. ► Functionalization of bentonite from Amazon region. ► Bentonite used as catalyst in esterification reactions. ► Functionalization of bentonite from Amazon region.

      PubDate: 2014-12-17T17:45:09Z
       
  • Experimental study on anti-seepage grout made of leachate contaminated
           clay in landfill
    • Abstract: Publication date: August 2013
      Source:Applied Clay Science, Volumes 80–81
      Author(s): Qiang Xue , Jiang-shan Li , Lei Liu
      Leachate-contaminated clay was used as the base material, where cement and the self-developed clay curing agent were added to form an anti-seepage grout that can repair the leachate-contaminated clay in landfills, exhibit low permeability, and retard pollutants in the leachate. The effect of grout formula on the concentration of leaching pollutants, concretion rate, compressive strength, and permeability coefficient of concretion bodies was studied through a series of laboratory experiments. The efficiency of concretion bodies in retarding the leachate pollutants was investigated through a permeability test. The results indicated that the pollutants in the leachate-contaminated clay were controlled effectively. At 20% cement, 2% clay curing agent, and 1:1 water–soil ratio, the permeability coefficient of the concretion bodies after 7days is ~10−7 cm/s, with >1 concretion rate and >1.2MPa unconfined compressive strength. In addition, the concretion bodies reached >85% retardation rate for COD in the leachate and >99.8% for NH3-N (including heavy metals such as Pb and Cd, among others). The retardation rate of the concretion bodies for the heavy metals is proportional to the ionic radius. As the cement content increased (clay curing agent=10% cement), the concretion rate and permeability of the concretion bodies decreased, whereas its compressive strength increased.


      PubDate: 2014-12-17T17:45:09Z
       
  • Preparation and characterisation of calcined Mg/Al hydrotalcites
           impregnated with alkaline nitrate and their activities in the combustion
           of particulate matter
    • Abstract: Publication date: August 2013
      Source:Applied Clay Science, Volumes 80–81
      Author(s): Nora A. Comelli , María L. Ruiz , Nora A. Merino , Ileana D. Lick , E. Rodríguez-Castellón , A. Jiménez-López , Marta I. Ponzi
      The effect of incorporating alkaline nitrates in hydrotalcites for use in the combustion of particulate matter from diesel emissions has been studied. The catalysts were characterised by X-ray diffraction (XRD), N2 adsorption, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), elemental analysis (EA), atomic absorption spectrophotometry (AAS) temperature programmed reduction (TPR) and Fourier transform infrared spectroscopy (FTIR). Activity measurements were carried out using a thermobalance in air and using a fixed-bed reactor with a NO/O2 flow. The observed activities decreased in the following order: HTMgAlcCs>HTMgAlcK>HTMgAlcLi>HTMgAlc.
      Graphical abstract image

      PubDate: 2014-12-17T17:45:09Z
       
  • Refinement of industrial kaolin by microbial removal of iron-bearing
           impurities
    • Abstract: Publication date: December 2013
      Source:Applied Clay Science, Volume 86
      Author(s): Asfaw Zegeye , Sani Yahaya , Claire I. Fialips , Maggie L. White , Neil D. Gray , David A.C. Manning
      The commercial value of kaolin raw materials is greatly affected by the presence and content of iron-bearing impurities, which can have a detrimental effect on the whiteness and refractoriness of manufactured products. Because of the high cost and environmental impact of techniques currently used to remove these impurities, some effort is now targeted toward the development of alternative methods, such as biological processes. This paper reports a series of anaerobic microcosm experiments conducted to evaluate the suitability of iron-respiring bacteria (IRB) of the Shewanella species (S. alga BrY, S. oneidensis MR-1, S. putrefaciens CN32, and S. putrefaciens CIP 8040), in bioleaching iron-bearing impurities from raw kaolin. All tested bacterial strains were able to reduce and leach ferric iron present in the kaolin, thereby substantially improving its color properties. Among the tested bacteria, S. putrefaciens CIP8040 produced the greatest improvements, with increases in ISO brightness and whiteness from 74% to 79% and from 54% to 66%, respectively, in 5days at 30°C. Neither secondary mineral nor crystal-chemical alteration of the kaolinite was observed by X-ray diffraction and infrared spectroscopy. Observations of the biotreated kaolins by scanning electron microscopy showed that the original hexagonal shape of the clay particles became less regular. Further research and development should now focus on optimising the rate and extent of the bioleaching process before its application at a larger pilot or industrial scale. In particular, further studies should evaluate the environmental and economical benefits compared to currently used approaches, such as the chemical bleaching with sodium hydrosulfite.


      PubDate: 2014-12-17T17:45:09Z
       
  • Microfabric change of electro-osmotic stabilized bentonite
    • Abstract: Publication date: November 2014
      Source:Applied Clay Science, Volume 101
      Author(s): Hui Wu , Liming Hu
      Electro-osmotic stabilization has long been studied as a soft soil improvement technique, while the influence of an applied electrical field on the soil microfabric and minerals is always ignored. In this study, three laboratory experiments were conducted on sodium bentonite using copper, iron and graphite electrodes to investigate the microfabric and chemical composition change before and after electro-osmotic stabilization. The soil samples near the anode were identified using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX). The microfabric of the sodium bentonite changed from flocculated fabric to aggregated fabric after electro-osmotic stabilization. Regular calcium sulfate tubes were generated near the copper and iron anodes. EDX tests showed that the content of sodium near the anode decreased, while the copper, iron and calcium presented substantial increase, indicating that the sodium ions were substituted by copper, iron, and calcium ions in copper, iron and graphite experiments respectively. The change of microfabric and the ion exchange reactions between sodium, copper, iron and calcium ions are the main reasons for the significant decrease of the plasticity index and free swelling ratio.


      PubDate: 2014-12-17T17:45:09Z
       
  • Promoting effect of cerium on the characteristic and catalytic activity of
           Al, Zr, and Al–Zr pillared clay
    • Abstract: Publication date: February 2014
      Source:Applied Clay Science, Volumes 88–89
      Author(s): S. Mnasri-Ghnimi , N. Frini-Srasra
      A series of pillared interlayered clays (PILCs) including Al-, Zr- and Al–Zr-PILC have been prepared and characterized by X-ray diffraction, elemental analyses, N2 adsorption, cationic exchange capacity and IR measurements after n-butylamine adsorption. Cerium introduced in the Zr4+ and/or Al3+ intercalated solution allows for an improvement of the stability and crystallinity of PILC and creates pillared clays with new properties. The resulting materials were used for the synthesis of 1,3-dioxolane. The addition of cerium has a major influence in this reaction.


      PubDate: 2014-12-17T17:45:09Z
       
  • The effect of organoclay addition on the properties of an acrylate based,
           thermally activated shape memory polymer
    • Abstract: Publication date: December 2014
      Source:Applied Clay Science, Volume 102
      Author(s): Michael J. Barwood , Chris Breen , Francis Clegg , Carol L. Hammond
      Shape Memory Polymers (SMPs) exhibit the intriguing ability to change back from an intermediate, deformed shape back to their original, permanent shape. In this contribution a systematic series of t-butylacrylate-co-poly(ethyleneglycol) dimethacrylate (tBA-co-PEGDMA) polymers have been synthesised and characterised prior to incorporation of organoclay. Increasing the poly(ethyleneglycol) dimethacrylate (PEGDMA) content in increments of 10% increased the storage modulus from 2005 to 2250MPa, reduced the glass transition temperature from +41 to −26°C and reduced the intensity of the associated tan δ peak. The tBA-co-PEGDMA crosslinked networks displayed useful shape memory properties up to PEGDMA contents of 40%. Above this PEGDMA percentage the materials were prone to fracture and too brittle for a realistic assessment of their shape memory capability. The system containing 90% t-butylacrylate (tBA) and 10% PEGDMA was selected as the host matrix to investigate how the incorporation of 1 to 5mass% of a benzyl tallow dimethylammonium-exchanged bentonite (BTDB) influenced the shape memory properties. X-ray diffraction data confirmed that BTDB formed a microcomposite in the selected matrix and exerted no influence on the storage modulus, rubbery modulus, glass transition temperature, Tg , or the shape or intensity of the tan δ peak of the host matrix. Therefore, it was anticipated that the presence of BTDB would have no effect, positive or negative, nor on the shape memory properties of the host matrix. However, it was found that the incorporation of clay, especially at the 1mass% level, significantly accelerated the speed, compared with the clay-free SMP, at which the microcomposite returned to the original, permanent shape. This accelerated return to the permanent shape was also observed when the microcomposite was coated onto a 100μm PET film.
      Graphical abstract image

      PubDate: 2014-11-10T13:52:23Z
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2014