The influence of interlayer interactions on the mechanical properties of polymeric nanocomposites J. Serb. Chem. Soc. 80 (11) 1449–1459 (2015) UDC 678.017+66.017:620.3:539.196:539.3 JSCS–4810 Original scientific paper 1449 The influence of interlayer interactions on the mechanical properties of polymeric nanocomposites MEHRDAD JABBARZADEH1* and AMIR REZA GOLKARIAN2 1Department of Mechanical Engineering, Mashhad Branch, Islamic Azad University, Mashhad, Iran and 2Department of Mechanical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran (Received 25 October 2014, revised 10 March, accepted 18 June 2015) Abstract: In this study, the influence of the type of interlayer interactions on the elastic modules of multilayer graphene sheets (GS) and nanocomposites was investigated. The modeling and investigation of mechanical properties of gra- phite layers were performed using the molecular mechanics (MM) method. Initially, for improving the model and decreasing the amount of computations, three types of elements, i.e., a beam, a linear spring and a nonlinear spring, were used. Continuing, the mechanical properties of multilayers and nanocom- posites were compared using three types of interlayer interactions. Initially, a nonlinear spring defined by the Leonard Jones potential was used to define the interlayer interactions (ordinary case). Then, a linear spring with a certain stiff- ness, to obtain an equal linear spring and to investigate the ultimate capacity of interlayer interactions in the translation of force, by increasing the stiffness of linear springs, was employed (chemical change). Then, by omitting all Van der Waals interactions and the creation of defects in the graphite layers, covalent interlayer interactions (using the Morse potential) were created. Finally, Van der Waals and covalent interlayer interactions were created spontaneously to study the properties of multilayers and nanocomposites (functionalization). The results were compared with other available literature data in order to validate the modeling. Keywords: structural mechanics approach; graphene sheet; elastic modules; vacancy defect; functionalization. INTRODUCTION Graphene sheets (GS) and carbon nanotubes (CNT) have attracted the attention of many researchers and scientists due to their wonderful properties and abundant applications in industry, medicine, martial science and other fields.1–6 Besides their unique mechanical, thermal and electrical properties, their signi- ficant capabilities in other fields have attracted further attention. Among these * Corresponding author. E-mail: jabbarzadeh@mshdiau.ac.ir doi: 10.2298/JSC141025054J 1450 JABBARZADEH and GOLKARIAN properties, their potential to be used as a reinforcement agent in polymeric com- posites and producing nanocomposites with exclusive properties could be men- tioned. High tensile strength beside the lightening and high flexibility of these products is one of their extraordinary mechanical properties that make them unique. Besides the mentioned benefits, weak interlayer interactions, which per- suade researchers to demonstrate the functionalization idea or chemical changes,7–12 should be noticed. Modeling approaches for these nanomaterials are needed, due to their small scales and expensive equipment in this field. One of the most attractive methods in this field is the molecular mechanic (MM) method, which was introduced for the first time by Li and Chou13 who used linear beam elements to simulate CNTs. Subsequently, many researchers devoted their time to improving this field by working on the type and quality of the employed elements. Among the studies performed in this field, one by Meo and Rossi,14 who introduced spring elements as a suitable replacement for beam elements, could be mentioned. Afterwards, Georgantzinos et al.15 presented the idea of using fully nonlinear spring-based models, which were then improved further by other researchers.16–20 To date, nonlinear spring elements were commonly used to simulate inter- layer interactions in nanocomposites.21–23 Rafiee et al.24 studied the idea of functionalization of CNT nanocomposites using linear beam elements (intro- duced by the AMBER potential) as covalent interlayer interactions and reported that this action decreased the elastic modulus of CNTs and reinforced nanocom- posites. The focus of this study was the important problem that the connector between the base material and the reinforcement (CNT) agent are weak Van der Waals interactions, which cannot translate the maximum power of the reinforce- ment to the base. Therefore, in this study, the effect of using different types of interlayer inter- actions was investigated. The most important goals were the calculation of the maximum limit of load transferring and the study of the influence of different types of functionalization (introduced by many researchers).7–12 The most important objectives investigated were: – The influence of different types of mechanical elements used to simulate monolayer GS. – The influence of four different types of interlayer interactions on the mech- anical properties of multilayer GSs and nanocomposites, i.e.: a) van der Waals interlayer interactions using nonlinear spring elements defined by the Leonard– –Jones potential (ordinary case), b) linear spring elements, whose the stiffness of which increased at each step to obtain the ultimate value of translating force (chemical change), c) covalent interlayer interaction using a linear spring element defined by the Morse potential energy and d) a combination of Van der Waals and covalent bonds. INTERLAYER INTERACTIONS IN POLYMERIC NANOCOMPOSITES 1451 – A comparison between the reinforcing effect of monolayer and multilayer GSs in nanocomposites. CONSIDERED MODELS Considered models, theoretical background and calculations are described in Supple- mentary material to this paper. RESULTS AND DISCUSSION Monolayer GS The results related to the elastic module of a monolayer GS for different types of mechanical elements are given in Table I. With change in the mech- anical element from linear beam to linear spring, the influence of the defined cross section area could be obtained. By replacing a nonlinear spring with a linear spring, the influence of the definition of the nonlinear behavior for the employed elements could be computed. It was observed that by a replacing a linear beam with a linear spring, the elastic module in model I increased by 11 % and in model II increased by 17 %. This shows that by assuming a cross section area for the element, a significant change was observed in the elastic module. In addition, in this step, the time of the computations for both cases was the same. To continue, by replacing a nonlinear spring with a linear spring, the elastic module of both models increased by about 3 %. This showed that by defining nonlinear behavior for the elements, the results did not show significant changes but the time of the computations was very long, which further increased on inc- reasing the dimensions of the sheets. Therefore, a linear spring element could be introduced as a suitable element to simulate interatomic interactions of GSs, because they make less error and require shorter computation times. TABLE I. Variation of the elastic module of a GS in dependence on the type of the mech- anical element Elastic module, TPa Type of the mechanical element Model I: 1.096 Linear beam Model II: 1.078 Lit.25: 1.025 Model I: 1.217 Linear spring Model II: 1.269 Lit.26: 1.367 Model I: 1.255 Nonlinear spring Model II: 1.308 Lit.18: 1.245 Double-layer GSs Interlayer interaction: type I. GS used at this step is perfect and its elastic module is about 1.2175 TPa. By defining a second layer at a distance of 0.34 nm 1452 JABBARZADEH and GOLKARIAN from the first one and the creation of Van der Waals interaction between the layers with a cut-off distance of 0.38 nm, the elastic module increased to 1.2275 TPa. This result is in good agreement with the results reported by other researchers (Table II). TABLE II. A comparison of the results related to the elastic module of double-layer GSs with Van der Waals interlayer interactions Elastic module of a double-layer, TPa Elastic module of a monolayer, TPa Study 1.2275 1.2175 Present study 1.2537 1.2447 Golkarian and Jabbarzadeh18 1.035 1.025 Li and Chou13 1.032 1.030 Bao et al.27 Interlayer interaction: type II. The results obtained at this step (Table III) showed that at a stiffness of 300 nN nm–1, the elastic module is about 1.2263 TPa, which is in good agreement with the value 1.2257 TPa related to the pre- vious step and showed that this stiffness is a good replacement for nonlinear Van der Waals interactions. It was observed that at a stiffness of about 108 nN nm–1 (330000 times stronger than 300 nN nm–1 equal to the van der Waals forces), the elastic module of double-layer GS increased to 1.59 TPa, showing a 30 % inc- rease. It could be deduced that if the maximum increase of 30 % was satisfactory and the complication of working on the power of interlayer interactions was possible, chemical work on the interlayer interactions could be helpful. TABLE III. Variation of the elastic module of double-layer GSs from the stiffness of linear springs as interlayer interactions Elastic module, TPa Stiffness, nN nm-1 1.2175 0 1.2176 1 1.2178 10 1.2205 100 1.2263 300 1.2452 103 1.5513 104 1.5905 106 1.5954 108 1.5955 1010 1.5955 1012 Interlayer interaction: type III. In the third step, by defining a defect in each layer, the elastic module of each layer was reduced to 1.1979 TPa; this negligible decrease is in the range of results reported by other researchers (Table IV). By defining van der Waals forces between two layers, the elastic module of the INTERLAYER INTERACTIONS IN POLYMERIC NANOCOMPOSITES 1453 layers increased to 1.2060 TPa. If the layers were linked together by covalent bonds, the elastic module increased to 1.1988 TPa and when a combination of van der Waals and covalent bonds was used, the elastic module increased to 1.2067 TPa, which shows a 0.7 % increase in comparison to defective mono- layers and 0.9 % reduction if compared to the perfect ones. TABLE IV. Variation of elastic module of a monolayer GS caused by defining a defect Defective elastic module, TPa Perfect elastic module, TPa Study 1.1979 1.2175 Present study 0.990 1.032 Rafiee & Pourazizi24 0.77 0.79 Ansari et al.28 1.036 1.042 Scalante et al.29 The results showed that by defining a defect in the layers, the elastic module showed a 1.6 % reduction and that the reduction after functionalization by defin- ing covalent and van der Waals forces was 1.5 %, which is a negligible differ- ence. From these results, it could be deduced that functionalization in order to repair existing defects or after defining the defects in the model, to form covalent interlayer interactions cannot improve the mechanical properties of the model. Therefore, other ways, such as a change in the type of interlayer interaction, should be considered. Nanocomposite Monolayer reinforcement. Interlayer interaction: type I. In this step, a GS with an elastic module of 1.2175 TPa was imported into a polymeric base with an elastic module of 3.5 GPa and they were coupled with Van der Waals forces. The elastic module of nanocomposite at this step was 63.7 GPa, which is in good agreement with the result of 64.2 GPa obtained from ROM. In a same research performed by Rafii-Tabar and Montazeri21 for a polymeric base with an elastic module of 3.5 GPa, the elastic module of nanocomposite was reported to be about 59.536 GPa, which is in suitable agreement with the results obtained in this study. Moreover, the elastic module of the polymeric base (3.5 GPa) in this step was found to be 3.67 GPa, which was a 4.8 % increase. Interlayer interaction: type II. By using linear springs instead of Van der Waals forces and increasing its stiffness, no significant change was observed in the translate ratio from reinforced to polymeric base (Table V). It could be seen that the maximum elastic module of the nanocomposite in a stiffness of 300 nN nm–1 (the same as when van der Waals forces existed) was obtained, which was equal to the 63.68 GPa. The maximum value for the elastic module of polymeric base was about 3.678 GPa, i.e., a 1.5 % increase. Interlayer interaction: type III. By omitting all van der Waals forces, defin- ing a defect and creating three covalent bonds, the elastic module of the nano- composite and the polymeric base were about 62.69 GPa and 3.5 GPa, respect- 1454 JABBARZADEH and GOLKARIAN ively. By defining, a second defect and the next three covalent bonds (bidirect- ional), the elastic module of the nanocomposite and of the polymeric base were 61.69 and 3.5 GPa, respectively. By defining van der Waals forces (together with bidirectional covalent bonds), the elastic modules reached 61.71 and 3.6 GPa, respectively. From these results, it can be deduced that the functionalization of nanocomposites reinforced by monolayer GS does not lead to an improvement of the elastic module of the nanocomposite. TABLE V. Variation of elastic module of polymeric base according to the stiffness of a linear spring as an interlayer interaction (monolayer reinforcement) Elastic module of polymeric base, GPa Stiffness, nN nm-1 3.5 0 3.557 0.1 3.67 10 3.677 300 3.678 1000 3.678 104 Double-layer reinforcement. Interlayer interaction: type I. By importing a double-layer GS in polymeric base, the elastic module of nanocomposite inc- reased to 64.11 GPa, which is a 0.7 % increase. In this step, the elastic module of polymeric base decreased to 3.6 from 3.67 GPa for a monolayer reinforcement. This showed that increasing the number of layers in the presence of van der Waals forces as interlayer interactions was inefficient. From the results of this step and the previous steps (related to the function- alization by using monolayer reinforcement), it can be deduced that the function- alization of double-layer GS would be inefficient, because the increase in the number of layers did not improve the elastic module of the nanocomposite and also defect creation (in order to make covalent bonds) decreased the elastic module of the nanocomposite. Interlayer interaction: type II. By increasing the stiffness of all interlayer interactions including the interactions GS–GS and GS–polymeric base, the elastic module of the nanocomposite increased to 82.5 GPa, i.e., a 30 % increase (in a stiffness of 1 nN nm–1) (Table VI), which is equal to the time that the elastic module of double-layer GS reached its maximum value. In addition, the elastic module of the polymeric base decreased to 3.605 GPa (in stiffness of 100 nN nm–1) from 3.67 GPa related to the use of monolayer reinforcement (Table VII). This shows that increasing the number of layers and the stiffness of interlayer interactions cannot improve the elastic module of the polymeric base. Some of the important points that can be deduced from the results are: 1. Making a defect in the graphene layer for replacing three carbon–carbon covalent bonds instead of three weak van der Waals interlayer interactions to inc- INTERLAYER INTERACTIONS IN POLYMERIC NANOCOMPOSITES 1455 rease the elastic module of nanocomposite or multilayers is a useless operation. This is because the decreasing effect of making a defect in a layer on the elastic module more than decreases the effect of this type of functionalization. TABLE VII. Variation of the elastic module of the polymeric base in dependence on the stiffness of the linear spring elements as interlayer interaction (double-layer reinforcement) Elastic module of the polymeric base, GPa Stiffness, nN nm-1 3.5 0 3.585 1 3.602 10 3.605 100 3.605 1000 2. By increasing the strength of interlayer interactions (which includes each type of functionalization or chemical changes), a maximum increasing effect of 30 % in the elastic module of nanocomposites reinforced by multilayer graphene sheets is estimated. Of course, this results may have some changes in experi- mental studies because, in this case, the influence of many graphene layers as a multilayer GS was only investigated and the influence of some important para- meters, such as the contribution, dispersion, local density, direction of the layers and some other parameters that could not be considered in the atomic mechanical modeling and appear only in real, experimental investigations. 3. This increasing effect is when the employment of multilayer graphene layers (in the experimental works most of the employed graphene layers are also multilayers, because monolayers are rarely available) and increasing the strength of interlayer interactions between a monolayer graphene sheet and a polymeric base does not lead to a significant increasing effect in the elastic module of the nanocomposite. TABLE VI. Variation of elastic module of nanocomposite according to the stiffness of the linear spring element as an interlayer interaction (double layer reinforcement) Elastic module of nanocomposite, GPa Stiffness, nN nm-1 63.7 0 63.68 1 63.69 10 63.74 100 64.18 1000 67.39 104 76.72 105 81.68 106 82.41 107 82.48 108 82.5 109 1456 JABBARZADEH and GOLKARIAN Among theoretical studies performed in this case, the study performed rec- ently by Rafiee and Rourazizi24 could be mentioned, in which they used the molecular mechanic modeling method and reinforced a polymeric cylindrical matrix with monolayer carbon nanotube and investigated the influence of this type of functionalization (making defect and replacing C–C covalent bonds ins- tead of van der Waals interlayer interactions) and reported the same results. They reported the decreasing effect of this type of functionalization on the elastic module of a cylindrical polymeric base reinforced by single layer carbon nanotube and they explained that the effect of functionalization cannot be obs- erved on the micro scale but its improving effect may appear on the meso or macro scale. Therefore, in the present study, time was devoted to investigate the effect of each type of functionalization (by increasing the strength of interlayer inter- actions up to its highest level) for both mono and multilayer graphene sheets. It was found that in the case of multilayers, an up to 30 % increase in the elastic module of the nanocomposite was possible by increasing the effect but in the case of monolayer reinforcements, no increase was observed in the case of graphene sheet, but not with carbon nanotubes As a general result, it could be deduced that, maybe, more attention should be paid to the interactions between the graphene layers than those between the graphene layer and the polymeric base. However, this objective cannot be strongly emphasized because, as explained previously, there are some crucial parameters that cannot be considered using this modeling approach. CONCLUSIONS In this paper the influences of three types of interlayer interactions on the elastic module of multilayer GSs and nanocomposites reinforced by monolayer and double-layer GS were studied. The following important cases were con- sidered in this investigation: The influence of type of element used for simulating of GSs on the elastic module and the amount of computations. The influence of type of element used for simulating interlayer interactions in double-layer GSs and nanocomposites reinforced by monolayer and double- -layer GS. Using four types of interlayer interactions: – van der Waals interlayer interaction using nonlinear spring element defined by the Leonard–Jones potential to validate the modeling method, – linear spring elements, the stiffness of which was increased at each step to find the ultimate value of the possible force translation ratio, – omitting all van der Waals forces, defining defects in the layers and make three covalent interlayer interactions by defining each defect and INTERLAYER INTERACTIONS IN POLYMERIC NANOCOMPOSITES 1457 – combination of van der Waals and covalent interlayer interactions. The influence of an increase in the number of layers on the reinforcement of the nanocomposites. The maximum amount of possible force translation ratio from reinforcement to polymeric base (chemical changes). Some of the important results are: – The linear spring element is in best agreement with other results and requires the lowest computations time. – Making defects and replacing van der Waals interlayer interactions with C–C covalent bonds cannot improve the elastic module of multilayer GSs and nanocomposites. This means that the decreasing effect of making defects is more than the increasing effect of the replacement by covalent interlayer interactions. – Chemical changes (functionalization) in interlayer interactions under the best conditions can lead to an increase of about 30 % in the elastic module of multilayer GSs and nanocomposites reinforced by multilayer GSs. – Improving the elastic modules of nanocomposites due to the functional- ization (reported by experimental works) is the consequence of functionalization of interlayer interactions between graphene layers not between graphene layer and polymeric base. – Improving the quality of interlayer interactions cannot help to improve the elastic module of polymeric base. Consequently, it could be deduced that by using multilayer GSs and improv- ing the strength of the interlayer interactions, significant increases in the elastic module of double-layer GSs and also nanocomposites reinforced by multilayer GSs of up to 30 % could be expected. In addition, improving the strength of the interlayer interactions or increasing the number of layers does not lead to an improvement in the elastic module of the polymeric base. SUPPLEMENTARY MATERIAL Details of the considered models, their theoretical background and method of calcul- ations are available electronically from http://www.shd.org.rs/JSCS/, or from the corres- ponding author on request. Acknowledgement. The authors wish to thank the Islamic Azad University of Mashhad for financing the project “The influence of quality of interlayer interactions on the mechanical properties of polymeric nanocomposites”. 1458 JABBARZADEH and GOLKARIAN И З В О Д УТИЦАЈ ИНТЕРАКЦИЈА МЕЂУСЛОЈА НА МЕХАНИЧКА СВОЈСТВА ПОЛИМЕРНИХ НАНОКОМПОЗИТА MEHRDAD JABBARZADEH и AMIR REZA GOLKARIAN Department of Mechanical Engineering, Mashhad Branch, Islamic Azad University, Mashhad, Iran Проучаван је утицај типова интеракције међуслоја на еластичне модуле више- слојног графена (GS) и нанокомпозита. Моделовање и испитивање механичких својстава графитних слојева изведено је методом молекулске механике (ММ). Најпре су, због побољшања модела и смањења обима израчунавања, коришћена три елемента: зрак, линеарна и нелинеарна опруга, а у наставку су упоређена механичка својства више- струких слојева и нанокомпозита применом три типа интеракције међуслоја. Прво је коришћена нелинеарна опруга дефинисана Leonard–Jones потенцијалом да би се дефи- нисале интеракције међуслоја (ординарни случај). Затим је примењена донекле пригу- шена линеарна опруга (еквивалентна линеарна опруга) и повећавањем пригушености линеарних опруга испитао крајњи капацитет интеракције међуслоја у транслацији силе (хемијска промена). Уз то су, у једном случају занемарене све van der Waals интеракције и настајање дефеката у графитним слојевима, те је оно доводило до ковалентних интер- акција међуслоја (Morse потенцијал), а у другом , van der Waals и ковалентне интер- акције међуслоја креиране су спонтано да би се проучила својства вишеструких слојева и нанокомпозита (функционализација). Резултати су поређени са подацима из литера- туре ради валидизације моделовања. (Примљено 25. октобра 2014, ревидирано 10. марта, прихваћено 18. јуна 2015) REFERENCES 1. M. Paradise, T. Goswami, Mater. Design 28 (2007) 1477 2. C. P. Firme, P. R. Bandaru, Nanomedicine 6 (2010) 245 3. D. 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Sci. 55 (2012) 255. << /ASCII85EncodePages false /AllowTransparency false /AutoPositionEPSFiles true /AutoRotatePages /None /Binding /Left /CalGrayProfile (Dot Gain 20%) /CalRGBProfile (sRGB IEC61966-2.1) /CalCMYKProfile (U.S. Web Coated \050SWOP\051 v2) /sRGBProfile (sRGB IEC61966-2.1) /CannotEmbedFontPolicy /Error /CompatibilityLevel 1.4 /CompressObjects /Tags /CompressPages true /ConvertImagesToIndexed true /PassThroughJPEGImages true /CreateJobTicket false /DefaultRenderingIntent /Default /DetectBlends true /DetectCurves 0.0000 /ColorConversionStrategy /CMYK /DoThumbnails false /EmbedAllFonts true /EmbedOpenType false /ParseICCProfilesInComments true /EmbedJobOptions true /DSCReportingLevel 0 /EmitDSCWarnings false /EndPage -1 /ImageMemory 1048576 /LockDistillerParams false /MaxSubsetPct 100 /Optimize true /OPM 1 /ParseDSCComments true /ParseDSCCommentsForDocInfo true /PreserveCopyPage true /PreserveDICMYKValues true /PreserveEPSInfo true /PreserveFlatness true /PreserveHalftoneInfo false /PreserveOPIComments true /PreserveOverprintSettings true /StartPage 1 /SubsetFonts true /TransferFunctionInfo /Apply /UCRandBGInfo /Preserve /UsePrologue false /ColorSettingsFile () /AlwaysEmbed [ true ] /NeverEmbed [ true ] /AntiAliasColorImages false /CropColorImages true /ColorImageMinResolution 300 /ColorImageMinResolutionPolicy /OK /DownsampleColorImages true /ColorImageDownsampleType /Bicubic /ColorImageResolution 300 /ColorImageDepth -1 /ColorImageMinDownsampleDepth 1 /ColorImageDownsampleThreshold 1.50000 /EncodeColorImages true /ColorImageFilter /DCTEncode /AutoFilterColorImages true /ColorImageAutoFilterStrategy /JPEG /ColorACSImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /ColorImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /JPEG2000ColorACSImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /JPEG2000ColorImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /AntiAliasGrayImages false /CropGrayImages true /GrayImageMinResolution 300 /GrayImageMinResolutionPolicy /OK /DownsampleGrayImages true /GrayImageDownsampleType /Bicubic /GrayImageResolution 300 /GrayImageDepth -1 /GrayImageMinDownsampleDepth 2 /GrayImageDownsampleThreshold 1.50000 /EncodeGrayImages true /GrayImageFilter /DCTEncode /AutoFilterGrayImages true /GrayImageAutoFilterStrategy /JPEG /GrayACSImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /GrayImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /JPEG2000GrayACSImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /JPEG2000GrayImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /AntiAliasMonoImages false /CropMonoImages true /MonoImageMinResolution 1200 /MonoImageMinResolutionPolicy /OK /DownsampleMonoImages true /MonoImageDownsampleType /Bicubic /MonoImageResolution 1200 /MonoImageDepth -1 /MonoImageDownsampleThreshold 1.50000 /EncodeMonoImages true /MonoImageFilter /CCITTFaxEncode /MonoImageDict << /K -1 >> /AllowPSXObjects false /CheckCompliance [ /None ] /PDFX1aCheck false /PDFX3Check false /PDFXCompliantPDFOnly false /PDFXNoTrimBoxError true /PDFXTrimBoxToMediaBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXSetBleedBoxToMediaBox true /PDFXBleedBoxToTrimBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXOutputIntentProfile () /PDFXOutputConditionIdentifier () /PDFXOutputCondition () /PDFXRegistryName () /PDFXTrapped /False /CreateJDFFile false /Description << /ARA /BGR /CHS /CHT /CZE /DAN /DEU /ESP /ETI /FRA /GRE /HEB /HRV (Za stvaranje Adobe PDF dokumenata najpogodnijih za visokokvalitetni ispis prije tiskanja koristite ove postavke. Stvoreni PDF dokumenti mogu se otvoriti Acrobat i Adobe Reader 5.0 i kasnijim verzijama.) /HUN /ITA /JPN /KOR /LTH /LVI /NLD (Gebruik deze instellingen om Adobe PDF-documenten te maken die zijn geoptimaliseerd voor prepress-afdrukken van hoge kwaliteit. De gemaakte PDF-documenten kunnen worden geopend met Acrobat en Adobe Reader 5.0 en hoger.) /NOR /POL /PTB /RUM /RUS /SKY /SLV /SUO /SVE /TUR /UKR /ENU (Use these settings to create Adobe PDF documents best suited for high-quality prepress printing. Created PDF documents can be opened with Acrobat and Adobe Reader 5.0 and later.) >> /Namespace [ (Adobe) (Common) (1.0) ] /OtherNamespaces [ << /AsReaderSpreads false /CropImagesToFrames true /ErrorControl /WarnAndContinue /FlattenerIgnoreSpreadOverrides false /IncludeGuidesGrids false /IncludeNonPrinting false /IncludeSlug false /Namespace [ (Adobe) (InDesign) (4.0) ] /OmitPlacedBitmaps false /OmitPlacedEPS false /OmitPlacedPDF false /SimulateOverprint /Legacy >> << /AddBleedMarks false /AddColorBars false /AddCropMarks false /AddPageInfo false /AddRegMarks false /ConvertColors /ConvertToCMYK /DestinationProfileName () /DestinationProfileSelector /DocumentCMYK /Downsample16BitImages true /FlattenerPreset << /PresetSelector /MediumResolution >> /FormElements false /GenerateStructure false /IncludeBookmarks false /IncludeHyperlinks false /IncludeInteractive false /IncludeLayers false /IncludeProfiles false /MultimediaHandling /UseObjectSettings /Namespace [ (Adobe) (CreativeSuite) (2.0) ] /PDFXOutputIntentProfileSelector /DocumentCMYK /PreserveEditing true /UntaggedCMYKHandling /LeaveUntagged /UntaggedRGBHandling /UseDocumentProfile /UseDocumentBleed false >> ] >> setdistillerparams << /HWResolution [2400 2400] /PageSize [612.000 792.000] >> setpagedevice