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Home > Synthesis and Characterization of Nanocomposites from Functionalized Graphene

Synthesis and Characterization of Nanocomposites from Functionalized Graphene

Thesis Info

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Author

Shah, Sajid Ali

Program

PhD

Institute

National University of Sciences & Technology

City

Islamabad

Province

Islamabad

Country

Pakistan

Thesis Completing Year

2018

Thesis Completion Status

Completed

Subject

Energetic Materials Engineering

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/10758/1/S%20Sajid%20Ali%20Shah-SCME_2019_NUST_21.03.2019.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727453771

Similar


The graphene study has become the most interested topic owing to its exceptional properties. Graphene brings dramatic changes in the possessions of composites, when it is used even at very low concentration. Though, the heterogeneous distribution of graphene in the matrix is its main drawback to be used as filler in the polymer composites. The strong intermolecular forces of graphene result in agglomeration of graphene in the host the polymer matrix. The surface of graphene is functionalized by different functional groups to reduce the π-π stacking to prevent the agglomeration of graphene. The main objective of this work was to develop an easy method for synthesizing the graphenebased polymer nanocomposites. To get the graphene-based nanocomposites, first graphene was exfoliated by using liquid-phase exfoliation in different organic solvents. Picric acid was also used as a surfactant. The addition of picric acid has doubled the concentration in most of solvents tested. Moreover, graphene oxide was produced by using Hummers’ methods, modified Hummers’ method and Brodie method. The results indicate that modified Hummers’ method is the best one among the three methods. In next step polyaniline was grafted on few layer graphene (FLG), and polyaniline grafted fewlayer graphene (PANI-g-FLG) samples were then blended with polyetherimide. The addition of PANI-g-FLG introduced the conductive behavior in the insulative polymer. The maximum dielectric constant (3.72 × 105) and AC conductivity (5.91 × 10−2 S⋅cm−1) were achieved at 1.5 wt.% of the FLG concentration. Moreover, polyaniline grafted few layer graphene was also added in polyvinyl alcohol (PVA) by solution blending method. The tensile strength was enhanced 62 % for the composites as compared to pure PVA. The dielectric constant was enhanced from 3.29 of pure PVA to 5.14 × 1004 (at 1000Hz) for nanocomposites having 0.5 wt.% FLG loading. Similarly, AC conductivity increased from 9.05 × 10−9 for pure PVA to 2.17 × 10−2 S⋅cm−1 (at 1000Hz) for composites having 0.5 wt.% FLG loading. The PANI-g-FLG was also combined with polystyrene to prepare nanocomposites with varying concentration of FLG (0 to 2 wt.%). The tensile strength was doubled for the composites as compared to pure polystyrene. The graphene oxide produced by modified Hummers’ method was further functionalized and incorporated into the diglycidyl ether of bisphenol A to prepare nanocomposites. The concentration of PANI-g-GO were varied from 0 to 2.5 wt.% in the nanocomposites. The tensile strength was enhanced 60% for the composites as compared to pure diglycidyl ether of bisphenol A. The dielectric constant was improved from 1 to 8 and AC conductivity increased from 1.05 × 10−8 S⋅cm−1 for pure to 6.15 × 10−8 S⋅cm−1 (at 1000Hz) for composites having 2.5 wt.% FLG loading. These results provide a possibility of using flexible nanocomposites as a dielectric material to be applied for energy storage devices such as embedded capacitors.
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نامرد

اس کا نام تو مراد بخش تھا لیکن اس کی قسمت میں نامرادی لکھ دی گئی تھی۔ خوش بختی سے اسے ایک چاند سی بیوی تو ملی تھی لیکن اس چاند کو گہن لگا ہوا تھا۔ اس کے ارد گرد جگ مگ کرتے ہوئے تاروں کا دور دور تک نام و نشان نہیں تھا۔ وہ اور اس کی بیوی امید و آس کے ہر ایک دروازے پر دستک دے چکے تھے لیکن مراد بخش کی آرزوؤں کا چاند نیلگوں آسمان پر تنہا ڈوبتا ابھرتا رہا۔ اس کی ماں بہو کی گود ہری دیکھنے کی تمنا لیے اس دنیا سے رخصت ہوگئی۔ آخر بارہ برس کا طویل انتظار کچھ کم تو نہیں ہوتا۔ یہاں تو بارہ گھنٹے بارہ منٹ اور بارہ پل میں دنیا کہاں سے کہاں جا پہنچتی ہے۔ اس کی ماں بھی اپنی سونی آنکھوں اور خالی بانہوں میں ایک نرم و گرم اور سبک و لطیف لمس کی تمنا لیے اپنے مالک حقیقی سے شکایت کرنے آپہنچی۔ لیکن پھر بھی گھر کا چراغ روشن نہ ہوا۔ آنگن میں لگے ہوئے بیلا کے پودوں پر اُجلے اُجلے پھول نہ کھلے۔ کیاریوں میں جمائے گئے رنگ برنگ تخم زمین کی نرمی سے ہم آغوش ہوکر بھی انکور نہ ہوسکے اور حسبِ معمول اس بار بھی نیم کے پیڑ پر پھل تو لگے لیکن کسی کوئل کے کوکنے کی صدا سنائی نہ دی۔
اب مراد بخش اپنے دوست احباب سے بھی کترانے لگا تھا۔ ہمدردی کے دو بول اسے اپنے سینے میں کانٹے کی طرح چبھتے ہوئے محسوس ہوتے۔ کچھ منہ پھٹ قسم کے شناسا اسے اپنے طنز کا نشانہ بنائے رکھتے تھے اور موقع پاکر کوئی نہ کوئی لطیفہ اس کی شخصیت سے جوڑنے میں انہیں خاصا لطف آتا تھا۔ وہ تلملا کر رہ جاتا۔ کبھی اپنی کڑواہٹ کو مسکراہٹ میں چھپانے اور کبھی اس طرح انجان...

Understanding Post-earthquake Gender Susceptibility in Balakot Tehsil, Khyber Pakhtunkhwa, Pakistan

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Numerical Simulation of Fluid Flow and Heat Transfer Analysis Through Annular Sector Duct

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