https://spaj.ukm.my/ijmc/index.php/ijmc <p>International Journal of Materials Chemistry is a triannual (three issues per year) multidisciplinary journal in materials chemistry research.</p> Department of Chemical Sciences, Faculty of Science and Technology, UKM en-US International Journal of Materials Chemistry (eISSN: 2716-6120) 2716-6120 <p><em><strong>COPYRIGHT</strong></em></p> <p><em>It is the author's responsibility to ensure that his or her submitted work does not infringe any existing copyright.&nbsp;Authors should obtain permission to reproduce or adapt copyrighted material and provide evidence of approval upon&nbsp;submitting the final version of a manuscript.</em></p> <div>&nbsp;</div> https://spaj.ukm.my/ijmc/index.php/ijmc/article/view/1 <p><strong>Abstrak</strong></p> <p>Beberapa tahun kebelakangan ini, pembangunan sensor asid deoksiribonukleik (DNA) secara elektrokimia telah berkembang dengan pesat. Salah satu langkah penting dalam fabrikasi sensor DNA elektrokimia adalah pemegunan prob DNA pada permukaan elektrod bagi memperoleh proses hibridisasi yang optimum dengan DNA sasaran. Pembinaan biosensor yang mempunyai kepekaan dan selektiviti yang baik memerlukan keberkesanan penghibridan yang tinggi dan meminimumkan penjerapan yang tidak spesifik. Oleh itu dalam kajian ini, pencirian elektrokimia menggunakan tiga kaedah pemegunan DNA berdasarkan lapisan swahimpunan sisteamina, asid 3-merkaptopropionik (MPA) dan matrik mikrosfera akrilik (nBA-NAS) telah di kaji. Antrakuinon-2-asid sulfonik monohidrat (AQMS) digunakan sebagai penanda penghibridan. Kedudukan arus puncak penurunan dan pengoksidaan penanda AQMS adalah pada keupayaan -0.72 V dan -0.66 V. Pengubahsuaian setiap lapisan menggunakan sisteamina, MPA dan nBA-NAS pada permukaan elektrod emas bercetak skrin (Au-SPEs) menunjukkan perubahan arus AQMS yang membuktikan setiap lapisan yang diubahsuai berjaya dilakukan. Hasil kajian menunjukkan&nbsp; hanya interaksi antara penanda penghibridan AQMS dengan DNA sasaran menggunakan MPA dan nBA-NAS memberikan rangsangan yang baik berbanding dengan sisteamina.</p> <p><strong>Kata Kunci</strong>: Biosensor; MPA; sisteamina; mikrosfera akrilik; DNA porsin</p> <p>&nbsp;</p> <p><strong>Abstract</strong></p> <p>In recent years, the interest in developing electrochemical deoxyribonucleic acid (DNA) sensor has been growing. One of the essential step in the fabrication of an electrochemical DNA sensor is DNA probe immobilization on the electrode surface to achieve a good hybridization process with the target of DNA. A biosensor with great sensitivity and selectivity needs high level of hybridization efficiency and minimization of non-specific adsorption. Herein, in this study, three DNA immobilization methods based on cysteamine, 3-mercaptopropionic acid (MPA) and acrylic microsphere (nBA-NAS) were analyzed. Anthraquinone-2-sulfonic monohydrate acid (AQMS) is used as a hybridization label. The reduction and oxidation peak positions of the AQMS markers are at the potential of -0.72 V and -0.66 V. Modifications of each layer using cysteamine, MPA and nBA-NAS on the surface of screen printed gold electrode (Au-SPEs) indicate changes in the current of AQMS that proves modification of each layer was successful. The results show that only the interaction between AQMS markers with DNA target using MPA and nBA-NAS provides a good response compared to the cysteamine.</p> <p>&nbsp;<strong>Keywords:</strong> Biosensor; MPA; cysteamine; acrylic microsphere; porcine DNA</p> Emma Izzati Zakariah Lee Yook Heng Haslina Ahmad Siti Aishah Hasbullah ##submission.copyrightStatement## 2019-12-27 2019-12-27 1 01 201901 201901 https://spaj.ukm.my/ijmc/index.php/ijmc/article/view/2 <p><strong>Abstrak </strong></p> <p>Dalam kajian ini, biolubrikan hipercabang berasaskan ester sintetik dihasilkan melalui tindak balas pengesteran dengan kehadiran pemangkin asid sulfurik. Trimetilolpropana (TMP) telah dilakukan tindak balas dengan asid 2,2-bis(hidroksimetil)propionik untuk menghasilkan trimetilolpropana tri-2,2-bis(hidroksimetil)propionat (TMPTP) dan diikuti tindak balas dengan asid oleik untuk menghasilkan trimetilolpropana tri-2,2-bis(hidroksimetil)propionat heksaoleat (TMPTPHO). Tindak balas pengesteran dijalankan pada suhu 140°C selama 5jam dengan nisbah mol 1:3.5 dan 1:6.5 dengan kehadiran 2 %wt pemangkin asid sulfurik. Hasil TMPTP dan TMPTPHO dianalisis dengan menggunakan spektroskopi inframerah (FTIR) dan spektroskopi resonans magnetik nukleus proton dan karbon (¹H dan ¹³C NMR) bagi menentukan struktur molekulnya. Analisis spektrum FTIR dan NMR membuktikan bahawa kedua-dua tindak balas pengesteran telah berjaya dilakukan. Hasil TMPTPHO juga didapati mempunyai indeks kelikatan 138, takat tuang -20°C dan takat kilat 270°C. Produk sintetik biolubrikan yang terhasil boleh digunakan sebagai bahan pelinciran untuk mesin.</p> <p><strong>Kata Kunci</strong>: biolubrikan; pengesteran; trimetilolpropana; asid oleik</p> <p><strong>&nbsp;</strong></p> <p><strong>Abstract </strong></p> <p>In this study, synthetic esters based hyperbranched biolubricant produced through an esterification reaction with the presence of a sulfuric acid catalyst. Trimethylolpropane (TMP) reacted with propionic 2,2-bis (hydroxymethyl) acid to produce tri-2,2-bis (hydroxymethyl) propionate (TMPTP) trimethylolpropane (TMPTP), afterward reacted with oleic acid to produce trimethylolpropane tri-2, 2-bis (hydroxymethyl) propionate hexaoleate (TMPTPHO). The reaction was carried out at 140 ° C for 5 h with a mol ratio of 1:3.5 and 1:6.5 in the presence of 2 %wt sulfuric acid catalyst. The results of TMPTP and TMPTPHO were analyzed using infrared spectroscopy (FTIR) and proton and carbon nuclear magnetic resonance spectroscopy (1H and 13C NMR) to confirm their molecular structure. All IR, proton and carbon spectrum proved the final product successfully synthesized and characterized. TMPTPHO results found to have a viscosity index of 138, a pour point of -20 ° C and a flashpoint of 270 ° C. The resulting synthetic biolubricant has the potential to be used used as machining lubricant.</p> <p><strong>Keywords</strong>: biolubricant; esterification; trimethylolpropane; oleic acid</p> <p><strong>&nbsp;</strong></p> <p><strong>&nbsp;</strong></p> Azira Abdul Razak Jumat Salimon Darfizzi Derawi ##submission.copyrightStatement## 2019-12-27 2019-12-27 1 01 201902 201902 https://spaj.ukm.my/ijmc/index.php/ijmc/article/view/3 <p><strong>Abstrak </strong></p> <p>Ester TMP berasaskan asid lemak tak tepu PFAD dan trimetilolpropana (TMP) sebagai stok asas biolubrikan telah disintesis melalui pengesteran <em>Fischer</em> menggunakan asid sulfurik sebagai mangkin. Bahan pelinciran sintetik dihasilkan secara optimum (79%) pada suhu tindak balas 150 °C selama 6 jam menggunakan 3% (w/w) pemangkin asid sulfurik dan 1: 3 mol (TMP: asid). Pembentukan ester TMP telah disahkan menggunakan kromatografi gas (GC-FID), Spektrum transformasi Fourier inframerah (FTIR) dan Resonans Magnetik Nuklear (¹H NMR dan ¹³C NMR). Ujian sifat pelinciran telah dijalankan ke atas ester TMP. Produk biolubrikan telah mencatatkan kelikatan kinematik pada 40°C dan 100 °C iaitu masing-masing pada 19.53 cSt dan 4.80 cSt, indeks kelikatan pada 169, takat tuang pada -30°C, takat kilat dan api pada suhu melebihi 350°C. Biolubrikan yang dihasilkan juga menunjukkan kestabilan oksidatif yang baik di mana suhu permulaan adalah 173 °C. Gred lubrikan yang dihasilkan diklasifikasikan sebagai ISO VG 22.&nbsp;</p> <p><strong>Kata Kunci</strong>: biolubrikan; asid lemak sawit tersuling; asid lemak tak tepu; ester TMP; trimetilolpropana</p> <p>&nbsp;</p> <p><strong>Abstract</strong></p> <p>TMP esters based biolubricant basestock was synthesised from unsaturated fatty acids of palm fatty acid distillate (PFAD) by Fischer esterification using a sulfuric acid catalyst. Synthetic lubricants were optimized (79%) at a reaction temperature of 150°C for 6 hours using 3% (w/w) sulfuric acid catalyst and 1: 3 mol (TMP: acid). TMP ester formation was confirmed using gas chromatography (GC-FID), infrared spectroscopy (FTIR), and nuclear magnetic resonance (1H NMR and 13C NMR). Lubrication properties have been analyzed. Biolubricant product recorded kinematic viscosity at of 19.53 cSt (40ºC) and 4.80 cSt (100 ºC), viscosity index of 169, pouring temperature of -30°C, flash point and flame at temperatures more than 350°C. The resulting biolubricant showed moderate oxidative stability at 173 ° C. It has been classified as ISO VG 22 grade lubricant.</p> <p><strong>Keywords</strong>: biolubricant; palm fatty acid distillate; unsaturated fatty acid; TMP esters; trimethylolpropane</p> Najihah Abdul Bar Darfizzi Derawi ##submission.copyrightStatement## 2019-12-27 2019-12-27 1 01 201903 201903 https://spaj.ukm.my/ijmc/index.php/ijmc/article/view/6 <p><strong>Abstract </strong></p> <p>Polypyrrole (PPy) is a conjugated polymer that can be conductive electrically and thermally due to its electron delocalization. PPy was prepared by chemical oxidative polymerization in the presence of ammomiun persulphate (APS) and trimethylglycene (TMG) as an oxidant and a doping agent respectively. The composite of TMG doped PPy / chloroprene rubber (CR) and TMG doped PPy / CR with thermally conductive agents; Aluminum Nitride (AlN), Aluminum Oxide (AlO) and Magnesium Oxide (MgO) were prepared by using colloidal dispersion method. Electrical conductivity was measured by using high frequency impedance spectroscopy, whereas thermal conductivity analyzer was used to measure thermal conductivity of the composites. Results obtained showed improvement in electrical conductivity with high weight percentage of PPy in the composites. Thermally conductive agents AlN, AlO and MgO were found to increase the electrical and vary the thermal conductivity of the composites.</p> <p><strong>Keywords</strong>: polypyrrole; conductivity; composite; thermally conductive agent; colloidal dispersion</p> Nurulhuda Abdullah Khairul Basyar Baharudin ##submission.copyrightStatement## 2019-12-31 2019-12-31 1 01 201904 201904 https://spaj.ukm.my/ijmc/index.php/ijmc/article/view/4 <p><strong>Abstract</strong></p> <p>This paper describes the synthesis procedure and photocatalytic activity of an active Niobium Pentoxide (Nb₂O₅) doped anatase phase Titanium Dioxide (TiO₂) photocatalyst. The catalysts were prepared by impregnating ammonium niobate oxalate (V) hydrate ethanolic solutions (1-5%) with oxalic-acid-precipitated TiO₂. XRD analysis of all synthesized TiO₂ and Nb₂O₅– doped TiO₂ construct an anatase phase, however with reduced intensity. Evidently, a linear expansion on cell parameters and extreme reduction in crystallite size was observed as the Nb₂O₅ loading percentage increases. All prepared catalysts exhibit similar irregular to nearly spherical shape morphology with the size accumulated in the range of 10 – 70 nm using Transmission Electron Microscopy (TEM) analysis. The effect of doping Nb₂O₅ became more prominent when it’s assembled different shapes of hysteresis loops as displayed in N₂ adsorption-desorption isotherms. Upon the addition of Nb₂O₅, the Brunauer-Emmett-Teller (BET) surface area showed incredible enhancement while pore size diameter as determined using Barrett, Joyner, and Halenda (BJH) method shifted to smaller pore size. The photocatalytic efficiency of synthesized Nb₂O₅– doped TiO₂ was evaluated and results exhibited an appreciable improvement in comparison to the undoped TiO₂. On the whole, 3% Nb₂O₅ doped TiO₂ offered the highest activity with an optimum of 13.34 mg methyl orange are degraded per gram of UV illuminated photocatalyst.&nbsp; Kinetically, the rate of Methyl Orange (MO) photocatalytic degradation by Nb₂O₅ doped TiO₂ followed first order.</p> <p><strong>Keywords:</strong> anatase phase titanium dioxide; niobium oxide; doped titanium dioxide; impregnation method; photocatalytic</p> Rusli Daik Dayangku Dianasari Awang Jubli ##submission.copyrightStatement## 2019-12-31 2019-12-31 1 01 201905 201905 https://spaj.ukm.my/ijmc/index.php/ijmc/article/view/7 <p><strong>Abstrak </strong></p> <p>Elektrolit polimer pepejal (EPP) berasaskan poli(propilena glikol)-blok-poli(L-asid laktik) (PPG-PLLA) sebagai hos polimer dan 1-butil-3-metilimidazolium klorida, [Bmim]Cl sebagai cecair ionik dihasilkan dan dicirikan dalam kajian ini. Agen gandingan heksametilena diisosianat dan mangkin timah(II)-etilheksanoat turut digunakan dalam penyediaan EPP. Sampel telah disediakan dengan kaedah pengacuanan larutan dan [Bmim]Cl divariasi dari 0 hingga 50 bt.%. Kesan penambahan [Bmim]Cl telah dikaji ke atas interaksi kimia, kekonduksian ionik, kekristalan dan morfologi bagi EPP PPG-PLLA/[Bmim]Cl. Analisis spektroskopi jelmaan Fourier inframerah menunjukkan anjakan nombor gelombang kumpulan berfungsi C=O, C-O dan regangan CH₃-N bagi hos polimer yang menunjukkan berlakunya interaksi antara hos polimer dan cecair ionik. Analisis kekonduksian ionik EPP PPG-PLLA mencapai nilai yang tertinggi iaitu 1.22 x 10^-5 S cm^-1 pada 20 bt.% [Bmim]Cl. Peratus kehabluran PPG-PLLA dapat diperhatikan berkurang dengan penambahan cecair ionik melalui analisis pembelauan sinar-X. Analisis morfologi menunjukkan dengan kehadiran cecair ionik, EPP mempunyai permukaan yang lebih homogen.</p> <p><strong>Kata Kunci</strong>: Elektrolit polimer pepejal, poli(propilena glikol), poli(L-asid laktik), cecair ionik, kekonduksian ionik</p> <p>&nbsp;</p> <p><strong>Abstract</strong></p> <p>Solid polymer electrolyte (SPE) based on poly(propylene glycol-block)-poly(L-lactic acid) (PPG-PLLA) as a polymer host and 1-butyl-3-metilimidazolium chloride, [Bmim]Cl as ionic liquid is prepared and characterised in this research. Hexamethylene diisocyanate as coupling agent and stannous(II)-ethylhexanoate catalyst were also used in the preparation of SPE. The sample was prepared by solution casting and [Bmim]Cl was varied from 0 to 50 wt.%. The effect of the addition of [Bmim]Cl was studied on the chemical interaction, ionic conductivity, crystallinity and morphology of PPG-PLLA/[Bmim]Cl. Fourier transform infrared spectroscopy analysis showed a shift in the wavenumbers for C=O, C-O and CH3-N functional groups stretchings which indicate the occurrence of interaction between polymer host and ionic liquid. Ionic conductivity of PPG-PLLA SPE achieved the highest value of 1.22 x 10-5 S cm-1 at 20 wt.% [Bmim]Cl. The reduction in the percentage crystallinity of PPG-PLLA by the addition of ionic liquid can be observed through X-ray diffraction analysis. Morphological analyis showed that at the presence of ionic liquid, the SPE exhibited more homogenous surfaces.</p> <p><strong>Keywords:</strong> Solid polymer electrolyte, poly(propylene glycol), poly(L-lactic acid), ionic liquid, ionic conductivity</p> Siti Sarah Hazwanee Zulkepli Nur Hasyareeda Hassan Farah Hannan Anuar ##submission.copyrightStatement## 2019-12-31 2019-12-31 1 01 201906 201906