Controlled growth of vertically aligned carbon nanotubes from palm oil precursor using thermal chemical vapour deposition method and its field electron emission properties / Suriani Abu Bakar

Vertically aligned carbon nanotubes (VACNT) were synthesized using palm oil as an environmentally friendly starting material. The synthesis was carried out in a thermal chemical vapour deposition reactor. Parametric studies were done to determine the optimum parameters to obtain VACNT with favourable properties at high volume. The parameters included seeded and floated catalyst preparation method, stacking substrate configuration (lower and upper growth), synthesis temperature (700- 900°C), palm oil vaporization temperature (300-600°C), synthesis time (5-90 min), different carbon precursor (palm oil and waste cooking palm oil), substrate positioning (position 1-6), ferrocene concentration (0.67-5.33 wt%) and different carrier gas (argon and nitrogen). The carbon nanotubes (CNT) products were then characterized using several analytical techniques which were electron microscopy, energy dispersive x-ray analysis, micro- Raman and Fourier transform infrared (FTIR) spectroscopy, thermogravimetry analysis (TGA) and CHNS-O analysis. Prior to the synthesis process, several analyses such as TGA, gas chromatography–mass spectrometry and FTIR characterizations were done on the carbon precursor namely palm oil and waste cooking palm oil in order to facilitate the optimization procedures of VACNT. For every synthesis parameter, the nanotubes growth rates were measured and the nucleation as well as termination factor were investigated

Kajian kes di Syarikat Philip Morris Malaysia (PMI) berkaitan amalan pengurusan sumber manusia dengan komitmen organisasi

Employee is a valuable asset and vital to any organization. Therefore a management practice to employees is important as it will enhance positive feelings to the organization. This study investigated the relationship between human resource management practices (HRM) and organizational commitment among employees in the company Philip Morris International (PMI) Malaysia. HRM practices, including training and development, performance evaluation, salary and benefits, recruitment and selection, and employee participation. A conceptual framework and built by two main hypotheses and ten specific hypothesis submitted for testing. Employees at PMI Malaysia are respondents in this study. A total of 180 questionnaires were sent to respondents. But only 110 questionnaires was collected from PMI Malaysia and used in statistical analysis. Data collected using a structured questionnaire adapted from previous studies and processed, managed and analysed using a computer program called SPSS version 21.0. The correlation analysis showed that there was a significant positive relationship between HRM practices and organizational commitment. While regression testing conducted to study the practice of HRM most influential organization with a commitment shows the performance appraisal is the most influential factor in organizational commitment at PMI Malaysia. The recommendations have been given to increase the level of organizational commitment among employees, especially at PMI Malaysia. In conclusion, the results of this study can contribute in increasing knowledge and understanding of the relationship between HRM practices and organizational commitment, and thus allows the practitioner to obtain a deeper knowledge on the impact of HRM practices on organizational performanc

TIME EVOLUTION OF THE GROWTH OF VERTICALLY ALIGNED CARBON NANOTUBES USING PALM OIL

We studied the change in morphology and microstructure of carbon nanotubes (CNT) grown for 5, 10, 15, 20, 25, 30, 35 and 40 mins respectively. The CNT was fabricated from palm oil using thermal chemical vapor deposition method at fixed synthesis temperature of 750°C in argon ambient. The samples were analyzed using field emission scanning electron microscopy and micro-Raman spectroscopy. At 5 min of growing time, a very thin layer of CNT was produced without any vertical growth of CNT. The tube walls were also defective and coated with amorphous carbon. The vertically aligned CNT (VACNT) was initially observed at 10 min synthesis time and the length increases with prolonged synthesis time at various growth rate. It should also be highlighted that as the nanotubes get longer and thickens with time, the development of secondary growth structures was also spotted particularly for synthesis time more than 30 min. From Energy-dispersive X-ray spectroscopy analysis, it is justifiable that the generation of secondary growth came from the raised catalyst. As a conclusion, it can be said that, the optimum synthesis time for higher growth rate VACNT, smaller diameter and mix with single-walled CNT, low ID/IG ratio was identified at 30 min time.Key words: Nanotubes, Chemical synthesis method, Scanning electron microscopy (SEM) and Raman spectra.ABSTRAK Kami mengkaji perubahan morfologi dan struktur mikro tabung nano karbon (CNT) yang ditumbuhkan selama 5, 10, 15, 20, 25, 30, 35 dan 40 menit. CNT difabrikasi dari minyak sawit menggunakan metode deposisi uap kimia termal pada suhu sintesis 750 °C dalam lingkungan argon. Sampel dianalisis menggunakan mikroskop elektron dan spektroskopi mikro-Raman. Pada waktu pertumbuhan 5 menit, diperoleh lapisan CNT yang sangat tipis tanpa pertumbuhan vertikal CNT. Dinding tabung juga rusak dan dilapisi dengan karbon amorf. Pertumbuhan CNT vertikal sejajar (VACNT) pada awalnya teramati pada waktu sintesis 10 menit dan panjangnya bertambah seiring dengan perpanjangan waktu sintesis di berbagai tingkat pertumbuhan. Harus digarisbawahi pula bahwa semakin panjang dan tebal tabung nano seiring bertambahnya waktu, perkembangan struktur pertumbuhan sekunder juga terlihat terutama untuk waktu sintesis lebih dari 30 menit. Dari analisis spektroskopi energi dispersif sinar-X, terlihat bahwa generasi pertumbuhan sekunder berasal dari katalis yang terangkat. Sebagai kesimpulan, dapat dikatakan bahwa waktu sintesis optimal untuk tingkat pertumbuhan VACNT yang lebih tinggi, diameter lebih kecil, bercampur dengan CNT berdinding tunggal, dan rasio ID/IG rendah diidentifikasi pada 30 waktu menit.Kata Kunci: tabung nano karbon, metode sintesis kimiawi, mikroskop electron (SEM), spectrum Rama

Effect of Synthesis Temperature on the Growth of Carbon-based Materials from Waste Engine Oil Precursor

Different stuctures of carbon material were succesfully synthesized from waste engine oil (WEO) as carbon source using double-stage thermal chemical vapor deposition method. In this work, 5.33 wt% ferrocene was used as catalyst, precursor temperature at 450°C and the synthesis temperatures were varied from 600-1000°C with 100°C increament. The prepared samples were characterized using field emission scanning electron microscopy and micro-Raman spectroscopy. Below 700°C, amorphous structure of carbon was formed. Well growth carbon spheres were produced at 800°C while at 900°C, bigger diameter and lower crystallinity of carbon spheres were resulted. At very high temperature, 1000°C, a highly defective structure of carbon was produced. These results show that the structure of carbon materials from WEO precursor was highly affected by synthesis temperature change

THE STRUCTURAL PROPERTIES OF GRAPHENE OXIDE AND REDUCED GRAPHENE OXIDE GROWN ON STAINLESS STEEL SUBSTRATE

In this paper, the structural properties of graphene oxide (GO) and reduced graphene oxide (rGO) based on custom-made, sodium 1,4-bis (neopentyloxy)-3-(neopentyloxycarbonyl)-1,4-dioxobutane-2-sulphonate (TC14) surfactant were investigated. GO was synthesized by electrochemical exfoliation and chemical reduction process utilizing hydrazine hydrate was further done to produce rGO. The obtained GO and rGO solution were then transferred to stainless steel substrate by spraying deposition method. Based on several characterizations, the fabricated film has potential to be used as electrode for water treatment application. Key words: Graphene Oxide, Reduced Graphene Oxide, Stainless Steel, Electrochemical, Spraying. ABSTRAK Dalam artikel ini diteliti sifat struktural dari oksida grafin (GO) dan oksida grafin yang direduksi (rGO) menggunakan surfaktan sodium 1,4-bis (neopentyloxy)-3-(neopentyloxycarbonyl)-1,4-dioxobutane-2-sulphonate (TC14) yang dibuat khusus. GO disintesis menggunakan eksfoliasi elektrokimia dan proses reduksi kimiawi menggunakan hidrazin hidrat untuk menghasilkan rGO. Larutan GO dan rGO yang dihasilkan kemudian ditransfer ke substrat stainless steel degan metode deposisi penyemprotan. Berdasarkan beberapa karakterisasi, film yang difabrikasi memiliki potensi untuk digunakan sebagai elektroda untuk aplikasi pengolahan air. Kata kunci: Oksida grafin, oksida grafin direduksi, stainless steel, elektrokimia, penyemprota

Optical properties of reduced graphene oxide-coated tellurite glass doped at different erbium composition

Graphene-based nanomaterials have significant potential to be used as coating materials for glass performance. In this work, reduced graphene oxide (rGO)-coated tellurite glass was synthesized via melt-quenching and low-cost spray coating techniques for improving the optical properties in the glassy matrix. The structural properties investigated using X-Ray Diffraction (XRD) confirmed the structural arrangement of an amorphous nature phase meanwhile, Scanning Electron Microscopy (SEM) analysis proved the morphological structure images of rGO onto the tellurite glass surface. The refractive index value of rGO-coated glass was found higher in the range of 2.402 - 2.775 due to the graphene-based effects. The optical bandgap energy value of rGO-coated glass was improved from 1.913 - 2.980 eV which correlated to the changes in rGO absorption characteristics. The Urbach energy showed a high number of defects in absorption with the presence of rGO structures. By virtue of improved optical properties, the rGO-coated glass may be beneficial to be used as a glass coating material f or high optical performance of fiber optics

THE STRUCTURAL PROPERTIES OF ZnO/TiO2 BILAYER THIN FILM AS PHOTOANODE

   The ZnO/TiO2 bilayer was fabricated on the fluorine-doped tin oxide (FTO) substrate. The ZnO nanorods and TiO2 nanoparticles were developed as photoanode material that were fabricated by using sol-gel immersion and squeegee method. The structure of ZnO/TiO2 bilayer showed a good properties for photoanode in DSSCs application. The ZnO/TiO2 bilayer has large surface area that could increase a dye loading and performance of photoanode. Meanwhile, the micro-Raman spectra of ZnO/TiO2 bilayer indicated a good crystallinity. Therefore, the ZnO/TiO2 bilayer showed a good structure for photoanode in DSSCs application.Key words: ZnO nanorods, TiO2 nanoparticles, ZnO/TiO2 bilayer, Photoanode ABSTRAKLapisan ZnO/TiO2 difabrikasi di atas substrat oksida timah yang di doping florin (FTO). Batang nano ZnO dan partikel nano TiO2 dikembangkan sebagai material fotoanoda yang difabrikasi menggunakan metode pencelupan sol-gel dan squeegee. Struktur lapisan ZnO/TiO2menunjukkan sifat fotoanoda yang baik dalam aplikasi DSSCs. Lapisan ZnO/TiO2memiliki luas permukaan yang besar yang bisa meningkatkan muatan dye dan performa fotoanoda. Sedangkan spktrum mikro-Raman lapisan ZnO/TiO2mengindikasikan kristalinitas yang bagus. Oleh karena itu, lapisan ZnO/TiO2menunjukkan struktur yang baik untuk fotoanoda di dalam aplikasi DSSCs.Kata Kunci: batang nano ZnO, partikel nano TiO2, lapisan ZnO/TiO2, fotoanod

Knowledge, attitude and practices on secondhand smoking among women who are exposed to secondhand smoking at home and at workplace

Introduction: Second-hand smoking (SHS) is involuntary smoking of exhaled smoke from smokers. SHS is dangerous to health as there is no safe level of exposure. Knowledge, attitude and practice towards SHS are important prevention measures especially among working women whose husbands are smokers. Methods: A cross-sectional study was conducted among staff members of a public university. Respondents were the wives of smokers and recruited using simple random sampling. Data was collected using a self-administered questionnaire. Chi-square test was used to determine the associations between variables. Results: Majority (66.2%) of the respondents have appropriate practices towards SHS and there was no significant differences within the socio-demographic characteristics. Correspondingly, 53.7% have good knowledge but only 46.3% have good attitude towards SHS and 74.6% showed lack of confidence in reprimanding smokers in no-smoking zone. Conclusion: The appropriate practices towards SHS among the wives of smokers in this study was good. However the self-efficacy to avoid SHS could be improved

PREPARATION OF LAYERED MATERIAL Zn/Al-LAYERED DOUBLE HYDROXIDE-FERULATE NANOCOMPOSITES

A new layered material-drug nanocomposite namely, Zn/Al-layered double hydroxide-ferulate (Zn/Al-LDH-FA) has been synthesized using the ion exchange method. PXRD pattern and elemental analysis showed that Zn/Al-LDH-FA nanocomposite yielded high crystalline and pure phase material with a basal spacing of 17.4 Å and anion loading of 35.9 % respectively. The FTIR spectra reveal the presence of FA in the interlayer of Zn/Al-LDH, while the thermal analysis shows that the Zn/Al-LDH has enhanced the thermal stability of FA in the interlayer compared to its pure form. Anionic FA intercalated into the interlayer of Zn/Al-LDH as vertical monolayer with the carboxylate groups pointing towards the Zn/Al-LDHs layers. The intercalation of FA into the interlayer of Zn/Al-LDH is also supported by morphology analysis, FESEM.Keywords: Synthesis, Intercalation, Layered Double Hydroxide, Ferulic AcidABSTRAKSebuah bahan-obat berlapis nanokomposit baru yaitu, Zn/Al-berlapis ganda hidroksida-ferulate (Zn/Al-LDH-FA) telah disintesis dengan menggunakan metode pertukaran ion. Pola PXRD dan analisis unsur menunjukkan bahwa Zn/Al-LDH-FA nanokomposit menghasilkan kristalinitas tinggi dan material fase murni dengan jarak basal dari 17,4 Å dan pemuatan anion 35,9%. Spektrum FTIR mengungkapkan adanya FA di lapisan Zn/Al-LDH, sedangkan analisis termal menunjukkan bahwa Zn/Al-LDH telah meningkatkan stabilitas termal FA di antar lapisan dibandingkan dengan bentuk murninya. Anionik FA diselingi ke dalam interlayer Zn/Al-LDH sebagai monolayer vertikal dengan gugus karboksilat menunjuk ke arah lapisan Zn/Al-LDHs. Interkalasi dari FA ke dalam interlayer Zn/Al-LDH juga didukung oleh analisis morfologi, FESEM.Kata kunci: Sintesis, interkalasi, hidroksida berlapis ganda, asam feruli

HYDROTHERMAL GROWTH AND SQUEEGEE METHOD IN THE FABRICATION OF MIXED-PHASE TiO2 NANOSTRUCTURES

In this work, the modification of TiO2 nanostructures based on its morphology and crystallinity phase were fabricated using a simple method. Hydrothermal growth method was used to synthesize nanorods and nanoflowers, while nanoparticles was applied using squeegee method. The average length and diameter of the as-grown nanorods were 3.5 and 46-215 nm, respectively. Meanwhile, the average total thickness and band gap value of mixed-phase TiO2 nanostructures were 15.98-24.54 nm and 2.84 eV, respectively. Based on its structural and electrical properties, the fabricated film has great potential to be applied as photoanode semiconductor layer for dye-sensitized solar cells application. Key words: TiO2, Nanostructures, Mixed-phase, Hydrothermal, Squeege