Hydrophobicity Performance Of Polyethylene Terephthalate, Thermoplastic Polyurethane And Aluminium Substrates Using Self-Fabricated Contact Angle Tool

• المؤلف الرئيسي: Jasmee, Solehah
• التنسيق: أطروحة
• اللغة: الإنجليزية; الإنجليزية
• منشور في: 2019
• الموضوعات: T Technology (General); TA Engineering (General). Civil engineering (General)
• الوصول للمادة أونلاين: http://eprints.utem.edu.my/id/eprint/24509/; https://plh.utem.edu.my/cgi-bin/koha/opac-detail.pl?biblionumber=116905

Electronic components have become increasingly important and critical especially when it comes to humid environment that potentially lead to corrosion which causes many damages including electrical stress, thermal expansion, mechanical vibration and reduction in production. Moisture that resides at the interface of the electronic components can result in interface delamination. Recent attention on Flexible Printed Circuit (PFC) to replace Printed Circuit Board (PCB) using Polyethylene Terephthalate (PET) and Thermoplastic Polyurethane (TPU) based substrate to avoid corrosion however, understanding on its behaviour is still at infant stage. In addition, the use of good water repellent coating using Titanium Dioxide (TiO2) coating is expected to further improve moisture resistance of electronic components due to its hydrophobicity behaviour. The performance of hydrophobicity can be analysed through contact angle analysis. This thesis is focus on the design and development of self-fabricated contact angle measurement tool for hydrophobicity analysis; to study the effect of temperature on hydrophobicity performance of PET, TPU and Aluminium (Al) substrates and the effect of ceramic coating (TiO2) on PET and TPU. The self-fabricated contact angle measurement tool was developed using Process Design and Development (PDD) involved Pugh Method followed by One-Sample T-Test to verify the accuracy measurement of the selected design. The polymer substrates had undergone thermal analysis by using Differential Scanning Calorimetry (DSC). The TiO2 was deposited by spin coating method and verified by using Fourier Transform Infrared Spectroscopy (FTIR) before heated at the selected heating temperatures (RT, 40ºC, 60ºC and 80ºC). The result on self-fabricated contact angle measurement tool found that this tool is reliable, consistent and precise for contact angle measurement for different surface conditions of hydrophilic (73.25°), hydrophobic (107.25°) and superhydrophobic (158.33°) surfaces. Moreover, the image of contact angle captured from this tool shows a very clear edge of water droplet which help to measure the contact angle accurately. The TPU, PET and Al have different hydrophobicity properties behaviour. PET and Al are hydrophilic meanwhile TPU as hydrophobic which is mainly due to the differences in surface energy. However, surface morphology also influenced the hydrophobicity behaviour when the substrates were modified through heat treatment that changed the geometrical structure or surface roughness of the surface in term of peak and valley (P-V) height, distance between peak- to -peak (D) and width of roughness protrusion (W). The changes of P-V, D and W has affected the formation of air trap between the solid-liquid interface which is the principle of Wenzel and Cassie-Baxter theory. TPU increase in contact angle (98° to 103°) while PET (75° to 70°) and Al (89° to 72°) decrease after thermally aged. The contact angle and surface roughness also show high correlation; PET (0.95), TPU (-0.90) and Al (-0.94) by using Pearson R Test. The TiO2 coating has further improved the hydrophobicity of the PET and TPU (between 94° to 113°) with no evidence of P-V, D and W geometrical structure modification. The knowledge gained would be beneficial to extend the use of TiO2 coating in electronic applications.