Development of hierarchical micro-nanostructured superhydrophobic surface for anti-biofouling application in marine environments | |
| Author | Anvesh, Ravula Surya Venkata Durga |
| Call Number | AIT Thesis no.JNTUK-16-03 |
| Subject(s) | Marine Nanostructures. Fibrous composites Composite materials. |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. JNTUK-16-03 |
| Abstract | This thesis focuses on applying biometric approach as a solution to major marine biofouling problems. A hierarchical micro nano structured coating made up of low surface energy molecules were expected to control biofouling at micro and macro level. Test results of standard steel panels coated with commercial superhydrophobic preparation having water contact angle 149.13 0 ± 1.86 0 revealed that 20 sessile barnacles ( Cirripedia , Crustacea ) were attached to the surface having a standard area of 50 cm 2 , whereas surfaces which were not superhydrophobic contained 104 barnacles per 50 cm 2 area this indicates that roughness plays an import ant role in decreasing the fouling. For effective antifouling, silver nanoparticles were synthesized by chemical reduction method using AgNO 3 and Na 3 C 6 H 5 O 7 as precursors due to their excellent antibacterial properties. These were characterized using Scanning Electron Microscope imagery which revealed that AgNP could not adhere on the surface due to their low concentration. Later zinc oxide nanoparticles were synthesized by precipitation method using Zn(NO 3 ) 2 ·4H 2 O and NaOH as precursors with and without starch. These were characterized using water contact angle and Scanning Electron Microscope imagery. The images revealed that ZnONP successfully adhered to the surface and the use of starch prevented the aggregation of ZnONP spreading it uniformly on the entire surface. A hierarchical micro nano structure was developed by a protocol combining perfluorinated silica nanoparticles with ZnONP. These were coated on s teel samples to test in the sea near Koh Sichang (Bight of Bankok) for 15 days by PTT Company. Results from these panels revealed that micro nano structured superhydrophobic ZnONP in conjunction with perfluorinated silica nanoparticles having water contact angle of 150 .0 0 ± 1.23 0 showed effective antifouling properties when compared with the available commercial preparation. The presence of micro nano structure created a rough surface, which was not suitable for attachment by microorganisms on a micro scale and barnacles on a macro scale . The presence of ZnONP improved the function of coating by creating roughness on micro scale and destroy ed fouling organisms due to its antibacterial properties by forming reactive oxygen species (ROS) . The environmentally friendly coating is economical, easy to apply, and durable as it strongly adheres to the surface making incisions up to 1.6mm on either side of the mark when tested for adhesion and had shown excellent anticorrosion properties when dipped in 5.0% NaCl solution. |
| Year | 2016 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. JNTUK-16-03 |
| Type | Thesis |
| School | School of Environment, Resources, and Development |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Previous Degree Jawaharlal Nehru Technological University Kainada, India (JNTUK) |
| Chairperson(s) | Shipin, Oleg V. |
| Examination Committee(s) | Hornyak, Louis;Nguyen, Thi Kim Oanh;Wichapun Weerapakkaroon |
| Scholarship Donor(s) | AIT Fellowship |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2016 |