en Research Paper Research Paper <span style="font-size:11pt"><span style="line-height:150%"><span style="font-family:Calibri,sans-serif"><b><span style="font-size:12.0pt"><span style="line-height:150%"><span new="" roman="" style="font-family:" times="">Abstract</span></span></span></b></span></span></span><br> <span style="font-size:11pt"><span style="line-height:150%"><span style="font-family:Calibri,sans-serif"><span style="font-size:12.0pt"><span style="background:white"><span style="line-height:150%"><span new="" roman="" style="font-family:" times=""><span style="color:black">The power line insulators are permanently exposed to various environmental pollutants such as dust and fine particles. This may lead to flashovers and therefore widespread power blackouts and heavy economic damage. One way to overcome this problem is to make the insulator surface superhydrophobic. In this research, the superhydrophobic properties of the insulators were improved by applying room-temperature cured composite coatings consisting of epoxy and hydrophobic nano-silica particles. Either octadecyl trichlorosilane (ODTS) or hexamethyldisilazane (HMDS) was used to coat the silica nanoparticles and make them hydrophobic. Then, the hydrophobic silica was added to a mixture of epoxy resin and hardener. The suspension was applied on the surfaces of a commercial </span></span></span></span></span><span style="font-size:12.0pt"><span style="background:white"><span style="line-height:150%"><span new="" roman="" style="font-family:" times=""><span style="color:red">porcelain</span></span></span></span></span><span style="font-size:12.0pt"><span style="background:white"><span style="line-height:150%"><span new="" roman="" style="font-family:" times=""><span style="color:black"> insulator and </span></span></span></span></span><span style="font-size:12.0pt"><span style="background:white"><span style="line-height:150%"><span new="" roman="" style="font-family:" times=""><span style="color:red">cold cured </span></span></span></span></span><span style="font-size:12.0pt"><span style="background:white"><span style="line-height:150%"><span new="" roman="" style="font-family:" times=""><span style="color:black">at ambient temperature. The coating increased the water contact angle from 50&deg; to 149&deg;. Even after 244 h exposure to the UV light, the samples preserved their hydrophobic properties. The adhesion of the coating was rated as 4B according to the ASTM D3359 standard. The coating decreased the leakage current by 40% and increased the breakdown voltage by </span></span></span></span></span><span style="font-size:12.0pt"><span style="background:white"><span style="line-height:150%"><span new="" roman="" style="font-family:" times=""><span style="color:red">86</span></span></span></span></span><span style="font-size:12.0pt"><span style="background:white"><span style="line-height:150%"><span new="" roman="" style="font-family:" times=""><span style="color:black">% compared to the uncoated sample and showed promise for making power line insulators self-cleaning.</span></span></span></span></span><b><span style="font-size:12.0pt"><span style="line-height:150%"><span style="font-family:"Times New Roman",serif"></span></span></span></b></span></span></span><br> &nbsp; Ceramic Insulator,Flashover,Hydrophobic Coating,Nano silica 60 73 http://ijmse.iust.ac.ir/browse.php?a_code=A-10-4243-1&slc_lang=en&sid=1 Mahnaz Dashti dashtimahnaz06@gmail.com 1800319475328460019264 1800319475328460019264 No Department of Materials Engineering, Faculty of Engineering, Imam Khomeini International University, Qazvin, Iran Saeid Baghshahi saeidbaghshahi@yahoo.com 1800319475328460019265 1800319475328460019265 Yes Department of Materials Engineering, Faculty of Engineering, Imam Khomeini International University, Qazvin, Iran Arman Sedghi sedghi@eng.ikiu.ac.ir 1800319475328460019266 1800319475328460019266 No Department of Materials Engineering, Faculty of Engineering, Imam Khomeini International University, Qazvin, Iran Hoda Nourmohammadi hoda.nourmohammadi@yahoo.com 1800319475328460019267 1800319475328460019267 No Department of Materials Engineering, Faculty of Engineering, Imam Khomeini International University, Qazvin, Iran