With the surrounding temperature regulated at 26.50 °C and 60.0% relative humidity, silicon substrates were placed on the spin coater (Headway PWM32). PS solutions were pipetted onto the silicon wafers until full saturation of the substrate's surface area. Within five seconds of solution the samples were spin coated at a velocity of 2500 rpm and acceleration of 1000 rpm/s for 30 seconds. For each concentration of a specific molecular weight, three samples were spin coated.