Carbon-coated holey polymer film (HPF), or ‘holey carbon grid’ used to support fragile samples, is a crucial part of Cryo-TEM technique. A film with high porosity and uniform hole size as well as mechanical strength is needed. Efforts to develop a reliable preparation method date back to the 1950s. Today's favorite by far for routine application employs condensation, dip-coating, drainage and drying.it is not difficult, it affords control of hole size, and its yield is comparatively good. In this study, the mechanisms of hole generation and film formation were uncovered by means of in situ microscopy at medium working distance, super-VHS video recording and a high-speed motion analyzer, SEM and TEM.Clean microscope slides were treated with Amine 105 (Kao-Atlas Co. Japan) to make the surface hydrophobic. A slide was then immersed in liquid nitrogen and exposed for 3 to 6 seconds to air with relative humidity of 30 to 60%.
In Situ Study of Ultrathin Film Formation on Au(111) Surface in Propylene Carbonate by Scanning Tunneling Microscopy under Potential Control