Two different interfaces were the focus of study: 1) the interface between disordered amorphous carbon and inorganic materials (metal nanostructures and silicon), and 2) the interface between partially ordered graphene (graphene oxide) and synthetic polymer matrix. Specifically, the uniqueness of this study can be summarized through the following novel findings, fabrication processes, and characterization techniques: • A simple and efficient process for faster, greener, less-expensive, and highly localized transformation of amorphous carbon nanostructures into graphitic nanostructures using low temperature heat and light treatments was developed for the fabrication of low-resistance interfaces between carbon nanomaterials and inorganic metal surfaces. • A new protocol for high resolution mapping the charge distribution and electronic properties of nanoscale chemically heterogeneous domains on non-homogeneous surfaces such as graphene oxide was established. • High strength laminated mechanical nanocomposites based on high interfacial stress transfer between polymer matrices and large area, flat, and non-wrinkled graphene oxide sheets were suggested and demonstrated. • Scanning Thermal Twist Microscopy – a thermal microscopy based technique was developed and demonstrated for characterizing the thermal properties of homogeneous and heterogeneous interfaces with nanoscale spatial resolution and high thermal sensitivity unachievable using traditional techniques.