Which bond should be
more stronger , C-C or C=C. why?

carbon - carbon double bonds are stronger . More is the overlapping , more stronger a bond is. Hence, carbon - carbon double bond is stronger than single bond.

Hey mate hope its help you

nanotechnology is a powerful tool in biomaterials research as it creates numerous possibilities for the engineering of functional molecules. nano-bio refers to projected ability to incorporate biomimicry into various materials at nanoscale.  

answer: the rate of diffusion increases with increase in temperature.

increase in temperature, increases the molecular/particles speed (kinetic energy. diffusion means movement of particles through the material.

generally, the heavier the particle the more it interacts with the environment and more the temperature matters. so higher temperature results in higher diffusion.