Figure 1
From: Kinetics of slow release of nitrogen fertiliser from multi-layered nanofibrous structures

SEM images and related diameter histograms of PLLA electrospun nanofibres containing urea at concentrations of 0% *(A,B), 10% **(C,D), 20% *(E,F), and 40% *(G,H). SEM images and diameter distribution of 7% PHB electrospun nanofibres (I,J). SEM image of cross section of PHB/PLLA/PHB triple-layer nanofibrous structure containing 10% urea at (K) 1000 × magnification, and (L) 2000 × magnification. * Gold coating** Carbon coating.