Direct solvothermal growth of the metal organic framework (MOP) UiO-66-NH2 on polymer surface was successfully demonstrated. By using acetone as the solvent for synthesis instead of N,N-dimethylformamide, polymers like polyacrylonitrile (PAN) can be used directly in the solvothermal synthesis step to grow MOF on the polymer surface. We use X-ray diffraction and FT-IR to confirm our method produces crystalline UiO-66-NH2 on the surface of electrospun PAN nanofibers. Characterization of this type of composite revealed up to 50 wt % MOF loading according to nitrogen isotherms. Since the MOFs are located on the surface of the polymer fibers, the composites are capable of high loadings of chlorine gas. Compared to electrospun composites made with preformed UiO-66-NH2, the in situ method is a simple alternative that produces composites with higher MOF loading.