داعی کے اوصاف: سیرت طیبہ کی روشنی میں

Preaching stands as an obligatory duty and Sunnah of all the Prophets from Adam to Muhammad (SAW). The Prophets (SAW) remained committed with this obligation. After the departure of Prophet (SAW) from this material world, this duty has been assigned to the followers of Prophet Muhammad (SAW) but preaching requires certain qualities/traits. The article presents the qualities of a preacher in the light of Prophet’s biography who stands as a model of Excellence. The qualities of the preacher include the gentleness, cooperation with the followers, benevolence, tolerance, patience, respect for others and intellectual compatibility of the followers.

Synthesis and Characterization of Biofunctionalized Polyurethanes

In this study new series of bio-functionalized polyurethane elastomers, blends and biocomposites with potential for biomedical applications were synthesized, employing hydroxy terminated polybutadiene (HTPB) and different diisocyanates (HMDI, H12MDI, IPDI, TDI, MDI) with stoichiometric balanced mole ratio of curcumin/BDO via step growth polymerization process (1:3:2). In the same way pristine and clay based polyurethanes were prepared, using HTPB/ diisocyanate with different blends of chitin, curcumin and 1,4- butane diol (BDO). Characterization of the sample series was done by means of Fourier transform infrared spectroscopy (FTIR), Solid-state proton nuclear magnetic resonance spectroscopy (SS1HNMR), Scanning electron microscope (SEM), X-ray diffraction (XRD), Thermogravimetric analysis (TGA) and Differential scanning calorimetry (DSC). The FT-IR and SS1HNMR analysis confirmed the involvement of chitin, curcumin and BDO in reaction by appearance of broad peak of N-H at 3327.21 cm-1 and disappearance of –NCO peak at 2268.29 cm-1 in final chitin, curcumin and BDO based polyurethanes. The SEM technique reported the surface morphology of elastomers and complete dispersion of nano-fillers in PU bio-nanocomposites. Crystalline behavior of the synthesized elastomers and bionanocomposites were investigated by X-ray diffraction (XRD), which showed crystallinity improved by chitin and nanofiller (bentonite clay). Thermal behaviors of synthesized blends were studied by using TGA and DSC techniques. The TGA peaks revealed that PU blends with mole ratio 1M:0.5M:0.5M, chitin:curcumin:BDO, respectively, and 0.1% clay have better thermal stability. The anti-bacterial and anti-fungal test for different samples of the curcumin based polyurethanes were studied in order to determine the biocompatibility of various diisocyanate structures based PU samples. It was found that aliphatic diisocyanate based PU showed substantially lower antimicrobial activity as compared to the PU having aromatic diisocyanate. Water absorption and swelling behavior of the synthesized polyurethane elastomers and bio-nanocomposites were also observed by immersing the samples in water and DMSO. In elastomers the chitin reduces the absorption and swelling behavior while against of it in bio-nanocomposites clay improved both of these characters.