Research On Immobilization Of Hydroxyapatite Particles Onto PET Filter Fabric And Property Analysis

Hydroxyapatite particles were embedded onto PET filter fabric surface via hot-press method and heat fusion method for heavy metal adsorption property. Particles were surface modified and connected with polymer chain to achieve better immobilizing effect. As pore size of filter fabric can be affected after treatment, immobilization ratio and pore size ratio are adopted to evaluate the effect of process conditions on immobilizing effect. Besides, FTIR and XRD are performed to characterize the structure of samples. Morphology of treated samples is observed with SEM.It can be learn from the results that under conditions of particle amount 10g/L, compress force of 3MPa at 245℃ for treating 120 s, immobilization ratio of 48.8% and pore size of 88.3um could be achieved with hot-press method while immobilization ratio of 41.0% and pore size of 110.2um could be obtained at particle amount of 20g/L under 250℃ for 180 s with heat fusion method. Hot-press method was significant in embedding hydroxyapatite particles onto fabric surface with sacrifice of pore size while heat fusion method could better maintain the pore size with lower immobilization rate. 45.2% of modified hydroxyapatite particles were immobilized onto PET filter fabric surface with particle amount of 20g/L under 250℃ for 180 s via heat fusion method, suggesting that surface modification is favorable for embedding particles. After introducing polymer chain onto particle surface, immobilization ratio of 63.6% and pore size of 102.3um can be obtained with particle amount of 10g/L, particle size of 309.5nm and polymer chain length of 13.57(mole ratio to particle) under 200℃ for 120 s with heat fusion method, indicating that introducing polymer chain onto particle surface can promote immobilization ratio with less damage to pore size.Adsorption peak at 564cm-1,602cm-1 and 1026cm-1 in FTIR spectra which were ascribed to PO43- and 2? angle at 25.45°,31.78°,32.54°,39.40°,46.21°, 49.18° in XRD patterns which were attributed to 002,211,300,310,222 and 213 crystal face respectively in hydroxyapatite lattice suggested that hydroxyapatite particles are embedded onto PET filter fabric successfully. Particles can also be observed decorated on fiber surface randomly with SEM graphs.Heavy metal adsorption property of samples prepared with optimized conditions is tested with 387.7mg/L of Cd2+ ions solution. Results showed that adsorption quantities of hydroxyapatite on as-prepared samples are 66.8mg/g, 65.4mg/g, 64.8mg/g and 118.4mg/g respectively. It is believed that embedding particles directly onto fabric surface can hinder the adsorption process while particles have fully access to heavy metal ions after immobilizing through molten polymer chain.