高分子改性黄原胶/羟基磷灰石复合水凝胶的制备及其吸附金属离子性能

以黄原胶为接枝骨架,丙烯酸为单体,羟基磷灰石为无机组分,通过氧化还原聚合反应,制备了高分子改性黄原胶/羟基磷灰石复合水凝胶(XG-g-PAA/HAP).红外光谱和扫描电镜表征发现,在低温条件下(50℃)成功制备了XG-g-PAA/HAP.将XG-g-PAA/HAP用作水体重金属离子吸附剂,结果表明:当pH1时,XG-g-PAA/HAP吸附容量较小,随着pH增大,吸附容量快速增大,当pH4时,吸附容量达到平衡;90%以上的金属离子在30 min内可被清除.当Cu~(2+)]=300 mg·L~(-1)和Pb~(2+)]=600 mg·L~(-1)时,XG-g-PAA/HAP吸附容量达到最大值.重复吸附-脱吸附5次后,吸附容量仍可保持初始的80%,所制备的XG-g-PAA/HAP有望成为一种有效的水体重金属离子吸附剂.

Preparation of polymer modified xanthan gum/hydroxyapatite composite hydrogel and its absorption for metal ions

Using xanthan gum (XG) as the natural polymer, hydroxyapatite (HAP) as inorganic materials, and acrylic acid (AA) as functional monomer, a novel polymer modified organic/inorganic composite hydrogel (XG-g-PAA/HAP) was prepared with in situ polymerization. The obtained polymer composite hydrogel (XG-g-PAA/HAP) was applied to absorb heavy metal ions, such as copper (Cu²⁺) and lead (Pb²⁺) ions. The result indicate that the polymer composite hydrogel has excellent adsorption activity for Cu²⁺ or Pb²⁺, reaching to 514.6 mg·g^-1 and 1169.5 mg·g^-1, respectively. It is found that the polymer composite hydrogel could be stable more than 5 times under adsorption-desorption process, and 80% of adsorption capacity was kept. In summary, the polymer composite hydrogel (XG-g-PAA/HAP) is a kind of valuable adsorbent for removing heavy metal ions in water.