双亲水性嵌段共聚物对CaCO_3结晶的影响

以合成的带有磺酸基为端基的线型-超支化二嵌段共聚物PEG-b-PEI-SO3H为模板,探讨了其对CaCO3结晶的影响,并用FTIR、XRD、SEM、TEM等对产物进行了表征.结果表明,带有—SO3H端基的线型-超支化双亲水性嵌段共聚物PEG-b-PEI-SO3H对CaCO3晶体形貌和晶型表现出较强的调控能力.培养1天时得到空心环状方解石型CaCO3晶体,但当培养时间为3天和5天时,得到的CaCO3晶体形貌既有河蚌状也有类球状,同时其晶型既有方解石也有球霰石,而当培养时间达到7天后,得到的就只有球状球霰石CaCO3晶体.

INFLUENCE OF A DOUBLE-HYDROPHILIC BLOCK COPOLYMER WITH SULFONIC GROUPS ON THE CRYSTALLIZATION OF CaCO3

A hybrid double-hydrophilic block copolymer(DHBC) of PEG-b-PEI-SO_3H with sulfonic groups was synthesized and investigated as a modifying additive for CaCO_3 crystallization.The DHBC was well characterized by FTIR.Primary investigations indicated that this hybrid double hydrophilic block copolymer(DHBC) possessed strong modifying ability for both polymorphism and morphologies of inorganic crystals due to the especial structure with sulfonic groups.The crystal morphologies were investigated by SEM and TEM.The SEM and TEM results indicated that pure hollow round ring calcite was obtained after 1 day,while mussel-like and spherical-like calcium carbonates were produced after 3 or 5 days.When the reaction time was 7 days,almost pure spherical particles were obtained.The crystal phases were fully characterized with FTIR,XRD.The XRD results indicated that the calcium carbonate obtained after 1 day was calcite,and not only calcite but also vaterite was formed after 3 or 5 days,pure vaterite was produced after 7 days.These results were accordant with the FTIR measurement.When the reaction time was 1 day,the peaks at 875 cm-1 and 712 cm-1 indicated the calcium carbonate obtained was calcite.With prolonging of reaction time from 1 day to 3 or 5 days,the peaks at 875 cm-1,745 cm-1 and 712 cm-1 identified the calcite as well as vaterite crystals.While the 875 cm-1 and 745 cm-1 peaks appeared after 7 days,but the peak at 712 cm-1 disappeared,which showed that the pure vaterite was produced.