Structure-Function Relationship of Calcium Alginate Hydrogels: A Novel Crystal-Forming Engineering
Structure-Function Relationship of Calcium Alginate Hydrogels: A Novel Crystal-Forming Engineering
复制标题
海藻酸钙水凝胶的结构-功能关系：一种新型的晶体形成工程
DOI：
10.1021/cg900154v
复制
发表时间：
2009-08-01
影响因子：
3.8
通讯作者：
Wang, Dujin
中科院分区：
文献类型：
--
作者：
Li, Xinping;Shen, Qiang;Wang, Dujin
海藻酸钙水凝胶是一种含有大量水的交联网络，首次被用作碳酸钙（CaCO3）矿化的前体。明确的几何形状，渗透性。并且这些预凝胶的离子交换性质有利于通过缓慢注入氨和二氧化碳气体来容易地制造方解石超结构。当海藻酸钙水凝胶吸收相对大量的液体时，所得产物具有外部方解石序列转录具有羧基的外部成核位点的海绵状预凝胶珠。这些碳酸钙超结构的内部特征显示了方解石的向心生长趋势。指示水凝胶珠的渗透性和渗透气体的扩散方向。在低液相含量下，预凝胶有利于形成表面相对光滑的方解石超结构，表明方解石纳米颗粒的内部层状阵列。这一战略方针在很大程度上表明了生物控制的成矿机制。处理（1）生物分子的官能团对钙离子的预吸附，（2）三维网络内的受限结晶，以及（3）通过与有机结构的关联使纳米尺寸的方解石适当排列。令人惊讶的是，即使是明显的“单晶”碳酸钙被证明是由微小的方解石菱面体组成的。此外，这些结构单元相对于聚合物的共轭主链彼此共配向。因此，这些建议的多价金属预凝胶相的仿生功能材料的制造的一种新途径。
Hydrogels of calcium alginate are the cross-linked networks containing a large fraction of water, which were used as the precursors of calcium carbonate (CaCO3) mineralization for the first time. The well-defined geometry, the permeability. and the ion-exchange property of these pregels favored the facile fabrication of calcite superstructures through the slow inpouring of ammonia and carbon dioxide gases. When calcium alginate hydrogels sponged up a relatively high amount of liquid, (he resulting products With the Outside calcite sequences transcribed the spongelike pregel beads with the outside nucleation sites of carboxyl groups. The inner characteristic of these CaCO3 superstructures showed the endocentric growth trends of calcite. indicating, the permeability of hydrogel beads and the diffusing directions of permeated gases. In the presence of low liquid content, the pregels favored the formation of calcite superstructures with relatively smooth Surfaces, demonstrating the inside lamellar array of calcite nanoparticles. This strategic approach indicated to a great extent the biologically controlled mineralization mechanism. dealing with (1) the preadsorption of calcium ions by the functional groups of biomolecules, (2) the confined crystallization within the three-dimensional networks, and (3) the proper arrangement of nanosized calcites by association with the organic architectures. Surprisingly, even the apparently "single-crystalline" CaCO3 was proven to comprise tiny calcite rhombohedrons. Furthermore, these building blocks coaligned each other with respect to the polymers' conjugated backbones. Therefore, these suggest a novel pathway of multivalent metal pregelation phases for the biomimetic fabrication of functional materials.