Mohamed H, Hkiri K, Botha N, Cloete K, Azizi Sh, Ahmed A A Q, Morad R, Motlamane Th, Krief A, Gibaud A, Henini M, Chaker M, Ahmad I, Maaza M
UNESCO-UNISA Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria, South Africa.
Nanosciences African Network (NANOAFNET), Materials Research Department, iThemba LABS-National Research Foundation of South Africa, 1 Old Faure Road, Somerset West, PO Box 722, Cape Town, 7129, Western Cape, South Africa.
Sci Rep. 2023 Oct 5;13(1):16783. doi: 10.1038/s41598-023-42905-5.
This contribution reports, for the first time, on an entirely green bio-engineering approach for the biosynthesis of single phase crystalline 1-D nano-scaled calcite CaCO. This was validated using HO as the universal solvent and natural extract of Hyphaene thebaica fruit as an effective chelating agent. In this room temperature green process, CaCl and CO are used as the unique source of Ca and CO respectively in view of forming nano-scaled CaCO with a significant shape anisotropy and an elevated surface to volume ratio. In terms of novelty, and relatively to the reported scientific and patented literature in relation to the fabrication of CaCO by green nano-chemistry, the current cost effective room temperature green process can be singled out as per the following specificities: only water as universal solvent is used, No additional base or acid chemicals for pH control, No additional catalyst, No critical or supercritical CO usage conditions, Only natural extract of thebaica as a green effective chelating agent through its phytochemicals and proper enzematic compounds, room Temperature processing, atmospheric pressure processing, Nanoscaled size particles, and Nanoparticles with a significant shape anisotropy (1-D like nanoparticles). Beyond and in addition to the validation of the 1-D synthesis aspect, the bio-engineered CaCO exhibited a wide-ranging functionalities in terms of highly reflecting pigment, an effective nanofertilizer as well as a potential binder in cement industry.
本论文首次报道了一种完全绿色的生物工程方法，用于合成单相结晶一维纳米级方解石CaCO₃。该方法以水作为通用溶剂，利用海枣果实的天然提取物作为有效的螯合剂进行了验证。在这个室温绿色过程中，鉴于形成具有显著形状各向异性和高表面积与体积比的纳米级CaCO₃，分别使用CaCl₂和CO₂作为Ca和CO₂的唯一来源。就新颖性而言，相对于已报道的有关通过绿色纳米化学制备CaCO₃的科学文献和专利文献，当前具有成本效益的室温绿色过程可根据以下具体特点脱颖而出：仅使用水作为通用溶剂，无需额外的碱或酸化学品来控制pH值，无需额外的催化剂，无需临界或超临界CO₂使用条件，仅使用海枣的天然提取物作为通过其植物化学物质和适当酶化合物的绿色有效螯合剂，室温处理，常压处理，纳米级尺寸颗粒，以及具有显著形状各向异性的纳米颗粒（一维状纳米颗粒）。除了验证一维合成方面之外，生物工程制备的CaCO₃在高反射颜料、有效的纳米肥料以及水泥工业中的潜在粘结剂方面展现出广泛的功能。
