Abstract
Large deposits of impure kaolins exist in Jordan and many parts of the world; geoplymers can reduce environmental impacts and have multi-application in many fields, such as water purification, waste treatment, fire proof construction, etc. The aim of this research is to investigate the use of alkali activated zeolitic tuff and low purity metakaolin as precursors for the production of functional geoplymers exhibiting proper mechanical properties and high potential for water storage and decontamination of polluted solutions. The results confirmed that this type of geopolymers showed superior mechanical characteristics and higher adsorption capacity towards heavy metals such as Cu(II) ions, which was similar to natural zeolite. X-ray diffraction analysis showed that phillipsite, a major zeolite mineral, disappeared upon geopolymerization, while scanning electron microscopy analysis showed that geopolymers exhibit a porous matrix of nano-particles. The geopolymers have also displayed high compressive strength and tensile bending strength of about 7.8 MPa and 45 MPa respectively, compared to reference geopolymers. This functional-geopolymers indicate that they are efficient, cost effective and have a potential for number of applications including construction, water storage and wastewater treatment.
Highlights
IntroductionIt has been observed that through chemical polymerization reactions, aluminosilicates such as clays could be hardened and transformed into aluminosilicate polymers, known as geopolymers, which are potential construction materials [1] [2]
Geopolymers have drawn attention because of their great mechanical characteristics
The scanning electron microscopy (SEM) image reveals that due to geopolymeric reactions the gaps between partially reacted metakaolin sheets have been filled with the formed of sodium aluminosilicate
Summary
It has been observed that through chemical polymerization reactions, aluminosilicates such as clays could be hardened and transformed into aluminosilicate polymers, known as geopolymers, which are potential construction materials [1] [2]. Geopolymers consist of an amorphous, three-dimensional structure resulting from the polymerization of aluminosilicate monomers in an alkaline solution [3], aluminosilicate monomers in an alkaline solution [3]. When aluminum is four coordinated coordinated to oxygen atoms, a negative charge is created and the presence of cations, such as Na+, is essential to balance electric charge in the geopolymeric matrix (hydroxysodalite). Hydroxysodalite, which maybe amorphous or microcrystalline, consists of SiO4 and AlO4 tetrahedra linked alternately by sharing all the oxygen atoms [6]. Positive ions (Na+, K+, Li+, Ca2+, Ba2+, NH4+, and H3O+) need be present in the framework cavities to balance the negative charge of Al in the fourfold coordination
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
