Fast microwave syntheses of fly ash based porous geopolymers in the presence of high alkali concentration

Onutai, Sujitra; Jiemsirilers, Sirithan; Thavorniti, Parjaree; Kobayashi, Takaomi

doi:10.1016/j.ceramint.2016.03.086

Cited by 69 publications

(30 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…28 The particle sizes in fly ash vary from < 1 µm up to more than 100 µm and the surface area is typically 300-500 m 2 /kg. 75,76 When fly ash was the only source of aluminosilicate reactive materials, there were many methods to prepare its porous structure, such as SFM, [77][78][79][80] DFM (Al), [81][82][83] DFM (H 2 O 2 ), 84,85 PSM, 86,87 and so forth. Its applications involve building lightweight, 20,88 adsorption mental ions, 89,90 building insulation, 91 permeable concrete, 92 and so on.…”

Section: Fly Ashmentioning

confidence: 99%

A review on the porous geopolymer preparation for structural and functional materials applications

Chen

et al. 2022

Int J Applied Ceramic Tech

View full text Add to dashboard Cite

Geopolymer (also called inorganic polymers) is a kind of amorphous gel material with a 3D structure consisting of SiO4 and AlO4 tetrahedra. It has drawn international attention due to its environmental friendliness and excellent performance. This review covers raw materials, preparation methods, and applications of porous geopolymer materials with micropore, mesopore, or macropore. The preparation methods can be divided into five categories: (i) self‐forming method, (ii) direct foaming method, (iii) adding filler method, (iv) particles stacking method, and (v) other methods. In this paper, different raw materials and applications were combined with the preparation methods, and some general conclusions of porous geopolymer were summarized. The applications of porous geopolymer materials in building materials, adsorbents, porous ceramics, membrane separation, catalyst, pH regulator, and other fields were introduced as well.

show abstract

Section: Fly Ashmentioning

confidence: 99%

A review on the porous geopolymer preparation for structural and functional materials applications

Chen

et al. 2022

Int J Applied Ceramic Tech

View full text Add to dashboard Cite

show abstract

“…Hence, its FTIR ( Fig. 1A) exhibits a broad band in the range 1,200 -900 cm -1 with a centre around 1,090 cm -1 which is attributed to the asymmetric stretching vibration peaks of Si-O-Si or Si-O-Al bonds of SiO2 or AlO4 tetrahedrons which overlap in this region (Böke et al 2015;Onutai et al 2016). The shoulder visible between 1,074 and 1,069 cm -1 corresponds to the Si-O-Si stretching vibration.…”

Section: Interaction Between the Antibiotics And The Sorbent Surfacesmentioning

confidence: 99%

Adsorptive removal of ciprofloxacin and isoniazid from aqueous solution

Dube¹,

Tandlich²,

Wilhelmi³

2018

Nova Biotechnologica Et Chimica

View full text Add to dashboard Cite

This paper describes study of ciprofloxacin and isoniazid removal from aqueous solutions using coal fly ash (FA), kaolinite, perlite, talc and vermiculite. The adsorptive features of the adsorbents were evaluated for ciprofloxacin and isoniazid with regards to the effects of contact time, pH, the solid/liquid ratio and antibiotic concentration. All adsorbents were sterilised by dry heat before use to avoid the proliferation of antimicrobial resistance by the bacteria present on the adsorbents during experiments. The regression correlation coefficients indicate that the Langmuir model gives the best fit for the sorption of both antibiotics onto FA and talc, ciprofloxacin onto kaolinite, and isoniazid onto perlite and vermiculite with R2 values ranging from 0.908 – 0.999. The Freundlich isotherm best describes the sorption of ciprofloxacin onto vermiculite and isoniazid onto kaolinite with R2 values of 0.999 for both. The Tempkin model best describes the sorption of ciprofloxacin onto perlite with an R2 = 0.997. The values of the Freundlich exponent, 1/n, range from 0.221 – 0.998, indicating a favourable adsorption of ciprofloxacin and isoniazid onto the adsorbents. The heat of sorption, B, calculated from the Temkin plots has values ranging from 0.018 – 10.460 J/mol, indicating a physical adsorption process (physisorption). Adsorption equilibrium was achieved after 30 min for both antibiotics and the kinetic data obtained conforms best to the pseudo-second order equation with R2 values ranging from 0.998 – 0.999. The removal of ciprofloxacin and isoniazid by all adsorbents except FA was strongly influenced by the pH suggesting that electrostatic interactions play a major role in the adsorption processes.

show abstract

“…The conventional curing method of geopolymer using a hot dry oven is, however, comparatively inefficient in terms of time and energy consumption. Recently, some researchers utilized an advanced, direct heating tool— a microwave oven, in place of or in combination with the dry oven 18–21 . It was shown that high-strength geopolymers can be produced more effectively because microwave energy can promote the dissolution and polycondensation of precursor species due to its penetrative and fast heating characteristics 18,19 .…”

Section: Introductionmentioning

confidence: 99%

Effects of Microwave Energy on Fast Compressive Strength Development of Coal Bottom Ash-Based Geopolymers

Hong

Kim

2019

Sci Rep

View full text Add to dashboard Cite

Microwave energy has been shown to be effective for geopolymer synthesis due to its fast and penetrative heating characteristics; however, the changes in the physicochemical properties of the geopolymer, resulting from the microwave irradiation, have not been fully elucidated. Therefore, this study is aimed at investigating the effect of the microwaving on the properties of coal bottom ash(CBA) geopolymers. We prepared geopolymer samples by casting a mixture of ground CBA and 14 M NaOH solution against cubic molds with a hand press machine, followed by pre-curing in a dry oven at 75 °C for 24 h and microwaving under various powers and durations. The compressive strength strongly depended on the moisture content, i.e., the strength increased from 21 to 65 MPa or higher as the moisture content decreased to critical values, after which the strength began to decrease. The results showed that microwave energy stimulated an additional geopolymerization by evaporating the redundant free water. This led to the strength gain, although the over-irradiation generated a high internal stress and poor structural integrity, which resulted in the strength loss. Therefore, the appropriate application of microwave energy is a promising option for synthesizing high-strength geopolymers in a cost- and time-effective manner.

show abstract

Fast microwave syntheses of fly ash based porous geopolymers in the presence of high alkali concentration

Cited by 69 publications

References 38 publications

A review on the porous geopolymer preparation for structural and functional materials applications

A review on the porous geopolymer preparation for structural and functional materials applications

Adsorptive removal of ciprofloxacin and isoniazid from aqueous solution

Effects of Microwave Energy on Fast Compressive Strength Development of Coal Bottom Ash-Based Geopolymers

Contact Info

Product

Resources

About