Roles of superabsorbent polymers (SAPs) and palm oil fuel ash (POFA) on the strength, cost analysis and CO emission of lightweight concrete: Comparison with aluminum-based aerated concrete.

This work investigated the effects of superabsorbent polymers (SAPs) as pore-forming agent and palm oil fuel ash (POFA) as sand replacement (0-100 % by weight) on the strength, economic feasibility, and CO emissions for lightweight concrete production. The product properties were compared with the traditional aerated concrete (with aluminum powder), which aimed to shed light on the use of SAPs and POFA for manufacturing a more sustainable lightweight concrete. The use of POFA to replace sand increased the cost of production by approximately 1-7% and CO emissions by approximately 3-12 % due primarily to the transportation of the POFA from the oil palm fuel power plant, which could be avoided if produced on site of or near the power plant.

Hard tissue formation in pulpotomized primary teeth in dogs with nanomaterials MCM-48 and MCM-48/hydroxyapatite: an in vivo animal study.

Background: This animal study sought to evaluate two novel nanomaterials for pulpotomy of primary teeth and assess the short-term pulpal response and hard tissue formation in dogs. The results were compared with mineral trioxide aggregate (MTA).

Methods: This in vivo animal study on dogs evaluated 48 primary premolar teeth of 4 mongrel female dogs the age of 6-8 weeks, randomly divided into four groups (n = 12).

Synthesis of belite cement from nano-silica extracted from two rice husk ashes.

Nano-silicas extracted from a pure rice husk ash calcined in the laboratory (RHA) and ash from an impure industrial rice husk waste (BRHA), were used to form belite cement by firing with two different calcium sources (calcium carbonate and calcium nitrate). The nano-silica extracted from RHA was highly reactive due to its high pore volume and low activation energy of dehydration. The formation of belite cement from both nano-silicas was studied by firing with two different calcium sources, Ca(NO) and CaCO at 800-1100 °C.

New composites of nanoparticle Cu (I) oxide and titania in a novel inorganic polymer (geopolymer) matrix for destruction of dyes and hazardous organic pollutants.

New photoactive composites to efficiently remove organic dyes from water are reported. These consist of Cu2O/TiO2 nanoparticles in a novel inorganic geopolymer matrix modified by a large tertiary ammonium species (cetyltrimethylammonium bromide, CTAB) whose presence in the matrix is demonstrated by FTIR spectroscopy. The CTAB does not disrupt the tetrahedral geopolymer structural silica and alumina units as demonstrated by (29)Si and (27)Al MAS NMR spectroscopy.

Porous ceramics mimicking nature-preparation and properties of microstructures with unidirectionally oriented pores.

Porous ceramics with unidirectionally oriented pores have been prepared by various methods such as anodic oxidation, templating using wood, unidirectional solidification, extrusion, etc. The templating method directly replicates the porous microstructure of wood to prepare porous ceramics, whereas the extrusion method mimics the microstructures of tracheids and xylems in trees. These two methods are therefore the main focus of this review as they provide good examples of the preparation of functional porous ceramics with properties replicating nature.

Synthesis and thermal behaviour of gallium-substituted aluminosilicate inorganic polymers.

A combined sol-gel and solid-state method reported for the synthesis of gallium silicate analogues of aluminosilicate inorganic polymers has also been extended to the formation of related compounds with a range of Al-for Ga substitutions. Homogeneous, robust products were obtained at an optimum composition of SiO(2):(Ga(2)O(3) + Al(2)O(3)) = 7. After curing at 40 °C, all the products were typically X-ray amorphous, and the Al and Ga was shown by (27)Al and (71)Ga MAS NMR spectroscopy to be in solely tetrahedral coordination.

Simultaneous uptake of Ni2+, NH4+ and PO4(3-) by amorphous CaO-Al2O3-SiO2 compounds.

Simultaneous uptake of Ni2+, NH4+, and PO4(3-) by amorphous CaO-Al2O3-SiO2 (C-A-S) compounds was investigated using batch and column methods. Fifteen different C-A-S samples with systematically varied chemical compositions were prepared by coprecipitation from ethanol-water solutions containing Ca(NO3)2.4H2O, Al(NO3)3.

Simultaneous uptake of ammonium and phosphate ions by compounds prepared from paper sludge ash.

Al-containing CaO-SiO(2)-H(2)O phases were prepared by hydrothermal treatment of mixtures of paper sludge ash (PSA) with various silica and calcia sources and their properties were determined with particular reference to the simultaneous uptake of ammonium and phosphate ions, which are implicated in the eutrophication of lakes and ponds. After examination of various silica and calcia sources, Ca(OH)(2) and SiO(2) sol were selected as the most appropriate starting materials. Dry milling was found to be superior to wet milling in avoiding contamination from the milling media during mixing.

Multi functional uptake behaviour of materials prepared by calcining waste paper sludge.

This study concerns with the utilization of waste paper sludge, which contains mainly cellulose fibers and inorganic fillers together with coating materials such as calcite, kaolinite and talc. Paper sludge was fired at 500-900 degrees C for 6 h. The crystalline phases originally present decomposed at increasing temperatures (up to 800 degrees C) in the order kaolinite < calcite < talc.

Effect of grinding and heating on Ni2+ uptake properties of waste paper sludge.

Uptake properties of Ni2+ were examined for unmilled and milled paper sludge calcined at various temperatures to develop a new usage of waste paper sludge. Since paper sludge mainly consists of cellulose ([C6H(10)O5]n) fibers, calcite (CaCO3), kaolinite (Al2Si2O5(OH)4) and talc (Mg3Si(4)O(10)(OH)2), amorphous and crystalline CaO(MgO)-Al(2)O(3)-SiO(2) compounds are formed by calcining paper sludge. Wet and dry milling treatments were performed to accelerate solid-state reaction to form the above mentioned target compounds.

Synthesis of high surface area Al-containing mesoporous silica from calcined and acid leached kaolinites as the precursors.

Al-containing mesoporous silicas were synthesized by hydrothermal treatment of microporous silica prepared by selectively acid leached metakaolinites with Si/Al = 3.9-92.5 mixed with a surfactant of cetyltrimethylammonium bromide (CTABr).

Uptake properties of Ni2+ by nCaO.Al2O3.2SiO2 (n=1-4) prepared from solid-state reaction of kaolinite and calcite.

A series of nCaO.Al2O3.2SiO2 samples (n=1-4) were prepared by solid-state reaction of mechanochemically treated mixtures of kaolinite and calcite fired at 600-1000 degrees C for 24 h.