Papers by Keyword: Calcium Carbonate

Abstract: Bio-cementation binding processes in soil particle pores are using ureolytic bacteria as the main ingredient to substitute cement. Environmental parameters around bacteria affect their activity, including soil water content. The purpose of the study is to evaluate the effect of water content on the cementation process in silica sand on a laboratory scale. The sand was placed in an acrylic box with dimensions of 15x10x11 cm³ and perforated drainage on the left and right sides. It was prepared in three conditions: dry, partially submerged, and fully submerged. Each sandbox receives periodic injections containing Sporosarcina pasteurii and cementation reagents for 15 days. After injection, the distribution of cementation products was visually examined, and the bonds between sand particles were stronger under lower initial water content. The total amount of CaCO₃ proportion was measured, and most formed in dry conditions.

Abstract: The study presents the mechanical performance, particularly energy absorption ability, under uniaxial quasi-static compression of aluminium foams fabricated by melt processing with CaCO₃ blowing agent and B₄C+TiB₂ powder with content varied from 30 to 70%. High-strength Al6Zn2.3Mg alloy comprising brittle eutectic domains was employed for manufacture of the foam. The optimal amount of B₄C + TiB₂ powder was determined to be 50% at which it results in the highest energy absorption. The key role of identity sizes for B₄C + TiB₂ and CaCO₃ powders for the efficiency of the foaming process with the formation of certain particle configurations in the melt was examined and discussed. The results of the present study could be helpful for selecting the aluminium alloy and additives for the foaming process and providing a certain level of the mechanical properties, particularly, energy absorption ability.

Abstract: The study presents electrical performance metrics, especially, electrical resistivity, of aluminium based foams. They were fabricated by melt processing with cheap CaCO₃ blowing agent and compared to those produced commercially with an expensive TiH₂. Relatively ductile Al1Mg0.6Si alloy and high strength Al6Zn2.3Mg alloy comprising brittle eutectic domains were employed as matrix alloys for carbonate foams manufacture, whereas only aluminium was used for production of hydride foams. The important difference concerns test method procedure employed for measuring the electrical properties of the foams. The novel system equipped by novel instrument GOM 805 was developed and used for direct determination of electrical resistivity of the foams. In contrast, the known measurement of a thick metal foam sheet resistivity concerns a routine four-point probe technique. The specific electrical resistivity obtained for the experimental foams was compared and discussed with the published data of the foams manufactured by melt processing with TiH₂ of trade name Alporas^Ò and prepared by powder metallurgical technique with trade mark Alulight^Ò.It was established after comparative study that the present porous samples exhibit higher values of specific electrical resistivity then available in the market that may provide wider engineering application of the studied foams.

Abstract: This study evaluates the effect of a starch-calcium carbonate coating on the quality of paper produced from empty fruit bunches (EFB) of oil palm. The primary objective is to assess the changes in water absorbance of the paper before and after the coating process. Samples of EFB paper were coated and subsequently tested using a Cobb tester to measure their water absorbance. The results indicate that the coating application significantly reduced the paper’ water absorbance. These findings suggest that a starch-calcium carbonate coating can improve the quality of paper made from agricultural waste. The implications of this research may lead to new opportunities for utilizing agro-industrial waste in the paper manufacturing industry.

Abstract: Oil contamination from petroleum hydrocarbons and other sources poses significant environmental and health risks due to its persistence and toxicity. This study developed polyethylene-calcium carbonate (PE-CC) composites with tailored structural and surface properties to enhance oil adsorption. The composites were fabricated through melt blending (PE:CC = 40:60), with the calcium carbonate (CC) filler first modified using oleic acid (OA) (0, 0.5, and 1.5 wt.%) to improve hydrophobicity and dispersion, followed by citric acid (1 M) treatment of the composites to induce porosity and optimize oil adsorption. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) confirmed successful surface modification of CC, as evidenced by reduced diffraction peak intensities and the emergence of new functional groups at 2970 cm^-1 and 1395.12 cm^-1. Citric acid treatment led to partial CC dissolution, resulting in up to 8.96 % weight loss, as confirmed by XRD and energy-dispersive spectroscopy (EDS). Scanning electron microscopy (SEM) revealed increased porosity (up to 40 μm) and enhanced surface roughness, particularly in TE 3. Wettability analysis demonstrated a maximum contact angle of 160.80° following OA modification of CC, while oil adsorption tests of the PE-CC composites showed substantial improvements in oil uptake, with vegetable oil adsorption increasing from 5.21 % (NE) to 18.75 % (TE 3), and hexane and diesel reaching 18.4 % and 12.5 % respectively, in TE 3. Photoluminescence analysis revealed wavelength-dependent blue-violet emissions with broad peaks at 405 and 570 nm when excited at 255 and 405 nm, respectively, indicating potential optical applications. These findings show the potential of OA and citric acid modifications in enhancing the surface properties, photoluminescence, and adsorption efficiency of PE-CC composites, positioning them as promising candidates for oil remediation and multifunctional industrial applications.

Abstract: Polystyrene (PS) is widely used in industries like packaging and insulation, but its performance can be enhanced by incorporating calcium carbonate as a filler. To improve polymer-filler compatibility, calcium carbonate was surface-modified with oleic acid, and PS-calcium carbonate composites were synthesized using the melt blending method, followed by citric acid treatment. X-ray diffraction (XRD) and FTIR analyses revealed no chemical interaction between the phases, with a reduction in calcium carbonate content due to citric acid treatment, suggesting partial dissolution of the filler. Scanning electron microscopy (SEM) images showed the formation of cavities in the matrix, especially in TPS3. Hardness testing indicated a decrease in hardness with increasing oleic acid concentration, with TPS3 exhibiting the lowest hardness (63.4 Shore D). Photoluminescence measurements showed a blue shift at lower oleic acid concentrations, while higher concentrations caused a red shift and broader emission, which was stabilized by citric acid treatment. Solvent absorption tests indicated that citric acid-treated composites had an enhanced absorption capacity, with TPS3 showing 38.3 % absorption in vegetable oil, suggesting potential for adsorption applications. Overall, the oleic acid and citric acid treatments significantly modified the mechanical, morphological, and optical properties of PS-calcium carbonate composites, creating tunable materials with potential for sensing applications.

Abstract: Cement is frequently utilized in the building business across the world, and experts are currently looking for an acceptable and usable unused product that would substantially reduce cement consumption and production costs. Eggshell is one of the waste materials created by the chicken egg industry, and its production has been gradually rising in recent years, adding to environmental and disposal concerns. The chicken eggshell is a bio-ceramic composite that is a solid waste material whose final disposal is complicated and expensive. Following that, the presence of organic egg shells in the form of calcium carbonate improves the self-compacting capabilities of concrete and increases particle packing and spacer effects. The aim of this paper is to evaluate the mechanical characteristics of bio-cement eggshell composites, investigate the microstructure of eggshells by scanning emission microscope (SEM) and determine the phase distribution of eggshell composites by using x-ray diffraction (XRD).

Abstract: Nowadays, thermoplastic starch-based biopolymers are an option to be developed into products for domestic use. However, thermoplastic starch (TPS) has poor antioxidant characteristic, which restricts its use in food packaging or films. To address this issue, the starch can be combined with a green and low-cost anti-oxidative agent, to create a new, reasonably priced TPS biocomposites. Anti-oxidative agent that derived from natural sources is the best option due to the non-toxicity, environmentally friendly and abundancy. In this study, the shear mixing and casting processes were employed to form biocomposite films made of TPS, red cabbage, and calcium carbonate with varying calcium carbonate loadings. Prior to the production of the biocomposite, the anthocyanins in the red cabbage was extracted for use as an antioxidant. The biocomposites' structures and morphology were examined using Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray Diffraction (XRD). Antioxidant and biodegradability testing were performed to assess the suitability of the TPS biocomposites for biodegradable food packaging application. Results indicate that the antioxidant activity and biodegradability of the TPS improved with the addition of the red cabbage, either in powder form or liquid form. Furthermore, the red cabbage powder not only acts as antioxidant but also as filler together with CaCO₃ to improve the performance of the TPS biocomposite for food packaging application.

Abstract: Calcium carbonate (CaCO₃) and silica are two types of additives for rubber. Through the implementation of a typical semi-efficient (Semi-EV) vulcanisation formulation, those additives were added separately into the compound of natural rubber (NR). The CaCO₃ or silica was added as the reinforcing filler and, incorporated into NR at a constant concentration i.e., 30 parts per hundred NR (phr). It was found that the CaCO₃ or silica have successfully provided an increase in mechanical properties including a greater tensibility (tensile strength) and abrasion resistance of the compound of NR. However, as hydrophilic fillers, the CaCO₃ or silica is hard to disperse homogeneously and hence, lauryl alcohol was used to improve their dispersion degrees. It was combined into the NR compound with varied concentrations such as 1, 3, 5 and 7 phr. Therefore, the effect of lauryl alcohol concentration on the processing and reinforcement properties of CaCO₃ or silica-filled NR was investigated. It could be found that lauryl alcohol has increased the rate coefficient of vulcanisation (Rv) of the CaCO₃ or silica-filled-NR. The greater the lauryl alcohol concentration; the greater the Rv value, tensile strength, and abrasion resistance. Overall, lauryl alcohol has a successful function as a plasticizing agent which increased the reinforcement effects of the fillers on NR through the increasing of crosslink density of CaCO₃-NR or silica-NR especially at the 5 phr of addition.

Abstract: The dust accumulation and dirt particles always degrade the transparency of glass, later hampers its various applications such as photovoltaic panels, building glass, and car-windshield. In this study, the hydrophilic self-cleaning coatings have been developed by using the nanocalcium Carbonate particles (nanoCaCO₃) and hydrophilic micro-titanium dioxide particles (µ-TiO₂). The presence of oxide groups, CO^-3 and TiO^2- forms a strong attraction of glass to polar water molecules. At the weight ratio of 1: 1 in the CaCO₃ to TiO₂ mixture, it forms a great hydrophilic property in which the water contact angle (WCA) of coated glass has been recorded as low as 11.46 ±0.85°. The coated glass also showed high transparency in UV and Visible regions. The optical transmission of coated glass was above 89% at the wavelength of 300-400nm and above 97% at the wavelength of 400-800nm. Due to its hydrophilic property, the coated glass is capable of removing the dust particles away via the water stream. The hydrophilic coating spontaneously forms the water-thin film after contact with coated glass without the presence of UV light.