Utilization of Physalis Pith Ash as a Pozzolanic Material in Portland Cement Pastes
Hassan Hassanien Mohamed Darweesh
Issue:
Volume 5, Issue 1, June 2021
Pages:
1-9
Received:
23 February 2021
Accepted:
15 March 2021
Published:
26 March 2021
Abstract: Physalis pith ash (PPA) is a renewable and green supplementary cementitious material. It is an effective approach to reduce the quantity of cement that could be used in blended cements. This will reduce the CO2↑ emission, which in turn will lower the environmental pollution. In the current study, the influence of PPA on physicomechanical characteristics of hydrated cement pastes containing various ratios of PPA (0-30 wt.%) up to 90 days was evaluated. Results showed that the water of consistensy as well as setting times, chemically-bound water content, bulk density and compressive strength increased with PPA content. The apparent porosity and calcium dioxide (or free lime) content were clearly reduced with increasing the PPA content. It is therefore concluded that the cement could be partially replaced by 25 wt.% PPA with no reverse response on the features of cement pastes. Any further increase of PPA content, it affected negatively on all the specific attributes of the hardened cement pastes. So, an optimum PPA content was 25 wt% PPA.
Abstract: Physalis pith ash (PPA) is a renewable and green supplementary cementitious material. It is an effective approach to reduce the quantity of cement that could be used in blended cements. This will reduce the CO2↑ emission, which in turn will lower the environmental pollution. In the current study, the influence of PPA on physicomechanical characteri...
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Synthesis and Characterization of Copper Ions Doped Octacalcium Phosphate Powders with Enhanced Osteogenic Property
Jiwen Chen,
Changshun Chen,
Yunjun Wu,
Riwang Li,
Youjie Liu,
Yiwan Shi,
Huige Hou,
Junting Liu,
Huajun Wang,
Tingting Wu,
Xiaofei Zheng
Issue:
Volume 5, Issue 1, June 2021
Pages:
10-15
Received:
27 March 2021
Accepted:
12 April 2021
Published:
16 April 2021
Abstract: Diverse biomaterials have been designed to promote bone regeneration, and due to their potential side effects of adverse inflammation and immune responses, only a few synthetic biomaterials displayed successful clinical outcomes in repairing bone defects. The repair of bone defects remains a big challenge for orthopedists. This study was dedicated to the synthesis of copper-doped octacalcium phosphate powder Cu-OCP with good bone repair potential, which provides a new way for the construction of bone regeneration biomaterials. Five kinds of copper-doped powders, OCP, 0.1Cu-OCP, 0.5Cu-OCP, Cu-OCP and 5Cu-OCP, were synthesized by chemical homogeneous precipitation method. The phases of the powders were analyzed by X-ray diffraction (XRD). The elemental compositions of the powders were analyzed by X-ray fluorescence spectrometer (XRF). The microstructures of the powders were observed by scanning electron microscopy (SEM). Inductively coupled plasma atomic emission spectrometry (ICP) was used to determine the 24-hour cumulative release of copper ions in Tris solution. The biocompatibility of the powders was measured by CCK8 and live/dead staining. The effect of the powders on bone differentiation was measured by ALP activity. the OCP powder was a long strip chip like crystal structure under SEM. The doping of Cu2+ made the chip structure smaller and finer. The main diffraction peak of OCP can be seen at 2θ=4.7° for all the five powders. XRF showed that the main composition of the powders was still Ca, P and O. The mass fractions of Cu2+ in the powders were 0.1Cu-OCP: 0.02%, 0.5Cu-OCP: 0.08%, Cu-OCP: 0.23%, and 5Cu-OCP: 0.76%, respectively. ICP results showed that Ca, P and Cu were released slowly in 24 hours in Tris solution. CCK8 and live/dead staining showed that all kinds of copper-doped OCP powders had good biocompatibility with mBMSCs, and could promote osteogenic differentiation. Among them, 0.5Cu-OCP promoted the proliferation and ALP activity of mBMSCs significantly. In conclusion, in this study, copper ions were successfully doped into OCP powder, and the physical and chemical properties of OCP powders doped with copper ions were characterized. In vitro cell experiment confirmed that the powders had good biocompatibility, non-toxic to mBMSCs, and could promote the proliferation of mBMSCs in vitro.
Abstract: Diverse biomaterials have been designed to promote bone regeneration, and due to their potential side effects of adverse inflammation and immune responses, only a few synthetic biomaterials displayed successful clinical outcomes in repairing bone defects. The repair of bone defects remains a big challenge for orthopedists. This study was dedicated ...
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