New hydraulic cements based on α-tricalcium phosphate–calcium sulfate dihydrate mixtures

Biomaterials ◽  
2004 ◽  
Vol 25 (4) ◽  
pp. 741-749 ◽  
Author(s):  
M. Bohner
Keyword(s):  
Tricalcium Phosphate ◽  
Calcium Sulfate ◽  
Calcium Sulfate Dihydrate

scholarly journals Antibiotic loaded β-tricalcium phosphate/calcium sulfate for antimicrobial potency, prevention and killing efficacy of Pseudomonas aeruginosa and Staphylococcus aureus biofilms

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nan Jiang ◽  
Devendra H. Dusane ◽  
Jacob R. Brooks ◽  
Craig P. Delury ◽  
Sean S. Aiken ◽  
...  
Keyword(s):  
Tricalcium Phosphate ◽  
Calcium Sulfate ◽  
Bone Graft Substitute ◽  
In Vitro Assays ◽  
In Vivo Experiments ◽  
Orthopaedic Infections ◽  
Clinical Investigations ◽  
Antimicrobial Potency

AbstractThis study investigated the efficacy of a biphasic synthetic β-tricalcium phosphate/calcium sulfate (β-TCP/CS) bone graft substitute for compatibility with vancomycin (V) in combination with tobramycin (T) or gentamicin (G) evidenced by the duration of potency and the prevention and killing efficacies of P. aeruginosa (PAO1) and S. aureus (SAP231) biofilms in in vitro assays. Antibiotic loaded β-TCP/CS beads were compared with antibiotic loaded beads formed from a well characterized synthetic calcium sulfate (CS) bone void filler. β-TCP/CS antibiotic loaded showed antimicrobial potency against PAO1 in a repeated Kirby-Bauer like zone of inhibition assay for 6 days compared to 8 days for CS. However, both bead types showed potency against SAP231 for 40 days. Both formulations loaded with V + T completely prevented biofilm formation (CFU below detection limits) for the 3 days of the experiment with daily fresh inoculum challenges (P < 0.001). In addition, both antibiotic loaded materials and antibiotic combinations significantly reduced the bioburden of pre-grown biofilms by between 3 and 5 logs (P < 0.001) with V + G performing slightly better against PAO1 than V + T. Our data, combined with previous data on osteogenesis suggest that antibiotic loaded β-TCP/CS may have potential to stimulate osteogenesis through acting as a scaffold as well as simultaneously protecting against biofilm infection. Future in vivo experiments and clinical investigations are warranted to more comprehensively evaluate the use of β-TCP/CS in the management of orthopaedic infections.

scholarly journals Scaling Risk Assessment in Nanofiltration of Mine Waters

Membranes ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 288
Author(s):  
Krzysztof Mitko ◽  
Ewa Laskowska ◽  
Marian Turek ◽  
Piotr Dydo ◽  
Krzysztof Piotrowski
Keyword(s):  
Calcium Sulfate ◽  
Flow Model ◽  
Membrane Surface ◽  
Mine Waters ◽  
Batch Mode ◽  
Single Pass ◽  
Calcium Sulfate Dihydrate ◽  
Dead End ◽  
In Series ◽  
Stirred Cell

Nanofiltration can be applied for the treatment of mine waters. One of the main problems is the risk of crystallization of sparingly soluble salts on the membrane surface (scaling). In this work, a series of batch-mode nanofiltration experiments of the mine waters was performed in a dead-end Sterlitech® HP 4750X Stirred Cell. Based on the laboratory results, the concentration profiles of individual ions along the membrane length in a single-pass industrial-scale nanofiltration (NF) unit was calculated, assuming the tanks-in-series flow model inside the membrane module. These calculations also propose a method for estimating the maximum achievable recovery before the occurrence of the calcium sulfate dihydrate scaling in a single-pass NF 40″ length spiral wound module, simultaneously allowing metastable supersaturation of calcium sulfate dihydrate. The performance of three membrane types (NF270, NFX, NFDL) has been evaluated for the nanofiltration of mine water.

The Effect of Solvent Polarity on Phase Transformation of Citrogypsum via Hydrothermal Process

2019 ◽  
Vol 803 ◽  
pp. 351-355 ◽  
Author(s):  
Thanakit Sirimahasal ◽  
Yutthana Kalhong ◽  
Lida Simasatitkul ◽  
Siriporn Pranee ◽  
Samitthichai Seeyangnok
Keyword(s):  
Physical Properties ◽  
Calcium Sulfate ◽  
Hydrothermal Process ◽  
Solvent Polarity ◽  
Sem Images ◽  
Crystal Water ◽  
Calcium Sulfate Dihydrate ◽  
Hexagonal Shape ◽  
Ft Ir ◽  
Hexane Solution

Calcium sulfate dihydrate (CaSO4•2H2O, CSD), gypsum is a by-product in the production of citric acid (citryogypsum). This by-product could neither be exploited nor distributed as a reactant because of its physical properties including those that are not equivalent to natural gypsum. Moreover, the mentioned citrogypsum has been continually increasing environmental problems. Therefore, this research aims at how to recycle gypsum that is synthesized by hydrothermal method at 95oC for 7 hrs under the atmospheric pressure via different solutions (MeOH, EtOH, PrOH, BuOH and Hexane). In order to produce alpha-calcium sulfate hemihydrate (α-CaSO4•0.5H2O, α-CSH) with improved physical properties that will be used for different industries. FT-IR reveals the chemical composition of crystal and the adsorption of methyl group on the surface. Besides, TGA thermogram shows the theoretical crystal water content of CSD and α-CSH 20.9 wt% and 6.2 wt% respectively. The DSC thermogram, shows that endothermic peaks at 151.2 oC and 168.5 oC. There were two steps of loss at 1.5 and 0.5 water molecule respectively. With SEM images of crystal shows the plate-like shape of citrogypsum, while α-CSH shows the hexagonal shape excluding hexane solution. Of all the results, the polarity of solution has an impact on the transition of CSD to α-CSH under this condition.

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