Phosphate Ceramics

Brook, I. M., Craig, G. T. Lamb, D. J. (1991a). In vitro interaction between primary bone organ cultures, glass-ionomer cements and hydroxyapatite/tricalcium phosphate ceramics. Biomaterials, 12, 179-86. 

For the preparation of metal phosphate ceramics by solid-state thermolysis [99, 117, 118] or for the preparation of thin films by CVD [110]... 

X. Miao, Y. Hu, J. Liu, A.P. Wong, Porous calcium phosphate ceramics prepared by coating polyurethane foams with calcium phosphate cements. Mater. Lett. 58 (2004) 397 02. 

Ceramicrete is an ex situ stabilization technology that uses chemically bonded phosphate ceramics to stabilize low-level radioactive waste and hazardous waste containing radionuclides and heavy metals. The technology mixes phosphates with acidic solution, causing an exothermic reaction similar to that used in forming concrete. But while concrete is based on relatively weak hydrogen and van der Waals bonding, Ceramicrete uses a combination of ionic, covalenf and van der Waals bonds to stabilize contaminants. 

Low-temperature treatment of low-level mixed wastes has also been accomplished by solidification/stabilization with chemically bonded phosphate ceramics (CBPC). These are made by hydrothermal chemical reaction rather than by sintering. Chemical bonding develops when acid phosphates react with oxides to form crystalline orthophosphate (Singh et al. 1997). The ceramic matrix stabilizes the wastes by microencapsulation. The low temperature of the reaction allows volatile radionuclides to be treated (Singh et al. 1997). 

Singh, D., Wagh, A. S., Cunnane, J. C. Mayberry, J. L. 1997. Chemically bonded phosphate ceramics for low-level mixed-waste stabilization. Journal of Environmental Science and Health, Part A Environmental Science and Engineering Toxic and Hazardous Substance Control, A32, 527-541. 

Wagh, A. S., Strain, R., Jeong, S. Y., Reed, D., Krause, T. Singh, D. 1999. Stabilization of Rocky Flats Pu-contaminated ash within chemically bonded phosphate ceramics. Journal of Nuclear Materials, 265, 295-307. 

CASH CBM CBO CBPC CC CCB CCM CCP CDB CEC CFBC CFC CFR CMM COP CSH CT Calcium aluminosilicate hydrate Coal bed methane Carbon burn-out Chemically-bonded phosphate ceramics Carbonate carbon Coal combustion byproducts Constant capacitance model Coal combustion product Citrate-dithionate-bicarbonate Cation exchange capacity Circulating fluidized bed combustion Chlorofluorocarbon Cumulative fraction Coal mine methane Coefficient of performance Calcium silicate hydrate Collision theory... 

Lavemia, C., and J. M. Schoenung, Calcium phosphate ceramics as bone substitutes, Ceram. Bull, 70(1), 95 (1991). 

Spray dryers rubber chemicals, sulfonates, inorganic phosphates, ceramics, kaolin, coffee, detergents, pharmaceuticals, pigments, inks, lignosulfonate wood waste, melamine and urea formaldehyde resins, polyvinyl chloride, microspheres, skim milk, eggs, starch, yeast, silica gel, urea, salts... 

Shirkhanzadeh, M. 2005. Microneedles coated with porous calcium phosphate ceramics Effective vehicles for transdermal delivery of solid trehalose. J Mater Sci 16 37. 

In spite of these investigations, many reports in the literature demonstrate that these nanoapatite ceramics are not always osteoinductive and, furthermore, do not possess mechanical properties similar enough to bone for sustained osseointegration (Muller-Mai el al., 1995 Doremus, 1992 Du et al., 1999 Weng et al., 1997), criteria necessary for increased orthopedic and dental implant efficacy. Moreover, mechanisms of osteoinduction of calcium phosphate ceramics are not clear and seem to depend on specific nanoapatite material properties (such as surface properties and crystallinity) and the animal tested (i.e., dog versus rabbit). Undoubtedly, the incidental cases of calcium phosphate biomaterial-induced osteogenesis indicate promise in... 

Flately, T. J., Lynch, K. L., and Benson, M., Tissue response to implants of calcium phosphate ceramics in the rabbit spine. Clinical Orthop. 179,246-252 (1983). 

Klein, C, de Groot, K., Chen, W., Li, Y., and Zhang, X., Osseous substance formation in porous calcium phosphate ceramics in soft tissues. Biomaterials 15, 31-34 (1994). 

Passuti, N., Daculsi, G, Rogez, J. M., Martin, S., and Bainvel, J. V., Macroporous calcium phosphate ceramic performance in human spine fusion. Clinical Orthop. 248, 169-176 (1989). 

Radin, S. R., and Ducheyne, P, The effect of calcium phosphate ceramic composition and structure on in vitro behavior. II. Precipitation. J. Bone and Mineral Res. 27, 35 45 (1993). 

Yang, Z., Yuan, H., Zou, P., Tong, W., Qu, S., and Zhang, X., Osteogenic responses to extraskele-tally implanted synthetic calcium phosphate ceramics an early stage histomorphological study in dogs. J. Mater. Sci. Med. 8, 697-701 (1997). 

Yuan, H., Li, Y., Yang, Z., Feng, X, and Zhang, X., Calcium phosphate ceramic induced osteogenesis in rabbits, in Biomedical Materials Research in the Far East (III), (X. Zhang and Y. Ikada, Eds.), pp. 228-229. Kobunshi Kankokai, Kyoto, Japan, 1997c. 

A number of spectacular applications in structural studies of glasses were reported employing the INADEQUATE experiment.174 175 The basic sequence and different modifications were discussed in Section 2.2.2. Smith and coworkers176 used 31P refocused INADEQUATE MAS NMR experiment for searching the length of phosphate chain and quantification of crystalline phases in ternary sodium calcium phosphate ceramic of composition (CaO)0.4(Na20)0.i(P205)o.5. 

The power of 31P INADEQUATE experiment in the investigations of multiphase phosphate ceramics, especially those composed of a mixture of crystalline and amorphous components, was demonstrated by O Dell et al.,177 who investigated Ti-, Sr- and Zn-containing sodium calcium phosphates. From conducted... 

One great advantage with phosphate bonded ceramics in biomaterial or dental applications is the phosphate ions in their structure. Bones contain calcium phosphate, and hence phosphate bonded ceramics are generally biocompatible with bones. While chemically bonded calcium phosphate ceramics have been difficult to produce, magnesium and zinc based phosphate bonded ceramics have been more easily synthesized and used as structural and dental cements. 

From a scientific viewpoint, calling all room-temperature-setting materials as cements is a misnomer. Highly crystalline structures, such as phosphate ceramics, are synthesized by chemical reaction at room temperature. They are ceramics because of their crystaHine structure, while they are cements because they are formed at room temperature. We would classify such materials as CBCs. If silicates are used to form them, they will be called chemically bonded silicate ceramics. When phosphates are used to form them, they are chemically bonded phosphate ceramics (CBPCs). By using the acronyms CBC and CBPC, we avoid the debate over the words cements and ceramics as the last letter C will stand for either of them. 

A.S. Wagh, D. Singh, and S.Y. Jeong, Chemically bonded phosphate ceramics for stabilization and solidification of mixed wastes, Hazardous and Radioactive Waste Treatment Technologies Handbook (CRC Press, Boca Raton, FL, 2001), pp. 6.3.1-6.3.18. 

A quick review of literature on phosphate cements and ceramics indicates that very little attention has been paid to CBPCs, and a large opportunity exists in developing practical applications of these materials. Westman [1] conducted the first review of work done during 1918-1973 on phosphate ceramic and cement materials. This review appeared in Ceramic Abstracts in 1977. He concluded that only 7% of the total number of articles on cements, lime and mortars were on phosphate-bonded materials and also found only one... 

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