Navigation Links
New insight to demineralization
Date:7/7/2008

Blacksburg, Va. From toothpaste to technology, noncrystalline or amorphous silica is an active ingredient in a myriad of products that we use in our daily lives. As a minor, but essential component of vertebrate bone, an understanding of silica reactivity in physiological environments is crucial to the development of successful biomedical implants and synthetic materials with bone-like properties.

One ongoing question is why solutions of water containing simple table salt or other electrolyte compounds (as in blood plasma for example) are able to break down noncrystalline silicas at speeds far faster than expected. Rates of decomposition by processes known as dissolution, or demineralization, are up to 100 times faster when the solutions contain little dissolved silica and suggest a means for controlling the speed of removal. Yet, traditional theory would say that the durability of amorphous solids, such as silica glasses, should change by a simple proportion to the amount of silica present in the dissolving solution.

In the July 7 󈝷, 2008 Online Early Edition of the Proceedings of the National Academy of Sciences (PNAS), Patricia Dove, professor of geosciences in the College of Science at Virginia Tech, and postdoctoral scientists Nizhou Han and Adam Wallace report that amorphous silica can dissolve by a nucleation process that was previously only viewed as possible in crystalline materials. The result is a very large increase in the rate of removal of ions from the surface of silica, which would not be predicted by classical theory.

In collaboration with James De Yoreo at the Molecular Foundry of the Lawrence Berkeley Laboratory, the Virginia Tech researchers demonstrate that structural order is not a requirement for a crystal-based model to describe dissolution when the reacting silica units are defined in terms of their coordination to the surface.

"This finding would seem heretical from the viewpoint of traditional thinking because classical nucleation theory is rooted in the concept that dissolution and growth occur by overcoming a barrier to forming a new phase within an existing phase," said Dove. "Because the transfer of units from a disordered amorphous surface to solution always leaves the surface free energy unchanged, the origin of a comparable energy barrier presents a paradox that is not easy to understand."

Using experimental and theoretical analyses, the paper explains this paradox and the dissolution behavior of silica glasses manufactured by different processes, a natural biologically produced silica, and a synthetic, dispersed or colloidal silica. Their findings present the basis for understanding how simple modulations in solution chemistry can tune the durability of silica in humid or wet environments. Moreover, the insights suggest a means by which one could use simple, environmentally benign solutions to regulate surface roughness at the nanoscale. "One example would be to add texture to a substrate surface for a biomedical application," said Dove "Or another could be to use a salt solution to clean a silica surface without toxic chemical compounds."


'/>"/>

Contact: Susan Trulove
STrulove@vt.edu
540-231-5646
Virginia Tech
Source:Eurekalert

Related biology technology :

1. Molecular changes in brain fluid give insight into brain-damaging disease
2. Microsurgery on the brain of the fruit fly leads to new insights into irreparable nerve injuries
3. Peripheral Vascular Device Market Insights Webinar
4. MammaPrint(R) Breast Cancer Test Provides Valuable Insight for Personalized Treatment Decisions
5. New insights into cellular reprogramming revealed by genomic analysis
6. Pharmaceuticals & Biotechs to Share Insights for Developing Leaders in a Fast-Paced, Competitive Industry
7. PAREXEL Experts to Offer Insights Into Outsourcing Best Practices at 17th Annual Partnerships with CROs Conference
8. Apieron, Inc. Announces FDA Clearance of the Insight(TM) eNO System to Assist Physicians with Patient Asthma Management
9. PAREXEL to Present Leading Insights Regarding Key Industry Topics at 20th Annual Drug Information Association EuroMeeting
10. New insights into the fate of anti-parasitics in manure and manured soils
11. New Scrip Report Provides Strategic Insight on the Burgeoning Biosimilars Market
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/19/2017)... ... April 18, 2017 , ... ... . The move comes after the company changed focus to making analytical tools ... brand and our new technology,” says CEO Robert Hart. Founders Bernardo Cordovez, Robert ...
(Date:4/19/2017)... ... April 19, 2017 , ... WHO: Peggy Lillis ... through education and advocacy. Founded in 2010 in memory of a single-parent mom ... foundation has become the most-consulted source for patient-focused information on C. diff infections ...
(Date:4/19/2017)... April 19, 2017  As a Bronze ... Heroin Summit ,  Proove® Biosciences, Inc. announces ... environmental, and lifestyle factors to accurately predict prescription ... of Southern California (USC), the Interventional Pain Institute ... publish results showing that Proove Opioid Risk® accurately ...
(Date:4/19/2017)... April 19, 2017   Thermo Fisher Scientific ... multi-center Procalcitonin MOnitoring SEpsis (MOSES) Study have been ... Critical Care Medicine . Researchers from the ... Sepsis Patients: Results From the Multicenter Procalcitonin MOnitoring ... B·R·A·H·M·S PCT (procalcitonin) assay to assess risk for ...
Breaking Biology Technology:
(Date:3/22/2017)... -- Vigilant Solutions , a vehicle location and ... today the appointment of retired FBI special agent ... development. Mr. Sheridan brings more than 21 ... on the aviation transportation sector, to his new role ... served as the Aviation Liaison Agent Coordinator (ALAC) in ...
(Date:3/16/2017)... CeBIT 2017 - Against identity fraud with DERMALOG solutions "Made in ... ... combined in one project, multi-biometric solutions provide a crucial contribution against identity fraud. (PRNewsFoto/Dermalog Identification ... Used combined in one project, multi-biometric solutions provide a ... ...
(Date:3/9/2017)... MOUNTAIN VIEW, Calif. , March 9, ... Simple," and 23andMe , the leading personal genetics ... choices.  Zipongo can now provide customers with personalized nutrition ... goals and biometrics, but also genetic markers impacting how ... Zipongo,s personalized food decision support platform uses biometrics ...
Breaking Biology News(10 mins):