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:5/25/2016)... ... May 25, 2016 , ... The Ankle ... plating options designed to address fractures of the distal tibia and fibula. This ... Acumed Ankle Plating System 3 is composed of seven plate families that span ...
(Date:5/25/2016)... ... May 25, 2016 , ... Founder of the Fitzmaurice ... surgery and surgery of the hand by the National Board of Physicians and ... above and beyond in his pursuit of providing the most comprehensive, effective treatment ...
(Date:5/25/2016)... Md. (PRWEB) , ... May 25, 2016 , ... ... request for information (RFI) issued by the Office of the National Coordinator for ... patient experience, and determines if clinically relevant data were available when and where ...
(Date:5/25/2016)... ... , ... Scientists at the University of Athens say they have evidence that ... the research that could lead to one good one. Surviving Mesothelioma has just posted ... , The team evaluated 98 mesothelioma patients who got a second kind ...
Breaking Biology Technology:
(Date:4/14/2016)... BioCatch ™, the global ... the appointment of Eyal Goldwerger as CEO. ... Goldwerger,s leadership appointment comes at a time of significant ... of its platform at several of the world,s largest ... unique cognitive and physiological factors, is a winner of ...
(Date:3/23/2016)... , March 23, 2016 ... Interesse erhöhter Sicherheit Gesichts- und Stimmerkennung mit ... Inc. (NASDAQ: MESG ), ein ... dass das Unternehmen mit SpeechPro zusammenarbeitet, um ... der Finanzdienstleistungsbranche, wird die Möglichkeit angeboten, im ...
(Date:3/17/2016)... LONDON , March 17, 2016 ... market intelligence, forecasts the global biometrics market will ... an impressive 118% increase from 2015. Consumer electronics, ... with embedded fingerprint sensors anticipated to reach two ... Dimitrios Pavlakis , Research Analyst ...
Breaking Biology News(10 mins):