title: Synthesis of brushite particles in reverse microemulsions of the biosurfactant surfactin.
abstract: In this study the "green chemistry" use of the biosurfactant surfactin for the synthesis of calcium phosphate using the reverse microemulsion technique was demonstrated. Calcium phosphates are bioactive materials that are a major constituent of human teeth and bone tissue. A reverse microemulsion technique with surfactin was used to produce nanocrystalline brushite particles. Structural diversity (analyzed by SEM and TEM) resulted from different water to surfactin ratios (W/S; 250, 500, 1000 and 40,000). The particle sizes were found to be in the 16-200 nm range. Morphological variety was observed in the as-synthesized microemulsions, which consisted of nanospheres (~16 nm in diameter) and needle-like (8-14 nm in diameter and 80-100 nm in length) noncalcinated particles. However, the calcinated products included nanospheres (50-200 nm in diameter), oval (~300 nm in diameter) and nanorod (200-400 nm in length) particles. FTIR and XRD analysis confirmed the formation of brushite nanoparticles in the as-synthesized products, while calcium pyrophosphate was produced after calcination. These results indicate that the reverse microemulsion technique using surfactin is a green process suitable for the synthesis of nanoparticles.
authors: Department of Earth and Environmental Sciences National Chung Cheng University, 168 University Road, Min-Hsiung, Chia-Yi 62102, Taiwan; E-Mails: jyoti_maity@yahoo.com (J.P.M.); answer75114@hotmail.com (T.-J.L.); akurireddy@gmail.com (A.S.R.); shashi_org@yahoo.com (S.B.A.); seichyo@eq.ccu.edu.tw (Y.-F.C.).
authors: Jyoti Prakash
authors: JP
authors: Maity
authors: Tz-Jiun
authors: TJ
authors: Lin
authors: Henry Pai-Heng
authors: HP
authors: Cheng
authors: Chien-Yen
authors: CY
authors: Chen
authors: A Satyanarayana
authors: AS
authors: Reddy
authors: Shashi B
authors: SB
authors: Atla
authors: Young-Fo
authors: YF
authors: Chang
authors: Hau-Ren
authors: HR
authors: Chen
authors: Chien-Cheng
authors: CC
authors: Chen
mesh_terms: D017610:Calcium Compounds / Q000737:chemistry; D002130:Calcium Phosphates / Q000138:chemical synthesis* / Q000737:chemistry; D003460:Crystallization; D004655:Emulsions / Q000737:chemistry*; D055666:Lipopeptides / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D009566:Nitrates / Q000737:chemistry; D010316:Particle Size; D010456:Peptides, Cyclic / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013501:Surface-Active Agents / Q000737:chemistry*; D013696:Temperature
chemical_list: D017610:Calcium Compounds; D002130:Calcium Phosphates; D004655:Emulsions; D055666:Lipopeptides; D009566:Nitrates; D010456:Peptides, Cyclic; D010710:Phosphates; D013501:Surface-Active Agents; C024788:ammonium phosphate; C009365:surfactin peptide; C059948:calcium nitrate; C494366:calcium phosphate, dibasic, dihydrate