Functional silica beads for biomedical imaging, drug delivery and other important applications could be made using an easy new flow synthesis method.


Date:
July 1, 2020
Source:
ARC Centre of Excellence in Exciton Science
Summary:
The synthesis of silica particles, used in bioimaging and drug
delivery, could become considerably cheaper and more efficient
by adopting a new flow synthesis method which involves a spiral
channel and simple Teflon pipe to promote the rapid mixing of
precursor fluids.



FULL STORY ========================================================================== Researchers in Australia and China have proposed an innovative and cost- effective new method for creating silica beads, which have a number of
key uses, ranging from nanomedicine and bioimaging to the production of
paper and polished concrete.


==========================================================================
The synthesis of silica particles for experimental and industrial uses
began in the 1960s, and usually takes place in large batches, where
controlled doping to induce functionality is difficult.

Control of the synthesis parameters can be achieved through costly
and time- consuming small-scale microfluidic reactors that require photolithography, etching, bonding and injection moulding, which are
prone to clogging.

Now, a surprisingly simple new approach has been demonstrated, and could
be adopted for various applications at a low cost and with a high degree
of reliability.

Researchers at the ARC Centre of Excellence in Exciton Science, based
at The University of Melbourne, and working with colleagues at South
China Normal University, constructed a flow synthesis device using a polytetrafluoroethylene (PTFE) or 'Teflon' pipe wound around a rod and connected to two syringes.

The key to the success of this approach is a spiral channel which promotes vortex flow characteristics, and this type of fluid flow encourages
extremely efficient mixing of the precursor fluids.

"When this happens you now have this very cheap and quite efficient
chemical reactor," corresponding author Dr Eser Akinoglu said.

"Once you have the fluids in a tube that is spiralled, then due to
these vortexes, they mix very quickly and ... the overall reaction is
more homogeneous, the product is homogeneous, and the silica particles
have a uniform size and shape." While this new mechanism is unlikely
to replace industrial-scale batch manufacturing for the creation of pure
silica particles, it could well rival the microfluidic approach used in synthesising silica nanoparticles for specialised, niche applications,
such as silica particles 'doped' with colourful dyes or encapsulating
quantum dots for fluorescence.

"From a material costs perspective, it's very reasonable," Dr Akinoglu
said.

"For the future, this flow synthesis method is ideal for the introduction
of new components into the reaction ... you could put something else
into this flow to mix together with the whole process and it will then
be encapsulated in these silica particles."

========================================================================== Story Source: Materials provided by ARC_Centre_of_Excellence_in_Exciton_Science. Note: Content may be edited
for style and length.


========================================================================== Journal Reference:
1. Hui Yang, Eser Metin Akinoglu, Lijing Guo, Mingliang Jin,
Guofu Zhou,
Michael Giersig, Lingling Shui, Paul Mulvaney. A PTFE helical
capillary microreactor for the high throughput synthesis of
monodisperse silica particles. Chemical Engineering Journal, 2020;
126063 DOI: 10.1016/ j.cej.2020.126063 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/07/200701100016.htm

--- up 23 weeks, 1 day, 2 hours, 40 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1337:3/111)