User:Mitchell Kaiser/sandbox

Soldier Joker Phoenix in Astoria seems to be an unreliable source.

"This name is a clear reference to the cannabis-legal city of Amsterdam in the Netherlands.[21]" Clear is a value statement and should be removed.

The 5th and 6th paragraphs under "History" have no citations, and neither does the 3rd paragraph under "Geography and Climate".

Generally, more citations are needed.

Neither Hazel Dell or Lake Shore elementary are in the incorporated city.

Mitchell Kaiser (talk) 02:51, 8 April 2017 (UTC)

Vancouver, Washington

As of yet, there is no section for chemical synthesis on the microfluidics page. I will create the heading and describe techniques and applications of microfluidics for chemical synthesis. An especially important concept will be ways of combining droplets (or phases withing droplets) to use the mobile phase as a reaction chamber. Uses include the synthesis of polymers, nanoparticles and molecules for pharmaceuticals.

1. Beesabathuni, S. N.; Stockham, J. G.; Kim, J. H.; Lee, H. B.; Chung, J. H.; Shen, A. Q., Fabrication of conducting polyaniline microspheres using droplet microfluidics. Rsc Advances 2013, 3 (46), 24423-24429.

2. Boken, J.; Soni, S. K.; Kumar, D., Microfluidic Synthesis of Nanoparticles and their Biosensing Applications. Critical Reviews in Analytical Chemistry 2016, 46 (6), 538-561.

3. Boken, J.; Soni, S. K.; Kumar, D., Microfluidic Synthesis of Nanoparticles and their Biosensing Applications. Critical Reviews in Analytical Chemistry 2016, 46 (6), 538-561.

4. Dai, J.; Yang, X. Y.; Hamon, M.; Kong, L. Z., Particle size controlled synthesis of CdS nanoparticles on a microfluidic chip. Chemical Engineering Journal 2015, 280, 385-390.

5. Dai, J.; Yang, X.; Hamon, M.; Kong, L., Particle size controlled synthesis of CdS nanoparticles on a microfluidic chip. Chemical Engineering Journal 2015, 280, 385-390.

6. Deng, N. N.; Wang, W.; Ju, X. J.; Xie, R.; Chu, L. Y., Spontaneous transfer of droplets across microfluidic laminar interfaces. Lab on a Chip 2016, 16 (22), 4326-4332.

7. Gu, T. H.; Yeap, E. W. Q.; Somasundar, A.; Chen, R.; Hatton, T. A.; Khan, S. A., Droplet microfluidics with a nanoemulsion continuous phase. Lab on a Chip 2016, 16 (14), 2694-2700.

8. Guan, X. W.; Hou, L. K.; Ren, Y. K.; Deng, X. K.; Lang, Q.; Jia, Y. K.; Hu, Q. M.; Tao, Y.; Liu, J. W.; Jiang, H. Y., A dual-core double emulsion platform for osmolarity-controlled microreactor triggered by coalescence of encapsulated droplets. Biomicrofluidics 2016, 10 (3).

9. Korczyk, P. M.; Dolega, M. E.; Jakiela, S.; Jankowski, P.; Makulska, S.; Garstecki, P., Scaling up the Throughput of Synthesis and Extraction in Droplet Microfluidic Reactors. Journal of Flow Chemistry 2015, 5 (2), 110-118.

10. Korczyk, P. M.; Dolega, M. E.; Jakiela, S.; Jankowski, P.; Makulska, S.; Garstecki, P., Scaling up the Throughput of Synthesis and Extraction in Droplet Microfluidic Reactors. Journal of Flow Chemistry 2015, 5 (2), 110-118.

11. Li, Y. H.; Jain, M.; Ma, Y. T.; Nandakumar, K., Control of the breakup process of viscous droplets by an external electric field inside a microfluidic device. Soft Matter 2015, 11 (19), 3884-3899.

12. Mashaghi, S.; Abbaspourrad, A.; Weitz, D. A.; van Oijen, A. M., Droplet microfluidics: A tool for biology, chemistry and nanotechnology. Trac-Trends in Analytical Chemistry 2016, 82, 118-125.

13. Mashaghi, S.; van Oijen, A. M., External control of reactions in microdroplets. Scientific Reports 2015, 5.

14. Mashaghi, S.; Abbaspourrad, A.; Weitz, D. A.; van Oijen, A. M., Droplet microfluidics: A tool for biology, chemistry and nanotechnology. Trac-Trends in Analytical Chemistry 2016, 82, 118-125.

15. Mashaghi, S.; van Oijen, A. M., External control of reactions in microdroplets. Scientific Reports 2015, 5.

16. Um, T.; Hong, J.; Im, D. J.; Lee, S. J.; Kang, I. S., Electrically Controllable Microparticle Synthesis and Digital Microfluidic Manipulation by Electric-Field-Induced Droplet Dispensing into Immiscible Fluids. Scientific Reports 2016, 6.

17. Witters, D.; Vermeir, S.; Puers, R.; Sels, B. F.; Lammertyn, J.; De Vos, D. E.; Ameloot, R., Controlled deposition of patterned metal-organic framework coatings through digital microfluidics. Abstracts of Papers of the American Chemical Society 2013, 245.

18. Yang, C. H.; Lin, Y. S.; Shih, M. C.; Chiu, H. C.; Huang, K. S., Droplet-based Microfluidic Technology Applications in Polymer Science. Current Proteomics 2014, 11 (2), 92-97.

Added a citation to an article about Stevie Nicks.

• (cur | prev) 23:32, 18 April 2017‎ Mitchell Kaiser (talk | contribs)‎ . . (97,400 bytes) (+133)‎ . . (→‎2014–2016: 24 Karat Gold: Songs from the Vault, and On With The Show Tour: Added citation) (undo) (Tag: Visual edit) Stevie Nicks

Mass Spectrometry- Zach Scott

[null The macro-scale versions of many applications of droplet-based microfluidics; incubation of cells within single droplets, droplet-based reaction vessels, sorting of small volume samples, etc., are typically verified by some form of per-sample assay. Often, this is done using a mass spectrometer (]MS)[MK1] . This remains true for micro-scale systems, with per-sample assays being scaled down to the detection and mass analysis of single droplets. The utility of MS detection of droplets is of particular relevance in cases where the generally cheaper and more resource efficient methods of fluorescence-based or optical detection are not viable due to the particular chemical composition of the droplets, which are commonly sensitive to fluorescent labels[1] or otherwise unsuitable for optical detection. Fields where MS detection is necessary include proteomics (where scarcity and difficulty of separation/purification make entirely-microfluidic scale systems ideal), enzyme kinetics, drug discovery, and newborn disease screening.[2][3][4][5][6][7] The two methods of analyte ionization for spectrometric analysis most commonly used in droplet-based microfluidics today are matrix-assisted laser desorption/ionization (MALDI) and electrospray ionization (ESI).[1][8][9][10][MK2] 

The primary advantages of MALDI detection over ESI in microfluidic devices are that MALDI allows for much easier multiplexing, which even further increases the device's overall throughput, as well as less reliance on moving parts and the absence of Taylor cone stability problems posed by microfluidic-scale flow rates.[11][12] [null The speed of MALDI detection, along with the scale of microfluidic droplets, allow for improvements upon macro-scale techniques in both throughput and time-of-flight (TOF) resolution.][MK3] [13] Where typical MS detection setups often utilize separation techniques such as liquid chromatography, MALDI setups [null require a sufficiently purified sample] [MK4] to be mixed with the [null organic matrix components][MK5] necessary for MALDI detection.[14] This can be the determining factor for the use of ESI over MALDI.

When device specifics do not allow for mixing with the [null organic matrix components] [MK6] required by MALDI, possibly due to device fabrication [null or too-low of an analyte mass][MK7] , ESI offers a similarly high throughput answer to the problem of label-free droplet detection. [15] Additionally, because [null of the advantages][MK8] of online droplet detection with ESI, other problems posed by segmented or off-chip detection based systems can be solved, such as minimizing sample (droplet) dilution.[16]

[need transition sentence relating to below topic in wiki article. waiting on conference with classmates]

1.   1 2 Lee, Jeonghoon; Soper, Steven A.; Murray, Kermit K. (2009-05-01). "Microfluidic chips for mass spectrometry-based proteomics". Journal of Mass Spectrometry. 44 (5): 579–593. doi:10.1002/jms.1585. ISSN 1096-9888.

2.   ↑ Moon, Hyejin; Wheeler, Aaron R.; Garrell, Robin L.; Loo, Joseph A.; Kim, Chang-Jin ?CJ? (2006-08-23). "An integrated digital microfluidic chip for multiplexed proteomic sample preparation and analysis by MALDI-MS". Lab on a Chip. 6 (9). doi:10.1039/b601954d. ISSN 1473-0189.

3.   ↑ Nichols, Kevin Paul; Gardeniers, J. G. E. (2007-11-01). "A Digital Microfluidic System for the Investigation of Pre-Steady-State Enzyme Kinetics Using Rapid Quenching with MALDI-TOF Mass Spectrometry". Analytical Chemistry. 79 (22): 8699–8704. doi:10.1021/ac071235x. ISSN 0003-2700.

4.   ↑ Dittrich, Petra S.; Manz, Andreas. "Lab-on-a-chip: microfluidics in drug discovery". Nature Reviews Drug Discovery. 5 (3): 210–218. doi:10.1038/nrd1985.

5.   ↑ Ji, Ji; Nie, Lei; Qiao, Liang; Li, Yixin; Guo, Liping; Liu, Baohong; Yang, Pengyuan; Girault, Hubert H. (2012-07-03). "Proteolysis in microfluidic droplets: an approach to interface protein separation and peptide mass spectrometry". Lab on a Chip. 12 (15). doi:10.1039/c2lc40206h. ISSN 1473-0189.

6.   ↑ Shih, Steve C. C.; Yang, Hao; Jebrail, Mais J.; Fobel, Ryan; McIntosh, Nathan; Al-Dirbashi, Osama Y.; Chakraborty, Pranesh; Wheeler, Aaron R. (2012-04-17). "Dried Blood Spot Analysis by Digital Microfluidics Coupled to Nanoelectrospray Ionization Mass Spectrometry". Analytical Chemistry. 84 (8): 3731–3738. doi:10.1021/ac300305s. ISSN 0003-2700.

7.   ↑ Pei, Jian; Li, Qiang; Lee, Mike S.; Valaskovic, Gary A.; Kennedy, Robert T. (2009-08-01). "Analysis of Samples Stored as Individual Plugs in a Capillary by Electrospray Ionization Mass Spectrometry". Analytical Chemistry. 81 (15): 6558–6561. doi:10.1021/ac901172a. ISSN 0003-2700. PMC 2846185 . PMID 19555052. CS1 maint: PMC format (link)

8.   ↑ Heron, Scott R.; Wilson, Rab; Shaffer, Scott A.; Goodlett, David R.; Cooper, Jonathan M. (2010-05-15). "Surface Acoustic Wave Nebulization of Peptides As a Microfluidic Interface for Mass Spectrometry". Analytical Chemistry. 82 (10): 3985–3989. doi:10.1021/ac100372c. ISSN 0003-2700. PMC 3073871 . PMID 20364823. CS1 maint: PMC format (link)

9.   ↑ Küster, Simon K.; Fagerer, Stephan R.; Verboket, Pascal E.; Eyer, Klaus; Jefimovs, Konstantins; Zenobi, Renato; Dittrich, Petra S. (2013-02-05). "Interfacing Droplet Microfluidics with Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry: Label-Free Content Analysis of Single Droplets". Analytical Chemistry. 85 (3): 1285–1289. doi:10.1021/ac3033189. ISSN 0003-2700.

10.  ↑ Lee, Jeonghoon; Musyimi, Harrison K.; Soper, Steven A.; Murray, Kermit K. (2008-07-01). "Development of an automated digestion and droplet deposition microfluidic chip for MALDI-TOF MS". Journal of the American Society for Mass Spectrometry. 19 (7): 964–972. doi:10.1016/j.jasms.2008.03.015. ISSN 1044-0305.

11.  ↑ Cherney, Leonid T. (1999-01-01). "Structure of Taylor cone-jets: limit of low flow rates". Journal of Fluid Mechanics. 378: 167–196. doi:10.1017/S002211209800319X. ISSN 1469-7645.

12.  ↑ Nichols, Kevin Paul; Gardeniers, J. G. E. (2007-11-01). "A Digital Microfluidic System for the Investigation of Pre-Steady-State Enzyme Kinetics Using Rapid Quenching with MALDI-TOF Mass Spectrometry". Analytical Chemistry. 79 (22): 8699–8704. doi:10.1021/ac071235x. ISSN 0003-2700.

13.  ↑ Moon, Hyejin; Wheeler, Aaron R.; Garrell, Robin L.; Loo, Joseph A.; Kim, Chang-Jin ?CJ? (2006-08-23). "An integrated digital microfluidic chip for multiplexed proteomic sample preparation and analysis by MALDI-MS". Lab on a Chip. 6 (9). doi:10.1039/b601954d. ISSN 1473-0189.

14.  ↑ DeVoe, Don L.; Lee, Cheng S. (2006-09-01). "Microfluidic technologies for MALDI-MS in proteomics". ELECTROPHORESIS. 27 (18): 3559–3568. doi:10.1002/elps.200600224. ISSN 1522-2683.

15.  ↑ Kelly, Ryan T.; Page, Jason S.; Marginean, Ioan; Tang, Keqi; Smith, Richard D. (2009-09-01). "Dilution-Free Analysis from Picoliter Droplets by Nano-Electrospray Ionization Mass Spectrometry". Angewandte Chemie International Edition. 48 (37): 6832–6835. doi:10.1002/anie.200902501. ISSN 1521-3773. PMC 2957286 . PMID 19688798. CS1 maint: PMC format (link)

Chemical synthesis

Vivian Baker –  Wiki Draft

Droplet-based microfluidics and chemical synthesis

Droplet-based microfluidics has become an important tool in chemical synthesis due to several attractive features. Microscale reactions allow for cost reduction through the usage of small reagent volumes, rapid reactions in the order of milliseconds, and efficient heat transfer, hence [null "the amount of energy consumed per unit temperature rise can be made extremely small, leading to environmental benefits"][MK1]  [1] [null The degree of control over local conditions within] [MK2] the device often makes it possible to select one product over another with high precision.[2][3] With high selectivity and small sizes come less stringent reaction clean-up and smaller footprint.[4] Microdispersed droplets created by droplet-based chemistry are capable of acting as environments in which chemical reactions occur, for example, reagent carriers in the process of generating complex nanostructures.[5] Droplets are also capable [null of being transformed int][MK3] o cell-like structures [6] which can be used to mimic human biological components and processes.[7][8] Some examples of the use of droplet-based microfluidics in nanochemistry can be found in Duraiswamy et al. literature "[null Droplet-Based Microfluidic Synthesis of Anisotropic Metal Nanocrystals" where anisotropic gold nanocrystal dispersions were prepared][9] and Caroll et al.'s "Droplet-Based Microfluidics for Emulsion and Solvent Evaporation Synthesis of Monodisperse Mesoporous Silica Microspheres" using droplet-based microfluidics as a method for the fabrication of monodisperse mesoporous silica particles.[10][MK4] 

Historically, one of the limitations of chemical synthesis using droplet-based microfluidics is most synthesis reactions performed within droplets are single-step synthesis reactions. [null Therefore, droplet-based m][MK5] icrofluidics were not particularly useful for complex systems that required multi-step chemical syntheses.[11][12][MK6]  [null However, with new research and] [MK7] technological development, droplet-based microfluidic systems are now capable of performing complex chemical synthesis[MK8] .[12] Taking advantage of continuous flows, droplet formation, and emulsions, advanced particles and particle-based materials, such as polymer particles, microcapsules, nanocrystals, and photonic crystal clusters or beads can be synthesized with the assistance of droplet-based microfluidics. [13] Nanoparticles, such as colloidal CdS and CdS/CdSe core-shell nanoparticles, can also be synthesized through multiple steps on a millisecond time scale in a microfluidic droplet-based system[14] Two most common methods to add reagents to droplets in multi-step synthesis are to [null directly deposit the] [MK9] reagents into the passing droplets or to [null "combine two individual droplets containing the different reactants"][MK10] , hence correcting channel clogging - a common problem in multi-step synthesis using droplet-based microfluidics.[MK11] [12][14]

In order for chemical synthesis using droplet-based microfluidics to be initiated and sustained, several elements have to be taken into consideration. [null As fluid flow in microfluidic systems are controlled by] Reynolds number[MK12] , low Reynolds numbers (Re) (generally below 250) have to be maintained in order to keep the fluid flow in the laminar flow regime[4]. Low Reynold’s numbers ensure that there is no turbulence and as a result, no back-mixing within the device when chemical reactions occur.[1] Control of multi-phase aspect in microfluidic devices is also a subject of interest in current research. Aside from simple molecular fluid systems comprising water or oil-based fluids, more complex fluid systems such as a [null nanoemulsion continuous phase are also being developed;][MK13] this could potentially expand the applications of droplet-based microfluidics in material fabrication.[15]

[null Chemical synthesis using droplet-based microfluidics has multiple implications in the discipline of life sciences.] Lab-on-a-chip[MK14]  uses microfluidics to successfully imitate chemical and biological processes in humans and other subjects of interest. [null Chemical syntheses performed on organs-on-a-chip can be used][MK15]  to generate new compounds and to study the effect and drug interaction of such compounds with the organs of interest.[16] Drug discovery and drug delivery can be studied using lab-on-a-chip.[16] Other organs-on-a-chip can be used to study interactions between cells and how cells respond to stimuli and drugs in vitro, with comparable composition characteristics and properties as humans' cells in vivo.[17] Other applications of chemical synthesis assisted by dropled-based microfluidics include cell engineering, cell and synthetic biology, etc.[11][MK16] 

1. ↑ Elvira, Katherine S.; i Solvas, Xavier Casadevall; Wootton, Robert C. R.; deMello, Andrew J. (2013-11-01). "The past, present and potential for microfluidic reactor technology in chemical synthesis". Nature Chemistry. 5 (11): 905–915. doi:10.1038/nchem.1753. ISSN 1755-4330. 
2. ↑ Elvira, Katherine S.; i Solvas, Xavier Casadevall; Wootton, Robert C. R.; deMello, Andrew J. (2013-11-01). "The past, present and potential for microfluidic reactor technology in chemical synthesis". Nature Chemistry. 5 (11): 905–915. doi:10.1038/nchem.1753. ISSN 1755-4330. 
3. ↑ Dittrich, Petra S.; Manz, Andreas (2006-03-01). "Lab-on-a-chip: microfluidics in drug discovery". Nature Reviews Drug Discovery. 5 (3): 210–218. doi:10.1038/nrd1985. ISSN 1474-1776. 
4. ↑ Elvira, Katherine S.; i Solvas, Xavier Casadevall; Wootton, Robert C. R.; deMello, Andrew J. (2013-11-01). "The past, present and potential for microfluidic reactor technology in chemical synthesis". Nature Chemistry. 5 (11): 905–915. doi:10.1038/nchem.1753. ISSN 1755-4330. 
5. ↑ Mashaghi, Samaneh; Abbaspourrad, Alireza; Weitz, David A.; van Oijen, Antoine M. (2016-09-01). "Droplet microfluidics: A tool for biology, chemistry and nanotechnology". TrAC Trends in Analytical Chemistry. 82: 118–125. doi:10.1016/j.trac.2016.05.019. 
6. ↑ Mashaghi, Samaneh; Abbaspourrad, Alireza; Weitz, David A.; van Oijen, Antoine M. (2016-09-01). "Droplet microfluidics: A tool for biology, chemistry and nanotechnology". TrAC Trends in Analytical Chemistry. 82: 118–125. doi:10.1016/j.trac.2016.05.019. 
7. ↑ Mashaghi, Samaneh; Abbaspourrad, Alireza; Weitz, David A.; van Oijen, Antoine M. (2016-09-01). "Droplet microfluidics: A tool for biology, chemistry and nanotechnology". TrAC Trends in Analytical Chemistry. 82: 118–125. doi:10.1016/j.trac.2016.05.019. 
8. ↑ Dittrich, Petra S.; Manz, Andreas (2006-03-01). "Lab-on-a-chip: microfluidics in drug discovery". Nature Reviews Drug Discovery. 5 (3): 210–218. doi:10.1038/nrd1985. ISSN 1474-1776. 
9. ↑ Duraiswamy, S. and Khan, S. A. (2009), Droplet-Based Microfluidic Synthesis of Anisotropic Metal Nanocrystals. Small, 5: 2828–2834. doi:10.1002/smll.200901453
10. ↑ Carroll, Nick J.; Rathod, Shailendra B.; Derbins, Erin; Mendez, Sergio; Weitz, David A.; Petsev, Dimiter N. (2008-02-01). "Droplet-Based Microfluidics for Emulsion and Solvent Evaporation Synthesis of Monodisperse Mesoporous Silica Microspheres". Langmuir. 24 (3): 658–661. doi:10.1021/la7032516. ISSN 0743-7463. 

 [MK1]Wikipedia does not except exact quotes

 [MK2]I edited this slightly

 [MK3]I altered this

 [MK4]Try to write this in a more narrative voice. Like “an example is the anisotropic gold nanocrystal dispersion prepared using (x method) by Duraiswamy et al.

 [MK5]Edited

 [MK6]

 [MK7]Edited

 [MK8]I may have missed it, but I don’t think this article talks about multi-step synthesis

 [MK9]edited

 [MK10]Restate in your words

 [MK11]How so?

 [MK12]Flows aren’t controlled by the low Reynold’s numbers, but show the characteristics of fluids at low Reynold’s numbers

 [MK13]What is this? You should elaborate, since we’re trying to create a comprehensive source.

 [MK14]Do you mean organ-on-a-chip?

 [MK15]Chemical synthesis is used to discover drugs which are tested using organ-on-a-chip models. This wording is a little confusing.

 [MK16]I’m not sure this is relevant to chemical synthesis.

 [MK1]Sentence clarity

 [MK2]Why choose mass spec? More details of its usefulness would be helpful.

 [MK3]More clarity needed. Do you mean that from a macro perspective, throughput and TOF resolution are increased? Or that principals learned through microfluidics can improve macroscale technique?

 [MK4]How?

 [MK5]Is this just organic solvents?

 [MK6]Again, what specifically?

 [MK7]Why would this be a problem with mixing in organics? Or is this a separate issue where the mass is too low to give a signal?

 [MK8]What advantages?

 [MK9]You had a duplicate, you should make sure your citation numbers line up.

Droplet-based microfluidics has been adopted as a method of chemical synthesis. Droplets act as individual reaction chambers protected from contamination through device fouling by the continuous phase. Benefits of synthesis using this regime include high throughput, continuous (rather than batch) experiments, low waste, portability, and a high degree of synthetic control. Some examples of possible synthesis are the creation of semi-conductor microspheres and nanoparticles. Generally, reactions are limited to one-step synthesis, as more complex synthesis require multiple additions of reagents to the droplet. This results in excess material which must be removed by splitting the droplet so that the excess is separated from the reaction chamber.  To ensure careful monitoring of reactions, techniques like laser-based spectroscopy, NMR spectroscopy, microscopy, mass spectrometry, electrochemical detection, absorbance detection, and chemiluminescent detection are used. Often, measurements are taken at different points along the microfluidic device to monitor the progress of the reaction.

An increased rate of reactions using micro-droplets is seen in the aldol reaction of silyl enol ethers and aldehydes performed by Wiles et al. Using a microfluidic device, reaction times were shortened to twenty minutes versus the twenty-four hours required for a batch process. Skelton et al. were able to achieve a high selectivity of cis-stilbene to the thermodynamically favored trans-stilbene compared to the batch reaction, showing the high degree of control afforded by micro-reactor droplets. This stereocontrol is beneficial to the pharmaceutical industry, for example. These and the other benefits of microfluidics can be scaled up by using larger channels to allow more droplets to pass or by increasing droplet size. Adjusting the rate of flow of the carrier and disperse phase at a t-junction tunes the size of droplets created. Droplet size is limited by the need to maintain the positive effects of microdroplets. Thus, increased channel size becomes attractive due to the ability to create and transport a large number of droplets and increasing throughput. In larger channels, dispersion of droplets and stability of droplets become a concern. These steps maximize droplet throughput in generation and transportation. In order to maximize reaction throughput, thorough mixing of droplets to expose the greatest possible number of reagents is necessary. This can be achieved using a curved channel to facilitate turbulent flow within the droplets.

A significant complication in chemical synthesis using micro-droplets is the limitation of the number of reagent additions. Adding reagents generally results in an increased droplet size. Matrix components must be removed from the droplet in order to maintain the droplet volume. One method of reagent addition with changing the volume of the droplet is achieved by dissolving amphipathic substances in the continuous phase and having an additional inlet for the solution when reagent addition is desired. The dissolved reagent diffuses into the reaction droplet without changing the droplet volume. Diffusion time is less than five seconds in this method. Reagents can also be added in multiple droplet fusion steps or by picoinjection. In this case, droplets must be enriched. This can be done by producing aqueous droplets in a continuous phase that is a mixture of oil and DMC. Water will dissolve into the DMC, shrinking the droplet and increasing the concentration of reagents.

1. ^ Jump up to:^a b c d 
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14. Jump up^ Ji, Ji; Nie, Lei; Li, Yixin; Yang, Pengyuan; Liu, Baohong. "Simultaneous Online Enrichment and Identification of Trace Species Based on Microfluidic Droplets". Analytical Chemistry. 85 (20): 9617–9622. doi:10.1021/ac4018082.

Droplet-based microfluidic methods have been adopted as a method of chemical synthesis. Droplets act as individual reaction chambers protected from contamination through device fouling by the continuous phase. Benefits of synthesis using this regime (compared to batch processes) include high throughput, continuous experiments, low waste, portability, and a high degree of synthetic control. Some examples of possible syntheses are the creation of semiconductor microspheres and nanoparticles. To ensure careful monitoring of reactions, techniques like NMR spectroscopy, microscopy, electrochemical detection, and chemiluminescent detection are used. Often, measurements are taken at different points along the microfluidic device to monitor the progress of the reaction.

Increased rate of reactions using micro-droplets are seen in the aldol reaction of silyl enol ethers and aldehydes. Using droplet based a microfluidic device, reaction times were shortened to twenty minutes versus the twenty-four hours required for a batch process. Other experimenters were able to show a high selectivity of cis-stilbene to the thermodynamically favored trans-stilbene compared to the batch reaction, showing the high degree of control afforded by micro-reactor droplets. This stereocontrol is beneficial to the pharmaceutical industry. For instance, L-Methotrexate, a drug used in chemotherapy, is more readily absorbed than the D isomer.

The benefits of microfluidics can be scaled up to higher throughput using larger channels to allow more droplets to pass or by increasing droplet size. Droplet size can be tuned by adjusting the rate of flow of the continuous and disperse phases, but droplet size is limited by the need to maintain the concentration, inter-analyte distances, and stability of microdroplets. Thus, increased channel size becomes attractive due to the ability to create and transport a large number of droplets, though dispersion and stability of droplets become a concern. Finally, thorough mixing of droplets to expose the greatest possible number of reagents is necessary to ensure the maximum amount of starting materials react. This can be accomplished by using a windy channel to facilitate turbulent flow within the droplets.

A significant complication in chemical synthesis using micro-droplets is the limitation of the number of reagent additions. Adding reagents generally results in an increased droplet size, and the resulting excess liquid must be separated from the droplet. Reagents can also be added in multiple droplet fusion steps or by picoinjection. In this case, droplets must be enriched. This can be done by producing aqueous droplets in a continuous phase that is a mixture of oil and dimethyl carbonate (DMC). Water will dissolve into the DMC, shrinking the droplet and increasing the concentration of reagents. New methods have achieved reagent addition without adding excess liquid by dissolving amphipathic substances in the continuous that are introduced where reagent addition is desired. The dissolved reagent diffuses into the reaction droplet without changing the droplet volume in less than five seconds.

1. I contributed to the droplet-based microfluidics page that was created by Nora. This was a new article , and the chemical synthesis section did not previously exist.
2. I provided a general overview of droplet-based microfluidics, included a section discussing specific experiments and benefits of droplet-based microfluidics, considerations when increasing reaction throughput and a section discussing the challenge of multi-step synthesis.
3. Generally, I edited the article to have better flow within the paragraphs as per a suggestion by Zach. I moved a sentence from the first paragraph to the final paragraph to reduce redundancy. I split the second paragraph into two to keep them focused on a specific topic. I also removed some redundant wording (as suggested by Nora) to shorten length. I added more links. Nora suggesting removing the final paragraph, since it overlaps slightly with droplet manipulation. I edited it down, but decided to keep it because of the significance of this challenge. I did not use the content expert or get feedback from any Wikipedia users other than my classmates.
4. This assignment was very interesting and helpful to me. I'm still relatively new to reading academic journals, so this gave me a lot of practice. Additionally, I learned how to better use SciFinder, Web of Science and Endnote. Wikipedia research writing also differs in the kind of research I had done before. The topics of journal articles are very specific, but Wikipedia is not like ordinary academic writing. Instead, I had to look for patterns and synthesize (pun intended) the articles I read into one piece of writing. I think my writing will be useful for readers to understand how and why droplet-based microfluidics is used for chemical synthesis. It also provides sources for further reading. However, I had a difficult time finding the balance of the amount of detail I needed. It was difficult to know whether things that I was writing were the same as someone else, even in other topics. Also, there are seemingly endless particular uses that could be mentioned or details that need to be considered to use droplets as a tool for synthesis, but I didn't want to end up writing a "how to", as this was not the assignment. I think it may be helpful to develop an outline as a class in the future, so everyone will understand what others are doing and what they specifically need to cover. Other than that, it was a lot of fun!

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