Layer by layer

Short description: Technique for making thin films

Layer-by-layer (LbL) deposition is a thin film fabrication technique. The films are formed by depositing alternating layers of complementary materials with wash steps in between. One of the key advantages of LbL technology compared with other film deposition techniques is its ability to produce highly uniform conformal coatings on both flat and curved surfaces.[1] This can be accomplished by using various techniques such as immersion, spin, spray, electromagnetism, or fluidics.[2]

## Contents

* 1 Development
* 2 Implementation
* 3 Applications
* 4 External links
* 5 See also
* 6 References

## Development

The first implementation of this technique is attributed to J. J. Kirkland and R. K. Iler of DuPont, who carried it out using microparticles in 1966.[3] The method was later revitalized by the discovery of its applicability to a wide range of polyelectrolytes by Gero Decher at the University of Mainz,[4] with Decher, Helmuth Möhwald, and Yuri Lvov credited for developing LbL assembly for multicomponent films made up of polyions (such as DNA, RNA, and proteins), as well as other charged materials.[5] Nicholas Kotov pioneered the development of biomimetic and high-performance composites through the LbL assembly of nanomaterials such as graphene oxide nanoplatelets.[6]

## Implementation

A simple representation can be made by defining two oppositely charged polyions as + and -, and defining the wash step as W. To make an LbL film with 5 bilayers one would deposit W+W-W+W-W+W-W+W-W+W-W, which would lead to a film with 5 bilayers, specifically + - + - + - + - + - .

The representation of the LbL technique as a multilayer build-up based solely on electrostatic attraction is a simplification. Other interactions are involved in this process, including hydrophobic attraction.[7] Multilayer build-up is enabled by multiple attractive forces acting cooperatively, typical for high-molecular weight building blocks, while electrostatic repulsion provides self-limitation of the absorption of individual layers. This range of interactions makes it possible to extend the LbL technique to hydrogen-bonded films,[8] nanoparticles,[9] similarly charged polymers, hydrophobic solvents,[10] and other unusual systems.[11]

LbL offers several advantages over other thin film deposition methods. LbL is simple and can be inexpensive. There are a wide variety of materials that can be deposited by LbL including polyions, metals, ceramics, nanoparticles, and biological molecules. Another important quality of LbL is the high degree of control over thickness, which arises due to the variable growth profile of the films, which directly correlates to the materials used, the number of bilayers, and the assembly technique.[2] By the fact that each bilayer can be as thin as 1 nm, this method offers easy control over the thickness with 1 nm resolution.

## Applications

LbL has found applications[2] in protein purification,[12] corrosion control, (photo)electrocatalysis,[13] biomedical applications,[14] ultrastrong materials,[15] and many more.[16] LbL composites from graphene oxide harbingered the appearance of numerous graphene and graphene oxide composites later on.[17] The first use of reduced graphene oxide composites for lithium batteries was also demonstrated with LbL multilayers.[18]

## External links

* Kotov official website

## See also

* Atomic layer deposition

## References

1. ↑ N. A. Kotov (2003). "Preparation of Nanoparticle Coatings on Surfaces of Complex Geometry". Nano Letters 3 (2): 173. doi:10.1021/nl025896f.
2. ↑ 2.0 2.1 2.2 J. J. Richardson (2015). "Technology-driven layer-by-layer assembly of nanofilms". Science 348 (6233): 6233. doi:10.1126/science.aaa2491. PMID 25908826.
3. ↑ J. J. Kirkland (1965). "Porous Thin-Layer Modified Glass Bead Supports for Gas Liquid Chromatography". Analytical Chemistry 37 (12): 1458. doi:10.1021/ac60231a004. R. K. Iler (1966). "Multilayers of colloidal particles". Journal of Colloid and Interface Science 21 (6): 569. doi:10.1016/0095-8522(66)90018-3. Bibcode: 1966JCIS...21..569I.
4. ↑ Gero Decher; Jong-Dal Hong (1991). "Buildup of ultrathin multilayer films by a self-assembly process, consecutive adsorption of anionic and cationic bipolar amphiphiles on charged surfaces". Macromolecular Symposia 46: 321. doi:10.1002/masy.19910460145.
5. ↑ Rusling, James; Hvastkovs, Eli; Hull, Dominic; Schenkman, John (August 30, 2007). "Biochemical Applications of Ultrathin Films of Enzymes, Polyions and DNA". ChemComm (Royal Society of Chemistry) (2): 141–154. doi:10.1039/B709121B. PMID 18092072.
6. ↑ Decher, Gero (2012). Multilayer thin films - sequential assembly of nanocomposite materials, vol 2.. Weinheim, Germany: Wiley-VCH.
7. ↑ Nicholas A. Kotov (1999). "Layer-by-layer self-assembly: The contribution of hydrophobic interactions". Nanostructured Materials 12 (5–8): 789. doi:10.1016/S0965-9773(99)00237-8.
8. ↑ André Laschewsky; Erik Wischerhoff; Steffen Denzinger; Helmut Ringsdorf; Arnaud Delcorte; Patrick Bertrand (1997). "Molecular Recognition by Hydrogen Bonding in Polyelectrolyte Multilayers". Chemistry: A European Journal 3 (1): 34. doi:10.1002/chem.19970030107. Bibcode: 1997ChEuJ...3...34L.
9. ↑ Nicholas A. Kotov; Imre Dekany; Janos H. Fendler (1995). "Layer-by-Layer Self-Assembly of Polyelectrolyte-Semiconductor Nanoparticle Composite Films". Journal of Physical Chemistry 99 (35): 13065. doi:10.1021/j100035a005.
10. ↑ Yuzuru Shimazaki; Masaya Mitsuishi; Shinzaburo Ito; Masahide Yamamoto (1997). "Preparation of the Layer-by-Layer Deposited Ultrathin Film Based on the Charge-Transfer Interaction". Langmuir 13 (6): 1385. doi:10.1021/la9609579.
11. ↑ Nejla Cini; Tülay Tulun; Gero Decher; Vincent Ball (2010). "Step-by-step assembly of self-patterning polyelectrolyte films violating (almost) all rules of layer-by-layer deposition". Journal of the American Chemical Society 132 (24): 8264–5. doi:10.1021/ja102611q. PMID 20518535. Bibcode: 2010JAChS.132.8264C.
12. ↑ Liu, Weijing (2016). "Layer-by-Layer Deposition with Polymers Containing Nitrilotriacetate, A Convenient Route to Fabricate Metal- and Protein-Binding Films". ACS Applied Materials & Interfaces 8 (16): 10164–73. doi:10.1021/acsami.6b00896. PMID 27042860. Bibcode: 2016AAMI....810164W.
13. ↑ Jeon, Dasom; Kim, Hyunwoo; Lee, Cheolmin; Han, Yujin; Gu, Minsu; Kim, Byeong-Su; Ryu, Jungki (22 November 2017). "Layer-by-Layer Assembly of Polyoxometalates for Photoelectrochemical (PEC) Water Splitting: Toward Modular PEC Devices". ACS Applied Materials & Interfaces 9 (46): 40151–40161. doi:10.1021/acsami.7b09416. PMID 29099571. Bibcode: 2017AAMI....940151J.
14. ↑ Hua Ai; Steven A. Jones; Yuri M. Lvov (2003). "Biomedical applications of electrostatic layer-by-layer nano-assembly of polymers, enzymes, and nanoparticles". Cell Biochemistry and Biophysics 39 (1): 23–43. doi:10.1385/CBB:39:1:23. PMID 12835527.
15. ↑ Zhiyong Tang; Nicholas A. Kotov; Sergei Magonov; Birol Ozturk (2003). "Nanostructured artificial nacre". Nature Materials 2 (6): 413–8. doi:10.1038/nmat906. PMID 12764359. Bibcode: 2003NatMa...2..413T.
16. ↑ Decher, Gero (2012). Multilayer thin films - sequential assembly of nanocomposite materials, vol 2.. Weinheim, Germany: Wiley-VCH.
17. ↑ Kotov, Nicholas A.; Dékány, Imre; Fendler, Janos H. (1996-08-01). "Ultrathin graphite oxide-polyelectrolyte composites prepared by self-assembly: Transition between conductive and non-conductive states" (in en). Advanced Materials 8 (8): 637–641. doi:10.1002/adma.19960080806. ISSN 1521-4095. Bibcode: 1996AdM.....8..637K.
18. ↑ Fendler, Janos H. (1999-01-01). "Colloid Chemical Approach to the Construction of High Energy Density Rechargeable Lithium - Ion Batteries". Journal of Dispersion Science and Technology 20 (1–2): 13–25. doi:10.1080/01932699908943776. ISSN 0193-2691.

0.00

(0 votes)

Original source: https://en.wikipedia.org/wiki/Layer by layer. Read more

|

Retrieved from "https://handwiki.org/wiki/index.php?title=Physics:Layer_by_layer&oldid=4369585"