TY - JOUR
T1 - Electrohydrodynamics in nanochannels coated by mixed polymer brushes
T2 - Effects of electric field strength and solvent quality
AU - Cao, Qianqian
AU - Tian, Xiu
AU - You, Hao
N1 - Funding Information:
The authors would like to deeply appreciate the support from the National Natural Science Foundation of China under Grant No. 31500801 and Project D of Qianjiang Talent Plan.
Publisher Copyright:
© 2018 IOP Publishing Ltd.
PY - 2018/2/2
Y1 - 2018/2/2
N2 - We examine the electrohydrodynamics in mixed polymer brush-coated nanochannels and the conformational dynamics of grafted polymers using molecular dynamics simulations. Charged (A) and neutral polymers (B) are alternately grafted on the channel surfaces. The effects of the electric field strength and solvent quality are addressed in detail. The dependence of electroosmotic flow characteristics and polymer conformational behavior on the solvent quality is influenced due to the change of the electric field strength. The enhanced electric field induces a collapse of the neutral polymer chains which adopt a highly extended conformation along the flow direction. However, the thickness of the charged polymer layer is affected weakly by the electric field, and even a slight swelling is identified for the A-B attraction case, implying the conformational coupling between two polymer species. Furthermore, the charged polymer chains incline entirely towards the electric field direction oppositely to the flow direction. More importantly, unlike the neutral polymer chains, the shape factor of the charged polymer chains, which is used to describe the overall shape of polymer chains, is reduced significantly with increasing the electric field strength, corresponding to a more coiled structure.
AB - We examine the electrohydrodynamics in mixed polymer brush-coated nanochannels and the conformational dynamics of grafted polymers using molecular dynamics simulations. Charged (A) and neutral polymers (B) are alternately grafted on the channel surfaces. The effects of the electric field strength and solvent quality are addressed in detail. The dependence of electroosmotic flow characteristics and polymer conformational behavior on the solvent quality is influenced due to the change of the electric field strength. The enhanced electric field induces a collapse of the neutral polymer chains which adopt a highly extended conformation along the flow direction. However, the thickness of the charged polymer layer is affected weakly by the electric field, and even a slight swelling is identified for the A-B attraction case, implying the conformational coupling between two polymer species. Furthermore, the charged polymer chains incline entirely towards the electric field direction oppositely to the flow direction. More importantly, unlike the neutral polymer chains, the shape factor of the charged polymer chains, which is used to describe the overall shape of polymer chains, is reduced significantly with increasing the electric field strength, corresponding to a more coiled structure.
KW - electrohydrodynamics
KW - molecular dynamics
KW - nanochannels
KW - polymer brush
UR - http://www.scopus.com/inward/record.url?scp=85044402788&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85044402788&partnerID=8YFLogxK
U2 - 10.1088/1361-651X/aaa6a1
DO - 10.1088/1361-651X/aaa6a1
M3 - Article
AN - SCOPUS:85044402788
SN - 0965-0393
VL - 26
JO - Modelling and Simulation in Materials Science and Engineering
JF - Modelling and Simulation in Materials Science and Engineering
IS - 3
M1 - 035003
ER -