Sains Malaysiana 46(2)(2017): 309–315

http://dx.doi.org/10.17576/jsm-2017-4602-16

Dominant Influence of the Terminal Molecule of PNIPA Chain on Wettability

(Pengaruh Dominan Molekul Terminal Raintaian PNIPA ke atas Kebolehbasahan)

 

NURUL HUDA¹*, MOHD. RASHID² & NAHIDA SULTANA¹

 

¹Center for Advanced Research in Sciences, University of Dhaka, Dhaka 1000, Bangladesh

 

²Malaysia-Japan International Institute of Technology, 54100 UTM Kuala Lumpur,

Federal Territory, Malaysia

 

Diserahkan: 6 April 2016/Diterima: 8 Jun 2016

 

ABSTRACT

Poly(N-isopropylacrylamide) (PNIPA) brushes on silicon substrate was constructed and molecular weight and polydispersity index was controlled precisely. Molecular behavior of the PNIPA grafted surface was observed by using captive bubble contact angle method. A very interesting phenomenon of high density PNIPA grafted membrane with a chloride terminal molecule was observed. The contact angle of high density PNIPA-Cl increased sharply while the temperature rises above 32oC. But in the case of PNIPA gel surface the contact angle result decreases sharply while the temperature reaches above lower critical solution temperature (LCST). In order to identify the reason behind this abnormal behavior of PNIPA-Cl grafted membrane, the terminal chloride molecule of PNIPA chain was modified to less electronegative azide (-N3) as well as carboxylic acid (-COOH). Finally it was found that terminal molecule of high density PNIPA grafted membrane has a great influences on the wettability change of PNIPA membrane in water by changing the temperature.

 

Keywords: ATRP; grafted membrane; monomer; PNIPA

 

ABSTRAK

Berus poli(N-isopropilakrilamida) (PNIPA) pada substrat silikon telah dibina dan berat molekul serta indeks kepoliserakan telah dikawal dengan tepat. Tingkah laku molekul permukaan cantuman PNIPA telah diperhatikan dengan menggunakan kaedah sudut sentuhan tangkapan gelembung. Suatu fenomena yang sangat menarik untuk membran cantuman PNIPA ketumpatan tinggi dengan klorida terminal molekul diperhatikan. Sudut sentuh PNIPA-Cl ketumpatan tinggi meningkat dengan ketara manakala suhu meningkat melebihi 32oC. Tetapi dalam kes gel permukaan PNIPA, keputusan sudut sentuh berkurangan secara mendadak semasa suhu mencapai tahap di atas suhu kritikal larutan (LCST). Untuk mengenal pasti sebab di sebalik tingkah laku tidak normal daripada PNIPA-Cl membran cantuman ini, molekul klorida terminal rantaian PNIPA diubah suai untuk mengurangkan azida elektronegatif (-N3) serta asid karbosilik (-COOH). Kesimpulannya, didapati bahawa molekul terminal ketumpatan tinggi PNIPA membran cantuman mempunyai pengaruh yang besar pada perubahan kebolehbasahan membran PNIPA dalam air dengan mengubah suhunya.

 

Kata kunci: ATRP; grafted membran; monomer; PNIPA

RUJUKAN

Abraham, M. 2004. Adhesion and wetting in an aqueous environment: Theoretical assessment of sensivity to the solid surface energy. Langmuir 20: 1317-1320.

Atsushi, S. & Yasuhiro, K. 1999. Static contact angle of sessile air bubble on polymer gel surface in water. Jpn. J. Appl. Phys. 38: 2910-2916.

Cassie, A.B.D. & Baxter, S. 1944. Wettability of porus surface. Trans Faraday Soc. 40: 546-551.

Chen, G. & Hoffman, A.S. 1995. Graft copolymers that exhibit temperature-induced phase transitions over a wide range of pH. Nature (London) 373: 49-52.

Grundke, K., Pöschel, K., Synytska, A., Frenzel, R., Drechsler, A., Nitschke, M., Cordeiro, A.L., Uhlmann, P. & Welzel, P.B. 2015. Experimental studies of contact angle hysteresis phenomena on polymer surfaces - toward the understanding and control of wettability for different applications. Advances in Colloid and Interface Science 222: 350-376. DOI: doi: 10.1016/j.cis.2014.10.012.

Hiromasa, S., Huda, M.N., Hisashi, H., Kazushige, K.,Takahiro, S. & Yukikazu, T. 2010. Precise synthesis and physicochemical properties of high-density polymer brushes designed with poly(N-isopropylacrylamide). Macromolecules 43: 9945- 9956.

Huda, M. & Kabir, A. 2013. Stimuli responsive morphological changes of Pnipa polymer brushes synthesized on silicon substrate. Journal of Molecular and Engineering Materials 2: 1-9.

Irem, E., Helmut, S. & Levent, D.A. 2011. Effect of structural isomerism and polymer end group on the pH-stability of hydrogen-bonded multilayers. Journal of Colloid and Interface Science 361(2): 477-482.

Jin, L., Yin, Z. & Zheng, L. 2014. Thermo-responsive brush copolymers with structure-tunable LCST and switchable surface wettability. Polymer 55: 6552-6560.

Kari, J.M. & Yoram, C. 2014. Wettability of terminally anchored polymer brush layers on a polyamide surface. Colloid and Interface Science 436: 286-295.

Lamson, M., Maciej, K., Hangjun, D., Mingjiang, Z. & Matyjaszewski, K. 2016. Synthesis of well-defined polyacrylonitrile by ICAR ATRP with low concentrations of catalyst. Polymer Chem. 54(13): 1961-1968. DOI: 10.1002/ pola.28055.

Manias, E., Rackaiti, M., Foley, T., Efimenko, K. & Genzer, J. 2005. Combinatorial polymer brushes formed by temperature responsive polymers with tunable onset of response. Polymer Preprints 46(2): 11-12.

Pawel, K., Thomas, G.R., Matyjaszewski, K. & Armando, G. 2016. Relation between overall rate of ATRP and rates of activation of dormant species. Macromolecules 49(7): 2467- 2476. DOI: 10.1021/acs.macromol.6b00058.

Okano, T. 1993. Molecular design of temperature-responsive polymers as intelligent materials. Adv. Polym. Sci. 110: 179-197.

Prokhorova, S.A., Kopytsev, A., Ramakrishnan, H.Z. & Rühe, J. 2003. Can polymer brushes induce motion of nano-objects? Nanotechnology 14: 1098-1103.

Shah, R.R., Merreceyes, D., Husemann, M., Rees, I., Abbott, N.L., Hawker, C.J. & Hedrick, J.L. 2000. Using atom transfer radical polymerization to amplify monolayers of initiators patterned by micro contact printing into polymer brushes for pattern transfer. Macromolecules 33: 597-605.

Yamamoto, S., Ejaz, M., Tsujii, Y. & Fukuda, T. 2000. Surface interaction forces of well- defined, high-density polymer brushes studied by atomic force microscopy. 2. Effect of graft density. Macromolecules 33(15): 5608-5612.

Wenzel, R.N. 1936. Resistance of solid surfaces to wetting by water. Ind. Eng. Chem. 28: 988-994.

 

 

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