Search

Article

x

留言板

尊敬的读者、作者、审稿人, 关于本刊的投稿、审稿、编辑和出版的任何问题, 您可以本页添加留言。我们将尽快给您答复。谢谢您的支持!

姓名
邮箱
手机号码
标题
留言内容
验证码

Effect of thiocyanate anions on switching of poly (N-isopropylacrylamide) tethered to nanoparticle surface

Zhao Xin-Jun Li Jiu-Zhi Shi Ming-Yun Ma Chao

Citation:

Effect of thiocyanate anions on switching of poly (N-isopropylacrylamide) tethered to nanoparticle surface

Zhao Xin-Jun, Li Jiu-Zhi, Shi Ming-Yun, Ma Chao
PDF
HTML
Get Citation
  • A recent experiment carried by Humphreys et al. (Humphreys B A, Wanless E J, Webber Grant B 2018 J. Colloid Interface Sci. 516 153) shows that when poly (N-isopropylacrylamide) (PNIPAM) tethered to nanoparticle surface is immersed in potassium thiocyanate solution, the thiocyanate anions (SCN) can increase the low critical solution temperature (LCST) of the PNIPAM below 500 mmol, though the LCST is reduced when at 1000 mmol. It is unclear why the SCN increases the LCST at low concentration and reduces the LCST at high concentration. In this paper, using a molecular theory, we investigate the effect of SCN on the switching and the structure of PNIPAM tethered to nanoparticle surface. In our model the PNIPAM-SCN bonding (P—S bonds), electrostatic effects and their explicit coupling to the PNIPAM conformations are taken into consideration. We find that under the low SCN concentration, as the SCN concentration increases, the SCN is associated with the PNIPAM chains through the PNIPAM—S bonds, and the PNIPAM segments become negatively charged, which makes electrostatic repulsion stronger and results in an increase in the LCST.According to our model, the reduction of LCST at high SCN concentration can be explained as follows: with the increase of SCN concentration, more and more PNIPAM-SCN bindings occur between SCN and PNIPAM segments, which will lead the hydrophobicity of PNIPAM chains to increase. On the other hand, the P—S bonds have been filled at the high SCN concentration, and the PNIPAM chains become more negatively charged. The increase of the SCN is accompanied with an increase in the concentration of counterions (K+). The increase of counterion concentration will give rise to the counterion-mediated attractive interactions along the chains and electrostatic screening within the negatively charged PNIPAM, thus the LCST can be reduced when further increasing the SCN concentration. The reduction of LCST can be attributed to the increased hydrophobicity of PNIPAM chains, or to the counterion-mediated attractive interaction along the chains and the screening of the electrostatic interactions. By analyzing the distribution of PNIPAM segments near the critical temperature, we find that the distribution of volume fractions of the PNIPAM tethered to nanoparticle surface shows a maximum when the hydration of PNIPAM and PNIPAM-SCN binding are stronger, which implies that a vertical phase separation may occur. Based on our theoretical model, a vertical phase separation and a two-step phase transition behaviors in the PNIPAM tethered to nanoparticle surface are predicted. We also analyze the height of the PNIPAM, which is a function of temperature at different SCN concentrations, and then obtain the critical temperature of the two-step phase transition. The results show that the vertical phase separation and the two-step phase transition are promoted by competition between hydrophobicity, hydrophilicity and electrostatic effects due to the P—S bonds. Our theoretical results are consistent with the experimental observations, and provide a fundamental understanding of the effects of SCN on the LCST of PNIPAM tethered to nanoparticle surface.
      Corresponding author: Zhao Xin-Jun, zhaoxinjunzxj@163.com
    • Funds: Project supported by the Joint Funds of Xinjiang Natural Science Foundation, China (Grant No. 2019D01C333) and the National Natural Science Foundation of China (Grant No. 21764015)
    [1]

    Wu C, Zhou S 1995 Macromolecules 28 5388Google Scholar

    [2]

    Howard G, Schild H G, Tirrell D A 1990 J. Phys. Chem. 94 4352Google Scholar

    [3]

    Lahann J, Mitragotri S, Tran T N, Kaido H, Sundaram J, Choi I S, Hoffer S, Somorjai A, Langer R 2003 Science 299 371Google Scholar

    [4]

    Kanazawa H, Okano T 2011 J. Chromatography A 1218 8738

    [5]

    Tang Z, Akiyama Y, Okano T 2012 Polymers 3 1478

    [6]

    Zhang Y J, Furyk S, Bergbreiter D E, Cremer P S 2005 J. Am. Chem. Soc. 127 14505Google Scholar

    [7]

    Du H, Wickramasinghe R, Qian X H 2010 J. Phys. Chem. B 114 16594

    [8]

    Okur H I, Kherb J, Cremer S 2013 J. Am. Chem. Soc. 135 5062Google Scholar

    [9]

    Naini C A, Thomas M, Franzka S, Frost S, Ulbricht M, Hartmann N 2013 Macromol. Rapid Commun. 34 417Google Scholar

    [10]

    Riehemann K, Schneider S W, Luger T A, Godin B, Ferrari M, Fuchs H 2009 Angew. Chem. Int. Ed. 48 872Google Scholar

    [11]

    Xia T, Kovochich M, Liong M, Meng H, Kabehie S, George S, Zink J I, Nel A E 2009 ACS Nano 3 3273Google Scholar

    [12]

    Croissant J, Zink J I 2012 J. Am. Chem. Soc. 134 7628Google Scholar

    [13]

    Thornton P D, Heise A 2010 J. Am. Chem. Soc. 132 2024Google Scholar

    [14]

    Yu Z Z, Li N, Zheng P P, Pan W, Tang B 2014 Chem. Commun. 50 3494Google Scholar

    [15]

    Humphreys B A, Wanless E J, Webber Grant B 2018 J. Colloid Interface Sci. 516 153Google Scholar

    [16]

    Zhao X J, Gao Z F 2016 Chin. Phys. B 25 074703

    [17]

    Liu L, Shi Y, Liu C, Wang T, Liu G M, Zhang G Z 2014 Soft Matter 10 2856Google Scholar

    [18]

    Murdoch T J, Humphreys B A, Willott J D, Gregory K P, Prescott S W, Nelson A, Wanless E J, Webber G B 2016 Macromolecules 49 6050Google Scholar

    [19]

    Humphreys B A, Willott J D, Murdoch T J, Webber G B, Wanless E J 2016 Phys. Chem. Chem. Phys. 18 6037Google Scholar

    [20]

    Szleifer I, Carignano M A 2000 Macromol. Rapid Commun. 21 423Google Scholar

    [21]

    Ren C L, Nap R J, Szleifer I 2008 J. Phys. Chem. B 112 16238Google Scholar

    [22]

    Kundagrami A, Muthukumar M 2008 J. Chem. Phys. 128 244901

    [23]

    Fujishige S, Kubota K, Ando I 1989 J. Phys. Chem. 93 3313

    [24]

    Furyk S, Zhang Y, Ortiz-Acosta D, Cremer P S, Bergbreiter D E 2006 J. Polymer Sci.: Part A: Polymer Chemistry 44 1492Google Scholar

    [25]

    Lund M, Vacha R, Jungwirth P 2008 Langmuir 24 3387Google Scholar

    [26]

    Dormidontova E E 2002 Macromolecules 35 987Google Scholar

    [27]

    Nap R J, Park S H, Szleife I 2018 Soft Matter 14 2365Google Scholar

    [28]

    Mahalik J P, Sumpter B G, Kumar R 2016 Macromolecules 49 7096Google Scholar

    [29]

    Humphreys B A, Prescott S W, Murdoch T J, Nelson A, Gilbert E P, Webber G B, Wanless E J 2019 Soft Matter 15 55Google Scholar

    [30]

    Mason P E, Neilson G W, Dempsey C E, Barnes A C, Cruickshank J M 2003 Proc. Natl. Acad. Sci. U S A 100 4557Google Scholar

  • 图 1  接枝在纳米粒子表面的PNIPAM球面刷系统(其中SCN通过P—S键与PNIPAM结合)

    Figure 1.  Schematic representation of the PNIPAM tethered to nanoparticle surface. Bonding between PNIPAM and SCN by formation of P—S bonds.

    图 2  接枝在纳米粒子表面的PNIPAM球面刷高度随温度的变化关系(其中结合能参数为${E_{\rm{p}}}/{k_{\rm{B}}}=1000\;{\rm{K}}$, 熵的损失为$\Delta {S_{\rm{p}}}= - 2.25$, ${\chi _{{\rm{p}}{\rm{w}}}}= - 0.45 + 135/T$, 接枝密度为$\sigma = 0.\, 05\;{\rm{n}}{{\rm{m}}^{ - 2}}$)

    Figure 2.  Height of the grafted PNIPAM brushes as a function of temperature. The P—S bond energetic gain is chosen as ${E_{\rm{p}}}/{k_{\rm{B}}}=1000\;{\rm{K}}$, and the entropic loss is given by $\Delta {S_{\rm{p}}}{\rm{ = }} - 2.25$. The surface coverage is $\sigma = 0.05\, \, {\rm{n}}{{\rm{m}}^{ - 2}}$.

    图 3  P—S 键分数在垂直纳米粒子表面方向的分布(其中温度T = 31 ℃, 其余参数与图2相同)

    Figure 3.  Local fraction of P—S bond as a function of SCN concentration at a given temperature of T = 31 ℃. All parameters are the same as those in Fig. 2.

    图 4  体系静电势在距离垂直纳米粒子表面方向的分布(温度T = 31 ℃, 其余参数与图2相同)

    Figure 4.  Electrostatic potential as a function of the distance from the surface at different thiocyanate anion concentrations at a given temperature of T = 31 ℃. All parameters are the same as those in Fig. 2

    图 5  C = 750 mmol时PNIPAM分子链单体的平均体积分数在垂直纳米粒子表面方向的分布 (a) ${\chi _{{\rm{p}} {\rm{w}}}}= - 0.45 + 135/T, $${E_{\rm{p}}}/{k_{\rm{B}}}=1000{\kern 1 pt} \, {\kern 1 pt} {\rm{K;}}$ (b) ${\chi _{{\rm{p}} {\rm{w}}}}= - 2.25 + 95/T, {E_{\rm{p}}}/{k_{\rm{B}}}=2000\; {\rm{K}}$; 其余参数与图2相同

    Figure 5.  Average volume fractions of the grafted PNIPAM chains as a function of the distance from the surface for C = 750 mmol: (a) ${E_{\rm{p}}}/{k_{\rm{B}}}=1000\; {\rm{K, }}\;{E_{\rm{p}}}/{k_{\rm{B}}}=1000\; {\rm{K}}$; (b) ${\chi _{{\rm{p}}{\kern 1 pt} {\rm{w}}}}= - 2.25 + 95/T,\; {E_{\rm{p}}}/{k_{\rm{B}}}=1800\; {\rm{K}}$. All parameters are the same as those in Fig. 2

    图 6  C = 750 mmol时PNIPAM球面刷高度随温度的变化(其中${\chi _{{\rm{p}}{\rm{w}}}}= - 2.25 + 95/T$, 其余参数与图2相同)

    Figure 6.  Height of the grafted PNIPAM brushes as a function of temperature at C = 750 mmol. The ${\chi _{{\rm{p}}{\rm{w}}}}= $ – 2.25 + 95/T. All parameters are the same as those in Fig. 2.

  • [1]

    Wu C, Zhou S 1995 Macromolecules 28 5388Google Scholar

    [2]

    Howard G, Schild H G, Tirrell D A 1990 J. Phys. Chem. 94 4352Google Scholar

    [3]

    Lahann J, Mitragotri S, Tran T N, Kaido H, Sundaram J, Choi I S, Hoffer S, Somorjai A, Langer R 2003 Science 299 371Google Scholar

    [4]

    Kanazawa H, Okano T 2011 J. Chromatography A 1218 8738

    [5]

    Tang Z, Akiyama Y, Okano T 2012 Polymers 3 1478

    [6]

    Zhang Y J, Furyk S, Bergbreiter D E, Cremer P S 2005 J. Am. Chem. Soc. 127 14505Google Scholar

    [7]

    Du H, Wickramasinghe R, Qian X H 2010 J. Phys. Chem. B 114 16594

    [8]

    Okur H I, Kherb J, Cremer S 2013 J. Am. Chem. Soc. 135 5062Google Scholar

    [9]

    Naini C A, Thomas M, Franzka S, Frost S, Ulbricht M, Hartmann N 2013 Macromol. Rapid Commun. 34 417Google Scholar

    [10]

    Riehemann K, Schneider S W, Luger T A, Godin B, Ferrari M, Fuchs H 2009 Angew. Chem. Int. Ed. 48 872Google Scholar

    [11]

    Xia T, Kovochich M, Liong M, Meng H, Kabehie S, George S, Zink J I, Nel A E 2009 ACS Nano 3 3273Google Scholar

    [12]

    Croissant J, Zink J I 2012 J. Am. Chem. Soc. 134 7628Google Scholar

    [13]

    Thornton P D, Heise A 2010 J. Am. Chem. Soc. 132 2024Google Scholar

    [14]

    Yu Z Z, Li N, Zheng P P, Pan W, Tang B 2014 Chem. Commun. 50 3494Google Scholar

    [15]

    Humphreys B A, Wanless E J, Webber Grant B 2018 J. Colloid Interface Sci. 516 153Google Scholar

    [16]

    Zhao X J, Gao Z F 2016 Chin. Phys. B 25 074703

    [17]

    Liu L, Shi Y, Liu C, Wang T, Liu G M, Zhang G Z 2014 Soft Matter 10 2856Google Scholar

    [18]

    Murdoch T J, Humphreys B A, Willott J D, Gregory K P, Prescott S W, Nelson A, Wanless E J, Webber G B 2016 Macromolecules 49 6050Google Scholar

    [19]

    Humphreys B A, Willott J D, Murdoch T J, Webber G B, Wanless E J 2016 Phys. Chem. Chem. Phys. 18 6037Google Scholar

    [20]

    Szleifer I, Carignano M A 2000 Macromol. Rapid Commun. 21 423Google Scholar

    [21]

    Ren C L, Nap R J, Szleifer I 2008 J. Phys. Chem. B 112 16238Google Scholar

    [22]

    Kundagrami A, Muthukumar M 2008 J. Chem. Phys. 128 244901

    [23]

    Fujishige S, Kubota K, Ando I 1989 J. Phys. Chem. 93 3313

    [24]

    Furyk S, Zhang Y, Ortiz-Acosta D, Cremer P S, Bergbreiter D E 2006 J. Polymer Sci.: Part A: Polymer Chemistry 44 1492Google Scholar

    [25]

    Lund M, Vacha R, Jungwirth P 2008 Langmuir 24 3387Google Scholar

    [26]

    Dormidontova E E 2002 Macromolecules 35 987Google Scholar

    [27]

    Nap R J, Park S H, Szleife I 2018 Soft Matter 14 2365Google Scholar

    [28]

    Mahalik J P, Sumpter B G, Kumar R 2016 Macromolecules 49 7096Google Scholar

    [29]

    Humphreys B A, Prescott S W, Murdoch T J, Nelson A, Gilbert E P, Webber G B, Wanless E J 2019 Soft Matter 15 55Google Scholar

    [30]

    Mason P E, Neilson G W, Dempsey C E, Barnes A C, Cruickshank J M 2003 Proc. Natl. Acad. Sci. U S A 100 4557Google Scholar

  • [1] Chen Guang-Lin, Zhang Zhi-Yong. Exploring proten’s conformational space by using encoding layer supervised auto-encoder. Acta Physica Sinica, 2023, 72(24): 248705. doi: 10.7498/aps.72.20231060
    [2] Zhang Yi-Wei, Song Heng-Bo, Li Xiao-Yan, Sun Li, Liu Xiao-Ying, Kou Zhao-Xia, Zhang Dong, Fei Hong-Yang, Zhao Zhi-Bin, Zhai Ya. Influence of Cr interlayer with different thickness on transition of magnetoresistance effect of Gd/FeCo thin films. Acta Physica Sinica, 2022, 71(21): 217501. doi: 10.7498/aps.71.20220472
    [3] Han Mei-Dou-Xue,  Wang Ya,  Wang Rong-Bo,  Zhao Jun-Tao,  Ren Hui-Zhi,  Hou Guo-Fu,  Zhao Ying,  Zhang Xiao-Dan,  Ding Yi. Improved electrical properties of cuprous thiocyanate by lithium doping and its application in perovskite solar cells. Acta Physica Sinica, 2022, 0(0): . doi: 10.7498/aps.7120221222
    [4] Han Mei-Dou-Xue, Wang Ya, Wang Rong-Bo, Zhao Jun-Tao, Ren Hui-Zhi, Hou Guo-Fu, Zhao Ying, Zhang Xiao-Dan, Ding Yi. Improved electrical properties of cuprous thiocyanate by lithium doping and its application in perovskite solar cells. Acta Physica Sinica, 2022, 71(21): 217801. doi: 10.7498/aps.71.20221222
    [5] Yan Hao-Lan, Cheng Ya-Qing, Wang Kai-Li, Wang Ya-Xin, Chen Yang-Wei, Yuan Qiu-Lin, Ma Heng. Terahertz wave absorption for alkylcyclohexyl-isothiocyanatobenzene liquid crystal materials. Acta Physica Sinica, 2019, 68(11): 116102. doi: 10.7498/aps.68.20190209
    [6] Qin Ya-Qiang, Chen Rui-Yun, Shi Ying, Zhou Hai-Tao, Zhang Guo-Feng, Qin Cheng-Bing, Gao Yan, Xiao Lian-Tuan, Jia Suo-Tang. The role of chain conformation in energy transfer properties of single conjugated polymer molecule. Acta Physica Sinica, 2017, 66(24): 248201. doi: 10.7498/aps.66.248201
    [7] Jin Xiao, Wang Li-Min. Enthalpy relaxation studies of memory effect in various glass formers in the vicinity of glass transition. Acta Physica Sinica, 2017, 66(17): 176406. doi: 10.7498/aps.66.176406
    [8] Wang Li-Lin, Wang Zhi-Jun, Lin Xin, Wang Jin-Cheng, Huang Wei-Dong. Effect of cooling rate on crystallization process of thermo-sensitive poly-N-isopropylacrylamide colloid. Acta Physica Sinica, 2016, 65(10): 106403. doi: 10.7498/aps.65.106403
    [9] Gao Xiao-Lin, Wang Shi-Fa, Xiang Xia, Liu Chun-Ming, Zu Xiao-Tao. Photoluminescence of macroporous-alumina prepared by polyacrylamide gel technique. Acta Physica Sinica, 2013, 62(1): 016105. doi: 10.7498/aps.62.016105
    [10] Chen Ke, Cheng Jian-Qun, Xiao Yong, Tang Dao-Guang, Huang Ming-Ju. Dynamics of acrylamide-based photopolymer holographic gratings. Acta Physica Sinica, 2009, 58(2): 1007-1013. doi: 10.7498/aps.58.1007
    [11] Huang Yuan, Liu Hong, Zhang Qing-Chuan. Detection of the self-assembly of poly-(N-isopropylacrylamide) on gold based on microcantilever sensor. Acta Physica Sinica, 2009, 58(9): 6122-6127. doi: 10.7498/aps.58.6122
    [12] Li Kai, Liu Hong, Zhang Qing-Chuan, Hou Yi, Zhang Guang-Zhao, Wu Xiao-Ping. Investigation of conformation transition of poly(N-isopropylacrylamide) by surface stress detection using micro-cantilever. Acta Physica Sinica, 2006, 55(8): 4111-4116. doi: 10.7498/aps.55.4111
    [13] YE XIAO-LAN, DENG WEN-JIE, LIANG ER-JUN. NEAR INFRARED SURFACE ENHANCED RAMAN-SCATTERING OF HALATE IONS. Acta Physica Sinica, 1997, 46(11): 2130-2137. doi: 10.7498/aps.46.2130
    [14] LIN MING-XI, CHEN GUAN-MIAN, A SHA, XU XIAO-ZHEN. ION COORDINATION AND STRUCTURAL TRANSITION OF YBa2Cu3-xFexOy. Acta Physica Sinica, 1992, 41(1): 128-135. doi: 10.7498/aps.41.128
    [15] LIN DONG, WANG SHAO-JIE. STRUCTURAL TRANSITIONS AND FREE-VOLUME PROPERTIES OF PMMA POLYMER STUDIED BY POSITRON ANNIHILATION. Acta Physica Sinica, 1992, 41(4): 668-674. doi: 10.7498/aps.41.668
    [16] Zhao Zong-yuan, Chen Li-quan. MUTUAL EFFECT ON PHASE TRANSITION TEMPERATURES OF TWO PHASES IN AgI(α-Fe2O3) COMPOSITION ELECTROLYTES. Acta Physica Sinica, 1986, 35(9): 1158-1163. doi: 10.7498/aps.35.1158
    [17] WANG CHAO-YING, CHEN LI-QUAN, CHEN ZHU-SHENG, HE YUAN-KANG. STUDY OF ELECTRICAL PROPERTIES OF POLY (ETHLENE OXIDE )-NaSCN POLYMER IONIC CONDUCTOR. Acta Physica Sinica, 1984, 33(6): 854-860. doi: 10.7498/aps.33.854
    [18] ZHAO GUANG-LIN. THE INFLUENCE OF IMPLANTED IONS ON THE SUPERCONDUCTING TRANSITION TEMPERATURE. Acta Physica Sinica, 1984, 33(4): 571-574. doi: 10.7498/aps.33.571
    [19] XU ZHANG-BAO, GU YUAN-XIN, ZHENG QI-TAI, SHEN FU-LIN, YAO XING-KAN, YAN SI-PIN, WANG GEN-LIN. RESEARCH ON DIBENZO-18-CROWN-6 AND YTTRIUM ISOTHIOCYANATE COMPLEX (Ⅱ) ——DETERMINATION OF THE CRYSTAL STRUCTURE. Acta Physica Sinica, 1982, 31(7): 956-962. doi: 10.7498/aps.31.956
    [20] Feng Ruo. ULTRSONIC INVESTIGATION OF THE AQUEOUS SOLUTION OF POLYACRYLAMIDE. Acta Physica Sinica, 1980, 29(7): 940-944. doi: 10.7498/aps.29.940
Metrics
  • Abstract views:  6868
  • PDF Downloads:  37
  • Cited By: 0
Publishing process
  • Received Date:  06 May 2019
  • Accepted Date:  02 July 2019
  • Available Online:  01 November 2019
  • Published Online:  05 November 2019

/

返回文章
返回