PMPS-b-PNIPAM copolymers synthesized by RAFT polymerization and their thermo-responsive nanoparticles

doi:10.11949/0438-1157.20190342

Abstract

Abstract:

A series of molecular weight-controlled, narrow molecular weight distributions of 3-trimethoxysilyl methacrylate (MPS) and N-isopropyl acrylamide (NIPAM) block copolymers were synthesized by reversible addition-fragmentation chain transfer (RAFT) living radical polymerization. Temperature-sensitive silicon-containing nanoparticle are prepared by dispersing in aqueous solution. With the same chain length of hydrophobic segment PMPS, by changing the chain length of hydrophilic segment PNIPAM and the pH of the water solutions, the critical aggregation concentrations, the diameters and morphologies of the nanoparticles, and the phase separation behavior happening in the process of temperature variation were studied. Thermo-responsive and spherical nanoparticles were attained. The nanoparticles possessed advantages of both organics and inorganics. And they may have wide applications in many fields such as biomedicine, chemical catalysis, nanoreactors, dyes, coatings and so on.

Key words: polymers, silicane, nanoparticles, pH, hydrolysis

摘要：

利用可逆加成-断裂链转移(RAFT)活性自由基聚合合成了一系列分子量可控、分子量分布窄的甲基丙烯酸-3-三甲氧基硅丙酯(MPS)和N-异丙基丙烯酰胺(NIPAM)的嵌段共聚物，在水溶液中分散制备温敏性的含硅纳米粒子。保持疏水链段PMPS的长度恒定，改变亲水链段PNIPAM的长度，在不同pH的水溶液中进行实验，研究亲水链段长度、pH对聚合物的临界聚集浓度、纳米粒子的尺寸和形貌以及温度变化过程中的相分离行为的影响，得到尺寸较小、溶液稳定的温度响应性含硅纳米粒子，同时具有有机物和无机物的优良特点，在生物医学、化学催化、纳米反应器、染料涂料等多领域具有广泛的应用前景。

关键词: 共聚物, 硅烷, 纳米粒子, pH, 水解

CLC Number:

TQ 316.344

Xiaoyan ZHAO, Guorong SHAN. PMPS-b-PNIPAM copolymers synthesized by RAFT polymerization and their thermo-responsive nanoparticles[J]. CIESC Journal, 2019, 70(10): 4080-4088.

赵小燕, 单国荣. RAFT聚合制备PMPS-b-PNIPAM嵌段共聚物及温敏性纳米粒子[J]. 化工学报, 2019, 70(10): 4080-4088.

Figures/Tables 13

Fig.1 Reaction process of MPS and NIPAM RAFT copolymerization

Table 1 Molecular weight and its distribution of PMPS and PMPS-b-PNIPAM block copolymers

Sample	$M n ˉ$ ^①	$M n ˉ$	PDI
PMPS	2800	2700	1.19
M10N10^②	4000	4100	1.68
M10N30^②	6400	6500	1.53
M10N50^②	8700	8500	1.32

Table 1 Molecular weight and its distribution of PMPS and PMPS-b-PNIPAM block copolymers

Sample	$M n ˉ$ ^①	$M n ˉ$	PDI
PMPS	2800	2700	1.19
M10N10^②	4000	4100	1.68
M10N30^②	6400	6500	1.53
M10N50^②	8700	8500	1.32

Fig.2 GPC curves of PMPS-b-PNIPAM block copolymers

Fig.3 1H NMR spectra of PMPS-b-PNIPAM block copolymers

Table 2 Ratio of peak areas in 1H NMR curves of PMPS-b-PNIPAM block copolymers

Sample	Ratio of peak areas of [—CH₂ —CH—,—CH₂—CH— and —CH₂ —C— in main chain] and [—CH₃ in PMPS]		Ratio of peak areas of [—CH(CH₃ )₂ in PNIPAM] and [—CH₃ in PMPS]
Sample	Calculated data	Theoretical data	Calculated data	Theoretical data
M10N10	1.90	1.67	2.32	2.00
M10N30	4.57	3.67	5.54	6.00
M10N50	5.90	5.67	9.37	10.00

Fig.4 Intensity ratio (I 339/I 333) of pyrene measured by fluorescence spectroscopy as function of PMPS-b-PNIPAM copolymers concentration in different pH solutions

Table 3 CAC of PMPS-b-PNIPAM copolymers in different environments

Sample	CAC/(mol/L)
Sample	NaOH	H₂O	HCl
M10N10	9.40×10^-6	19.10×10^-6	42.23×10^-6
M10N30	4.21×10^-6	11.68×10^-6	25.35×10^-6
M10N50	2.10×10^-6	5.56×10^-6	12.71×10^-6

Table 4 Average nanoparticle size in different environments/nm

Sample	H₂O		NaOH(10^-3mol/L)		HCl(10^-3mol/L)
Sample	15℃	60℃	15℃	60℃	15℃	60℃
M10N10	193	158.5	103.8	90.91	—	—
M10N30	212.7	147.1	145.3	98.14	—	—
M10N50	328.8	63.82	226.2	127.9	314.4	—

Fig.5 Optical transmittance changes of nanoparticles in different pH solutions

Fig.6 TEM photographs of nanoparticles in water solution

Fig.7 TEM photographs of nanoparticles in NaOH solution

Fig.8 TEM photograph of M10N50 nanoparticles in HCl solution

Fig.9 Formation mechanism of PMPS-b-PNIPAM nanoparticles

References 34

1	Li J J , Zhou Y N , Luo Z H , et al . A polyelectrolyte-containing copolymer with a gas-switchable lower critical solution temperature-type phase transition[J]. Polymer Chemistry, 2019, 10(2): 260-266.
2	Li X Y , Gao Y , Boott C E , et al . “Cross” supermicelles via the hierarchical assembly of amphiphilic cylindrical triblock comicelles[J]. Journal of the American Chemical Society, 2016, 138(12): 4087-4095.
3	Li X Y , Gao Y , Boott C E , et al . Non-covalent synthesis of supermicelles with complex architectures using spatially confined hydrogen-bonding interactions[J]. Nature Communications, 2015, 6: No8127.
4	Palmer L C , Stupp S I . Molecular self-assembly into one-dimensional nanostructures[J]. Accounts of Chemical Research, 2008, 41(12): 1674-1684.
5	Mao H L , Shan G R , Bao Y Z , et al . Thermoresponsive physical hydrogels of poly(lactic acid)/poly(ethylene glycol) stereoblock copolymers tuned by stereostructure and hydrophobic block sequence[J]. Soft Matter, 2016, 12(20): 4628-4637.
6	Li S Y , Lin D L , Zhou J F , et al . Preparation of silver nanoparticles loaded photoresponsive composite microgels and their light-controllable catalytic activity[J]. Journal of Physical Chemistry C, 2016, 120(9): 4902-4908.
7	Cao Z H , Ziener U , Landfester K . Synthesis of narrowly size-distributed thermosensitive poly(N-isopropylacrylamide) nanocapsules in inverse miniemulsion[J]. Macromolecules, 2010, 43(15): 6353-6360.
8	Bajpai A K , Shukla S K , Bhanu S , et al . Responsive polymers in controlled drug delivery[J]. Progress in Polymer Science, 2008, 33(11): 1088-1118.
9	Qin S H , Geng Y , Discher D E , et al . Temperature-controlled assembly and release from polymer vesicles of poly(ethylene oxide)-block-poly(N-isopropylacrylamide)[J]. Advanced Materials, 2006, 18(21): 2905-2909.
10	Valade D , Jeon Y , Kessel S , et al . Influence of the Z-group on the RAFT-mediated polymerizations in nanoreactors[J]. Journal of Polymer Science Part A-Polymer Chemistry, 2012, 50(22): 4762-4771.
11	Urbani C N , Monteiro M J . RAFT-mediated emulsion polymerization of styrene in water using a reactive polymer nanoreactor[J]. Australian Journal of Chemistry, 2009, 62(11): 1528-1532.
12	Song S , Lv H , Bi Y , et al . Research of the synthesis and film performance of silica/poly(St-BA-MPS) core-shell latexes obtained by miniemulsion co-polymerization[J]. Macromolecular Research, 2017, 25(5): 408-414.
13	Wang F Z , Luo Y . The morphology and mechanical properties of the hybrid films of styrene-butyl acrylate block copolymer/MMT from colloid blending[J]. Macromolecular Reaction Engineering, 2016, 10(1): 63-70.
14	Li F , Du M , Zheng Q . Dopamine/silica nanoparticle assembled, microscale porous structure for versatile superamphiphobic coating[J]. ACS Nano, 2016, 10(2): 2910-2921.
15	Cao Z H , Shan G R , Sheibat-othman N , et al . Synthesis of oily core-hybrid shell nanocapsules through interfacial free radical copolymerization in miniemulsion: droplet formation and nucleation[J]. Journal of Polymer Science Part A-Polymer Chemistry, 2010, 48(3): 593-603.
16	Cao Z H , Shan G R . Synthesis of polymeric nanocapsules with a crosslinked shell through interfacial miniemulsion polymerization[J]. Journal of Polymer Science Part A-Polymer Chemistry, 2009, 47(6): 1522-1534.
17	Koh K , Ohno K , Tsujii Y , et al . Precision synthesis of organic/inorganic hybrid nanocapsules with a silanol-functionalized micelle template[J]. Angewandte Chemie-International Edition, 2003, 42(35): 4194-4197.
18	Marcu I , Daniels E S , Dimonie V L , et al . A Miniemulsion Approach to the Incorporation of Vinyltriethoxysilane into Acrylate Latexes[M]. Berlin: Springer-Verlag Berlin, 2004.
19	Marcu I , Daniels E S , Dimonie V L , et al . Incorporation of alkoxysilanes into model latex systems: vinyl copolymerization of vinyltriethoxysilane and n-butyl acrylate[J]. Macromolecules, 2003, 36(2): 328-332.
20	Zhang S W , Zhou S X , Weng Y M , et al . Synthesis of silanol-functionalized latex nanoparticles through miniemulsion copolymerization of styrene and gamma-methacryloxypropyltrime-thoxysilane[J]. Langmuir, 2006, 22(10): 4674-4679.
21	Ni K F , Sheibat-Othman N , Shan G R , et al . Kinetics and modeling of hybrid core-shell nanoparticles synthesized by seeded emulsion (co)polymerization of styrene and gamma-methacryloyloxypropyltrimethoxysilane[J]. Macromolecules, 2005, 38(22): 9100-9109.
22	Ni K F , Shan G R , Weng Z X , et al . Synthesis of hybrid core-shell nanoparticles by emulsion (co)polymerization of styrene and gamma-methacryloxypropyltrimethoxysilane[J]. Macromolecules, 2005, 38(17): 7321-7329.
23	Jovanovic A V , Underhill R S , Bucholz T L , et al . Oil core and silica shell nanocapsules: toward controlling the size and the ability to sequester hydrophobic compounds[J]. Chemistry of Materials, 2005, 17(13): 3375-3383.
24	Ni K F , Shan G R , Weng Z X . Synthesis of hybrid nanocapsules by miniemulsion (co)polymerization of styrene and gamma-methacryloxypropyltrimethoxysilane[J]. Macromolecules, 2006, 39(7): 2529-2535.
25	Liu B L , Deng X B , Cao S S , et al . Preparation and characterization of core/shell particles with siloxane in the shell[J]. Appl. Surf. Sci., 2006, 252(6): 2235-2241.
26	Ikem V O , Menner A , Bismarck A . High internal phase emulsions stabilized solely by functionalized silica particles[J]. Angewandte Chemie-International Edition, 2008, 47(43): 8277-8279.
27	Kan C Y , Liu D S , Kong X Z , et al . Study on the preparation and properties of styrene-butyl acrylate-silicone copolymer latices[J]. Journal of Applied Polymer Science, 2001, 82(13): 3194-3200.
28	Kan C , Yuan Q , Wang M , et al . Synthesis of silicone-acrylate copolymer latexes and their film properties[J]. Polymers for Advanced Technologies, 1996, 7(2): 95-97.
29	Zhu Y , Bi S Y , Gao X , et al . Comparison of RAFT ab initio emulsion polymerization of methyl methacrylate and styrene mediated by Oligo(methacrylic acid-b-methyl methacrylate) trithiocarbonate surfactant[J]. Macromolecular Reaction Engineering, 2015, 9(5): 503-511.
30	Moad G , Rizzardo E , Thang S H . Living radical polymerization by the RAFT process — a third update[J]. Australian Journal of Chemistry, 2012, 65(8): 985-1076.
31	Chong B Y K , Krstina J , Le T P T , et al . Thiocarbonylthio compounds [SC(Ph)S-R] in free radical polymerization with reversible addition-fragmentation chain transfer (RAFT polymerization). Role of the free-radical leaving group (R)[J]. Macromolecules, 2003, 36(7): 2256-2272.
32	Quinn J F , Davis T P , Rizzardo E . Ambient temperature reversible addition-fragmentation chain transfer polymerisation[J]. Chemical Communications, 2001, 24(11): 1044-1045.
33	Mayadunne R T A , Rizzardo E , Chiefari J , et al . Living polymers by the use of trithiocarbonates as reversible addition-fragmentation chain transfer (RAFT) agents: ABA triblock copolymers by radical polymerization in two steps[J]. Macromolecules, 2000, 33(2): 243-245.
34	Du B Y , Mei A X , Yang Y , et al . Synthesis and micelle behavior of (PNIPAm-PtBA-PNIPAm) _m amphiphilic multiblock copolymer[J]. Polymer, 2010, 51(15): 3493-3502.

[1]	Xin WU, Jianying GONG, Long JIN, Yutao WANG, Ruining HUANG. Study on the transportation characteristics of droplets on the aluminium surface under ultrasonic excitation [J]. CIESC Journal, 2023, 74(S1): 104-112.
[2]	Shaohua ZHOU, Feilong ZHAN, Guoliang DING, Hao ZHANG, Yanpo SHAO, Yantao LIU, Zheming GAO. Experimental study of flow noise in short tube throttle valve and noise reduction measures [J]. CIESC Journal, 2023, 74(S1): 113-121.
[3]	Wei SU, Dongxu MA, Xu JIN, Zhongyan LIU, Xiaosong ZHANG. Visual experimental study on effect of surface wettability on frost propagation characteristics [J]. CIESC Journal, 2023, 74(S1): 122-131.
[4]	Xiaoqing ZHOU, Chunyu LI, Guang YANG, Aifeng CAI, Jingyi WU. Icing kinetics and mechanism of droplet impinging on supercooled corrugated plates with different curvature [J]. CIESC Journal, 2023, 74(S1): 141-153.
[5]	Shuangxing ZHANG, Fangchen LIU, Yifei ZHANG, Wenjing DU. Experimental study on phase change heat storage and release performance of R-134a pulsating heat pipe [J]. CIESC Journal, 2023, 74(S1): 165-171.
[6]	Yingying TAN, Xiaoqing LIU, Lin WANG, Lisheng HUANG, Xiuzhen LI, Zhanwei WANG. Experimental study on startup dynamic characteristics of R1150/R600a auto-cascade refrigeration cycle [J]. CIESC Journal, 2023, 74(S1): 213-222.
[7]	He JIANG, Junfei YUAN, Lin WANG, Guyu XING. Experimental study on the effect of flow sharing cavity structure on phase change flow characteristics in microchannels [J]. CIESC Journal, 2023, 74(S1): 235-244.
[8]	Yanpeng WU, Qianlong LIU, Dongmin TIAN, Fengjun CHEN. A review of coupling PCM modules with heat pipes for electronic thermal management [J]. CIESC Journal, 2023, 74(S1): 25-31.
[9]	Yanpeng WU, Xiaoyu LI, Qiaoyang ZHONG. Experimental analysis on filtration performance of electrospun nanofibers with amphiphobic membrane of oily fine particles [J]. CIESC Journal, 2023, 74(S1): 259-264.
[10]	Mingkun XIAO, Guang YANG, Yonghua HUANG, Jingyi WU. Numerical study on bubble dynamics of liquid oxygen at a submerged orifice [J]. CIESC Journal, 2023, 74(S1): 87-95.
[11]	Ruitao SONG, Pai WANG, Yunpeng WANG, Minxia LI, Chaobin DANG, Zhenguo CHEN, Huan TONG, Jiaqi ZHOU. Numerical simulation of flow boiling heat transfer in pipe arrays of carbon dioxide direct evaporation ice field [J]. CIESC Journal, 2023, 74(S1): 96-103.
[12]	Kaijie WEN, Li GUO, Zhaojie XIA, Jianhua CHEN. A rapid simulation method of gas-solid flow by coupling CFD and deep learning [J]. CIESC Journal, 2023, 74(9): 3775-3785.
[13]	Yubing WANG, Jie LI, Hongbo ZHAN, Guangya ZHU, Dalin ZHANG. Experimental study on flow boiling heat transfer of R134a in mini channel with diamond pin fin array [J]. CIESC Journal, 2023, 74(9): 3797-3806.
[14]	Minghao SONG, Fei ZHAO, Shuqing LIU, Guoxuan LI, Sheng YANG, Zhigang LEI. Multi-scale simulation and study of volatile phenols removal from simulated oil by ionic liquids [J]. CIESC Journal, 2023, 74(9): 3654-3664.
[15]	Xuejin YANG, Jintao YANG, Ping NING, Fang WANG, Xiaoshuang SONG, Lijuan JIA, Jiayu FENG. Research progress in dry purification technology of highly toxic gas PH₃ [J]. CIESC Journal, 2023, 74(9): 3742-3755.