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1.
利用接触角、XPS、SFG、AFM等技术研究了环己酮、甲苯和三氟甲苯为成膜溶剂所得聚甲基丙烯酸甲酯-b-聚(甲基丙烯酸-2-全氟辛基乙酯)(PMMA—b—PFMA)嵌段共聚物膜的表面结构与性能.发现浇铸成膜时成膜溶剂对聚合物氟化组分向表面富集程度的影响相对较小,而旋涂成膜时溶剂的影响很大.不管以何种形式成膜,三氟甲苯溶剂最有利于氟化组分向表面富集,甲苯次之,环己酮最差.这一现象与溶剂的挥发速度无关.聚合物在溶液中的聚集结构、气/液界面结构是造成成膜方式对聚合物表面结构与性能产生巨大影响的主要原因.当聚合物在溶液中形成以PFMA为核、PMMA为冠的胶束结构时,在溶液固化过程中氟化组分向表面富集需要较长的时间,这时由于成膜方法直接影响溶液的固化速度,造成其对氟化组分向表面富集的程度影响很大.当聚合物在溶液中以单分子或松散聚集体存在,在溶液固化过程中氟化组分向表面富集的速度很快,这时成膜方法对氟化组分向表面富集的程度影响很小.以上结果无论对理论研究还是应用研究都具有重要意义. 相似文献
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JuPing Yang QiDi Zhao Bin Zhou HuaGang Ni XinPing Wang ZhiQuan Shen 《中国科学B辑(英文版)》2009,52(12):2295-2306
Most research on copolymers with fluorinated monomers has focused on the relationship between fluorinated monomer content
and the corresponding surface structure. However, the influence of the non-fluorinated block on the surface structure of the
copolymer film is unknown. Various molecular weight poly(butyl methacrylates) (PBMA) end-capped with 2-perfluorooctylethyl
methacrylate (FMA) units (PBMA-ec-FMA) have been synthesized by atom transfer radical polymerization (ATRP). The effect of the PBMA block length on the surface
structure and properties of the polymers both in the solid state and in solution was investigated using various techniques.
X-ray photoelectron spectroscopy (XPS), sum frequency generation (SFG) vibrational spectroscopy and X-ray diffraction (XRD)
analyses indicated that longer PBMA blocks enhanced both the enrichment of the fluorinated moieties and the order of the packing
orientation of the perfluoroalkyl side chains on the surface. This enhancement was attributed mainly to the molecular aggregate
structure of the end-capped polymers with long PBMA blocks in the solution and to the interfacial structure at the air/liquid
interface, which favors the -(CF2)7CF3 moieties self-assembling on the polymer surface during film formation. This observation suggests that the polyacrylate block
structure in fluorinated diblock copolymers, in addition to the fluorinated monomer content, plays an important role in structure
formation on the solid surface. 相似文献
4.
Yang J Yuan D Zhou B Gao J Ni H Zhang L Wang X 《Journal of colloid and interface science》2011,359(1):269-278
The effects of the alkyl group on the surface segregation of poly(n-alkyl methacrylate) end-capped with various numbers of units of 2-perfluorooctylethyl methacrylate (FMA) (PnAMA-ec-PFMA) were investigated by differential scanning calorimetry, angle-resolved XPS analysis, contact angle measurements, and X-ray diffraction (XRD). The results show that with similar numbers of FMA units at the polymer chain end the extent of fluorine segregation (Q) increased with increasing the number of carbon atoms in the side n-alkyl chains of poly(n-alkyl methacrylate). The surface fluorine content within 5 nm deep of the film of poly(n-octadecyl methacrylate) end-capped with one FMA unit (PODMA(160)-ec-PFMA(1.0)) was 208-fold higher than that of the bulk level. These observed differences in Q values were found due to the aggregate structure of the end-capped polymers in the solution, the flexibility, and the crystallinity of the n-alkyl side chains. When the nonfluorinated block was completely amorphous, the molecular aggregate structure of the end-capped polymers in the solution played an important role in the surface segregation of the fluorinated moieties on the resulting film. However, when the nonfluorinated block was crystalline, crystallinity would enhance greatly the segregation of the fluorinated moieties. 相似文献
5.
New fluorinated copolymers of poly(methyl methacrylate)-b-poly(butyl methacrylate) or poly(n-octadecyl methacrylate) end-capped with 2-perfluorooctylethyl methacrylate (PMMA(x)-b-PBMA(y)-ec-PFMA(z) or PMMA(x)-b-PODMA(y)-ec-PFMA(z)) were synthesized by living atom transfer radical polymerization. Thin films made of PMMA(230)-b-PODMA(y)-ec-PFMA(1) were characterized by differential scanning calorimetry, angle-resolved X-ray photoelectron spectroscopy and X-ray diffraction. These films were found to exhibit robust surface segregation of the end groups. Furthermore, the fluorine enrichment factor at the film surface was found to increase linearly with increasing degree of polymerization of poly(n-octadecyl methacrylate) and its increasing fusion enthalpy in the second block, which enhances the segregation of the fluorinated moieties. 相似文献
6.
Hideo Sawada Yasufumi Shikauchi Hiroshi Kakehi Yoshihiro Katoh Masashi Miura 《Colloid and polymer science》2007,285(5):499-506
Calcium chloride reacted with sodium carbonate in the presence of a variety of self-assembled molecular aggregates formed
by fluoroalkyl end-capped acrylic acid, 2-methacryloyloxyethane sulfonic acid, dimethylacrylamide, and acryloylmorpholine
oligomers in aqueous solutions to afford the corresponding fluorinated oligomers/calcium carbonate composites in excellent
to moderate isolated yields. These fluorinated calcium carbonate composites thus obtained were shown to have a good dispersibility
not only in water but also in traditional organic media including fluorinated solvents. Dynamic light scattering measurements
(DLS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that these fluorinated composites
are nanometer-size-controlled particles and well dispersed in these media. Cross-linked fluoroalkyl end-capped acrylic acid
co-oligomer containing poly(oxyethylene) units was also applied to the preparation of new cross-linked fluorinated calcium
carbonate nanocomposites under similar conditions. The obtained cross-linked fluorinated calcium carbonate nanocomposites
were found to have an extremely higher dispersibility in aqueous and organic media including fluorinated solvents, compared
to that of the corresponding fluoroalkyl end-capped oligomer nanocomposites. In particular, it was verified that these fluorinated
calcium carbonate nanocomposites are applicable to the dispersion above poly(methyl methacrylate) (PMMA) film surface. Interestingly,
field-emission SEM (FE-SEM) images of the cross-section of the modified PMMA films showed that calcium carbonate particles
dispersed into these PMMA films could be arranged regularly above the modified film surface. More interestingly, cross-linked
fluorinated oligomeric aggregates were able to provide suitable host moieties for the crystallization of calcium carbonate. 相似文献
7.
Sawada H Takahashi K Mugisawa M Oya T Ogino S 《Langmuir : the ACS journal of surfaces and colloids》2007,23(24):11947-11950
Fluoroalkyl end-capped N-(1,1-dimethyl-3-oxobutyl)acrylamide--acryloylmorpholine co-oligomers were prepared by the co-oligomerizations of fluoroalkanoyl peroxides with the corresponding monomers. These fluorinated co-oligomers exhibited a lower critical solution temperature (LCST) characteristic in aqueous solutions. Of particular interest, a steep time dependence of contact angle values for dodecane was observed from 40 to 60 degrees C to decrease their values, effectively, on the modified PMMA [poly(methyl methacrylate)] film surface treated with fluorinated co-oligomer possessing the LCST: 36 degrees C (in water), although such a steep time dependence was not observed from 20 to 30 degrees C. 相似文献
8.
Nanometer size-controlled gold particles were prepared under mild conditions by reducing the corresponding metal precursor in the presence of self-assembled molecular aggregates formed by fluoroalkyl end-capped N-(1,1-dimethyl-3-oxobutyl)acrylamide oligomers. The stable gold nanoparticles protected by these fluorinated molecular aggregates were applied to the dispersion above the poly(methyl methacrylate) film surface. 相似文献
9.
核壳型含氟丙烯酸酯共聚物的合成及性能 总被引:5,自引:1,他引:4
采用饥饿态半连续种子乳液聚合方法, 在十二烷基硫酸钠(SDS)/辛基苯基聚氧乙烯醚(TX-10)复合乳化剂的作用下, 分别选用甲基丙烯酸三氟乙酯(TFEM)、甲基丙烯酸六氟正丁酯(HFBM)和甲基丙烯酸十二氟庚酯(DFHM)为含氟单体, 合成以丙烯酸正丁酯(BA)、甲基丙烯酸甲酯(MMA)和含氟单体为原料的核壳型结构含氟丙烯酸酯共聚物乳液. FTIR, 1H NMR, TEM和DSC分析结果显示, 获得了BA/MMA/含氟单体的共聚物乳液, 且乳液具有明显的核壳结构. DSC, TGA和SEM-EDX的分析显示, 核壳型结构的共聚物具有优异的热力学稳定性能和成膜性能; 长侧链或短侧链含氟单体对共聚物的热稳定性影响不明显, 但侧链较长的含氟单体所获得的聚合物在成膜过程中更易向表面迁移, 更能体现含氟聚合物的优点. 相似文献
10.
Younsik Cha Masahiro Tsunooka Makoto Tanaka 《Journal of polymer science. Part A, Polymer chemistry》1984,22(11):2973-2981
Photocrosslinking of poly(methyl methacrylate) (PMMA) was studied in the solid state in the presence of various quinones. For the study of photocrosslinking mechanism, a PMMA film containing p-benzoquinone (Q) was irradiated with UV light (λ > 370nm) and then purified by reprecipitation. It was found that the reprecipitated polymer has quinone-type moieties, besides the hydroquinone-type moieties, chemically bound to the polymer chain. The reprecipitated polymer film also crosslinking efficiency was higher than that of PMMA film containing Q. It was concluded that the formation of quinone-type structure during irradiation played an important role in the photocrossing of PMMA containing Q. 相似文献
11.
Takashima H Iwaki K Furukuwa R Takishita K Sawada H 《Journal of colloid and interface science》2008,320(2):436-444
A variety of fluoroalkyl end-capped oligomers were applied to the preparation of fluorinated oligomer/hydroxyapatite (HAp) composites (particle size: 38-356 nm), which exhibit a good dispersibility in water and traditional organic solvents. These fluoroalkyl end-capped oligomer/HAp composites were easily prepared by the reactions of disodium hydrogen phosphate and calcium chloride in the presence of self-assembled molecular aggregates formed by fluoroalkyl end-capped oligomers in aqueous solutions. In these fluorinated HAp composites thus obtained, fluoroalkyl end-capped acrylic acid oligomers and 2-methacryloyloxyethanesulfonic acid oligomer/HAp nanocomposites afforded transparent colorless solutions toward water; however, fluoroalkyl end-capped N,N-dimethylacrylamide oligomer and acryloylmorpholine oligomer were found to afford transparent colorless solutions with trace amounts of white-colored HAp precipitants under similar conditions. HAp could be encapsulated more effectively into fluorinated 2-methacryloyloxyethanesulfonic acid oligomeric aggregate cores to afford colloidal stable fluorinated oligomer/HAp composites, compared to that of fluorinated acrylic acid oligomers. These fluorinated oligomer/HAp composites were applied to the surface modification of glass and PVA to exhibit a good oleophobicity imparted by fluorine. HAp formation was newly observed on the modified polyethylene terephthalate film surface treated with fluorinated 2-methacryloyloxyethanesulfonic acid oligomers and acrylic acid oligomer/HAp composites by soaking these films into the simulated body fluid. 相似文献
12.
Fluoroalkyl end-capped acrylic acid oligomer-encapsulated magnetic nanoparticles were prepared by the coprecipitation of aqueous ferric and ferrous ions in the presence of the corresponding oligomers under alkaline conditions. The dynamic light scattering measurements showed that these fluorinated oligomer magnetic nanoparticles were encapsulated in the self-assemblies of fluoroalkyl end-capped oligomers. Fluoroalkyl end-capped oligomer-encapsulated magnetic nanoparticles thus obtained were applied to the dispersion of magnetic particles on the poly(methyl methacrylate) film surface to exhibit not only the surface active property imparted by fluorine but also magnetic behavior toward a permanent magnet. 相似文献
13.
Fluoroalkyl end-capped N-(1,1-dimethyl-3-oxobutyl)acrylamide polymers were found to be a convenient tool for the arrangements of fullerenes above the poly(methyl methacrylate) [PMMA] surface, and the higher fluorescent intensity of fullerene was obtained in the modified PMMA surface, although the reverse side of this modified film surface afforded an extremely weak fluorescent intensity. 相似文献
14.
Fluoroalkyl end-capped vinylphosphonic acid cooligomers-encapsulated magnetite nanocomposites were prepared by the magnetization of aqueous ferric and ferrous ions in the presence of the corresponding fluorinated cooligomers and magnetic nanoparticles under alkaline conditions. These fluorinated cooligomers magnetic composites are nanometer size-controlled very fine particles and have a good dispersibility and stability in water and traditional organic solvents. These fluorinated nanocomposites were also applied to the surface modification of poly(methyl methacrylate) to exhibit a good oleophobicity imparted by fluorine on their surface. Fluoroalkyl end-capped 2-methacryloyloxyethanesulfonic acid oligomer-encapsulated magnetite nanocomposites and fluoroalkyl end-capped 2-acrylamide-2-methylpropanesulfonic acid oligomer-encapsulated magnetite nanocomposites were prepared in good isolated yields by the magnetization of iron chlorides in the presence of the corresponding oligomers and magnetic nanoparticles under similar conditions. Colloidal stability of these fluorinated nanocomposites thus obtained in water was demonstrated to become extremely higher than that of fluorinated vinylphosphonic acid cooligomers/magnetic nanocomposites. 相似文献
15.
We have studied on the solubilization of single-walled carbon nanotubes (SW-CNTs) into aqueous and organic media by the use of a variety of nanometer size-controlled fluorinated self-assemblies, which were formed by the aggregations of end-capped fluoroalkyl segments in fluoroalkyl end-capped acrylic acid oligomers [RF-(ACA)n-RF], N,N-dimethylacrylamide oligomers [RF-(DMAA)n-RF], acryloylmorpholine oligomers [RF-(ACMO)n-RF], and N-(1,1-dimethyl-3-oxobutyl)acrylamide oligomers [RF-(DOBAA)n-RF]. Fluorinated self assemblies formed in organic media (colorless solutions) could solubilize SW-CNTs into organic media to afford the transparent pale yellow solutions. The dynamic light scattering measurements showed that the size of fluorinated self-assemblies increased after the solubilization of SW-CNTs into organic media. It was suggested that the solubilization of SW-CNTs into organic media is due to the encapsulation of SW-CNTs into fluorinated assemblies. Fluorinated assemblies were also able to solubilize SW-CNTs into water to give the transparent gray solutions. Among a variety of fluorinated assemblies, fluorinated assemblies formed by RF-(ACMO)n-RF [RF = CF(CF3)OC6F13] oligomer was more effective for the solubilization of SW-CNTs into both aqueous and organic media. Contact angle measurements of dodecane and the fluorescence spectra for poly(methyl methacrylate) cast film modified by fluorinated self-assemblies—SW-CNTs complexes showed that SW-CNTs are dispersed above the PMMA surface. 相似文献
16.
Composition and solution properties of fluorinated block copolymers and their surface structures in the solid state 总被引:1,自引:0,他引:1
HuaGang Ni DongWu Xue XiaoFang Wang Wei Zhang XinPing Wang ZhiQuan Shen 《中国科学B辑(英文版)》2009,52(2):203-211
A series of diblock copolymers composed of methyl methacrylate and 2-perfluorooctylethyl methacrylate (PMMA144-b-PFMA
n
) with various PFMA block lengths were prepared by atom transfer radical polymerization (ATRP). The surface structures and
properties of these polymers in the solid state and in solution were investigated using contact angle measurement, X-ray photoelectron
spectroscopy (XPS), sum frequency generation (SFG) vibrational spectroscopy, surface tension and dynamic laser light scattering
(DLS). It was found that with increasing PFMA block length, water and oil repellency decreased, the ratio of F/C increased
with increasing film depth, and the degree of ordered packing of the perfluoroalkyl side chains at the surface decreased.
When the number of PFMA block units reached 10, PMMA segments were detected at the copolymer surface, which was attributed
to the PFMA block length affecting molecular aggregation structure of the copolymer in the solution and the interfacial structure
at the air/liquid interface, which in turn affects surface structure formation during solution solidification. The results
suggest that copolymer solution properties play an important role in structure formation on the solid surface.
Supported by the National Natural Science Foundation of China (Grant Nos. 50573069 and 20704038) and Program for Changjiang
Scholars and Innovative Research Team in University (Grant No.IRT 0654) 相似文献
17.
Preparation of Super-Water-Repellent Fluorinated Inorganic-Organic Coating Films on Nylon 66 by the Sol-Gel Method Using Microphase Separation 总被引:3,自引:0,他引:3
We have prepared super-water-repellent fluorinated inorganic-organic coating films on nylon 66 substrate from poly(methyl methacrylate) (PMMA), tetraethoxysilane (TEOS), and 2-perfluorooctylethyltriethoxysilane (17F) by the sol-gel method. The contact angle for water of the film was 149°. The fluorinated inorganic-organic film including PMMA particles exhibits the super-water-repellence on nylon 66 and the high ultrasonics-resistance in spite of the low 17F content of the molar ratio of 0.001 per mol of TEOS. The surfaces of the films were characterized by using XPS and SEM in combination with the surface roughness data. It was considered that the fluorinated component was segregated to form separated microphase regions, appropriate surface roughness being resulted to develop high water-repellence. 相似文献
18.
The novel fluorinated acrylate resin was successfully prepared by solution polymerization of 2-(perfluoro-(1,1-bis-isopropyl)-2-propenyl)oxyethyl methacrylate (POMA) with butyl acrylate (BA), methyl methacrylate (MMA) and methacrylic acid (MAA) initiated by AIBN in the co-solvents of ethyl acetate, butyl alcohol and toluene. POMA was synthesized from the intermediate perfluoro nonene and 2-hydroxyethyl methacrylate as the staring reactants. Films of the novel fluorinated acrylate resin were prepared by coating the resin directly on the clean glass sheet and allowed to dry at room temperature. The characteristics of the film such as hydrophobicity, glass transition temperature and thermal stability were characterized with the contact angle, differential scanning calorimetry and thermo-gravimetric analysis respectively. The structure of the novel fluorinated acrylate resin was investigated by Fourier transform infrared (FTIR) spectrometry. The influences of the fluorine content on the performance of the acrylate resin were studied. Results show that the hydrophobicity, chemical resistance, glass transition temperature and thermal stability of the acrylate resin are improved when the fluorinated monomer is introduced to copolymerize with other monomers. However, the hydrophobicity of the fluorinated acrylate resin is improved slightly via annealing. 相似文献
19.
Gong Y Hu Z Chen Y Huang H He T 《Langmuir : the ACS journal of surfaces and colloids》2005,21(25):11870-11877
We report observation of ring-shaped morphology formed in thin films of a cylinder-forming polystyrene-b-poly(methyl methacrylate) (PS-b-PMMA) diblock copolymer cast from 1,1,2,2-tetrachloroethane (Tetra-CE) solution via relatively fast solvent evaporation rates, in which Tetra-CE is a good solvent for both blocks but preferential affinity for the minority PMMA block. We studied the microstructure of a set of solution-cast block copolymer films dried with different solvent evaporation rates, R. The control with different R leads to keeping microstructures in different solution concentrations (phi) and bringing mechanical strain fields with different strength in the film, for which faster evaporation rates result in microstructures of lower solution concentrations and mechanical strain fields of higher strength. As R decreases from rapid evaporation (approximately 0.1 mL/h), the film microstructure evolved from an intermediate ringlike morphology sequentially to ring-shaped morphologies including loose and tight rings and then inverted phase of PS spheres in a PMMA matrix and finally reached the equilibrium phase, namely, cylinders of PMMA in a PS matrix. In view of the influence of the film constraints, the microstructure of a film with a terraced free surface profile has been examined. The results indicate that the ring-shaped morphology can form as long as the film thickness is larger than a critical value of about one microdomain spacing. In the case where the film thickness is larger than that value, the nature of solvent and the kinetics of solvent evaporation are shown to be mainly responsible for the ring-shaped morphology formation. 相似文献
20.
Hideo Sawada Tamikazu Narumi Atsushi Kajiwara Katsuya Ueno Kazuo Hamazaki 《Colloid and polymer science》2006,284(5):551-555
Fluoroalkyl end-capped oligomers reacted with tetraethoxysilane and silica/nanoparticles under alkaline conditions to afford
fluoroalkyl end-capped oligomers/silica nanoparticles (mean diameters: 31–54 nm) with a good dispersibility and stability
in organic media. Interestingly, the isolated fluorinated particle powders were found to afford nanometer size-controlled
colloidal particles with a good redispersibility and stability in these media. In addition, fluoroalkyl end-capped oligomers/silica
nanoparticles-encapsulated guest molecules such as stable organic radicals and ionic liquids were prepared under similar conditions.
These fluorinated nanoparticles-encapsulated guest molecules were applied to a new type of surface-modification agent, and
these particles were able to disperse well above the poly (methyl methacrylate) films. 相似文献