PS-COOH

Fig. 1 Chemical formulas of the polymers used a carboxy-terminated polystyrene PS-COOH b random carboxy-terminated copolymer of polystyrene and 2,3,4,5,6-pentafluoropolystyrene FPS-COOH c 3-glycidoxypropyl trimethoxysilane (GPS) d tridecafluoro-1,1,2,2-tetrahydrooctyl) dimethylchlorosilane FSI...

In the next step, polymer films (thickness 200 nm) of PS-COOH or FPS-COOH were spin coated on the top of the GPS layer from 2% toluene solutions. After casting, the films were annealed in a vacuum oven at 150 °C for 15 h. Non-grafted polymer was removed by Soxhlet extraction in toluene for 6 h. The thickness of PS and FPS grafted layers was determined using null ellipsometiy. 

FTIR-ATR spectra were taken with an IFS 55 (Bruker, Germany) spectrometer for both the chemisorbed GPS, FSI, and grafted PS-COOH and FPS-COOH layers using the Si prism with a native SiC>2 layer as a substrate for the grafting. 

In order to synthesize polyfpropylene imine) dendrimers onto polystyrene via the divergent method, well-defined primary amine functionalized polystyrene had to be prepared as the core molecule. The anionic polymerization technique was chosen for the preparation of polystyrene (PS), because of the possibility of control over molecular weight and end group functionalization. An indirect amination procedure was developed [50], In this procedure a standard quantitative end-cap reaction with CO2 is used and a spacer is created between polystyrene and the primary amine function. The obtained polystyrene-COOH (PS-COOH), with Af around 3kgmol and values around 1.05, could be quantitatively reduced to the... 

Fig. 2 A comparison of thermal FFF elution profiles for 0.2 jum particles of polystyrene (PS), carboxylated PS (PS/COOH), and aminated PS (PS/AB) in (a) an aqueous solution containing 9 mMNaN2 and 0.05 wt% FL-70 surfactant (pH 8.5) (b) 10 mM phosphate buffer (pH 4.7). Differences in retention are due to differences in thermodiffusion, which is governed by the surface composition of the particle.

PS-COOH PS chain with a carboxylic acid end-group... 

Three homopolymer (diblock copolymer) phase boundary systems have been studied extensively the system of polystyrene (PS) and poly(2-vinylpyridine) (PVP) reinforced with diblock copolymers ofPS-PVP [22,25,28,31-33], the system of poly(methyl methacrylate) (PMMA) and PS reinforced with diblock copolymers of PMMA-PS [17,24,34,35] and the system of PMMA and poly(phe-nylene oxide) (PPO) reinforced by diblock copolymers of PMMA-PS [ 14,36,37]. Phase boundaries between PS and a crosslinked epoxy (XEp) were reinforced with carboxy-terminated PS chains whose -COOH ends reacted with either excess amines or epoxy to form a grafted brush at the interface [38,39]. In a similar manner, interfaces between rubber-modified PS (HIPS) and XEp reinforced with grafted PS-COOH chains have been investigated [40]. 

Figures la and Ic show the structure of the phase-separated polymer blend films obtained by dip coating from a PS-COOH/PMMA (30 70 weight ratio) solution. The morphology of the as-deposited films of two different (15 and 30 nm) thicknesses agreed well with their PS content of 30%. Indeed, the minor PS phase was dispersed in the major PMMA phase. However, after the anneahng and extraction of PMMA, the grafted PS layer demonstrated a rather different type of surface structures for the PS-COOH /PMMA films of different...

Figure 2. Effect of PGMA layer thickness on the grafting of PS-COOH and SIP of PEGMA on the surfaces covered with the grafted PS layer.

Segregated polymer brushes were fabricated utilizing phase-separation phenomena in ultrathin polymer blend films (PS-COOH/PMMA) and the combination of grafting-to and grafting-from methods. 

The morphology of the grafted PS layer could be regulated by the thickness of the deposited PS-COOH/PMMA film. A thicker film led to continuous PS matrix grafted surface structures, while a thinner film resulted in a dispersed surface morphology. 

Fig. 2 A comparison of ThFFF elution profiles for 0.2 jjum particles of polystyrene (PS), carboxylated PS (PS/COOH), and (aminated PS (PS/AB) a) in an aqueous solution containing...

Fig. 14. Water contact angle data illustrating the reorganization of end-functional polystsrenes in the glassy state. The number in the sample designation refers to the molecular weight in thousands PS is polystyrene, PS-F is fluorosilane-terminated polystyrene, and PS-COOH is carboxylic acid-terminated polyst3rrene. lOOK PS 5K PS-F lOK PS-F X 25K PS-F 6.5K PS-COOH O lOK PS-COOH. From Ref 60.

Atomic force microscopy (AFM) images in phase-contrast mode of PS-COOH/polymethyl methacrylate (PMMA)-NH2 = 40/60 (vol.%) prepared at 190°C (A) (B) like (A), prepared at 200°C (C) like (B), with SCA (D) like (B), with SCA+Pt (frame size 10 x 10 pm). Influence of silane-containing coupling agent (SCA) and processing conditions on morphology of PS-COOH/PMMA-NH2 = 40/60 (vol.%) blends. (From J. Pionteck, V. B. Sadhu, L. Jakisch, P. Potschke, L. HSufiler, and A. Janke, Polymer 46,6563-6574, 2005. With permission.)... 

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