Optimization of Co2+ ions removal from water solutions via polymer enhanced ultrafiltration with application of PVA and sulfonated PVA as complexing agents

The paper presents the results of the studies of UF-complexation process applied for the removal of Co(2+) ions from water solutions. As binding agents for cobalt ions, the PVA polymer (M(w)=10,000) and its sulfonated form, synthesized in the laboratory, have been used. The method of experimental design and response surface methodology have been employed to find out the optimal conditions for the complexation process and to evaluate the interaction between the input variables, i.e., initial cobalt concentration, pH and amount of the polymer used, expressed as a polymer/Co(2+) ratio r. The data collected by the designed experiments showed that sulfonation of polymer has improved significantly the binding ability of PVA. The optimal conditions of cobalt ions complexation established by response surface model for non-sulfonated PVA polymer have been found to be as follows: the initial concentration of Co(2+)=5.70 mg L(-1), the ratio between polymer and metal ions, r=8.58 and pH=5.93. The removal efficiency of Co(2+) in these conditions was 31.81%. For sulfonated PVA polymer, the optimal conditions determined are as follows: initial concentration of [Co(2+)](0)=10 mg L(-1), r=1.2 and pH=6.5. For these conditions, a removal efficiency of 99.98% has been determined. The experiments showed that Co(2+) removal ability of sulfonated PVA was much higher than its non-sulfonated precursor. Although the polymer concentrations used in the tests with sulfonated PVA were approximately ten times lower than the non-sulfonated one, the removal efficiency of cobalt ions was significantly higher.     

Use of a ruthenium-containing conjugated polymer as a photosensitizer in photovoltaic devices fabricated by a layer-by-layer deposition process

Multilayer polymer films composed of a ruthenium terpyridine complex containing poly(p-phenylenevinylene) (Ru-PPV) and sulfonated polyaniline (SPAN) were prepared by a layer-by-layer electrostatic self-assembly deposition. The deposition process was carried out from SPAN solution in water and Ru-PPV in dimethylformamide (DMF). Optical-quality multilayer thin films were obtained. The film growth process was monitored by quartz crystal microbalance, and the surface morphology of the films was studied by atomic force microscopy. It was found that the properties of the multilayer films were dependent on deposition conditions such as the pH of the SPAN solution, the presence of salt in the polymer solutions, and the post-film-forming thermal annealing process. Cross-section transmission electron microscopic images suggested that there was no stratified structure formed in the multilayer films. Photovoltaic cells were fabricated by sandwiching the multilayer films between indium-tin-oxide and aluminum electrodes. The device performances were examined by illumination with AM 1.5 simulated solar light. The power conversion efficiencies of these devices were on the order of 10(-3)%. The maximum incident photon-to-electron conversion efficiency (IPCE) of the devices was found to be approximately 2% at 510 nm, which is consistent with the absorption maximum of the ruthenium complex. This indicates that the photosensitization process is due to the electronic excitation of the ruthenium complex.     

Direct copolymerization of sulfonated poly(phthalazinone arylene ether)s for proton‐exchange‐membrane materials

Sulfonated poly(phthalazinone ether ketone) (SPPEK) copolymers and sulfonated poly(phthalazinone ether sulfone) (SPPES) copolymers containing pendant sodium sulfonate groups were prepared by direct copolymerization. The reaction of disodium 3,3′‐disulfonate‐4,4′‐difluorobenzophenone (SDFB‐Na), 4,4′‐difluorobenzophenone (DFB), and 4‐(4‐hydroxyphenyl)‐1(2H)‐phthalazinone (DHPZ) at 170 °C in N‐methyl‐2‐pyrrolidione containing anhydrous potassium carbonate gave SPPEKs. SPPESs were similarly obtained with 3,3′‐disulfonate‐4,4′‐difluorophenyl sulfone, 4‐fluorophenyl sulfone (DFS), and DHPZ as monomers. The sulfonic acid groups, being on deactivated positions of the polymer backbone, were expected to be hydrolytically more stable than postsulfonated polymers. Fourier transform infrared and ¹H NMR were used to characterize the structures and degrees of sulfonation of the sulfonated polymers. Membrane films of SPPEKs with SDFB‐Na/DFB molar feed ratios of up to 60/40 and SPPESs with sulfonated 4‐fluorophenyl sulfone/DFS molar feed ratios of up to 50/50 were cast from N,N‐dimethylacetamide polymer solutions. Membrane films in acid form were then obtained by the treatment of the sodium‐form membrane films in 2 N sulfuric acid at room temperature. An increase in the number of sulfonate groups in the copolymers resulted in an increased glass‐transition temperature and enhanced membrane hydrophilicity. The sodium‐form copolymers were thermally more stable than their acid forms. The proton conductivities of the acid‐form copolymers with sulfonated monomer/unsulfonated monomer molar feed ratios of 0.5 and 0.6 were higher than 10^?2 S/cm and increased with temperature; they were less temperature‐dependent than those of the postsulfonated products. SPPESH‐50 showed higher conductivity than the corresponding postsulfonated poly(phthalazinone ether sulfone). © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2731–2742, 2003     

Molecular properties of sulfonated polyaniline

The molecular characteristics of internally doped sulfonated polyaniline with a sulfonation degree of ∼1 are studied by the methods of viscometry and dynamic light scattering. In diluted aqueous-saline solutions, the molecules of sulfonated polyaniline are individual entities; they do not form intermolecular associates and do not dissociate into separate components. An increase in the concentration of NaCl in solution from 0 to 1 mol/l brings about a sharp gain in the intrinsic viscosity of the polymer and in the hydrodynamic radius of molecules. This effect results from the decomposition of zwitterion pairs responsible for the compact conformation of polymer molecules in water. The equilibrium rigidity of sulfonated polyaniline molecules is calculated from the hydrodynamic characteristics determined in a 1 M NaCl solution, where the electrostatic interaction may be considered to be suppressed. A length of the Kuhn segment of 1.46 nm is higher by a factor of 1.5 than the corresponding length for the initial polyaniline.     

Structure of macronet styrene polymer as studied by inverse steric exclusion chromatography and by selective sulfonation

The structure of macronet styrene polymer in original, partially sulfonated and fully sulfonated form was studied using inverse steric exclusion chromatography. By alternative measurements of the partially sulfonated sample in water and in tetrahydrofuran, it was possible to characterize separately sulfonated and unsulfonated domains. It was found that the polymer contains 10–15% of highly expandable polymer mass and the rest is formed by much more dense polymer skeleton.     

Ionic conductivity of conjugated water-soluble rigid-rod polymers

Poly[(1,7-dihydrobenzo[1,2-d:4,5-d′] diimidazole-2,6-diyl)-2-(2-sulfo)-p-phenylene], a conjugated rigid-rod polymer, was derivatized with pendants of propane-sulfonated ionomers. The derivatized rigid-rod polymer was soluble in aprotic solvents as well as in water for isotropic solutions that were processed into isotropic films. Direct-current electrical conductivity σ of the films was measured using the four-probe technique. Room-temperature σ as high as 2.9 × 10^?4S/cm was achieved on pristine isotropic films without using dopants. When the rigid-rod polymer concentration exceeded 25 wt %, the isotropic solution could be transformed into a liquid-crystalline solution that allowed deformations to be applied to produce anisotropic films. Significant increase in σ was obtained in a sheared film along both the parallel direction (∥) and the transverse direction (⊥) with a σ_∥/σ_⊥ = 5. Additionally, enhanced σ was realized in films heat-treated at about 100°C, in the derivatized polymer with higher molecular weight from dialysis, and in substituting the sulfonated ion Na⁺ by H⁺ in the pendants of the polymers. Constant-voltage measurements were applied to the polymers to monitor the σ stability for ascertaining the nature of the conductivity. No electronic contribution in σ was detected. Instead, a monotonically decreasing σ was consistently observed indicative of ionic conductivity. © 1993 John Wiley & Sons, Inc.     

Development of molecularly imprinted polymer films used for detection of profenofos based on a quartz crystal microbalance sensor

A quartz crystal microbalance (QCM) sensor based on molecularly imprinted ultra-thin films was developed for detecting profenofos in real samples. Films prepared by physical entrapment (MIP-A) and in situ self-assembly (MIP-B) were compared. The results indicated that the best sensing signal was obtained through the in situ self-assembly method. The QCM sensor chip was pretreated with 11-mercaptoundecanoic acid (MUA) to form a self-assembled monolayer (SAM), and then polymer films were immobilized directly on the SAM using surface-initiated radical polymerization. In this paper, all detection experiments were taken in air. The reaction was processed in solution, and the electrode was washed with deionized water and dried with N(2) before QCM measurement. The film was characterized by a scanning electron microscope (SEM), AC impedance and cyclic voltammetry. Analysis of the QCM response in the presence of different concentrations of profenofos showed a good linear correlation during 1.0 × 10(-8) to 1.0 × 10(-5) mg mL(-1) (y = 5log x + 42.5, R = 0.9960) and 1.0 × 10(-5) to 1.0 × 10(-3) mg mL(-1) (y = 25.86log x + 146, R = 0.9959), respectively. The MIP-QCM sensor was used to detect profenofos in tap water, and showed good recovery and repeatability.     

Spontaneous formation of hierarchical proton‐conductive structures in sulfonated poly(p‐phenylene terephthalamide) copolymer films

Two partially sulfonated copolymers of poly(p‐phenylene terephthalamide) were studied; the sulfonated diamine to nonsulfonated diamine ratios were x = 1 and x = 2. Polymer solutions in water demonstrated lyotropic liquid‐crystalline behavior, with the critical concentration for nematic phase formation being around 0.7 wt %. Films of these copolymers could be considered for fuel‐cell applications. The in‐plane proton conductivities were of the order of 10^?3 to 10^?2 S cm^?1 between 20 and 90 °C. Increasing the sulfonation level resulted in a more conductive material. Spontaneous alignment of the polymer occurred during film formation, as revealed by X‐ray diffraction. Scattering along the polymer backbone was observed perpendicular to the film, implying that the polymer chains were homeotropically aligned with respect to the film. The average degree of alignment was determined to be 0.66 and 0.77 for x = 1 and x = 2, respectively. Evidence of secondary layering within the plane of the film was seen in SEM images. These layers could provide a pathway for proton conduction to occur within the plane of the film. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 666–676, 2007     

Two-dimensional rhombohedral grid coordination polymers [M(bbbt)(2)(NCS)(2)](n)(M = Co,Mn, or Cd; bbbt = 1,1'-(1,4-butanediyl) bis-1H-benzotriazole): synthesis,crystal structures,and third-order nonlinear optical properties

In this paper, treatment of 1,1'-(1,4-butanediyl) bis-1H-benzotriazole (bbbt) and KSCN with Co(II), Mn(II), or Cd(II) afforded three two-dimensional rhombohedral grid coordination polymers [M(bbbt)(2)(NCS)(2)](n)(M = Co, 1; Mn, 2; Cd, 3). The two-dimensional rhombohedral grids are parallel to the crystallographic ac plane. The rhombohedral grid consists of 44-membered rings of M(4)(bbbt)(4), and gives the dimensions of 12.913 x 10.764 A for polymer 1, 13.106 x 10.797 A for polymer 2, and 13.256 x 10.870 A for polymer 3. The three polymers' third-order nonlinear optical (NLO) properties were determined by Z-scan technique in DMF solution. The results show that all three polymers show very large NLO absorption and strong NLO refraction properties. The third-order NLO absorptive coefficients alpha(2) are 5.4 x 10(-9) m W(-1) for polymer 1, 5.2 x 10(-9) m W(-1) for polymer 2, and 5.0 x 10(-9) m W(-1) for polymer 3. The alpha(2) values are larger than those of all the reported cluster compounds. The NLO refractive index values n(2) of the three polymers are 5.73 x 10(-19), 3.55 x 10(-19), and 3.07 x 10(-19) m(2) W(-1), respectively. Their hyperpolarizability gamma values are calculated to be 2.40 x 10(-30) esu for polymer 1, 1.52 x 10(-30) esu for polymer 2, and 1.50 x 10(-30) esu for polymer 3. The gamma values are comparable to those of clusters and better than those of organometallic compounds, semiconductors, and fullerene.     

Modification of indium-tin oxide electrodes with thiophene copolymer thin films: optimizing electron transfer to solution probe molecules

We describe the modification of indium-tin oxide (ITO) electrodes via the chemisorption and electropolymerization of 6-{2,3-dihydrothieno[3,4-b]-1.4-dioxyn-2-yl methoxy}hexanoic acid (EDOTCA) and the electrochemical co-polymerization of 3,4-ethylenedioxythiophene (EDOT) and EDOTCA to form ultrathin films that optimize electron-transfer rates to solution probe molecules. ITO electrodes were first activated using brief exposure to strong haloacids, to remove the top approximately 8 nm of the electrode surface, followed by immediate immersion into a 50:50 EDOT/EDOTCA co-monomer solution. Potential step electrodeposition for brief deposition times was used to grow copolymer films of thickness 10-100 nm. The composition of these copolymer films was characterized by solution depletion studies of the monomers and atomic force microscopy (AFM), X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy (reflection-absorption infrared spectroscopy (RAIRS)) of the product films. The spectroscopic data suggest that the composition of the copolymer approaches 80% EDOTCA when electropolymerization occurs from concentrated (10 mM) solutions. AFM characterization shows that electrodeposited poly(EDOT)/poly(EDOTCA) (PEDOT/PEDOTCA) films are quite smooth, with texturing on the nanometer scale. RAIRS studies indicate that these films consist of a combination of EDOTCA units with noninteracting -COOH groups and adjacent hydrogen-bonded -COOH groups. The EDOTCA-containing polymer chains appear to grow as columnar clusters from specific regions, oriented nearly vertically to the substrate plane. As they grow, these columnar clusters overlap to form a nearly continuous redox active polymer film. ITO activation and formation of these copolymer films enhances the electroactive fraction of the electrode surface relative to a nonactivated, unmodified "blocked" ITO electrode. Outer-sphere solution redox probes (dimethylferrocene) give standard rate coefficients, kS > or = 0.4 cm.s-1, at 10 nm thick copolymer films of PEDOT/PEDOTCA, which is 3 orders of magnitude greater than that on the unmodified ITO surface and approaches the values for kS seen on clean gold surfaces.     

Surface characterization and liquid crystal alignment behavior of comb-like poly(oxyethylene)/poly(3-hexylthiophene) blend films

The blend surfaces of poly[oxy(n-decylsulfonylmethyl)ethylene] (CH(3)-10SE) and poly (3-hexylthiophene) (P3HT) with different weight ratios were prepared by spin coating the polymer solution mixtures. In this study, their surface properties such as surface morphology, chemical composition, molecular structure, and wettability were systematically studied and correlated with liquid crystal (LC) alignment behaviors on the blend films. Therefore, we found that CH(3)-10SE part with a well-ordered side chain structure predominantly affects the both of wettability and LC alignment behavior of the blend films while there was no clear association between the wettability and the LC alignment behavior.     

Polymer-initiated photogeneration of silver nanoparticles in SPEEK/PVA films: direct metal photopatterning

Cross-linking of sulfonated poly(ether-ether)ketone-poly(vinyl alcohol) (SPEEK-PVA) materials yields flexible polymer films, possessing high light-sensitivity and ion-exchange capabilities. Adsorbed Ag+ ions are photoreduced in the film under illumination (lambda = 350 nm), leading to metal nanoparticle formation in places where the film has been exposed to the light. Nanoparticles form via reduction of Ag+ by the polymeric alcohol radicals, generated in the system as a result of photochemical H-abstraction from PVA molecules by the excited carbonyl triplet state of SPEEK. Use of the films for direct metal photopatterning is demonstrated.     

Fabrication of polymer Langmuir-Blodgett films containing regioregular poly(3-hexylthiophene) for application to field-effect transistor

Semiconducting thin films consisting of regioregular poly(3-hexylthiophene) (RR-PHT) and poly(N-dodecylacrylamide) (pDDA) were constructed by the Langmuir-Blodgett (LB) technique. A mixture of RR-PHT and pDDA spread from a chloroform solution on a water surface forms a stable monolayer, which can be transferred onto solid substrates by the LB method, yielding a well-defined polymer LB film. Surface morphology studies of the LB film indicate that the RR-PHT is dispersed uniformly throughout the surface. The polymer thin film was chemically doped by contacting with FeCl3 acetonitrile solution, and a conductivity of 5.6 S/cm was achieved. Further, the LB film was utilized as the semiconducting film in the field-effect transistor (FET), and mobilities of 2.2 x 10(-4) and 4.4 x 10(-4) cm2 V(-1) s(-1) were obtained by analyzing the saturated and linear regions of the current-voltage characteristic, respectively.     

Weak surface anchoring energy of 4-cyano-4'-pentyl-1,1'-biphenyl on perfluoropolyether Langmuir-Blodgett films

Functional director alignment layers are needed for high performance liquid crystal displays (LCDs). Reported herein is a novel polymer material for LC alignment, namely, perfluoropolyether (PFPE), which exhibits a weak surface anchoring energy for bend deformation and is amenable to simple fabrication of grooved surfaces by soft lithography, a surface topography desired for multistable LCDs. Liquid crystal optical cells fabricated using Langmuir-Blodgett films of PFPE (of variable thickness) exhibited weak surface anchoring energies on the order of 10(-5) Jm2 for the nematic liquid crystal 4-cyano-4'-pentyl-1,1'-biphenyl with no dependence on film thickness.     

Synthesis and characterization of thermally stable sulfonated polybenzimidazoles

A series of sulfonated polybenzimidazoles (sPBI-IS) with controlled sulfonation degrees (SDs) were synthesized from various stoichiometric ratio mixtures of 5-sulfoisophthalic acid monosodium salt (SIPN), 4,4′-sulfonyldibenzoic acid and 3,3′-diaminobenzidine by solution copolycondensation in poly(phosphoric acid). The resulting sulfonated polymers were characterized by means of FTIR, ¹H NMR and GPC, in addition to TGA and DMA. The number-average molecular weights (M_n) of the sPBI-IS are in the range of 45,500-64,000, and the polydispersity indices (M_w/M_n) vary from 1.9 to 2.4. The synthesized sPBI-IS samples present good solubilities in polar aprotic solvents and they are easy to form the transparent, flexible and tough films by solution casting. These polymer membranes show excellent thermal stabilities and dynamic mechanical properties. The thermal stability of the sodium form sPBI-IS remarkably increases with increasing SD. However, the acidic form sPBI-IS presents less thermal stability than the non-sulfonated sample (sPBI-IS0). The onset decomposition temperature (T_d) and the glass-transition temperature (T_g) of the acidic form sPBI-IS70 are 439 °C and 196 °C, respectively. The sulfonated membranes show higher storage moduli and loss moduli than sPBI-IS0. The resulting sPBI-IS membranes with high hygroscopicity show potential application as the high temperature proton exchange membrane in fuel cell.     

Polarized optical spectroscopy applied to investigate two poly(phenylene-vinylene) polymers with different side chain structures

Two related poly(phenylene-vinylene) (PPV) light-emitting polymers have been investigated by means of polarized optical spectroscopy. The purpose of the investigation was to investigate the nature of the interactions in thin films and to examine what impact the difference in side chain structure and molecular weight in poly(2'-methoxy-5-2-ethyl-hexoxy)-1,4-phenylene vinylene (MEH-PPV) and poly(2-(3',7'-dimethyloctyloxy)-5-methoxy-1,4-phenylene-vinylene) (OC1C10-PPV) has on the electronic and optical properties of the two polymers. Aligning the polymers by dispersing them in anisotropic solvents and stretched films shows that the side chains have an impact on the relative orientations of the transition dipole moments. In anisotropic solvents the linear dichroism is larger for MEH-PPV than for the related polymer OC1C10-PPV, while in stretched films the opposite situation prevails. A lower polarization of the luminescence from OC1C10-PPV, relative to MEH-PPV, was also obtained independent of alignment medium used. The data therefore suggest that while mechanical stretching may align the OC1C10-PPV to a greater degree, the emitting species is distinct from the absorbing species. The circular dichroism (CD) spectra of both polymers undergo dramatic changes when the liquid phase and the solid state (film) are compared. The solution CD spectra shows no evidence of interchain interactions; instead the spectra of both systems indicate a helical conformation of the polymers. The CD spectra of films are dramatically different with the strong Cotton effect being observed. This points to the formation of an aggregate in the film, with an associated ground state interaction, an interchain species such as a physical dimer, or a more complex higher aggregate.     

Radical-induced generation of small silver particles in SPEEK/PVA polymer films and solutions: UV-Vis, EPR, and FT-IR studies

The present study is centered on the processes involved in the photochemical generation of nanometer-sized Ag particles via illumination at 350 nm of aqueous solutions and cross linked films containing sulfonated poly(ether ether ketone) and poly(vinyl alcohol). Optical and electron paramagnetic resonance experiments, including electron nuclear double resonance data, proved conclusively that the photogenerated chromophore exhibiting a band with lambda(max) = 565 nm is an alpha-hydroxy aromatic (ketyl) radical of the polymeric ketone. This reducing species was produced by illumination of either solutions or films, but the radical lifetime extended from minutes in the fluid phase to hours in the solid. Direct evidence is presented that this long-lived chromophore reduces Ag(I), Cu(II), and Au(III) ions in solution. A rate constant of k = 1.4 x 10(3) M(-)(1) s(-)(1) was obtained for the reduction of Ag(+) by the ketyl radical from the post-irradiation formation of Ag crystallites. FTIR results confirmed that the photoprocess yielding polymeric ketyl radicals involves a reaction between the macromolecules. The photochemical oxidation of the polymeric alcohol, as well as the formation of light-absorbing macromolecular products and polyols, indicates that the sulfonated polyketone experienced transformations similar to those encountered during illumination of the benzophenone/2-propanol system.     

A novel quartz crystal microbalance gas sensor based on porous film coatings. A high sensitivity porous poly(methylmethacrylate) water vapor sensor

We describe a novel and generally applicable approach for creating voids in films deposited on the surface of solid substrates. Such films are advantageous when a quartz crystal microbalance (QCM) is the basis of a sensor. We show that films with large void volumes produce more sensitive sensors than with the original film. Poly(methylmethacrylate) (PMMA) was used as the polymer layer deposited on a quartz crystal microbalance (QCM) to demonstrate our technique for the model system of water vapor analysis in flowing nitrogen gas. A film of pure PMMA on a QCM is a sensor for water vapor in a gas phase. A more sensitive sensor was created by dip coating QCM crystals into solutions containing mixtures of PMMA and poly(d,l-lactide) (PDLL) and then evaporating the solution films on the QCM crystals to form mixed polymer films of varying PDLL content. The PDLL was then removed from the mixed polymer films by exposure to a NaOH solution to form pure PMMA films having various void volumes. A leached PMMA film that originally contained 50% by weight PDLL had a 3.7 times larger QCM sensitivity for water vapor than a pure PMMA film.     

Electrochemical synthesis of soluble sulfonated poly(3-methyl thiophene)

Electrochemical polymerization of poly(3-methyl thiophene) films (3-MTy) which are self-doped with SO₃⁻ was investigated. The sulfonated poly(3-methyl thiophene) films synthesized from the solution which contained different amounts of HSO₃F. The sulfonated polymer films were found to be soluble in DMF and KOH. The solubility values increased and the conductivity values decreased with the increase in sulfonation ratio. The resulting polymers were characterized by cyclic voltammetry, UV-Vis, FT-IR, elemental analysis, dry conductivity measurements and SEM techniques.     

Robust, functionalizable, nanometer-thick poly(acrylic acid) films spontaneously assembled on oxidized aluminum substrates: structures and chemical properties

Immersion of oxidized aluminum substrates in ethanol solutions of poly(acrylic acid) (PAA), followed by extensive solvent immersion, results in tenaciously chemisorbed, nanometer scale, controllable thickness films for a wide range of solution concentrations and molecular weights. Atomic force microscope images reveal isolated polymer globules from adsorption in low-concentration solutions with crossover to conformal, highly uniform, nanometer-thickness films at higher concentrations, an indication that the chemisorbing chains start to overlap and trap underlying segments to form planar chemisorbed films only two or three chains in thickness. Quantitative IR reflection spectroscopy in combination with chemical derivitization on a standard set of 1.0(±0.2) nm thick films reveals a film structure with 5.5(±1) chemisorbed -CO(-)(2) groups/nm(2) and 6.3 unattached -CO(2)H groups/nm(2), with up to ～3.6/nm(2) available for chemical derivitization, a comparable number to typical self-assembled monolayer coverages of ～4-5 molecules/nm(2). Thermal treatment of the ～1 nm chemisorbed films, at even extreme temperatures of ～150 °C, results in almost no anhydride formation via adjacent -CO(2)H condensation, in strong contrast to bulk PAA, a clear indication that the films have a frozen glass structure with effectively no segment and side group mobility. Overall, these results demonstrate that these limiting thickness nanometer films provide a model surface for understanding the behavior of strongly bound polymer chains at substrates and show potential as a path to creating highly stable, chemically functionalized inorganic substrates with highly variable surface properties.