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We sought to identify potential communication markers predicting the success of cochlear implantation, that might be observed within the first year of life. According the last ten years literature review volubility can be considered as a potentially important vocal measure predicting later language development.

Background We sought to identify potential communication markers predicting the success of cochlear implantation, that might be observed within the first year of life. According the last ten years literature review volubility can be considered as a potentially important vocal measure predicting later language development. Aims The present review aims to review existing evidence related with: (i) why volubility posits a plausible marker of cochlear implantation success in infancy, and (ii) presents the clinical usefulness of volubility data in predicting later language trajectory. Methods Rate of vocalization or volubility measured in terms of frequency of syllable production and it is clearly affected by parental interactivity. A low percentage of volubility can be predictive of significant communication impairment. Vocalization growth during the first year of life, as demonstrated in publications examining sound production characteristics of normally hearing (NH) and hearing impaired (HI) infants fitted with CI, were reviewed. Results Literature results revealed differences in linguistic performance among NH and CI infants which are typically attributed to auditory deprivation. Infants received late CI, produce fewer syllables (low volubility) and exhibit late-onset babbling, especially those who underwent the procedure as late as the age of 12 months or thereafter. Early recipients (implanted before the age of 12-months) related with more vocalizations, which is thought to stem from CI-initiated auditory feedback. In sum, total syllables produced (volubility) demonstrate the developmental trajectory of language acquisition which in turn is a crucial factor related with the success of cochlear implantation. Conclusion Contemporary findings collectively endorse volubility as a plausible criterion of differentiation between successful and non-successful early CI. It is argued that volubility measures predict language development and, in doing so, carry vast implications on designing efficient clinical assessment and intervention practices.

One-pot, sequential reversible addition - fragmentation chain transfer (RAFT) polymerization was employed for the preparation of five end-linked semifluorinated amphiphilic polymer conetworks based on 2,2,2-trifluoroethyl methacrylate (TFEMA, hydrophobic monomer) and 2-(dimethylamino)ethyl methacrylate (DMAEMA, hydrophilic monomer). 1,4-Bis[2-(thiobenzoylthio)prop-2- yl]benzene (1,4-BTBTPB) was used as the chain transfer agent, while ethylene glycol dimethacrylate (EGDMA) served as the cross-linker. Three of the end-linked conetworks were based on ABA triblock copolymers with polyDMAEMA midblocks with degrees of polymerization (DPs) of 50 and polyTFEMA end-blocks with overall polyTFEMA DPs of 25, 50, and 75. The fourth end-linked amphiphilic polymer conetwork was based on an equimolar BAB triblock copolymer with a polyTFEMA midblock and an overall copolymer DP of 100. The last end-linked conetwork was based on a statistical copolymer. A randomly cross-linked conetwork was also prepared by the simultaneous terpolymerization of the two comonomers (equimolar) and the cross-linker. The molecular weights and compositions of all the polymer precursors to the conetworks were characterized using gel permeation chromatography and 1H NMR spectroscopy, respectively. The conetworks were characterized in terms of their degrees of swelling (DS) in THF and in water as a function of the solution pH. All conetworks swelled more in acidic than in pure water due to the ionization of the DMAEMA units in acidic water. The low pH aqueous DS of the statistical copolymer-based end-linked conetwork was higher than those of its triblock copolymer counterparts due to lack of microphase separation within the former conetwork. Finally, the microphase separation of the amphiphilic conetworks in deuterium oxide was investigated using small-angle neutron scattering which indicated a distance between the hydrophobic scattering centers of about 15 nm. © 2010 American Chemical Society. 43 12 5195 5204 Cited By :22

Group transfer polymerization was employed for the preparation of six amphiphilic terpolymer networks comprising the hydrophilic, pH-responsive 2-(dime- thylamino)ethyl methacrylate (DMAEMA), the neutral hydrophilic methoxy hexa (ethylene glycol) methacrylate (HEGMA), and the hydrophobic n-butyl methacrylate (BuMA). 1,4-Bis(methoxytrimethylsiloxymethylene)cyclohexane was used as a bifunc- tional initiator, whereas ethylene glycol dimethacrylate served as the crosslinker to interconnect the linear terpolymer precursors to three-dimensional terpolymer net- work structures. Five of the terpolymer networks were model, with linear chains between crosslinks of precise length. Four of the five model networks were based on ABCBA pentablock terpolymers with theoretical structure DMAEMA5-b-BuMAn/2-b- HEGMA10-b-BuMAn/2-b-DMAEMA5 with n values equal to 5, 10, 20, and 30. The model network based on the equimolar statistical terpolymer and the nonmodel ran- domly crosslinked terpolymer network were also prepared. The molecular weights and compositions of the linear pentablock terpolymer precursors to the networks were found to be close to the theoretically expected, while the network sol fractions were found to be relatively low. The degrees of swelling of the networks in water were found to decrease with increasing the hydrophobic content, whereas those in THF exhibited the opposite trend. Small-angle neutron scattering in deuterium oxide indicated structural organization in the most hydrophobic pentablock terpolymer net- works. V C 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4420-4432, 2008

A series of amphiphilic conetworks of methacrylic acid (MAA) and methyl methacrylate (MMA) were synthesized using group transfer polymerization (GTP). The MAA units were introduced via the polymerization of tetrahydropyranyl methacrylate (THPMA), followed by the removal of the protecting tetrahydropyranyl group by acid hydrolysis after network formation. 1,4-Bis(methoxytrimethylsiloxymethylene)-cyclohexane (MTSCH) was used as a bifunctional GTP initiator, while ethylene glycol dimethacrylate (EGDMA) served as the cross-linker. Nine of the conetworks were model conetworks, comprising copolymer chains between the cross-links of precise molecular weight and composition. Eight of the model conetworks were based on ABA triblock copolymers, while the ninth was based on a statistical copolymer. The tenth conetwork was not model but randomly cross-linked. The molecular weight and the composition of the linear conetwork precursors were analyzed by gel permeation chromatography and 1H NMR, respectively, and were found to bear values close to the theoretically expected. FTIR spectroscopic analyses indicated complete polymerization of the EGDMA cross-linker vinyl units and complete hydrolysis of the THPMA units. The degrees of swelling (DS) of all the conetworks were measured in water and in THF as a function of the degree of ionization (DI) of the MAA units. The DSs in water increased with the DI of the MAA units (and the pH), while the DSs in THF presented the opposite trend. Finally, small-angle neutron scattering and atomic force microscopy confirmed nanophase separation in a triblock copolymer-based model conetwork and lack of it in its statistical copolymer counterpart. © 2007 American Chemical Society. 40 6 2192 2200 Cited By :67

Περιέχει βιβλιογραφικές αναφορές (σ. 618-621). Αριθμός δεδηλωμένων πηγών στη βιβλιογραφία: 63 Διατριβή (Διδακτορική) -- Πανεπιστήμιο Κύπρου, Σχολή Κοινωνικών Επιστημών και Επιστημών Αγωγής, Τμήμα Κοινωνικών και Πολιτικών Επιστημών, 2015. Η βιβλιοθήκη διαθέτει αντίτυπο της διατριβής σε έντυπη μορφή. Το θέμα της παρούσας διατριβής είναι η έννοια του «υποκειμένο» στο Μ. Φουκώ. Έχοντας απορρίψει το υποκείμενο της φαινομενολογίας, του μαρξισμού και της ψυχανάλυσης ο Φουκώ έχει ανοίξει νέες προοπτικές στον τρόπο με τον αντιλαμβανόμαστε το υποκείμενο, τον εαυτό και την ταυτότητα. Δεν εκπόνησε μια θεωρία του «υποκειμένου», αλλά εννοιολογικά εργαλεία τα οποία διαρκώς αναδιατύπωνε. Το έργο του μπορεί να διατυπωθεί σύμφωνα με: Α) τη μεθοδολογία (αρχαιολογία-γενεαλογία) Β) την πρωτοκαθεδρία ενός θέματος: πρακτικές λόγου, σχέσεις εξουσίας, πρακτικές του εαυτού Γ) με ένα άξονα: της γνώσης, της εξουσίας, της ηθικής. Τα μεθοδολογικά εργαλεία, οι τρεις τομείς και άξονες δεν αποκλείουν οι μεν τους δε, αλλά αλληλοσυμπληρώνονται. Η μεθοδολογία που ακολουθήθηκε για την εκπόνηση της παρούσας διατριβής ήταν μια εις βάθος έρευνα και ανάλυση πρωτογενών πηγών ( τα βιβλία, οι διαλέξεις στο College de France, η μεταθανάτια έκδοση των «Dits et Ecrits» που περιέχουν οτιδήποτε άλλο δημοσιεύτηκε κατά τη διάρκεια της ζωής του). Στο πρώτο μέρος του έργου που χαρακτηρίζεται από τη χρήση της αρχαιολογίας και αντιστοιχεί στις πρακτικές λόγου και τον άξονα της γνώσης τον ενδιαφέρουν οι προϋποθέσεις που καθιστούν δυνατή την εμφάνιση λόγων γνώσης σε μια ορισμένη εποχή. Το δεύτερο μέρος χαρακτηρίζεται από τη χρήση της γενεαλογίας, νιτσεϊκής έμπνευσης, που συμπληρώνει την οριζόντια ανάγνωση των καθεστώτων λόγου με μια κάθετη ιστορική ανάγνωση αυτού που προσδιόρισε το δικό μας καθεστώς λόγου. Αντιστοιχεί στις σχέσεις εξουσίας και τον άξονα της εξουσίας. Ενδιαφέρεται για τις σχέσεις εξουσίας και αναπτύσσει την αναλυτική της και τη σχέση της με τη γνώση και την αλήθεια. Η σύγχρονη εξουσία που παρουσιάζεται στα τέλη του 18ου αιώνα και αρχές του 19ου αιώνα, είναι αφενός η πειθαρχική εξουσία που ασκείται πάνω στα σώματα που καθιστά υπάκουα και παραγωγικά και αφετέρου η βιο-εξουσία που ασκείται πάνω στον πληθυσμό προς μεγιστοποίηση των δυνατοτήτων του. Στη συνέχεια η εξουσία εννοιολογείται ως «κυβέρνηση» με την έννοια της καθοδήγησης της συμπεριφοράς των άλλων. Η έννοια αυτή οδηγεί στο τρίτο μέρος του έργου του. Σε αυτό τον ενδιαφέρουν οι πρακτικές του βίου στην κλασική Ελλάδα και Αυτοκρατορική Ρώμη με τις οποίες το άτομο συγκροτείται και αναγνωρίζει τον εαυτό του ως «υποκείμενο». Χρησιμοποιείται η γενεαλογική και αρχαιολογική μέθοδος και αντιστοιχεί στις πρακτικές του εαυτού και τον άξονα της ηθικής. Το «υποκείμενο» εμφανίζεται αρχικά ως το ιδανικό υποκείμενο τομέων γνώσης και ως επιστημολογική έννοια. Στη συνέχεια παρουσιάζεται ως ένα παθητικό παράγωγο των σχέσεων εξουσίας και υποκείμενο με την έννοια της υποταγής. Σταδιακά με τη διεύρυνση της έννοιας της εξουσίας, παρουσιάζεται ως προικισμένο με μια σχετική ελευθερία και τη δυνατότητα της αντίστασης . Το τρίτο μέρος, των πρακτικών του εαυτού και του άξονα της ηθικής παρουσιάζει ένα «υποκείμενο» που συγκροτεί και μεταμορφώνει μέσα από τις τεχνικές του εαυτού, που είναι ιστορικά προσδιορισμένες, Συμπερασματικά μπορούμε να πούμε ότι το «υποκείμενο» είναι παρόν σε όλο το έργο του Φουκώ, εννοιολογημένο διαφορετικά, με ένα τρόπο που το διευρύνει διαρκώς. Είναι ιστορικό, δεν είναι μια ουσία αλλά μια μορφή που πραγματώνεται με διάφορους τρόπους διαμέσου των αιώνων. The present work deals with the concept of the “subject” in M. Foucault’s work. Foucault rejected the phenomenological, Marxist and psychoanalytical subject, changing the way we perceive it, the self and identity. He didn’t elaborate a theory of the subject but created conceptual tools which he continuously developed. However this re-elaboration leads to a broadening of the whole conceptualization of the “subject” in Foucault’s work. Foucault’s work can be approached through basic tools: A) His methodology: archeology-genealogy B) The predominance of a domain: discursive practices, power relations, practices of the self C) An axe: knowledge, power, ethics The methodological tools, the three domains and axes don’t exclude but complement each other in his analyses. The methodology used by particular work, was an in depth analysis of primary sources (books, lectures at the College de France as well as everything else published during Foucault’s life and assembled in the four volumes of “Dits et ecrits”). In the first part of his work, that of discursive practices, the axe of knowledge and the archeological method as used by Foucault, he was interested in the conditions allowing the emergence of knowledge domains in different time periods. In the second part, Foucault uses the genealogical method inspired by Nietzsche. It complements the horizontal study of discursive practices with a vertical study of the historical forces that determined our own discursive regime. It corresponds to the domain of power relations and the axe of power. During this period he develops the analytic of power and its relations to knowledge and truth. Contemporary power, which emerges at the end of the 18th and beginning of the 19th century constitute a) disciplinary power, exercised on bodies to render them docile and productive b) bio-power, which is exercised on the population, aiming at the maximization of its capabilities. Subsequently, power is conceptualized as “government” in the sense of guiding the behavior of others.

In an effort to explore new biocompatible substrates for biomedical technologies, we present a structural study on a crosslinked gelatinous protein extracted from marine mussels. Prior studies have shown the importance of iron in protein crosslinking and mussel adhesive formation. Here, the structure and properties of an extracted material were examined both before and after crosslinking with iron. The structures of these protein hydrogels were studied by SEM, SANS, and SAXS. Viscoelasticity was tested by rheological means. The starting gel was found to have a heterogeneous porous structure on a micrometer scale and, surprisingly, a regular structure on the micron to nanometer scale. However disorder, or "no periodic structure", was deduced from scattering on nanometer length scales at very high q. Crosslinking with iron condensed the structure on a micrometer level. On nanometer length scales at high q, small angle neutron scattering showed no significant differences between the samples, possibly due to strong heterogeneity. X-ray scattering also confirmed the absence of any defined periodic structure. Partial crosslinking transformed the viscoelastic starting gel into one with more rigid and elastic properties. © 2006 Wiley-VCH Verlag GmbH & Co. KGaA. 6 9 711 718 Cited By :31

The shear response of a series of polymer-clay gels has been investigated by means of rheology and small-angle neutron scattering (SANS). The gels have the same composition by mass but different polymer molecular weights (M w). While long polymer chains can interconnect several platelets, which act as multifunctional cross-links, very short polymer chains should not be able to do so, allowing us to explore the effects of bridging on structure and dynamical responses. Increasing the polymer M w in the gels leads to increasingly strong anisotropy in the SANS data, indicating a larger and larger degree of shear orientation. This relative increase in orientation, however, is accompanied by a relatively lower amount of shear thinning. Simple solutions of anisotropic particles usually shear thin by alignment of the particles with the flow, allowing them for example to slide past each other more easily. In a connected gel, breaking of the connectivity should also lead to shear thinning. Thus, the inverse relationship between shear orientation and shear thinning, combined with the fact that the lowest M w, which exhibits the highest shear thinning, does not orient at all, supports our earlier hypothesis that the alignment mechanism in these systems stems from the coupling between the clay and the polymer mediated by the shear flow and nicely demonstrates the effect of bridging on the strength and dynamics of these gels. © 2006 American Chemical Society. 39 4 1614 1619 Cited By :49

Amphiphilic polymer conetworks are cross-linked polymers that swell both in water and in organic solvents and can phase separate on the nanoscale in the bulk or in selective solvents. To date, however, this phase separation has only been reported with short-range order, characterized by disordered morphologies. We now report the first example of amphiphilic polymer conetworks, based on end-linked "core-first" star block copolymers, that form a lamellar phase with long-range order. These mesoscopically ordered systems can be produced in a simple fashion and exhibit significantly improved mechanical properties. © 2015 American Chemical Society. 4 10 1163 1168 Cited By :21

The physical picture of the large scale structures in nanocomposite hydrogels and some of their unique behavior were discussed. The aqueous solutions of the synthetic hectorite type clay, Laponite RD (LRD) and poly(ethylene oxide) (PEO) were used and the clay particles composed of platelets of high purity and uniform size. It was demonstrated that polymer-clay gels contained structures on a multiple scale length. Analysis suggests that the clay platelets can interconnect by network-active polymer through their edges with many strings being much longer than the 30 nm nominal platelet diameter. 38 6 2047 2049 Cited By :69

End-linked, degradable, amphiphilic polymer conetworks (APCNs) of various compositions and architectures were synthesized by sequential atom transfer radical terpolymerization of monomers and cross-linker using a cleavable, bifunctional initiator, bearing two acid-labile hemiacetal ester groups. The incorporation of the initiator residue into the conetworks rendered them cleavable in the middle of their elastic polymer chains. The temporal evolution of the swollen mass of the conetworks in acidified THF-water mixtures was studied and it was determined that the APCN hydrolysis rates were dependent on both conetwork composition and architecture. Regarding the former, hydrophobic APCNs degraded slowly or they even did not dissolve at all. Regarding the latter, conetworks with hydrophobic monomer and hydrophobic cross-linker units distributed around the initiator fragment also dissolved more slowly or they did not degrade at all. Finally, characterization of the star copolymers, produced from conetwork hydrolysis, allowed the determination of the APCN core functionality to be around 30. 3 1 105 116 Cited By :25

Four well-defined end-linked triblock polyampholyte conetworks composed of positively ionizable 2-(dimethylamino)ethyl methacrylate (DMAEMA) repeating units and negatively ionizable methacrylic acid (MAA) repeating units were synthesized using one-pot, sequential reversible addition-fragmentation chain transfer (RAFT) polymerization, by employing 1,4-bis[2-(thiobenzoylthio)prop-2- yl]benzene (1,4-BTBTPB) as the chain transfer agent, and ethylene glycol dimethacrylate (EGDMA) as the cross-linker. From the four end-linked conetworks, three were based on ABA triblock polyampholytes with polyDMAEMA midblocks with a constant degree of polymerization (DP) and polyMAA end-blocks of different DPs. The fourth end-linked polyampholytic conetwork was based on an equimolar BAB triblock polyampholyte with a polyMAA midblock. Furthermore, two polyampholyte networks were also prepared: one based on an end-linked equimolar statistical polyampholyte, and one with a randomly cross-linked, rather than an end-linked, architecture. Finally, the two homopolymer networks based on the DMAEMA and the MAA monomers were also synthesized. The MAA units were introduced in the (co)networks via the polymerization of 2-tetrahydropyranyl methacrylate (THPMA) followed by its acid hydrolysis after (co)network formation. The linear precursors to the (co)networks were found to have molecular weights and compositions close to the expected values, whereas the extractables from the (co)networks were determined to be lower than 30%. In water, the degrees of swelling (DS) of all the polyampholyte (co)networks presented a characteristic minimum at intermediate pH values, around the (co)network isoelectric point (pI), while they increased at acidic and basic pHs. The pI values of the ampholytic (co)networks were estimated as the midpoints of the regions of reduced swelling and ranged between 5.3 and 6.8, decreasing with the increase of the MAA content in the (co)networks. Finally, small-angle neutron scattering (SANS) studies of the polyampholyte (co)networks swollen in D2O provided SANS profiles without any peaks but broad shoulders whose location was consistent with the spacing of the cross-linking cores. © 2011 American Chemical Society. 44 13 5352 5362 Cited By :34

The structural responses of a polymer-clay nanocomposite hydrogel to an imposed shear field are investigated from the nanometer to the micrometer length scales. The effects of polymer molecular weight and concentration of the components are probed, and the structural response of the individual components is explored using contrast matching techniques with small-angle neutron scattering. At rest the clay structure appears minimally perturbed by the presence of the polymer. As the network begins to be disrupted under the effect of low shear, large-scale inhomogeneities roll up and orient with their long axis parallel to the neutral direction. With increasing shear rates the effect of the polymer-clay interactions becomes apparent with nanoscopic orientation of both the clay platelets and the polymer chains, but only in systems where polymer bridging of the clay can occur. The clay and polymer concentration dependence of the shear response suggests an ideal combination of concentrations and polymer molecular weights with implications for materials design. © 2009 American Chemical Society. 43 2 1041 1049 Cited By :26

Four linear amphiphilic multiblock copolymers based on 2-(dimethylamino) ethyl methacrylate (DMAEMA, hydrophilic) and methyl methacrylate (MMA, hydrophobic), bearing from two to five blocks, were synthesized using reversible addition - fragmentation chain transfer polymerization and stepwise monomer additions. The degree of polymerization of each hydrophilic poly DMAEMA block was ~50, while that of the hydrophobic polyMMA blocks was ca. 20. The stepwise monomer addition procedure secured that each higher multiblock was composed of its immediately lower homologue plus exactly one extra block. The molecular weights (MW) of the synthesized (co)polymers, as measured by gel permeation chromatography (GPC), were close to the theoretically expected. GPC also indicated rather narrow molecular weight distributions which, however, broadened with the number of blocks. The compositions of the copolymers, as determined by proton nuclear magnetic resonance spectroscopy, were also close to the expected values. The cloud points of the copolymers, measured by turbidimetry, were found to increase with the number of blocks. The sizes of the micelles formed by the copolymers in aqueous solution were characterized using dynamic light scattering and small-angle neutron scattering. The determined values of the hydrodynamic radii, the radii of gyration, and the aggregation numbers of the micelles increased slightly with the block number from the triblock to the pentablock copolymer, implying extensive folding of the chains of the tetrablock and the pentablock copolymers in their micelles. The aggregation number of the tetrablock copolymer was approximately one-half that of the diblock copolymer whose unimer MW was onehalf that of the tetrablock, suggesting that the micellar cores of these two types of micelles were composed of the same number of hydrophobic units. © 2010 American Chemical Society. 43 6 2713 2720 Cited By :33

The effect of pigment dispersion on (i) surface morphology and appearance, and (ii) the weathering durability of a TiO2 pigmented epoxy coating was investigated. The microstructure and dispersion of pigmented epoxy coatings were characterized using ultra small angle neutron scattering (USANS). Atomic force microscopy (AFM) and laser scanning confocal microscopy (LSCM) were used to characterize surface morphology of unexposed and weathered coatings. Surface optical scattering and commercial gloss measurements were carried out to study the corresponding optical properties of the coatings. Preliminary results of optical and surface morphological changes are presented and related to material properties as a function of outdoor weathering for two coatings of different dispersion states. © 2009 American Chemical Society. 1004 276 286 Cited By :2

We investigate the influence of ionic strength on the structural heterogeneity and viscoelastic properties of nanocomposite hydrogels. We use small-angle scattering and rheology to monitor structural changes as a function of ionic strength. Increasing ionic strength makes the nanocomposite gels macroscopically heterogeneous, stiffer and more turbid. At high shear rates, nanometre structures rearrange within aggregates and orient in the flow direction. The changing structural properties that develop with ionic strength are due to increased heterogeneity of nanoparticle distribution and polymer-nanoparticle interactions as well as to the formation of PEO [poly(ethylene oxide)] aggregates interacting with sodium cations, which reinforce the overall hydrogel network. © 2009 the Owner Societies. 11 15 2760 2766 Cited By :18

The structure of two series of model amphiphilic polymer conetworks based on the hydrophilic anionic methacrylic acid was characterized by atomic force microscopy (AFM) and small-angle neutron scattering (SANS). In the first series, the hydrophobic component was the glassy poly(methyl methacrylate), while the rubbery poly(2-butyl-1-octyl methacrylate) constituted the hydrophobic segments in the second series. Each series comprised conetworks in which the hydrophile / hydrophobe ratio was systematically varied as well as conetworks with different architecture of the linear chain: ABA and BAB triblock and statistical. The AFM and SANS measurements indicated nanophase separation in the triblock copolymer-based conetworks and provided the spacing, size and shape of the formed nanodomains. © 2008 American Chemical Society. 996 286 302 Cited By :2

Seven amphiphilic conetworks of methacrylic acid (MAA) and a new hydrophobic monomer, 2-butyl-1-octyl-methacrylate (BOMA), were synthesized using group transfer polymerization. The MAA units were introduced via the polymerization of tetrahydropyranyl methacrylate (THPMA) followed by the removal of the protecting tetrahydropyranyl group by acid hydrolysis after network formation. Both THPMA and BOMA were in-house synthesized. Ethylene glycol dimethacrylate (EGDMA) was used as the cross-linker. Six of the conetworks were model conetworks, containing copolymer chains between cross-links of precise molecular weight and composition. The prepared conetwork series covered a wide range of compositions and architectures. In particular, the MAA content was varied from 67 to 94 mol %, and three different conetwork architectures were constructed: ABA triblock copolymer-based, statistical copolymer-based, and randomly cross-linked. The linear conetwork precursors were analyzed by gel permeation chromatography and 1H NMR spectroscopy in terms of their molecular weight and composition, both of which were found to be close to the theoretically calculated values. The degrees of swelling (DS) of all the amphiphilic conetworks were measured in water and in THF over the whole range of ionization of the MAA units. The DSs in water increased with the degree of ionization (DI) and the content of the hydrophilic MAA units in the conetwork, while the DSs in THF increased with the degree of polymerization of the chains between the cross-links and by reducing the DI of the MAA units. Finally, the nanophase behavior of the conetworks was probed using small-angle neutron scattering and atomic force microscopy. © 2007 American Chemical Society. 23 21 10746 10755 Cited By :65

Two series of model amphiphilic polymer conetworks were synthesized by group transfer polymerization (GTP). The first one contained methyl methacrylate (MMA) and the second one 2-butyl-l-octyl methacrylate (BOMA) as hydrophobic monomers. Methacrylic acid (MAA) was used as the hydrophilic monomer for both series. Network synthesis was performed by sequential monomer/cross-linker additions to form conetworks in a wide range of compositions and architectures. All conetwork precursors and the extractables were characterized in organic solvents by gel permeation chromatography and 1H NMR. The polymer conetworks were investigated in terms of their degree of swelling in aqueous media and in THF. The nanophase separated structure was proved by atomic force microscopy and small-angle neutron scattering measurements for the triblock copolymer model conetworks. 2 60 63

We investigate the multilayered structures of poly(ethylene)oxide/ montmorillonite nanocomposite films made from solution. The shear orientation of a polymer-clay network in solution combined with simultaneous solvent evaporation leads to supramolecular multilayer formation in the film. The resulting films have highly ordered structures with sheet-like multilayers on the micrometer length scale. The polymer covered clay platelets were found to orient in interconnected blob-like chains and layers on the nanometer length scale. Inside the blobs, scattering experiments indicate the polymer covered and stacked clay platelets oriented in the plane of the film. The polymer is found to be partially crystalline although this is not visible by optical microscopy. Atomic force microscopy suggests that the excess polymer, which is not directly adsorbed to the clay, is wrapped around the stacked platelets building blobs and the polymer also interconnects the polymer-clay layers. Overall our results suggest the re-intercalation of clay platelets in films made from exfoliated polymer-clay solutions as well as the supramolecular order and hierarchical structuring on the nanometer, via micrometer to the centimeter length scale. © the Owner Societies 2006. 8 14 1739 1746 Cited By :23

The shear orientation of three polymer-clay gels has been investigated by means of small angle neutron scattering (SANS). The gels have the same polymer and clay concentrations but different polymer molecular weight. The polymer B adsorbed to the clay platelets. While long polymer chains can interconnect several platelets shorter polymer chains cannot. Although the polymer concentration is above c* the polymer chain length and cross linking between clay platelets strongly influence their shear orientation which leads to anisotropy in SANS. Our data suggest that the flow is strong enough to enhance and maintain a continuous increase in the shear orientation of the polymer clay gels only when the polymer chains are long enough to interconnect or strongly entangle between platelets. © 2005 Materials Research Society. 840 51 56 Sponsors: Materials Research Society, MRS Conference code: 65003

Group transfer polymerization (GTP) was used for the preparation of eight networks based on two hydrophilic monomers, 2-(dimethylamino)ethyl methacrylate (DMAEMA) and poly(ethylene glycol) methacrylate (PEGMA). Ethylene glycol dimethacrylate (EGDMA) served as the cross-linker, whereas 1,4-bis-(methoxytrimethylsiloxymethylene)cyclohexane (MTSMC) was used as a bifunctional initiator. Seven of the networks had linear segments of accurate molecular weight between the cross-links, i.e., they were model networks, whereas the eighth was an equimolar randomly cross-linked network. Five of the seven model networks were based on ABA triblock copolymers with PEGMA midblocks and DMAEMA endblocks, in which the DMAEMA/PEGMA ratio was varied. The remaining two model networks were equimolar isomers, the one based on BAB triblocks (with a DMAEMA midblock) and the other based on the statistical copolymer. The degrees of swelling of all of the networks were measured as a function of pH and were found to increase below pH 7. The degrees of swelling at low pH values increased with the percentage of the DMAEMA monomer, which is ionized under these conditions. These swelling results were confirmed qualitatively by theoretical calculations. Finally, the pH-dependence of the adsorption of the proteins pepsin, bovine serum albumin, and lysozyme onto one of the model networks was studied. 4 5 1150 1160 Cited By :33