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It has been indicated that doxorubicin (Dox) can induce some unwanted cardiotoxicity through different signaling pathways. In the present study, calycosin-PEG-PPG-PEG copolymer nanomicelles were developed and well-characterized by different techniques. Afterwards, the protective effects of calycosin-triblock copolymer nanomicelles against Dox-stimulated cardiotoxicity in H9C2 cardiomyocytes were explored by viability, reactive oxygen species (ROS), and reactive nitrogen species (RNS) assays. Also, the expression of ERp57, p53, Bax, and Bcl-2 at both mRNA and protein levels were assessed by qPCR and western blot , respectively. It was seen that synthesized calycosin-triblock copolymer nanomicelles had a size of around 20–30 nm with good colloidal stability, sustained drug release and improved dissolution rate. Also, it was shown that calycosin-triblock copolymer nanomicelles can mitigate Dox-induced cardiotoxicity through a remarkable reduction in ROS and RNS generation. Also, it was found that calycosin-triblock copolymer nanomicelles resulted in the downregulation of Bax and p53 and overexpression of Bcl-2 and ERp57 at both mRNA and proteins levels and these protective effects were inhibited in the presence of ERp57-siRNA silencing. Therefore, this study may provide useful information about the development of drug-loaded nanomicelles for mitigation of Dox-induced toxicity.

Developing a technology that enables oral vaccines to work efficiently remains a considerable effort since a number of difficulties must be addressed. The key objective being to ensure the safe passage through the harsh conditions within the gastrointestinal tract, promoting delivery that induces enhanced immune response. In the particular case of hepatitis B, the oral formulation in the nanostructured silica SBA-15 is a viable approach. As a result of its porous structure, low toxicity and structural stability, SBA-15 is capable to protect and release the hepatitis B surface antigen (HBsAg), used in the vaccination scheme, at the desired destination. Furthermore, when compared to the currently used injection based delivery method, better or similar antibody response has been observed. However, information about the organisation of the antigen protein remains unknown. For instance, HBsAg is too large to enter the 10 nm ordered mesopores of SBA-15 and has a tendency to agglomerate when protected by the delivery system. Here we report on the pH dependence of HBsAg aggregation in saline solution investigated using small angle X-rays scattering that resulted in an optimisation of the encapsulation conditions. Additionally, X-ray microscopy combined with neutron and X-ray tomography provided full 3D information of the HBsAg clustering (i.e. agglomeration) inside the SBA-15 macropores. This method enables the visualisation of the organisation of the antigen in the interior of the delivery system, where agglomerated HBsAg coexists with its immunological effective uniformly distributed counterpart. This new approach, to be taken into account while preparing the formulation, can greatly help in the understanding of clinical studies and advance new formulations.

Clean, usable water is quickly becoming a less abundant natural resource for residential, commercial, and industrial applications. Developing advanced and efficient membranes as filtration components for water-treatment processes will help supply a growing society the clean water it needs. Triblock polymers have recently become of interest for their potential to create membranes that have higher selectivity while also having higher flux values than current commercially available ultrafiltration membranes. The synthesis of a triblock polymer consisting of polyisoprene (PI), polystyrene (PS), and either poly(N,N-dimethylacrylamide) (PDMA) or poly(tert-butyl acrylate) (PtBA) is reported. Each block of the polymer is synthesized via a sequential reverse addition-fragmentation chain transfer (RAFT) polymerization mechanism to achieve controlled, high molecular weights and narrow molecular weight distributions. The triblock polymer is synthesized such that the volume fractions of the PI, PS, and PDMA/PtBA blocks are about 25%, 45%, and 30%, respectively, to achieve optimal mechanical properties and pore functionality within the membrane. Subsequently, the membrane is prepared following the non-solvent induced phase separation (SNIPS) method.

The effect of the mild detemplation method, based on Fenton chemistry (with and without previous solvent extraction), and calcination was evaluated by the drug uptake capacity of SBA-15 materials. A number of characterization techniques were applied for evaluation and comparison of the materials properties such as TGA, CNH, N-2 physisorption and Si-29 NMR. The mild Fenton detemplation method rendered a nearly pristine SBA-15 without structural shrinkage, low residual template, improved surface area, pore volume and silanol concentration. The drug (ibuprofen) adsorption experiments were carried out by solution immersion in powdery form. The mild detemplated samples experienced an enhanced uptake that could be explained by the enhanced density of silanols (mmol/g), originated from the absence of calcination in the Fenton approaches. (C) 2014 Elsevier B.V. All rights reserved.

Well-defined segmented block copolymers were studied as the number and position of hard segments in the chain was varied. The hard segments were diamides of uniform length (A), and the synthesized copolymers were mono-, di-, tri- or multiblock using the soft segment (B), poly(tetramethylene oxide), with a molecular weight of 2 900 g mol−1 and extended with terephthalate groups to reach a maximum of 20 000 g mol−1. The diamide segments in the chain displayed very high crystallinities and a ribbon-like structure with high aspect ratio. The copolymer without hard segments was a semi-solid. For the materials with one diamide unit in the chain, the modulus was high but the yield and fracture strengths low. When two or more diamide units were used, both the modulus and values for the yield and fracture strengths were high.

Segmented block copolymers of polysulphone with monodisperse amide segments were synthesized by a melt and a solution polymerization method. Both triblock and multiblock copolymers were prepared. The length of the difunctional polysulphone was varied from 2000 to 20,000 g/mol. The monodisperse amide segment was the tetra-amide T6T6T based on terephthalic acid (T) and hexamethylene diamine (6) units. The main goal of this work was to study if the high Tg amorphous polysulphone could be modified to a high Tg semi-crystalline PSU-T6T6T copolymer. The copolymers were characterized by viscosity measurements, NMR, FTIR, MALDI-TOF, DSC, and DMA. Depending on the amide concentration in the copolymers the T6T6T melting temperatures ranged between 220 and 270 °C and thus the crystallization window was small 50–100 °C. From the FTIR results, it was revealed that the crystallinity of the T6T6T segments in the copolymer could be very high, up to 92–97%. The T6T6T has crystallized out into nanoribbons with a high aspect ratio. These high Tg semi-crystalline copolymers had a high dimensional and solvent resistance.

In this thesis, emphasis is given to the study of temperature-responsive amphiphilic triblock copolymers and their use for in situ drug delivery systems. Two polymers have been studied with approximately the same composition of the two hydrophobic caprolactone copolymerised with lactic acid (PCLA) end groups. The middle hydrophilic poly(ethylene glycol) (PEG) spacer is different between the polymers; respectively with a molecular weight of 1000 and 1500 g/mol. PCLA-PEG-PCLA is showed to form a gel that is temperature dependent. The polymeric systems were characterised in terms of their rheological properties through laboratory measurements, i.e. gel point, dynamic viscosity, gel properties and thermodynamic features in form of cloud point. It was proven that both the concentration and length of the hydrophilic PEG spacer affects the rheology and structure of the system. A sol-gel-sol (phase separation) transition was observed for both polymer systems via the tube inverting method. It was only possible to determine a critical gel point for the PCLA-PEG(1000)-PCLA polymer. The properties of the polymer with the short PEG spacer, observed from small angle neutron scattering measurements, could be explained by formation of worm-like cylindrical micelles. The polymer with the longer PEG spacer forms flower-like spherical core-shell micelles. It was shown through rheology tests that these cylinders were less stable upon heating and therefore more temperature-responsive.

International audience; Thermo-responsive triblock copolymers were synthesized by atom transfer radical polymerization of N-isopropyl acrylamide (NIPAAm) and N,N-dimethyl acrylamide (DMAAm) using α,ω-bromopropionyl poly(L-lactide) as the macro-initiator and a CuCl/tris(2-dimethylaminoethyl) amine (Me6TREN) complex as the catalyst. The polymerization was realized at 25 °C in a DMF–water mixture. DMAAm was incorporated in the copolymer as a hydrophilic comonomer in order to tune the lower critical solution temperature (LCST). The LCST linearly increases from 32.2 to 39.1 °C upon increasing the DMAAm content from 0 to 24%. The phase transition of polymeric micelles at the LCST occurs in a narrow temperature interval below 0.5 °C. Reversible size changes are observed when the temperature increases from 25 to 45 °C and then decreases down to 25 °C. Nano-size micelles (37 to 54 nm) with narrow distribution were obtained by self-assembly of amphiphilic copolymers in aqueous medium. The critical micelle concentration (CMC) ranges from 0.010 to 0.015 mg mL−1. In vitro drug release studies show a much faster release at temperatures above the LCST. The MTT assay was conducted to evaluate the cytotoxicity of copolymers. Therefore, the nano-scale size, low CMC, rapid phase transition, LCST slightly above body temperature and thermo-responsive drug release indicate that these copolymers could be potential candidates for applications in targeted delivery of drugs.

ENERGIE:RAFFINAGE+EML:SLO; In the context of the search for higher performance hydrodesulfurization catalysts, materials made by a novel method of immobilizing heteropolyoxometalates on mesoporous oxides were compared to those derived by incipient wetness impregnation for the hydrogenation of toluene. The catalysts prepared by the one-pot encapsulation of HPMo into the walls of SBA-15 silica were found to be significantly more active for the reaction.

International audience; A series of poly(ethylene glycol)-polylactide-poly(ethylene glycol) (PEG-PLA-PEG) triblock copolymers with symmetric or asymmetric chain structures were synthesized by combination of ring-opening polymerization and copper-catalyzed click chemistry. The resulting copolymers were used to prepare self-assembled aggregates by dialysis. Various architectures such as nanotubes, polymersomes and spherical micelles were observed from transmission electron microscopy (TEM), cryo-TEM and atomic force microscopy (AFM) measurements. The formation of diverse aggregates is explained by modeling from the angle of both geometry and thermodynamics. From the angle of geometry, a "blob" model based on the Daoud-Cotton model for star polymers is proposed to describe the aggregate structures and structural changes with copolymer composition and molar mass. In fact, the copolymer chains extend in aqueous medium to form single layer polymersomes to minimize the system's free energy if one of the two PEG blocks is short enough. The curvature of polymersomes is dependent on the chain structure of copolymers, especially on the length of PLA blocks. A constant branch number of aggregates (f) is thus required to preserve the morphology of polymersomes. Meanwhile, the aggregation number (Nagg) determined from the thermodynamics of self-assembly is roughly proportional to the total length of polymer chains. Comparing f to Nagg, the aggregates take the form of polymersomes if Nagg ≈ f, and change to nanotubes if Nagg > f to conform to the limits from both curvature and aggregation number. The length of nanotubes is mainly determined by the difference between Nagg and f. However, the hollow structure becomes unstable when both PEG segments are too long, and the aggregates eventually collapse to yield spherical micelles. Therefore, this work gives new insights into the self-assembly behavior of PEG-PLA-PEG triblock copolymers in aqueous solution which present great interest for biomedical and pharmaceutical applications.

Periodic mesoporous benzene-silica (Ph-PMO) are interesting materials for catalytic applications due to their high surface area, meso- and molecular-scale order, high organic content in the wall and alternated hydrophobic-hydrophilic behavior. Then, propylsulfonic acid-functionalized Ph-PMO material (Ph-PMO-PrSO 3 H) is a very active acid solid for catalyzing aqueous organic reaction. Acid strength and hydrophobic properties are usually suggested to explain the distinct behavior of Ph-PMO-PrSO 3 H compared to the less active propylsulfonic acid-functionalized periodic mesoporous silica catalysts (PMS-PrSO 3 H). Here we present a systematic study in which, the catalytic performances in the reaction of indole with benzaldehyde of propylsulfonic acid-functionalized SBA-15 (SBA-15-PrSO 3 H) and Ph-PMO-PrSO 3 H are compared. The causes of the different activities are investigated. The strength of the Bronsted acidity of the sulfonic acid groups SO 3 H are characterized by adsorption of 2,6-dimethylpyridine (DMP) monitored by FTIR spectroscopy. The hydrophobic index (HI) of each solid is determined by water/toluene competitive adsorption. The calculation of the turnover frequencies (TOFs) enables to show that, among all the samples studied, Ph-PMO-PrSO 3 H exhibit the higher catalytic activity. The TOF depends on the SO 3 H loadings. The aromatic phenyl rings that composed the mesoporous hybrid organosilica walls of the Ph-PMO-PrSO 3 H materials does not confer to the sulfonic groups a stronger acidity since a very low difference was observed between the ν 8a vibration wavenumbers of the DMPH + molecule of SBA-15-PrSO 3 H and Ph-PMO-PrSO 3 H catalysts. The strength of the acid sites is influenced by the close SiOH or SO 3 H environment. The HI values are slightly superior for Ph-PMO-PrSO 3 H solid than for SBA-15-PrSO 3 H sample even when trimethylsilyl groups are incorporated in this latter catalyst. The HI values decrease a lot as a function of increasing concentration of hydrophilic SO 3 H groups.

International audience; Solid lipid nanoparticles (SLN) stabilized by nonionic polysorbate or block copolymer surfactants were used for the preparation of hierarchical meso-macroporous silica through a co-templated approach combining a cooperative templating mechanism (CTM) with micelles and spherical soft matter particles imprinting. Depending on the reaction conditions, the morphology of the final material can be tuned to capsules or to block matter. The size of the mesopores is strongly dependent on the nature of the surfactant in excess: 3 nm (Tween 20), 5 nm (Tween 40) or 9 nm (Pluronic (R) P123), whereas the size of the macropores depends only on the size of SLN (250 +/- 150 nm). The macroporous texture was clearly evidenced by TEM. The organization degree of the silica wall depends on the surfactant: only wormlike mesoporous capsules were obtained with Tween 20, and hexagonally ordered microdomains embedded in wormlike mesoporous silica capsules were obtained with Tween 40. Hexagonally ordered silica with circularly ordered mesoporosity could be achieved with Pluronic block copolymer P123. Combining mesoporous silica with solid lipid nanoparticles is a straightforward approach for the design of advanced formulations in drug delivery or food chemistry.

Amphiphilic block copolymers are macromolecules composed of at least one hydrophilic block chemically linked to one or several hydrophobic blocks. In water, these macromolecules self-assemble to form micelles composed of a hydrophobic core surrounded by a hydrated hydrophilic corona. The majority of amphiphilic block copolymers form “frozen” micelles in aqueous solution. This means that there is no dynamic exchange of chains between micelles because the energy necessary to extract a hydrophobic block from the core of micelles is too high. Consequently, the characteristics of the micelles are controlled kinetically and not thermodynamically. In order to decrease this energy, we have incorporated acrylic acid units (AA) in the hydrophobic block of poly(n-butyl acrylate) (PnBA). It was previously shown that the incorporation of 50% molar of AA units in the hydrophobic block led to generation of pH-sensitive micelles in the case of PAA-b-P(AA0.5-stat-nBA0.5) diblocks. This thesis presents of a quantitative analysis of the dynamics of self-assembled amphiphilic diblock and triblock copolymer based on acrylic acid units and n-butyl acrylate units. The hydrophobic blocks contained 50% of acrylic acids units incorporated randomly. The block copolymers were synthesized by controlled radical polymerization (ATRP). The influence of the concentration, pH, temperature and the ionic strength on the structure and the mechanical properties of the self-assembled systems was systematically studied. At low concentrations, static light scattering measurements showed the formation of star-like micelles (diblock) or flower-like micelles (triblock) above a critical aggregation concentration (CAC). At higher concentrations, purely repulsive excluded volume interactions between micelles appeared in the case of diblock copolymers. In the case of triblock copolymers bridging of flower-like micelles induced in addition attractive interactions leading to network formation above the percolation concentration. At high ionic strength and low pH, we showed that the attraction between flower-like micelles became sufficiently stong to induce phase separation. Dynamic light scattering measurements showed besides a fast mode due to cooperative diffusion, a second slow relaxation mode that appeared at the percolation concentration. The origin of this mode was explained by a balistic motion induced by the relaxation of heterogeneities inside the system. The velocity of heterogeneities was determined by the mechanical relaxation of the hydrogels. The formation of the network and the exchange dynamic of chains were studied by rheology. The viscosity of solutions increased sharply at the percolation concentration. The terminal visco-elastic relaxation time of the network is related to the lifetime of bridges. It could be controlled and tuned over several decades by varing of pH, temperature and the ionic strength. The in-situ formation of networks revealed an aging of networks after their formation before they reached their stationary state. Aging caused a slow increase of the relaxation time before reaching its steady value. This explains why it is possible to generate homogeneous networks even if the network at steady is kinetically frozen., Les copolymères à blocs amphiphiles sont des macromolécules composées d’au moins un bloc hydrophile lié chimiquement à un ou plusieurs blocs hydrophobes. En milieu aqueux, ils s’auto-associent pour former des micelles dont les cœurs constitués des blocs hydrophobes sont protégés de l’eau par une couronne constituée des blocs hydrophiles hydratés. La majorité des copolymères à blocs amphiphiles génèrent dans l’eau des micelles « gelées » ne présentant aucun échange de chaînes entre elles. Ceci vient du fait que l’énergie nécessaire pour extraire un bloc hydrophobe du cœur des objets est beaucoup trop importante. Par conséquent, les caractéristiques des micelles sont plus contrôlées cinétiquement que thermodynamiquement. Pour diminuer cette énergie nous avons incorporé des unités hydrophile acide acrylique (AA) dans le bloc hydrophobe de poly(acrylate de n-butyle) (PnBA). L’incorporation de 50% molaire d’unités AA dans le bloc hydrophobe conduit à la formation d’agrégats pH-sensibles dans le cas du dibloc PAA-b-P(AA0.5-stat-nBA0.5) comme montré dans une étude antérieure. Cette thèse a consisté en une analyse quantitative de la dynamique d’auto-association de copolymères dibloc et tribloc amphiphiles à base d’acrylate de n-butyle et d’acide acrylique dont les blocs hydrophobes contiennent 50% d’unités hydrophiles réparties de manière statistique. Les copolymères à blocs ont été synthétisés par polymérisation radicalaire contrôlée par ATRP. L’influence de la concentration, du pH, de la température et de la force ionique sur la structure et les propriétés mécaniques des systèmes auto-assemblés a été systématiquement étudiée. Par diffusion statique de la lumière nous avons montré la présence d’une concentration d’agrégation critique (CAC) au-dessus de laquelle, des micelles de type étoile (dibloc) ou fleur (tribloc) sont formées par auto-association des blocs hydrophobes. A plus fortes concentrations, des interactions répulsives de type volume exclu apparaissent entre les micelles étoiles. Pour les micelles fleurs, à l’inverse des interactions attractives conduisent au pontage des fleurs jusqu’à l’obtention de réseaux tri-dimensionnels au-dessus de la concentration de percolation. Une attraction trop importante entre les fleurs peut même conduire à une séparation de phase à forte force ionique et bas pH. En diffusion dynamique de la lumière, nous avons montré que la formation des réseaux s’accompagnait de l’apparition d’un mode lent dont l’origine a été expliquée par un mouvement balistique d’hétérogénéités relaxées dans les systèmes. La vitesse de relaxation de ces hétérogénéités s’avèrent être dépendantes des propriétés mécaniques des hydrogels.La formation des réseaux et la dynamique d’échange des chaînes ont été étudiées par rhéologie. La viscosité augmente régulièrement avec la concentration jusqu’à la concentration de percolation où une augmentation brusque de la viscosité se produit et un temps de relaxation apparaît. Le temps de vie des ponts a été finement contrôlé et modulé sur plusieurs décades par modification du pH, de la température et de la force ionique. La formation in-situ des hydrogels nous a permis de mettre en évidence un phénomène de vieillissement des réseaux après leur formation avant d’atteindre un état stationnaire. Ce phénomène s’est traduit par une augmentation du temps de relaxation au cours du temps avant d’atteindre une valeur plateau. Ceci nous a également permis de comprendre pourquoi il était possible de générer des réseaux homogènes, par vieillissement, possédant une dynamique extrêmement lente voir nulle.

Novel periodic nanoporous organosilicas (PNOs) were synthesized by direct co-condensation of tetraethylorthosilicate and of the prior synthesized compound triethoxy(naphthalen-1-yl)silane. Structural characterization of materials was performed with various techniques such as H-1 and C-13 nuclear magnetic resonance, X-ray powder diffraction, Fourier transform infrared spectroscopy, ultraviolet-visible and photoluminescence emission and excitation spectroscopy, differential thermal and thermo-gravimetric analyses, nitrogen porosimetry and helium pycnometry. Naphthalene-based moieties were grafted on the silicate matrix through oxygen bonds resulted to novel organosilicate final materials that exhibited high naphthalene content up to 17 wt.% with a corresponding 1.33 mmol/g molar concentration, high crystallinity, specific surface area larger than 1000 m(2)/g and pore size distributions in the microporous/mesoporous boundary. Optical properties have been found to be comparable to the naphthalene. The attachment of the optically active part to the mesopores walls and its specific tuning for blue/UV luminescence demonstrates that this type of the reported low cost materials can be considered as phosphors in UV Leds. Tuning by using the red shift of similar larger molecules, all simultaneously trapped within the PNO, may prove to be efficient white light phosphor. Moreover, the nonlinear active properties of the active naphthalene may also allow for novel applications. Finally, materials were studied for hydrogen and methane storage with Sieverts' apparatus and demonstrated high H-2 and CH4 weight proportions for PNOs materials at various temperatures up to 4.3 MPa and 3.5 MPa respectively as presented in part II. (C) 2012 Elsevier Inc. All rights reserved. Microporous and Mesoporous Materials

SSCI+PDE; International audience; Merging a colloidal approach for the synthesis of Pt nanoparticles and a supramolecular pathway for generating mesostructured oxides can provide via a one-pot synthesis a well-defined, active, and stable heterogeneous catalyst. This material contains regularly distributed Pt nanoparticles along the channel pores of a highly ordered silica matrix.

Melt rheological behavior of a ABA triblock polymer made of poly(tetramethylene oxide) (PTMO) (Mn = 2,900 g mol−1) soft segment and aramide hard segment was studied. The aramide end-segments (A) were short and mono-disperse in length. The mid-segment (B) consisted of PTMO2900 extended with terephthalate units to a molecular weight of 9000 g mol−1. The molecular weight of the triblock was 9700 g mol−1. Rheological behavior of this material was studied by parallel-plate and capillary method. The ABA triblock copolymer was compared with a B polymer (PTMO-terephthalate) of a similar molecular weight. The low molecular weight B polymer had a Newtonian behavior. The low molecular weight triblock copolymer had at high frequencies a low complex viscosity. However, at low frequencies the triblock copolymer had a very high complex viscosity. Also the G″/G′ ratio decreased with decreasing frequency to values less then one and the G′ seemed to have at low frequencies a plateau value. The activation energy of the process increased in value with decreasing shear rate. All these results indicate that the triblock copolymer at low frequencies had a gel-like behavior and this probably due to the clustering of the aramide segments. The aramide clusters are thought to be the (weak) network points of the gel. This network was also found to have a time dependant rheological response and thus a thixotropic behavior.

The tensile and elastic behavior of triblock copolymers containing uniform aramide (TΦB) hard end-segments (HS) and poly(tetramethylene oxide) (PTMO, Mn = 2900 g/mol) soft segments (SSs) was studied. The molecular weight of the copolymer was varied by changing the length of the soft mid-segment; by extending the PTMO2900 with terephthalate units, the SS length was increased from 2900 g/mol to 21,000 g/mol and concurrently the aramide concentration decreased from 18 to 3 wt %. The mechanical properties were investigated by means of tensile testing, stress relaxation (SR) experiments, and cyclic tensile set (TS) tests. The E-modulus was found to increase with increasing aramide content. The low molecular weight copolymers were brittle whereas the high molecular weight copolymers displayed large fracture strain values. The transition from brittle to ductile seemed to occur at a triblock copolymer molecular weight of 6600 g/mol. A strain-induced crystallization was observed at strains above 250%, and both the fracture strain and stress were found to be highly dependant on the molecular weight of the copolymer. Cyclic tensile experiments showed that the materials had low TS values up to the strain hardening point. On the other hand, the SR data at 10% strain seemed to be little dependant on the molecular weight. The higher molecular weight copolymers did not display lower SR values than their low molecular weight counterparts.

Segmented block copolymers of polysulphone with monodisperse amide segments were synthesized by a melt and a solution polymerization method. Both triblock and multiblock copolymers were prepared. The length of the difunctional polysulphone was varied from 2000 to 20,000 g/mol. The monodisperse amide segment was the tetra-amide T6T6T based on terephthalic acid (T) and hexamethylene diamine (6) units. The main goal of this work was to study if the high Tg amorphous polysulphone could be modified to a high Tg semi-crystalline PSU-T6T6T copolymer. The copolymers were characterized by viscosity measurements, NMR, FTIR, MALDI-TOF, DSC, and DMA. Depending on the amide concentration in the copolymers the T6T6T melting temperatures ranged between 220 and 270 °C and thus the crystallization window was small 50–100 °C. From the FTIR results, it was revealed that the crystallinity of the T6T6T segments in the copolymer could be very high, up to 92–97%. The T6T6T has crystallized out into nanoribbons with a high aspect ratio. These high Tg semi-crystalline copolymers had a high dimensional and solvent resistance.

Well-defined segmented block copolymers were studied as the number and position of hard segments in the chain was varied. The hard segments were diamides of uniform length (A), and the synthesized copolymers were mono-, di-, tri- or multiblock using the soft segment (B), poly(tetramethylene oxide), with a molecular weight of 2 900 g mol−1 and extended with terephthalate groups to reach a maximum of 20 000 g mol−1. The diamide segments in the chain displayed very high crystallinities and a ribbon-like structure with high aspect ratio. The copolymer without hard segments was a semi-solid. For the materials with one diamide unit in the chain, the modulus was high but the yield and fracture strengths low. When two or more diamide units were used, both the modulus and values for the yield and fracture strengths were high.

In this work the self-organized mesophases obtained by the ionic interaction of poly( amino acids) poly(L-aspartic acid (P-L-Asp) and poly(L-glutamic acid) (P-L-Glu) with the cationic surfactants C(14)TAB and C(16)TAB, as well as the mesoporous silicate materials obtained by addition and hydrolysis of tetraethyl orthosilicate ( TEOS) on the hybridic mesophases, are described. The mesophases isolated at pH 6.5-8.5 were examined by X-ray diffraction (XRD) analysis for their structure, thermogravimetry for their thermal stability, scanning electron microscopy for their structural features, and circular dichroism (CD) for the conformation of the polypeptide-C(n)TAB (n = 14, 16) complexes. The mesophases P-L-Asp/C(14)TAB isolated at pH 7.5 and 8.5 showed in XRD a single peak at d = 3.45 nm and d = 3.54 nm, respectively, corresponding to typical hexagonal packing of the micellar aggregates. The mesophases P-L-Asp/C(16)TAB isolated at pH 7.5 showed an XRD peak at d = 3.90 nm, corresponding to a similar hexagonal packing of larger micellar aggregates and also two peaks at d = 3.37 nm and d = 1.69 nm indicating a layered configuration of the micellar sheets. The layered component decreases by the increase of pH from 7.5 to 8.5 or the addition of small amounts (0.5%) of EtOH. The P-L-Glu/C(14)TAB mesophases isolated at pH 7.5 and 8.5 showed a single XRD peak at d = 3.60 nm, while the P-L-Glu/C(16)TAB system showed also a single XRD peak at d = 4.10 nm. The CD spectra showed that the complexes P-L-Asp/ C(14)TAB possess a more random configuration compared to the P-L-Glu/C(14)TAB, which have the tendency to form alpha- and 3(10)-helices. The mesoporous silicate materials obtained from the systems P-L-Asp/C(16)TAB/ TEOS and P-L-Glu/C(16)TAB/ TEOS showed a single XRD peak corresponding to hexagonal pore arrangement typical in MCM-41 materials. The nitrogen adsorption-desorption isotherms of the silicate mesostructures indicate that they possess high surface areas in the range 500-800 m(2) g(-1) for the P-L-Asp/ C(n)TAB/TEOS and 1000-1070 m(2) g(-1) for the P-L-Glu/C(n)TAB/ TEOS and ordered or semi-ordered porosity depending on the hybridic system used for isolating the corresponding mesophases. Chemistry of Materials

Synthetic and degradable polymers are an attractive choicein many areas, since it is possible to control the way in whichthey are manufactured; more specifically, pathways tomanipulate the architecture, the mechanical properties and thedegradation times have been identified. In this work,L-lactide, 1,5-dioxepan-2-one and ε-caprolactone were usedas monomers to synthesize polymers with different architecturesby ring-opening polymerization. By using novel initiators,triblock copolymers, functionalized linear macromonomers andstar-shaped aliphatic polyesters with well-defined structureshave been synthesized. To synthesize triblock copolymers,cyclic germanium initiators were studied. The polymerizationproceeded in a controlled manner although the reaction rateswere low. To introduce functionality into the polymer backbone,functionalized cyclic tin alkoxides were prepared and used asinitiators. During the insertion-coordination polymerization,the initiator fragment consisting mainly of a double bond wasincorporated into the polymer backbone. The double bond wasalso successfully epoxidized and this gave unique possibilitiesof synthesizing graft polymers with precise spacing. Themacromonomer technique is a very effective method for producingwell-defined graft polymers. Spirocyclic tin initiators weresynthesized and used to construct star-shaped polymers. Thestar-shaped polymers were subsequently crosslinked in apolycondensation reaction. These crosslinked structures swelledin water, and swelling tests showed that by changing thestructure of the hydrogel network, the degree of swelling canbe altered. A first evaluation of the surface characteristicsof the linear triblock copolymers was also performed. AFManalysis of the heat-treated surfaces revealed nanometer-scalefibers and tests showed that keratinocytes were able to growand proliferate on these surfaces. QC 20100602

Here we report for the first time on the preparation of well-ordered titanium substituted KIT-6 at low acid concentration using polymeric surfactant. The characterization results show that the pore diameter and the unit cell constant of TiKIT-6 increase with increasing Ti incorporation. UV-vis results reveal that most of the Ti are in tetrahedral coordination. In addition, the materials showed higher activity in the epoxidation of styrene than TiSBA-15. Refereed/Peer-reviewed