Pentafluorophenyl Methacrylate Research Articles

Multi-hierarchical nanoparticles with tunable core by emulsion polymerization processes

Nanoparticles (NPs) with functional cores are gaining research interest due to their advanced architecture. However, exposed reactive groups on NP surfaces can lead to material side reactions and biomedical tissue damage. NPs with multi-hierarchical morphologies can be synthesized by various methods; however, controlling the size and position of the functional groups using conventional and scalable methods is still a challenge. This study explores emulsion-based polymerization methods for producing multi-hierarchical NPs with varying sizes and compositions. We compared micro-, macro-, and semi-batch emulsion polymerization using 2-hydroxyethyl methacrylate (HEMA) and pentafluorophenyl methacrylate (PFMA) as co-monomers. The components present in PFMA can be substituted and are used for post-synthetic functionalization. The results suggest that the architecture of the synthesized NPs is multi-hierarchical, with the substitutable pentafluorophenyl units surrounded by HEMA monomers. Additionally, we evaluated the NPs' ability to enhance dermal drug penetration using nile red as a hydrophobic drug model. Significant variations in skin permeation enhancement properties were observed among the NPs, underscoring the impact of the synthesis method on nanocarriers' drug delivery performance.

Novel concrete superplasticizers containing crown ether pendant side chains for improved cement paste workability

In this work, new concrete superplasticizers based on crown ethers as the bulky pendant side chains have been prepared. First, reversible addition-fragmentation chain transfer (RAFT) polymerization of methacrylic acid (MAA) and pentafluorophenyl methacrylate (PFPMA) was performed to prepare poly(MAA-co-PFPMA) as a precursor. A subsequent transesterification reaction with hydroxymethyl-crown ethers (CR) was performed to prepare poly(MAA-co-CR) superplasticizers with different crown ether side chains, namely 12-crown-4 (12CR4), 15-crown-5 (15CR5), and 18-crown-6 (16CR6). The prepared copolymers were characterized using nuclear magnetic resonance (NMR) spectroscopy and size exclusion chromatography (SEC) to confirm their structure and elucidate their molecular weights, respectively. Rheological studies and fluidity measurements revealed that the ring size of crown ether plays a crucial role in enhancing the dispersion and workability retention of cement pastes. It has been found that a moderate ring size can result in the highest cement flowability and workability retention performance, and thus polymers with this pendant group could be of potential interest in the concrete industry as novel superplasticizers containing new pendant groups.

Grafting-To and From for Multiplexed Chemical-Warfare-Agent Responsive Polymer Brushes

Surface-tethered polymers have important applications in functional polymer coatings, particularly for the development of chemically responsive surfaces. Here, we combined the traditional grafting-to and grafting-from methods to create a new surface grafting strategy, termed grafting-to and from, using surface-initiated ring-opening metathesis polymerization (SI-ROMP). In this method, poly(pentafluorophenyl methacrylate) is grafted to an amine terminated surface. Surplus reactive esters after reaction with surface amines render this polymer a connecting or tie layer that can be further reacted to provide dense ROMP initiation sites. This amplification of grafting sites results in thick and environmentally stable polymer brushes upon SI-ROMP. With the goal of developing polymer-grafted breathable membranes that autonomously react to multiple chemical warfare agents (CWAs), we demonstrate the benefit of this method by employing amine reactive monomers in the grafting-from step. This enables diverse postsynthetic functionalization for the facile screening of chemical motifs to enhance response capabilities to mustard blister agents. Surface-tethered triarylmethanol-containing polymers with four distinct functional groups are prepared and challenged with the vapor of 2-chloroethyl ethyl sulfide (CEES), a simulant of mustard agent, in humid air. Importantly, hydroxyl groups effectively improve CWA response and the resulting polymer brushes show chain collapse after both CEES and diethylchlorophosphate (DCP) treatment. Our results illustrate that the grafting-to and from method can be used to grow functional and robust polymer coatings for various applications.

Post-Polymerization Modification of Fluoropolymers via UV Irradiation in the Presence of a Photoacid Generator.

Fluorinated polymers have unique wettability and protein adsorption properties. The site-specific alteration of these properties could expand their application to different research areas. In this work, a fluorinated homopolymer and two of its copolymers with 4-vinylbenzyl glycidyl ether (VBGE) are synthesized by free radical polymerization. The produced polymers are then used to develop resist formulations by the addition of a photoacid generator. Films of these formulations are exposed to ultraviolet radiation through a binary mask and heated to create the pattern. It is found that the water contact angle values of the exposed films areas are reduced compared to those of the unexposed ones, with the exception of pentafluorophenyl methacrylate (PFMA) homopolymer film. This is attributed to the reaction of the epoxy groups creating x-links and producing hydroxyl groups and the cleavage of the pentafluorophenyl group from the ester group leading to carboxylic acid groups. Both modifications on the exposed areas are verified by FTIR spectroscopy and ToF-SIMS analysis. In addition, the biomolecules adsorption ability of the exposed area is increasing 10-15 times compared to the unexposed one for the PFMA homopolymer and the PFMA/VBGE 1:1 copolymer. Thus, the proposed polymers and patterning procedure could find application to spatially directed immobilization of biomolecules and/or cells onto a surface for both biosensing and tissue engineering purposes.

Copolymers Derived from Two Active Esters: Synthesis, Characterization, Thermal Properties, and Reactivity in Post-Modification.

Copolymers with two distinguished reactive repeating units are of great interest, as such copolymers might open the possibility of obtaining selective and/or consequent copolymers with different chemical structures and properties. In the present work, copolymers based on two active esters (pentafluorophenyl methacrylate and p-nitrophenyl methacrylate) with varied compositions were synthesized by Cu(0)-mediated reversible deactivation radical polymerization. This polymerization technique allows the preparation of copolymers with high to quantitative conversion of both comonomers, with moderate control over dispersity (Đ = 1.3–1.7). Additionally, by in-depth study on the composition of each copolymer by various techniques including elemental analysis, NMR, FT-IR, and XPS, it was possible to confirm the coherence between expected and obtained composition. Thermal analyses by DSC and TGA were implemented to investigate the relation between copolymers’ composition and their thermal properties. Finally, an evaluation of the difference in reactivity of the two monomer moieties was confirmed by post-modification of copolymers with a primary amine and a primary alcohol as the model.

Plasma-induced nanostructured metallic silver surfaces: study of bacteriophobic effect to avoid bacterial adhesion on medical devices

Biofilm formation in medical devices represents one of the major problems for the healthcare system, especially those that occur on implantable silicone-based devices. To provide a general solution to avoid biofilm formation in the first stages of development, this work studied how nanostructured metallic silver coatings hinder bacteria-surface interaction by preventing bacteria adhesion. The three studied silver nanostructures (“Sharp blades”, “Thick blades” and “Leaves”) combined superhydrophobic behavior with a physical impediment of the coating nanostructure that produced a bacteriophobic effect avoiding the adhesion mechanism of different bacterial strains. These silver nanostructures are immobilized on stretchable substrates through a polymeric thin film of plasma–polymerized penta-fluorophenyl methacrylate. The control over the nanostructures and therefore its bacteriophobic—bactericidal effect depends on the plasma polymerization conditions of the polymer. The characterization of this bacteriophobic effect through FE-SEM microscopy, live/dead cell staining, and direct bacterial adhesion counts, provided a complete mapping of how bacteria interact with the surface in each scenario. Results revealed that the bacterial adhesion was reduced by up to six orders of magnitude in comparison with uncoated surfaces thereby constituting an effective strategy to avoid the formation of biofilm on medical materials.

Zwitterionic nano-objects having functionalizable hydrophobic core: Formation via polymerization-induced self-assembly and their morphology

Functionalizable poly(pentafluorophenyl methacrylate) (PPFPMA) and zwitterionic poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) are two polymers with an extremely different solubility. It is, therefore, almost impossible to synthesize their block copolymers in a controlled manner using a conventional approach. Herein, it is demonstrated, for the first time, that the synthesis and in situ formation of nanoassemblies of their diblock copolymers (PMPC-b-PPFPMA) can be achieved via polymerization-induced self-assembly using reversible addition-fragmentation chain-transfer dispersion polymerization in ethanol as a selective solvent. The PMPC was synthesized as the first block and further employed as a macro chain transfer agent (PMPC Macro-CTA) for the synthesis of the PPFPMA second block. In situ self-assembled nanostructures of the diblock copolymers were found to be mostly spherical with a varied degree of inter-micellar aggregation depending on the solid concentration and the relative length of the two blocks. Apparently, the limited chain mobility of the core-forming PPFPMA block, due to π-π stacking and hydrophobic interactions, hampered the formation of nanostructures of high-order morphologies. It is possible to perform core functionalization via post-polymerization modification with 1-pyrenemethylamine to yield fluorescently labeled nanostructures that may be applicable as biocompatible and non-fouling nanocarriers and nanosensors in the future.

Cu(0)-mediated RDRP as new alternative for controlled synthesis of poly(pentafluorophenyl methacrylate)

The present work addresses for the first time the controlled synthesis of poly(pentafluorophenyl methacrylate) (PPFPMA) using Cu(0)-mediated reversible deactivation radical polymerization (Cu(0)-mediated RDRP). The influences of several components like ligand, initiator, and solvent are examined and discussed in details to deduce the best-found condition to synthesize PPFPMA with low dispersity (1.05–1.33) in a wide range of molecular weight (6000 g mol−1 to 129 000 g mol−1). The polymerization under the best-found condition shows controlled polymerization features with no induction period, linear first-order kinetics, and linear correlation in monomer conversion. In addition, the chain-end fidelity of polymer obtained by found-optimized conditions is also investigated by various techniques including 1H NMR, MALDI-ToF, and chain extension experiments.

Polymerization-Induced Self-Assembly (PISA) for in situ drug encapsulation or drug conjugation in cancer application

HypothesisWe describe the possibility of using the same block copolymer carriers prepared by PISA for in situ drug encapsulation or drug conjugation. ExperimentsBlock copolymers containing poly((ethylene glycol) methacrylate)–co-poly(pentafluorophenyl methacrylate)-b-poly(hydroxypropyl methacrylate) (P((PEGMA-co-PFBMA)-b-PHPMA)) were synthesized at 10 wt% using PISA. The first approach involved in situ Doxorubicin (DOX) loading during PISA, while the second exhibited surface functionalization of PISA-made vesicles with dual drug therapies, N-acetyl cysteine (NAC) and DOX using para-fluoro-thiol reaction (PFTR) and carbodiimide chemistry, respectively. Cytotoxicity, cell uptake, and cell apoptosis were assessed on MDA-MB-231 cell lines. FindingsP((PEGMA-co-PFBMA)-b-PHPMA) nanocarriers were prepared, showing size and shape transformations from spheres, cylinders to raspberry-forming vesicles. DOX was readily loaded into NPs during PISA with relatively high encapsulation efficiency of 70 %, whereas the plain PISA-made vesicles could be functionalized with NAC and DOX at high yields. DOX-free NPs showed biocompatibility, whilst DOX-conjugated NPs imparted a concentration-dependent cytotoxicity, as well as an enhanced cell uptake compared to free DOX. The results demonstrated that the same PISA-derived self-assemblies enabled either in situ drug encapsulation, or post-polymerization surface engineering with useful functionalities upon tuning the macro-CTA block, thus holding promises for future drug delivery and biomedical applications.

Backbone-Degradable Polymers via Radical Copolymerizations of Pentafluorophenyl Methacrylate with Cyclic Ketene Acetal: Pendant Modification and Efficient Degradation by Alternating-Rich Sequence.

This work deals with syntheses of backbone-degradable polymers via the radical copolymerization of pentafluorophenyl methacrylate (PFMA) with 5,6-benzo-2-methylene-1,3-dioxepane (BMDO), which undergoes ring-opening propagation to afford an ester-bonded backbone. The combination of the electron-deficient methacrylate with the electron-rich cyclic monomer allowed high crossover copolymerization, and the electronic effect was clarified by the comparison with the copolymerization of methyl methacrylate (MMA) and BMDO. The PFMA units of the resultant copolymer underwent quantitative alcoholysis or aminolysis transformation into methacrylate or methacrylamide units along with the pendant functionalization. The alternating-rich sequence was achieved by feeding an excess ratio of BMDO, which was supported by MALDI-TOF-MS of the copolymer obtained by the RAFT copolymerization. The methanolysis-transformed copolymer carrying MMA units was decomposed under basic condition, and the degradation efficiency was superior to that of the copolymer obtained via radical copolymerization of MMA with BMDO because of the alternating-rich sequence.

Towards a Polymer-Brush-Based Friction Modifier for Oil

To meet the need for oil-compatible friction modifier additives that can significantly reduce energy consumption in the boundary-lubrication regime, a macromolecular design approach has been taken. The aim was to produce a lubricious polymer film on the sliding surfaces. A series of readily functionalizable block copolymers carrying an oleophilic poly(dodecyl methacrylate) block and a functionalizable poly(pentafluorophenyl methacrylate) block of various lengths was synthesized by means of reversible addition-fragmentation chain-transfer (RAFT) polymerization. The poly(pentafluorophenyl methacrylate) block was used to attach surface-active nitrocatechol anchoring groups to the polymer. The friction-reduction properties of these polymers were assessed with 0.5 wt% solutions in hexadecane by means of rolling-sliding macroscopic tribological tests. Block copolymers with roughly equal block lengths and moderate molecular weights were significantly more effective at friction reduction than all other architectures investigated. They also displayed lower friction coefficients than glycerol monooleate—a commercially used additive. The film-formation ability of these polymers was examined using a quartz-crystal microbalance with dissipation (QCM-D), by monitoring their adsorption onto an iron oxide-coated QCM crystal. The polymer with highest lubrication efficiency formed a thin film of ~ 17 nm thickness on the crystal, indicating the formation of a polymer brush. Interferometric rolling-sliding experiments with the same polymer showed a separating film thickness of ~ 20 nm, which is consistent with the QCM-D value, bearing in mind the compression of the adsorbed layers on the two sliding surfaces during tribological testing.Graphical

Analytical Parameters of a Novel Glucose Biosensor Based on Grafted PFM as a Covalent Immobilization Technique.

Bioanalytical methods, in particular electrochemical biosensors, are increasingly used in different industrial sectors due to their simplicity, low cost, and fast response. However, to be able to reliably use this type of device, it is necessary to undertake in-depth evaluation of their fundamental analytical parameters. In this work, analytical parameters of an amperometric biosensor based on covalent immobilization of glucose oxidase (GOx) were evaluated. GOx was immobilized using plasma-grafted pentafluorophenyl methacrylate (pgPFM) as an anchor onto a tailored HEMA-co-EGDA hydrogel that coats a titanium dioxide nanotubes array (TiO2NTAs). Finally, chitosan was used to protect the enzyme molecules. The biosensor offered outstanding analytical parameters: repeatability (RSD = 1.7%), reproducibility (RSD = 1.3%), accuracy (deviation = 4.8%), and robustness (RSD = 2.4%). In addition, the Ti/TiO2NTAs/ppHEMA-co-EGDA/pgPFM/GOx/Chitosan biosensor showed good long-term stability; after 20 days, it retained 89% of its initial sensitivity. Finally, glucose concentrations of different food samples were measured and compared using an official standard method (HPLC). Deviation was lower than 10% in all measured samples. Therefore, the developed biosensor can be considered to be a reliable analytical tool for quantification measurements.

Understanding the Polymer Rearrangement of pH-Responsive Nanoparticles

The use of self-assembled nanoparticles for drug delivery has received significant attention in recent years. However, the dynamic nature of self-assembled polymeric systems means there is a need to develop greater understanding of the inherent stability of these systems. In particular, understanding if these materials remain as discrete nanoparticles, or if there is dynamic exchange of material between particles is critical. Herein, we labelled pH-responsive nanoparticles with fluorescent dyes and then investigated the change in fluorescence when the particles were mixed with unlabelled nanoparticles in order to investigate their potential for polymer rearrangement. Nanoparticles were formed by the nanoprecipitation of pH-responsive poly(ethylene glycol)-block-poly(2-(diethylamino)ethyl methacrylate) (PEG-b-PDEAEMA) as the shell and poly(2-(diethylamino)ethyl methacrylate)-random-poly(2-(diisopropylamino)ethyl methacrylate) (PDEAEMA-r-PDPAEMA) as the core. The core and shell were labelled by incorporating pentafluorophenyl methacrylate (PFPMA) in core or shell respectively and then coupling with either Sulfo-cyanine5 amine or Cyanine3 amine. Exchange of material between nanoparticles was probed by tracking changes in the self-quenching of fluorescently labelled polymers in the core of the nanoparticles. The fluorescence intensity of the labelled nanoparticles was stable when mixed with unlabelled nanoparticles at physiological pH (pH 7.4), suggesting there is limited migration of polymers between particles in this system. This study provides important insights into the use of non-crosslinked nanoparticles under biologically relevant conditions.

Kinetic investigations on homo- and co-polymerizations of pentafluorophenyl (meth)acrylates

Pentafluorophenyl methacrylate (PFPMA) and pentafluorophenyl acrylate (PFPA) are frequently used monomers to produce advanced materials for biomedical applications via (co)polymerization reactions. This contribution reports kinetic investigations of the reversible addition fragmentation chain transfer (RAFT) copolymerization of PFPMA and methyl methacrylate (MMA) mediated by a dithiobenzoate chain transfer agent (CTA) at 70 °C in dimethyl formamide (DMF). Control with respect to the molar mass of the copolymers was observed for initial PFPMA monomer feeds ≤40 mol%. The rate of PFPMA incorporation decreased with increasing initial PFPMA feed ratios. Reactivity ratios were estimated with a nonlinear regression that utilizes a visualization of the sum of squares space method (rPFPMA = 1.06 and rMMA = 0.44). The slight preference for MMA-type radicals to add PFPMA monomers increased the rate of consumption of PFPMA especially in low initial PFPMA monomer feeds. In addition, kinetic investigations of the RAFT homopolymerization of PFPA revealed an induction period and poor control on the polymer molar mass in the polar solvents acetonitrile and DMF using a dithiobenzoate CTA. A better control using the same CTA was observed in 1,4-dioxane. Polymerizations carried out in the presence of a trithiocarbonate CTA were less affected by the solvent polarity and a good control on the polymer molar mass was achieved in acetonitrile and 1,4-dioxane even at high monomer conversion (>95%, dispersity value (Ð) ≤ 1.19).

Caspofungin Functionalized Polymethacrylates with Antifungal Properties.

We describe the synthesis of hydrophilic poly(poly(ethylene glycol) methyl ether methacrylate) (PmPEGMA) and hydrophobic poly(methyl methacrylate) (PMMA) caspofungin conjugates by a post-polymerization modification of copolymers containing 10 mol % pentafluorophenyl methacrylate (PFPMA), which were obtained via reversible addition-fragmentation chain transfer copolymerization. The coupling of the clinically used antifungal caspofungin was confirmed and quantified in detail by a combination of 1H-, 19F- and diffusion-ordered NMR spectroscopy, UV-vis spectroscopy, and size exclusion chromatography. The trifunctional amine-containing antifungal was attached via several amide bonds to the hydrophobic PMMA, but sterical hindrance induced by the mPEGMA side chains prohibited intramolecular double functionalization. Both polymer-drug conjugates revealed activity against important human-pathogenic fungi, that is, two strains of Aspergillus fumigatus and one strain of Candida albicans (2.5 mg L-1 < MEC < 8 mg L-1, MIC50 = 4 mg L-1), whereas RAW 264.7 macrophages as well as HeLa cells remained unaffected at these concentrations.

Post-polymerization modification of polymeric active esters towards TEMPO containing polymers: A systematic study

Organic radical batteries (ORB) are a novel promising class for energy storage, particularly featuring a fast charging capability and extraordinary cycle life. The representative polymer, i.e. poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl methacrylate) (PTMA), is usually synthesized by a post-polymerization oxidation method. As an alternate strategy for developing TEMPO-containing polymers, we focused on the post-polymerization modification of poly(pentafluorophenyl acrylate) and poly(pentafluorophenyl methacrylate) with three different TEMPO nucleophiles by transesterification or amidation reactions. Optimizing the conditions of the post-polymerization functionalization reaction by varying different parameters, such as the type of nucleophile, catalyst and solvent, the feeding ratios of catalysts and nucleophiles, along with reaction time and temperatures, resulted in structurally distinct TEMPO containing polymers with varying backbone composition. Intriguingly, poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl acrylamide) revealed the highest degree functionalization with TEMPO (96.2%) within 3 hrs. under considerably mild conditions, while poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl methylmethacrylamide) exhibited the lowest TEMPO content owing to the steric hindrance from methyl group on both the methacrylate chain and the TEMPO derivative. All other four TEMPO containing polymers had a radical content similar to PTMA (66.6%) synthesized by the post-oxidation methodology. Noteworthy, compared to TEA (trimethylamine), DMAP (4-dimethylaminopyridine) facilitated an efficient ester bond cleavage independent of the polymer precursor, thus, side reactions such as hydrolysis were increased. Though hydrolysis side reaction occurred, the resulting carboxylic acid group was proven to accelerate ion transfer in a certain way during the redox process. Furthermore, due to the higher TEMPO content, poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl acrylamide) exhibited a 12–22 mAh/g higher specific capacity compared to the PTMA-oxidation when running at 5C for 500 cycles.

Biomimetic Asymmetric Polymer Brush Coatings Bearing Fencelike Conformation Exhibit Superior Protection and Antifouling Performance.

Antifouling surfaces with optimized conformation and compositional heterogeneities are presented with the goal of improving the efficacy of surface protection. The approach exploits the adhesive group (thiol or catechol chain end) to anchor asymmetric polymer brushes (APBs) bearing amphiphilic side chains with synergistic nonfouling and fouling-release abilities onto the surface. The conformation of the APB surface is close to the fencelike structure, which mimics lubricating protein lubricin, endowing the surface with capacity of enhanced protection and antiadhesivity, even facing the high compression of fouling. By utilizing a poly(Br-acrylate-alkyne) macroagent comprising alkynyl and 2-bromopropionate groups, we prepared a series of APB surfaces based on polyacrylate-g-poly(ethylene oxide)/poly(pentafluorophenyl methacrylate) (PA-g-PEO/PPFMA) APBs to explore the influence of the content of the fluorinated segment and bioinspired topological polymer chemistry on their antifouling performance. The APB surfaces can not only provide compositional heterogeneities of PEO and fluorinated segments in each side chain but also give a high surface coverage because of the characteristic of high grafting density of macromolecular brushes. It was found for the first time, as far as we are aware, the fencelike APB surface shows excellent antifouling performance with less protein adsorption (up to 91% off) and cell adhesion (up to 84% off) in comparison with the controlled substrate under relatively long incubation time.

Copolymerization of Pentafluorophenylmethacrylate with Hydrophilic Methacrylamide Monomers Induces Premature Hydrolytic Cleavage.

Active ester polymers are commonly used for fast development of novel polymer libraries, but they require post-polymerization modification, which is not atom-efficient or economical. In order to more efficiently produce 2-hydroxypropyl methacrylamide (HPMAm) libraries, it would be advantageous to perform a direct copolymerization with active ester monomers. In this work, the synthesis of copolymer libraries of pentafluorophenyl methacrylate (PFPMA) and the hydrophilic monomer HPMAm is investigated. Surprisingly, HPMAm induces premature hydrolytic cleavage of PFPMA, which occurs during polymerization and depends on the HPMAm/PFPMA feed ratio. Copolymerization of PFPMA with N-isopropylmethacrylamide and the methacrylate monomers 2-hydroxypropylmethacrylate and N-isopropylmethacrylate reveals that the hydrolytic cleavage is promoted by copolymerization with methacrylamides only. By switching from a thermal- to a light-based initiator and lowering the reaction temperature, premature hydrolytic cleavage of PFPMA is avoided and allows direct copolymerization of HPMAm together with PFPMA to create polymer libraries for biomaterial screening.

Improving linking interface between collagen-based hydrogels and bone-like substrates

Regenerative medicine requires the use of heterogeneous scaffolds when the tissue that needs to be repaired presents a gradient in its properties and cannot be replaced by a homogeneous graft. Then, an intimate contact between the different layers is critical to guarantee the optimal performance of the construct. This work presents a procedure that allows the immobilization of collagen-based hydrogels by self-assembly onto any desired substrate, by means of a pentafluorophenyl methacrylate (PFM) coating obtained by plasma enhanced chemical vapor deposition and a collagen monolayer. The latter is attached onto the PFM-coated substrate thanks to its high reactivity towards amines and it will act as anchoring point for the subsequent collagen fibrillation and hydrogel formation. The interaction between collagen and PFM-coated substrates has been evaluated using the quartz crystal microbalance with dissipation (QCM-D) technique. In addition, QCM-D has been used to design and monitor the collagen fibril formation process. A correlation between QCM-D data and optical microscopy has been established, and fibril formation has been confirmed by atomic force microscopy (AFM).

Facile and efficient Cu(0)-mediated radical polymerisation of pentafluorophenyl methacrylate grafting from poly(ethylene terephthalate) film

Grafting polymers bearing active esters, especially pentafluorophenyl methacrylate (PFPMA), onto or from surface is a promising approach towards the preparation of highly functional materials due to the ease in post-polymerisation modification of their corresponding polymers. Herein, a handy and efficient chemical modification process is proposed to modify extreme surface of poly(ethylene terephthalate) (PET) films towards the final purpose of grafting PFPMA polymer from PET surface via surface-initiated Cu(0)-mediated radical polymerisation. The characteristics of modified surface were evaluated after each step using various techniques including water contact angle, attenuated total reflectance Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy, and scanning electron spectroscopy. Due to its robust conditions, the proposed approach allows grafting at ease PFPMA polymer from PET supporting surface, which not only enhances the reactivity of this inert material but also improves significantly the hydrophobicity of the surface.