Two new photopolymerizable vinyl (2-(allyloxy) 1,4-naphthoquinone, HNQA) and epoxy (2-(oxiran-2yl methoxy) 1,4-naphthoquinone, HNQE) photoinitiators derived from lawsone were designed in this paper. ...These new photoinitiators can be used as one-component photoinitiating systems for the free-radical photopolymerization of acrylate bio-based monomer without the addition of any co-initiators. As highlighted by the electron paramagnetic resonance (EPR) spin-trapping results, the formation of carbon-centered radicals from an intermolecular H abstraction reaction was evidenced and can act as initiating species. Interestingly, the introduction of iodonium salt (Iod) used as a co-initiator has led to (1) the cationic photopolymerization of epoxy monomer with high final conversions and (2) an increase of the rates of free-radical polymerization of the acrylate bio-based monomer; we also demonstrated the concomitant thiol–ene reaction and cationic photopolymerizations of a limonene 1,2 epoxide/thiol blend mixture with the HNQA/Iod photoinitiating system.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Abstract Healthcare‐associated infections remain a significant health concern, particularly with the emergence of antibiotic resistance. While these antibiotics have saved countless lives, their ...overuse reduces their efficacy promoting the emergence of multidrug‐resistant (MDR) bacteria. This prompts researchers to explore new alternatives for treating bacteria proliferation. In this context, antibacterial photodynamic therapy (aPDT) has emerged as a promising approach for treating localized infections. It utilizes reactive oxygen species (ROS) as oxidative stress agents, thereby minimizing the risk of developing MDR. The success of aPDT significantly hinges on the careful selection of photosensitizers (PSs) and polymer matrices for the synthesis of polymer‐based photoactive materials. Various light‐absorbing PSs are therefore designed for enhancing ROS production and antimicrobial efficacy. By incorporating PSs into polymer matrices, these materials can harness the light power to generate ROS, destroying bacterial cells upon irradiation. This review aims to provide a comprehensive overview of advancements in this field, specifically focusing on the use of polymer‐based materials. The mechanism of the four main ROS generated in aPDT, the methods used for their detection, and their mode of action against bacteria has been outlined. The recent improvement in polymer‐based aPDT materials and their antibacterial efficacy have been also addressed.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Cationic photopolymerization is amongst the greenest processes used to obtain polymers since light is abundant, inexpensive and allows for rapid and waste-less curing at room temperature. Moreover, ...in the current search for the reduction of the environmental impacts of polymers, the use of biobased monomers is one of the most crucial stakes. At the crossroads of these domains, biobased monomers photopolymerization offers the best of both. Hence, this review aims at underlying the increasing importance of cationic photopolymerization in combination with bio-based photopolymerizable monomers, and describes the numerous reactive species derived from bioresources that can lead to innovative materials through cationic photopolymerization reactions. This review intends to be a guide to orientate academic teams and industries involved in reducing both environmental impacts and toxicity towards the synthesis of environmentally safe materials. The recent advances on the photochemical systems used, the toxicity of the cationic photoinitiating systems, the reactivity of the new epoxy bio-sourced monomers, their thermomechanical properties as well as the applications of the targeted materials will be described.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A novel anthraquinone-based oxime ester system (AQ-Ox) was successfully synthesized and used as a Type I visible-light photoinitiating system. The introduction of an anthraquinone moiety to the oxime ...ester group makes this system suitable for promoting photopolymerization under visible-light irradiation (LEDs@385, 405 and 455 nm) and allowed us to obtain high final acrylate conversions under laminate and air conditions in the free-radical polymerization (FRP) of an acrylate bio-based monomer. AQ-Ox also demonstrated better photoinitiating properties than commonly used Type I photoinitiators
i.e.
2,2-dimethoxy-2-phenylacetophenone (DMPA) and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO), and allowed the design of 3D objects by 3D photoprinting technology. This is the first example of an anthraquinone based oxime-ester used as a Type I photoinitiator for FRP at
λ
> 405 nm and under air.
An anthraquinone-based oxime ester photoinitiating system as a new Type I photoinitiator for 3D photoprinting under LEDs@405 nm irradiation.
A near‐infrared‐absorbing heptamethine (HM+) incorporating three bulky benzocdindole heterocycles was designed to efficiently prevent self‐aggregation of the dye, which results in a strong ...enhancement of its photoinitiating reactivity as compared to a parent bis‐benzocdindole heptamethine (HMCl+) used as a reference system. In this context, we highlight an efficient free‐radical NIR‐polymerization up to a 100 % acrylates C=C bonds conversion even under air conditions. Such an important initiating performance was obtained by incorporating our NIR‐sensitizer into a three‐component system leading to its self‐regeneration. This original photoredox cycle was thoroughly investigated through the identification of each intermediary species using EPR spectroscopy. In memory of Professor Yusuf Yağci
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
A near-infrared-absorbing heptamethine (HM+) incorporating three bulky benzocdindole heterocycles was designed to efficiently prevent self-aggregation of the dye, which results in a strong ...enhancement of its photoinitiating reactivity as compared to a parent bis-benzocdindole heptamethine (HMCl+) used as a reference system. In this context, we highlight an efficient free-radical NIR-polymerization up to a 100% acrylates C=C bonds conversion even under air conditions. Such an important initiating performance was obtained by incorporating our NIR-sensitizer into a three-component system leading to its self-regeneration. This original photoredox cycle was thoroughly investigated through the identification of each intermediary species using EPR spectroscopy.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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•New visible-light epoxy-based alizarin photosensitizer for the cationic polymerization of epoxidized eugenol monomers.•Eugenol-based photoinduced materials with tremendous ...antibacterial properties.•New photoactivable bio-based materials for antibacterial applications.
We report herein the design of a new visible-light epoxy-based alizarin photosensitizer (AE) of iodonium salt (Iod) for the cationic polymerization (CP) of epoxidized eugenol monomers under visible-light irradiation. The combination of AE and Iod demonstrates highly efficient photoinitiating properties under air. As highlighted by fluorescence, laser flash photolysis (LFP) and electron paramagnetic resonance spin-trapping (ESR ST) experiments, AE acts as an electron donating molecule, and reacts with Iod under light exposure through its excited singlet and triplet states via a photoinduced electron transfer reaction, producing thus protonic acids, H+, able to initiate CP. Also, we demonstrate by EPR ST that the addition of diepoxy eugenol monomer may lead to the formation of reactive radical species which may be oxidized by Iod to form cationic species. Thus, new bio-based and photoactivable materials were designed by cationic photopolymerization with the use of alizarin-based photosensitizer and eugenol derived monomers. By tuning the weight proportion of eugenol derived epoxy monomers (mono- (EE) and di-epoxidized (EdE) eugenol), we can modulate the thermal and mechanical properties of the resulting materials. The new AE-based materials have demonstrated two interesting properties: first, the presence of EE in the polymer network has considerably decreased the number of colony forming units (CFUs) at the surface of materials whatever the bacterial strains used, and these samples demonstrate photoactivable properties as they produce, under visible-light irradiation, singlet oxygen, a biocide agent against bacteria. Interestingly, the irradiation of the AE/Iod/EE(50)/EdE(50) materials lead to a tremendous decrease of the number of E. coli and S. aureus CFUs at their surface. A reduction by 100% of the bacterial adhesion is observed upon visible-light exposure.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract
A near‐infrared‐absorbing heptamethine (
HM
+
) incorporating three bulky benzo
cd
indole heterocycles was designed to efficiently prevent self‐aggregation of the dye, which results in a ...strong enhancement of its photoinitiating reactivity as compared to a parent bis‐benzo
cd
indole heptamethine (
HMCl
+
) used as a reference system. In this context, we highlight an efficient free‐radical NIR‐polymerization up to a 100 % acrylates C=C bonds conversion even under air conditions. Such an important initiating performance was obtained by incorporating our NIR‐sensitizer into a three‐component system leading to its self‐regeneration. This original photoredox cycle was thoroughly investigated through the identification of each intermediary species using EPR spectroscopy.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
A near‐infrared‐absorbing heptamethine (HM+) incorporating three bulky benzocdindole heterocycles was designed to efficiently prevent self‐aggregation of the dye, which results in a strong ...enhancement of its photoinitiating reactivity as compared to a parent bis‐benzocdindole heptamethine (HMCl+) used as a reference system. In this context, we highlight an efficient free‐radical NIR‐polymerization up to a 100 % acrylates C=C bonds conversion even under air conditions. Such an important initiating performance was obtained by incorporating our NIR‐sensitizer into a three‐component system leading to its self‐regeneration. This original photoredox cycle was thoroughly investigated through the identification of each intermediary species using EPR spectroscopy.In memory of Professor Yusuf Yağci
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
To fight nosocomial infections, the excessive use of antibiotics has led to the emergence of multidrug-resistant microorganisms, which are now considered a relevant public health threat by the World ...Health Organization. To date, most antibacterial systems are based on the use of petro-sourced polymers, but the global supplies of these resources are depleting. Besides, silver NPs are widely accepted as the most active biocide against a wide range of bacterial strains but their toxicity is an issue. The growing interest in natural products has gained increasing interest in the last decade. Therefore, the design of functional antibacterial materials derived from biomass remains a significant challenge for the scientific community. Consequently, attention has shifted to naturally occurring substances such as essential oils (EOs), which are classified as Generally Recognized as Safe (GRAS). EOs can offer an alternative to the common antimicrobial agents as an inner solution or biocide agent to inhibit the resistance mechanism. Herein, this review not only aims at providing developments in the antibacterial modes of action of EOs against various bacterial strains and the recent advances in genomic and proteomic techniques for the elucidation of these mechanisms but also presents examples of biobased polymer resource-based EO materials and their antibacterial activities. Especially, we describe the antibacterial properties of biobased polymers,
e.g.
cellulose, starch, chitosan, PLA PHAs and proteins, associated with EOs (cinnamon (CEO), clove (CLEO), bergamot (BEO), ginger (GEO), lemongrass (LEO), caraway (CAEO), rosemary (REO),
Eucalyptus globulus
(EGEO), tea tree (TTEO), orange peel (OPEO) and apricot (
Prunus armeniaca
) kernel (AKEO) essential oils). Finally, we discuss the influence of EOs on the mechanical strength of bio-based materials.
Essential oils (EOs) can act as natural biocide agents when introduced in renewable/bio-based polymers. The nature of EOs influences the mechanical properties and the antibacterial activities of the final bio-based materials.
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