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Materials Horizons Oct 2022Post-polymerisation functionalisation provides a facile and efficient way for the introduction of functional groups on the backbone of conjugated polymers. Using... (Review)
Review
Post-polymerisation functionalisation provides a facile and efficient way for the introduction of functional groups on the backbone of conjugated polymers. Using post-polymerisation functionalisation approaches, the polymer chain length is usually not affected, meaning that the resulting polymers only differ in their attached functional groups or side chains, which makes them particularly interesting for investigating the influence of the different groups on the polymer properties. For such functionalisations, highly efficient and selective reactions are needed to avoid the formation of complex mixtures or permanent defects in the polymer backbone. A variety of suitable synthetic approaches and reactions that fulfil these criteria have been identified and reported. In this review, a thorough overview is given of the post-polymerisation functionalisations reported to date, with the methods grouped based on the type of reaction used: cycloaddition, oxidation/reduction, nucleophilic aromatic substitution, or halogenation and subsequent cross-coupling reaction. Instead of modifications on the aliphatic side chains of the conjugated polymers, we focus on modifications directly on the conjugated backbones, as these have the most pronounced effect on the optical and electronic properties. Some of the discussed materials have been used in applications, ranging from solar cells to bioelectronics. By providing an overview of this versatile and expanding field for the first time, we showcase post-polymerisation functionalisation as an exciting pathway for the creation of new conjugated materials for a range of applications.
Topics: Polymers; Polymerization; Electronics
PubMed: 35983884
DOI: 10.1039/d2mh00519k -
Sensors (Basel, Switzerland) Jun 2022Scientific injection molding technologies involve the integration and collaboration of cyber-physical systems and smart manufacturing. In order to achieve adaptive...
Scientific injection molding technologies involve the integration and collaboration of cyber-physical systems and smart manufacturing. In order to achieve adaptive process control and production optimization, injection molding systems with real-time sensing have gradually become the development- and application-trend of smart injection molding. At the same time, this technology is a highly non-linear process in which many factors affect the product quality during long-run fabrication processes. Therefore, in order to grasp changes in the characteristics of plastic materials and product quality monitoring, the injection process has become an important research topic. We installed sensors in the molding machine (injection barrel, nozzle, and mold-cavity) to collect the melting pressure and used different materials (semi-crystalline and amorphous polymer; the melting-fill-index (MFI) is unified to 14.5 ± 0.5 g/10 min) to explore the influences of melting pressure variation and its viscosity index on the quality characteristics of molded products. The experiment reveals that a combination of barrel, nozzle, and mold-cavity sensing on the melt-pressure trend-based injection process-control incorporated with viscosity index monitoring can confirm the weight and shrinkage variation of the injection product. At the same time, the pressure and viscosity index value measured and calculated during the melt-filling of two materials with similar MI resulted in significant variations in the amorphous polymer. This study showed the possibility of mastering and controlling the rheology (barrel position) and shrinkage properties of polymers and successful application in various product-quality monitoring platforms.
Topics: Polymers; Rheology; Viscosity
PubMed: 35808288
DOI: 10.3390/s22134792 -
The Journal of Chemical Physics Mar 2022Many macromolecules of biological and technological interest are both chiral and semi-flexible. DNA and collagen are good examples. Such molecules often form chiral...
Many macromolecules of biological and technological interest are both chiral and semi-flexible. DNA and collagen are good examples. Such molecules often form chiral nematic (or cholesteric) phases, as is well-documented in collagen and chitin. This work presents a method for studying cholesteric phases in the highly successful self-consistent field theory of worm-like chains, offering a new way of studying many biologically relevant molecules. The method involves an effective Hamiltonian with a chiral term inspired by the Oseen-Frank (OF) model of liquid crystals. This method is then used to examine the formation of cholesteric phases in chiral-nematic worm-like chains as a function of polymer flexibility, as well as the optimal cholesteric pitch and distribution of polymer segment orientations. Our approach not only allows for the determination of the isotropic-cholesteric transition and segment distributions, beyond what the OF model promises, but also explicitly incorporates polymer flexibility into the study of the cholesteric phase, offering a more complete understanding of the behavior of semiflexible chiral-nematic polymers.
Topics: DNA; Liquid Crystals; Polymers
PubMed: 35317576
DOI: 10.1063/5.0078937 -
Molecules (Basel, Switzerland) Mar 2021Atmospheric plasma treatment is an effective and economical surface treatment technique. The main advantage of this technique is that the bulk properties of the material... (Review)
Review
Atmospheric plasma treatment is an effective and economical surface treatment technique. The main advantage of this technique is that the bulk properties of the material remain unchanged while the surface properties and biocompatibility are enhanced. Polymers are used in many biomedical applications; such as implants, because of their variable bulk properties. On the other hand, their surface properties are inadequate which demands certain surface treatments including atmospheric pressure plasma treatment. In biomedical applications, surface treatment is important to promote good cell adhesion, proliferation, and growth. This article aim is to give an overview of different atmospheric pressure plasma treatments of polymer surface, and their influence on cell-material interaction with different cell lines.
Topics: Animals; Atmospheric Pressure; Biocompatible Materials; Cell Adhesion; Cell Culture Techniques; Cell Line; Humans; Plasma Gases; Polymers; Surface Properties
PubMed: 33802663
DOI: 10.3390/molecules26061665 -
Molecules (Basel, Switzerland) Feb 2018Precise structure-property relation of a biodegradable polymer (e.g., aliphatic polyester) is anticipated only if monomer units and chiral centers are arranged in a... (Review)
Review
Precise structure-property relation of a biodegradable polymer (e.g., aliphatic polyester) is anticipated only if monomer units and chiral centers are arranged in a defined primary sequence as a biomacromolecule. An emerging synthetic methodology, namely segmer assembly polymerization (SAP), is introduced in this paper to reveal the latest progress in polyester synthesis. Almost any periodic polyester envisioned can be synthesized via SAP using a programed linear or cyclic monomer. In this context, the macroscopic properties of a biodegradable polymer are fundamentally determined by microstructural information through a bottom-up approach. It can be highlighted that SAP ideally combines the precision of organic synthesis and the high efficiency of a polymerization reaction. Previously reported strategies including nucleophilic displacement, polyesterification, cross-metathesis polymerization (CMP), ring-opening polymerization (ROP), ring-opening metathesis polymerization (ROMP) and entropy-driven ring-opening metathesis polymerization (ED-ROMP) are critically reviewed in this paper to shed light on precision synthesis of aliphatic polyesters via SAP. Emerging yet challenging, SAP is a paradigm which reflects the convergence of organic and polymer chemistries and is also an efficient pathway to microstructural control. The current status, future challenges and promising trends in this realm are analyzed and discussed in this overview of the state-of-the-art.
Topics: Biodegradable Plastics; Catalysis; Lactones; Polyesters; Polymerization; Polymers; Structure-Activity Relationship
PubMed: 29463013
DOI: 10.3390/molecules23020452 -
Advanced Drug Delivery Reviews Aug 2015RAFT- mediated polymerization, providing control over polymer length and architecture as well as facilitating post polymerization modification of end groups, has been... (Review)
Review
RAFT- mediated polymerization, providing control over polymer length and architecture as well as facilitating post polymerization modification of end groups, has been applied to virtually every facet of biomedical materials research. RAFT polymers have seen particularly extensive use in drug delivery research. Facile generation of functional and telechelic polymers permits straightforward conjugation to many therapeutic compounds while synthesis of amphiphilic block copolymers via RAFT allows for the generation of self-assembled structures capable of carrying therapeutic payloads. With the large and growing body of literature employing RAFT polymers as drug delivery aids and vehicles, concern over the potential toxicity of RAFT derived polymers has been raised. While literature exploring this complication is relatively limited, the emerging consensus may be summed up in three parts: toxicity of polymers generated with dithiobenzoate RAFT agents is observed at high concentrations but not with polymers generated with trithiocarbonate RAFT agents; even for polymers generated with dithiobenzoate RAFT agents, most reported applications call for concentrations well below the toxicity threshold; and RAFT end-groups may be easily removed via any of a variety of techniques that leave the polymer with no intrinsic toxicity attributable to the mechanism of polymerization. The low toxicity of RAFT-derived polymers and the ability to remove end groups via straightforward and scalable processes make RAFT technology a valuable tool for practically any application in which a polymer of defined molecular weight and architecture is desired.
Topics: Animals; Biocompatible Materials; Drug Delivery Systems; Humans; Molecular Weight; Polymerization; Polymers; Thiones
PubMed: 26050529
DOI: 10.1016/j.addr.2015.05.016 -
Colloids and Surfaces. B, Biointerfaces Feb 2024The covalent functionalization of polymers with fluorinated moieties represents a promising strategy for the development of multimodal systems. Moreover, polymer...
The covalent functionalization of polymers with fluorinated moieties represents a promising strategy for the development of multimodal systems. Moreover, polymer fluorination often endows the resulting nanocarriers with improved colloidal stability in the biological environment. In this work, we developed fluorinated pegylated (PEG) biodegradable poly(ε-caprolactone) (PCL) drug nanocarriers showing both high colloidal stability and stealth properties, as well as being (F)-Nuclear Magnetic Resonance (NMR) detectable. The optimized nanocarriers were obtained mixing a PEG-PCL block copolymer with a nonafluoro-functionalized PCL polymer. The role of PEGylation and fluorination on self-assembly and colloidal behavior of the obtained nanoparticles (NPs) was investigated, as well as their respective role on stealth properties and colloidal stability. To prove the feasibility of the developed NPs as potential F NMR detectable drug delivery systems, a hydrophobic drug was successfully encapsulated, and the maintenance of the relevant F NMR properties evaluated. Drug-loaded fluorinated NPs still retained a sharp and intense F NMR signal and good relaxivity parameters (i.e., T and T relaxation times) in water, which were not impaired by drug encapsulation.
Topics: Polyethylene Glycols; Drug Delivery Systems; Polyesters; Polymers; Drug Carriers; Nanoparticles
PubMed: 38176337
DOI: 10.1016/j.colsurfb.2023.113730 -
Molecules (Basel, Switzerland) Nov 2019This review deals with two overlapping issues, namely polymer chemistry and deep eutectic solvents (DESs). With regard to polymers, specific aspects of synthetic... (Review)
Review
This review deals with two overlapping issues, namely polymer chemistry and deep eutectic solvents (DESs). With regard to polymers, specific aspects of synthetic polymers, polymerization processes producing such polymers, and natural cellulose-based nanopolymers are evaluated. As for DESs, their compliance with green chemistry requirements, their basic properties and involvement in polymer chemistry are discussed. In addition to reviewing the state-of-the-art for selected kinds of polymers, the paper reveals further possibilities in the employment of DESs in polymer chemistry. As an example, the significance of DES polarity and polymer polarity to control polymerization processes, modify polymer properties, and synthesize polymers with a specific structure and behavior, is emphasized.
Topics: Cellulose; Chemistry, Organic; Green Chemistry Technology; Ionic Liquids; Nanostructures; Polymerization; Polymers; Solvents
PubMed: 31684174
DOI: 10.3390/molecules24213978 -
Acta Biomaterialia Feb 2022Conducting polymers (CPs) possess unique electrical and electrochemical properties and hold great potential for different applications in the field of bioelectronics.... (Review)
Review
Conducting polymers (CPs) possess unique electrical and electrochemical properties and hold great potential for different applications in the field of bioelectronics. However, the widespread implementation of CPs in this field has been critically hindered by their poor processibility. There are four key elements that determine the processibility of CPs, which are thermal tunability, chemical stability, solvent compatibility and mechanical robustness. Recent research efforts have focused on enhancing the processibility of these materials through pre- or post-synthesis chemical modifications, the fabrication of CP-based complexes and composites, and the adoption of additive manufacturing techniques. In this review, the physicochemical and structural properties that underlie the performance and processibility of CPs are examined. In addition, current research efforts to overcome technical limitations and broaden the potential applications of CPs in bioelectronics are discussed. STATEMENT OF SIGNIFICANCE: This review details the inherent properties of CPs that have hindered their use in additive manufacturing for the creation of 3D bioelectronics. A fundamental approach is presented with consideration of the chemical structure and how this contributes to their electrical, thermal and mechanical properties. The review then considers how manipulation of these properties has been addressed in the literature including areas where improvements can be made. Finally, the review details the use of CPs in additive manufacturing and the future scope for the use of CPs and their composites in the development of 3D bioelectronics.
Topics: Polymers
PubMed: 34111518
DOI: 10.1016/j.actbio.2021.05.052 -
Molecules (Basel, Switzerland) May 2020Great efforts have been devoted to the invention of environmental sensors as the amount of water pollution has increased in recent decades. Chitosan, cellulose and... (Review)
Review
Great efforts have been devoted to the invention of environmental sensors as the amount of water pollution has increased in recent decades. Chitosan, cellulose and nanocrystalline cellulose are examples of biopolymers that have been intensively studied due to their potential applications, particularly as sensors. Furthermore, the rapid use of conducting polymer materials as a sensing layer in environmental monitoring has also been developed. Thus, the incorporation of biopolymer and conducting polymer materials with various methods has shown promising potential with sensitively and selectively toward heavy metal ions. In this feature paper, selected recent and updated investigations are reviewed on biopolymer and conducting polymer-based materials in sensors aimed at the detection of heavy metal ions by optical methods. This review intends to provide sufficient evidence of the potential of polymer-based materials as sensing layers, and future outlooks are considered in developing surface plasmon resonance as an excellent and valid sensor for heavy metal ion detection.
Topics: Biopolymers; Biosensing Techniques; Chitosan; Environmental Monitoring; Metals, Heavy; Polymers; Surface Plasmon Resonance
PubMed: 32486124
DOI: 10.3390/molecules25112548