Polymer Modification Research Articles

Highly Selective Ethylene/Ethane Separation in MOF Composites through Pore Contraction and Particle Size Enlargement Strategy.

The discrimination of ethylene (C2H4) and ethane (C2H6) by the precise regulation of porous materials is important and challenging. In this work, the quasi-exclusion of C2H6 from C2H4 is realized through a facile polymer modification and shaping method of metal-organic framework ZnAtzPO4 (Atz = 3-amino-1,2,4-triazole). The polymer (carboxymethyl cellulose, CMC) modification and shaping of ZnAtzPO4@CMC result in pore contraction and particle size enlargement, which impedes the diffusion of larger C2H6 molecules and improves the kinetic separation of C2H4/C2H6. The C2H6 capacity decreases steeply from 1.63 (ZnAtzPO4 powder) to 0.27 mmolg-1 (ZnAtzPO4@CMC), and the resulting C2H4/C2H6 uptake ratio increases from 1.38 to 6.67. Kinetic adsorption experiments confirm that ZnAtzPO4@CMC presents a negligible C2H6 dynamic capacity and the diffusion difference between C2H4 and C2H6 is amplified significantly. The corresponding kinetic C2H4/C2H6 separation selectivity of ZnAtzPO4@CMC increases from 13.06 (ZnAtzPO4) to 34.67, superior to the most reported benchmark materials. Furthermore, ZnAtzPO4@CMC exhibits excellent breakthrough performance for equimolar C2H4/C2H6 mixture separation. This study provides guidance to discriminate similar gases through polymer modification of MOFs.

Synthesis of MWCNTs for successive polymeric and nano modification of a Nigerian bitumen, optimization using response surface methodology

Synthesis of MWCNTs for successive polymeric and nano modification of a Nigerian bitumen, optimization using response surface methodology

Transforming Polymers: Innovative Physical and Chemical Modification Techniques for Advanced Functional Applications

Abstract: Polymer modification encompasses a diverse array of techniques aimed at enhancing the physical and chemical properties of polymers, thereby expanding their applicability across various fields. Physical modification methods include self-assembled monolayers, radiation-induced surface modifications, UV irradiation, γ-irradiation, and laser-induced surface modifications. These techniques primarily focus on altering surface properties and enhancing characteristics such as strength, toughness, and thermal stability through non-chemical means. Chemical modification methods, on the other hand, involve reactions that change the polymer’s chemical structure. Common chemical reactions used in polymer modification include PEGylation, conjugation, wet chemical oxidation treatments, and plasma treatments. These processes introduce new functional groups, improve compatibility with other materials, and tailor properties like solubility, adhesion, and biodegradability. Despite the significant advancements in polymer modification techniques, challenges such as maintaining polymer integrity, controlling modification precision, and ensuring scalability persist. This review provides a comprehensive overview of both physical and chemical polymer modification methods, discussing their mechanisms, applications, and the challenges involved, thereby highlighting their critical role in the development of advanced materials for industrial, biomedical, and environmental applications.

Sialic Acid-Modified NIR-II Fluorophore with Enhanced Brightness and Photoconversion Capability for Targeted Lymphoma Phototheranostics.

Lymphoma is a malignant cancer characterized by a rapidly increasing incidence, complex etiology, and lack of obvious early symptoms. Efficient theranostics of lymphoma is of great significance in improving patient outcomes, empowering informed decision-making, and driving medical innovation. Herein, we developed a multifunctional nanoplatform for precise optical imaging and therapy of lymphoma based on a new photosensitizer (1-oxo-1H-benzoo[de]anthracene-2,3-dicarbonitrile-triphenylamine (OBADC-TPA)). OBADC-TPA is a donor-acceptor (D-A) molecule characterized by a novel small coplanar and strong electron-withdrawing acceptor skeleton, while the OBADC moiety facilitates strong intramolecular charge transfer. OBADC-TPA-based nanoparticles (NPs) were prepared through encapsulation with an amphiphilic polymer and subsequent modification with sialic acid (SA). Both in vitro and in vivo studies demonstrated that NPs-SA possessed good biocompatibility, effective tumor accumulation, high photoacoustic (PA) contrast, bright second near-infrared (NIR-II) fluorescence emission, and efficient photothermal/photodynamic conversion capabilities, which can serve as a multifunctional nanocomposite for targeted PA/NIR-II fluorescence imaging-guided synergistic type I/II photodynamic and photothermal therapy (PDT/PTT) of lymphoma. This work not only provides a new NIR-II fluorophore with a novel acceptor moiety but also offers a new, accurate, and effective approach for the targeted diagnosis and treatment of lymphoma, holding promising prospects for clinical application.

Emerging trends in designing polysaccharide based mucoadhesive network hydrogels as versatile platforms for innovative delivery of therapeutic agents: A review.

The rapid progress in polymer science has designed innovative materials for biomedical applications. In the case of drug design, for each new therapeutic agent, a drug delivery system (DDS) is required to improve its pharmacokinetic and pharmacodynamic parameters. Therefore, significant research has been carried out to develop drug delivery (DD) carriers for these new therapeutic agents. Hydrogels have been explored as potential candidates to prepare controlled drug delivery (CDD) systems to address the challenges related to the performance of the conventional DD formulations. Mucoadhesive drug delivery system (MUCO-DDS) is a specialized form of CDD system, facilitating site-specific DD, protecting the drug from first pass metabolism and enhancing its overall bioavailability. The present article provides a comprehensive discussion of the synthesis, properties and applications of polysaccharide-derived MUCO-DDS. Different natural polymer-derived MUCO-DDS including chitosan, alginate, pectin, xanthan gum, psyllium, gelatin, cellulose, hyaluronic acid, guar gum, sterculia gum and tragacanth gum have been reported. Herein, these DDS were elaborately discussed along with their applications and future-prospective. These DDS are classified on the basis of drug administration (nasal, ocular, vagina/rectal & buccal DDS) and drug distribution (reservoir and monolithic polymer matrix). Factors contributing to modifications of properties of MUCO-DDS were also demonstrated along with different stages and theories of mucoadhesion. Polysaccharides exhibit properties such as biocompatibility, biodegradability, and flexibility, making them ideal for CDD applications. MUCO-DDS demonstrates several significant advantages. Moreover, the article bridges theoretical insights with practical applications and future research prospects, ensuring its relevance for advancements in the concerned field. This review serves as a comprehensive resource, addressing gaps in previous literature and paving the way for innovations in MUCO-DDS, through a comparative analysis of the advantages, limitations, and modifications of natural polymers. In conclusion, this review gives an overview of the current developments in the field of mucoadhesive DD systems and also gives insights into the future perspectives. The MUCOAD of DDS could be modulated by the inclusion of various natural and synthetic components in hydrogels. Future directions for the researchers are underway to integrate nanotechnology with mucoadhesive systems to create hybrid platforms. Overall, by addressing current limitations and leveraging emerging technologies, these systems can revolutionize drug delivery for a wide range of therapeutic applications.

Amphiphilic polymer modification of graphene oxide (AGO) to enhance the barrier and corrosion protection properties of waterborne polyurethane coatings

Amphiphilic polymer modification of graphene oxide (AGO) to enhance the barrier and corrosion protection properties of waterborne polyurethane coatings

Simultaneous Toughening and Strengthening of Ductile Polymer by Rigid Polymeric Fillers: The Role of Interfacial Entanglement.

The modification of thermoplastic polymers is frequently impeded by the inherent contradiction between their toughness and strength. In this study, an effective strategy to significantly improve the mechanical properties of ductile polymers by simply adding a complimentary rigid polymer is introduced. This work uses a semi-crystalline polymer aliphatic polyketone (POK) as the matrix material and a small quantity of polymethyl methacrylate (PMMA) as the rigid polymer, through establishing molecular chain entanglements at the interface to produce POK/PMMA blends with exceptional mechanical property. The experimental study shows that PMMA as a small island phase is homogeneously dispersed in the POK matrix, while the interfacial adhesion between the POK matrix and PMMA island is enhanced by the high-density molecular chain entanglement between PMMA and the POK matrix. The strong entanglements and high concentration of PMMA domains promote uniform crazes and overall shear yielding. As a result, the POK/PMMA blend exhibits exceptional mechanical properties with notched impact strength, elongation at break, tensile strength, and Young's modulus, of 20kJm-2, 326%, 60 and 2185MPa, respectively. A universal approach is further suggested for enhancing the toughness and strength of ductile polymers using a complimentary rigid polymer.

Finite element modelling and indirect tensile strength of SBS and CR modified asphalt mixtures

Different modifications in asphalt mixtures can be employed to improve the performance of asphalt pavements in terms of rutting and fatigue damage resistance enhancement. Performance of asphalt mixtures can be further enhanced with the use of different proportions of modifiers added to bitumen, however the optimum proportion of the modifiers added require further experimentation in terms of indirect tensile strength of asphalt mixtures. This research consists of selection of different proportions of Polymer (SBS—Styrene Butadiene Styrene) and CR (Crumb Rubber) modifiers, that have been used in various amounts at 7% CR, 15% CR, 20% CR, 4% SBS, 7% SBS to base bitumen and the performance has been compared with base asphalt mixture. Indirect tensile strength for each mixtures type has been evaluated in the lab with varying rise time. Furthermore, stiffness moduli of each mixture have been evaluated at four different frequency values of 1.2 Hz, 1.9 Hz, 3.5 Hz and 5 Hz at 20 °C.Moreover, tensile strength for each mixture type and its progression with varying loading rates from 10 MPa/s to 70 MPa/s has been evaluated. A 2D finite element software, ABAQUS has been used to perform microstrain analysis for each mixture type. Fatigue and rutting damage models have been used to evaluate performance of each mixture type. Results show superior performance of SBS-7 and CR-20 mixtures in terms of rutting and fatigue damage resistance when compared to base asphalt. SBS-7 and CR-20 show 28% better performance in terms of fatigue damage resistance when compared to base asphalt. SBS-7 outperforms CR-20 in terms of rutting resistance by 22%.

The Application and Properties of Impermeable Materials in Solid Waste Treatment at Red Mud Yard

Red muds pose a significant risk of environmental contamination, particularly through soil and groundwater pollution during their storage. While sodium bentonite geosynthetic clay liners (NaB GCL) have traditionally been employed extensively in red mud storage facilities, their inherent chemical sensitivity has constrained their longevity and effectiveness as a reliable barrier. This review zeroes in on the application and performance of polymer-modified bentonite geosynthetic clay liners (BPC GCL) within the context of red mud storage. The polymer modification process endows BPC GCL with a significantly reduced permeability coefficient and bolsters its chemical resistance. By subjecting BPC GCL to rigorous testing for chemical compatibility and permeability, we have been able to evaluate its efficacy in terms of impermeable and anti-fouling properties within red mud storage environments.

In-situ modification of wood polymer via impregnation with ultra-low molar ratio urea-formaldehyde resins

In-situ modification of wood polymer via impregnation with ultra-low molar ratio urea-formaldehyde resins

Orderly Arranged Cubic Quantum Dots along Supramolecular Templates of Naphthalenediimide Aggregates.

Precise control of assembled structures of quantum dots (QDs) is crucial for realizing the desired photophysical properties, but this remains challenging. Especially, the one-dimensional (1D) control is rare due to the nearly isotropic nature of QDs. Herein, we propose a novel strategy for controlling the 1D-arrangement range of cubic perovskite QDs in solution based on the morphological modification of a supramolecular polymer (SP) template. The original template with a short and tangled fibrous structure is prepared in a low-polarity solvent mixture via self-assembly of a naphthalenediimide-functionalized cholesterol derivative with an adhesion group for QDs. Mixing this template with QDs leads to the co-aggregation into short-range 1D-arrays of QDs on the templates. Notably, subsequent heating and cooling of the co-aggregate solution forms longer-range 1D-arrays of QDs with lateral growth, where arranged QDs are sandwiched between reconstructed SP templates. Furthermore, the longer-range 1D-array of QDs is achieved via an alternative route involving the pre-organization of templates into longer and dispersed fibers by heating and cooling of the original template, succeeded by co-assembly with QDs. Finally, we reveal continuous fluorescence resonance energy transfer between 1D-arranged QDs by an in-depth analysis of the photoluminescence decay curves.

Oxygen, light, and mechanical force mediated radical polymerization toward precision polymer synthesis.

The synthesis of polymers with well-defined composition, architecture, and functionality has long been a focal area of research in the field of polymer chemistry. The advancement of controlled radical polymerization (CRP) has facilitated the synthesis of precise polymers, which are endowed with new properties and functionalities, thereby exhibiting a wide range of applications. However, radical polymerization faces several challenges, such as oxygen intolerance, and common thermal initiation methods may lead to side reactions and depolymerization. Therefore, we have developed some oxygen-tolerant systems that directly utilize oxygen for initiating and regulating polymerization. We utilize oxygen/alkylborane as an effective radical initiator system in the polymerization, and also as a reductant for the removal of polymer chain ends. Moreover, we employ the gentler photoinduced CRP to circumvent side reactions caused by high temperatures and achieve temporal and spatial control over the polymerization. To enhance the penetration of the light source for polymerization, we have developed near-infrared light-induced atom transfer radical polymerization. Additionally, we have extended photochemistry to reversible addition-fragmentation chain transfer polymerization involving ion-pair inner-sphere electron transfer mechanism, metal-free radical hydrosilylation polymerization, as well as carbene-mediated polymer modification through C-H activation and insertion mechanisms. Furthermore, we propose a new method for polymerization initiation synergistically triggered by oxygen and mechanical energy. This review not only showcases the current advancements in CRP but also outlines future directions, such as the potential for 3D printing and surface coatings, and the exploration of new heteroatom radical polymerizations. By expanding the boundaries of polymer synthesis, these innovations could lead to the creation of new materials with enhanced functionality and applications.

Fabrication of phospholipid polymer-modified alginate hydrogels for bioartificial pancreas.

The bioartificial pancreas, composed of a semi-permeable hydrogel encapsulating insulin-secreting cells, has attracted attention as a treatment for type 1 diabetes. In this study, we developed phospholipid polymer-modified alginate hydrogel beads that encapsulated spheroids of the pancreatic beta cell line MIN6. The hydrogel beads were composed of methacrylated alginic acid, which enabled both ionic and covalent cross-linking, resulting in a hydrogel that was more stable than conventional alginate hydrogels. Furthermore, modification of biocompatible 2-methacryloyloxyethyl phosphorylcholine (MPC) polymers suppressed protein adsorption to the hydrogel beads. Hydrogel beads encapsulating MIN6 spheroids maintained the cell viability and insulin secretion ability in response to glucose levels invitro. Allogenic transplantation of gel beads lowered blood glucose levels in diabetic mice for 30 days, whereas gel beads without MPC polymer modification failed to regulate blood glucose levels. These results indicate that MPC polymer modification of hydrogels provides a new strategy for the fabrication of functional bioartificial pancreas and transplantable biomaterials for cell therapies.

Toward improved antifouling properties and monovalent anion selectivity of anion exchange membrane via interfacial polymerization modification

Toward improved antifouling properties and monovalent anion selectivity of anion exchange membrane via interfacial polymerization modification

Chemical Modification of Acrylonitrile-Divinylbenzene Polymer Supports with Aminophosphonate Groups and Their Antibacterial Activity Testing.

Bacterial contamination is a major public health concern on a global scale. Treatment resistance in bacterial infections is becoming a significant problem that requires solutions. We were interested in obtaining new polymeric functionalized compounds with antibacterial properties. Three components (polymeric amine, aldehyde, and phosphite) were used in the paper in a modified "one-pot" Kabachnik-Fields reaction, in tetrahydrofuran at 60 °C, to create the N-C-P skeleton in aminophosphonate groups. Two copolymers were thus prepared starting from an acrylonitriledivinylbenzene (AN-15%DVB) copolymer containing pendant primary amine groups modified by grafting aminophosphonate groups, i.e., aminobenzylphosphonate (Bz-DVB-AN) and aminoethylphosphonate (Et-DVB-AN). The two copolymers were characterized by FT-IR spectroscopy, SEM-EDX, TGA, and antibacterial properties. It was shown that the novel products have antibacterial qualities against S. aureus and E. coli bacteria. The sample with the strongest antibacterial activity was Et-DVB-AN. We assessed how well the Weibull model and the first-order kinetic model represent the inactivation of microbial cells in our samples. The main advantage of the new antibacterial agents developed in this work is their easy recovery, which helps to avoid environmental contamination.

Preparation of manganese-doped carbon quantum dots@halloysite nanotube composites films for advanced UV shielding properties.

The development of ultraviolet (UV) shielding materials is of great importance to protect human health and prevent the degradation of organic matter. However, the synthesis of highly efficient UV shielding polymer nanocomposites is currently limited by the agglomeration of inorganic anti-UV nanoparticles (NPs) within the polymer matrix and the limited absorption spectrum of UV shielding agents. In this study, highly effective manganese doped carbon quantum dots@halloysite nanotube composites (Mn-CDs@HNTs/PAS) were successfully synthesized by loading manganese-doped carbon quantum dots (Mn-CDs) into UV shielding effective halloysite nanotubes (HNTs) via the solvothermal method, followed by polymerization modification (PAS). The results show that inorganic NPs are evenly dispersed into the polymer matrix. The resulting UV shielding film prepared by mixing Mn-CDs@HNTs/PAS composites with polyvinyl chloride (PVC) shows enhanced UV absorption and thermal stability compared with pure PVC film. It thus appears that Mn-CDs@HNTs/PAS composites have a promising future in UV protection.

Impact of Acetylation, Succinylation, and pH on DNA Packaging in PEI-Based Polyplexes.

Polyethylenimine (PEI) is a widely used cationic polymer for nonviral gene delivery, often modified to enhance transfection efficiency and reduce cytotoxicity. This study investigates how acetylation, succinylation (acPEI and zPEI), and pH influence the internal DNA packaging of polyplexes. Both modifications alter physicochemical properties, leading to complexes that decondense more readily with increasing modification. X-ray scattering reveals that high acetylation produces loosely packed DNA, while succinylation unexpectedly tightens DNA packing at higher modification levels. Polyplexes formed at low pH (pH 4) are more stable and tightly packed than those formed at pH 7.5. Acidifying polyplexes initially formed at pH 7.5 induces structural rearrangement to tighter DNA packing accompanied by significant PEI release, providing direct evidence for models where free PEI aids endosomal escape. These findings challenge conventional assumptions about PEI behavior and offer new insights into DNA packaging, emphasizing tailored polymer modifications and pH conditions to optimize gene delivery.

Innovative Polymer Modifications: Unlocking New Horizons in Drug Delivery Applications

Innovative Polymer Modifications: Unlocking New Horizons in Drug Delivery Applications

Hydroxyl-yne click reaction for facile modification of commercial polyvinyl butyral

Hydroxyl-yne click reaction, the reaction between mainly primary or secondary alcohols and electron-deficient alkynes in the presence of a catalytic amount of base, fulfills many requirements of “click” reactions, such as high efficiency, stereoselectivity, and mild reaction conditions. The reaction has proven to be useful for both small organic molecules and has then gained much popularity in polymer synthesis. In this study, we aimed to investigate the efficiency of hydroxyl-yne click reaction for post-polymerization modification (PPM) of commercial polymers possessing alcohol functionality. Polyvinyl butyral with some degree of free OH units was chosen as the polymer platform and modified with various propiolate esters in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) as the organobase at room temperature in only 5 min, affording vinyl ether pendant polymers only in E-configuration. The modified polymers were obtained in high to quantitative efficiencies and high yields, and their chemical structures were confirmed by several spectroscopic analyses. We believe the presented strategy will extend our knowledge of X-yne click reactions and emerge as a powerful tool for the PPM method.

Building Block for Designing Bright Type I AIE-Active Photosensitizers with Deep/Near-infrared Red Fluorescence.

Bright deep red/near-infrared red (DR/NIR) active type I photosensitizers (PSs) with generating superoxide anion and hydroxyl radical have been regarded as powerful functional materials to fight the "Achilles's heel" of hypoxia from solid tumor. But some problems have still existed, for example, lacking effective molecular designed strategy or typical building block to design precisely type I PSs. In addition, the relationship between fluorescent quantum efficiency and NIR fluorescent color is inconsistent according to energy gap rule. To overcome above mentioned problems, in this work, we propose a typical building block to design precisely type I PSs with DR/NIR fluorescence and high photoluminescent quantum yield at aggregation by combining molecular design of aggregation-induced emission and hybrid locally and charge transfer (HLCT) theory. The synthetic small molecular PSs just produce superoxide anion without any singlet oxygen production, which is ascribed to their lower T1 energy levels to suppress energy transfer from triplet state to oxygen. Two strategies of small molecular structural designing and polymeric nanoparticles modification are utilized to improve efficiency of type I ROS. More interestingly, original small molecular PSs is in capable to produce hydroxyl radical, once forming BSA encapsulated nanoparticles, obvious hydroxyl radical is appeared.