Nonporous Polymer Research Articles

Synthesis and characterization of non-porous amorphous polymers for enhanced iodine adsorption

Synthesis and characterization of non-porous amorphous polymers for enhanced iodine adsorption

In vitro vascularization of 3D cell aggregates in microwells with integrated vascular beds

Most human tissues possess vascular networks supplying oxygen and nutrients. Engineering of functional tissue and organ models or equivalents often require the integration of artificial vascular networks. Several approaches, such as organs on chips and three-dimensional (3D) bioprinting, have been pursued to obtain vasculature and vascularized tissues in vitro. This technical feasibility study proposes a new approach for the in vitro vascularization of 3D microtissues. For this, we thermoform arrays of round-bottom microwells into thin non-porous and porous polymer films/membranes and culture vascular beds on them from which endothelial sprouting occurs in a Matrigel-based 3D extra cellular matrix. We present two possible culture configurations for the microwell-integrated vascular beds. In the first configuration, human umbilical vein endothelial cells (HUVECs) grow on and sprout from the inner wall of the non-porous microwells. In the second one, HUVECs grow on the outer surface of the porous microwells and sprout through the pores toward the inside. These approaches are extended to lymphatic endothelial cells. As a proof of concept, we demonstrate the in vitro vascularization of spheroids from human mesenchymal stem cells and MG-63 human osteosarcoma cells. Our results show the potential of this approach to provide the spheroids with an abundant outer vascular network and the indication of an inner vasculature.

Electroactive Ionic Polymer of Intrinsic Microporosity for High-Performance Capacitive Energy Storage.

Here, an ionic polymer of intrinsic microporosity (PIM) as a high-functioning supercapacitor electrode without the need for conductive additives or binders is reported. The performance of this material is directly related to its large accessible surface area. By comparing electrochemical performance between a porous viologen PIM and a nonporous viologen polymer, it is revealed that the high energy and power density are both due to the ability of ions to rapidly access the ionic PIM. In 0.1m H2SO4 electrolyte, a pseudocapacitve energy of 315 F g-1 is observed, whereas in 0.1m Na2SO4, a capacitive energy density of 250 F g-1 is obtained. In both cases, this capacity is retained over 10000 charge-discharge cycles, without the need for stabilizing binders or conductive additives even at moderate loadings (5mg cm-2). This desirable performance is maintained in a prototype symmetric two-electrode capacitor device, which has >99% Coloumbic efficiency and a <10 mF capacity drop over 2000 cycles. These results demonstrate that ionic PIMs function well as standalone supercapacitor electrodes and suggest ionic PIMs may perform well in other electrochemical devices such as sensors, ion-separation membranes, or displays.

Graphene conductance modulation through controlled molecular release in a hybrid coordination polymer/graphene field-effect transistor

Coordination polymers, including metal-organic frameworks (MOFs), present a wide range of functionalities ranging from sensing to energy storage. Despite this, many coordination polymers are typically insulating which prevents their implementation into nanoscale electronic devices. Besides, the hybridization of MOFs with other conducting materials, like graphene, is rather unexplored. Here we introduce the grafting of a soft non-porous coordination polymer, the 1·2CH3CN, on a single-layer graphene to form a hybrid 1·2CH3CN/graphene field effect transistor. Electron transport measurements show that the sharp structural transformations in 1·2CH3CN, triggered at two specific temperatures, are detected in graphene as two sharp increments in the electrical current. Gate spectroscopy measurements show that the origin of the electrical modulation is an abrupt p-doping due to the sudden release of acetonitrile right at the structural transition temperatures. Reciprocally, the sensitivity of graphene to external perturbations allows to detect additional transformations in the coordination polymer not observed in direct transport measurements across crystals. Finally, the results have been reproduced in in-situ grown 1·2CH3CN nanoscale films on CVDG FETs. This simple method optimizes the contact area between graphene and 1·2CH3CN and facilitates the integration of coordination polymers with van der Waals materials and electronic devices. Further, a selective doping at specific temperatures could be obtained by modifying the nature of the interstitial molecule in 1.

Nitrogen-rich nonporous covalent organic polymers for highly efficient and reversible iodine capture

Radioactive iodine is a high proportion of the fission product of nuclear power, and it is crucial to fabricate materials for capturing iodine from both vapor and solution media. The large-scale synthesis of materials in low-temperature deoxidation and high-temperature with long-time environments presented significant challenges. The Chichibabin pyridine coupling reaction was employed to design and synthesize a nonporous piperazine-linked COP (PIPCOP) under atmospheric pressure within a short reaction time of only 2 h. The PIPCOP material had a comparatively low BET surface area measurement of 4.28 m2 g−1 with an exceptionally low pore volume of 0.0083 cm3 g−1. However, it had a high ability to accept iodine vapor and iodine in hexane, with a capacity of 5.18 g g−1 and 1.95 g g−1, respectively. A novel proposal is presented in this study for the synthesis of functional nonporous polymers with enhanced iodine absorption capacity, aiming to address environmental concerns.

Enhancing the Crystallinity of Keto-enamine-Linked Covalent Organic Frameworks through an in situ Protection-Deprotection Strategy.

β-Keto-enamine-linked 2D covalent organic frameworks (COFs) have emerged as highly robust materials, showing significant potential for practical applications. However, the exclusive reliance on 1,3,5-triformylphloroglucinol (Tp aldehyde) in the design of such COFs often results in the production of non-porous amorphous polymers when combined with certain amine building blocks. Attempts to adjust the crystallinity and porosity by a modulator approach are inefficient because Tp aldehyde readily forms stable β-keto-enamine-linked monomers/oligomers with various aromatic amines through an irreversible keto-enol tautomerization process. Our research employed a unique protection-deprotection strategy to enhance the crystallinity and porosity of β-keto-enamine-linked squaramide-based 2D COFs. Advanced solid-state NMR studies, including 1D 13 C CPMAS, 1 H fast MAS, 15 N CPMAS, 2D 13 C-1 H correlation, 1 H-1 H DQ-SQ, and 14 N-1 H HMQC NMR were used to establish the atomic-level connectivity within the resultant COFs. The TpOMe -Sqm COFs synthesized utilizing this strategy have a surface area of 487 m2 g-1 , significantly higher than similar COFs synthesized using Tp aldehyde. Furthermore, detailed time-dependent PXRD, solid-state 13 C CPMAS NMR, and theoretical DFT studies shed more light on the crystallization and linkage conversion processes in these 2D COFs. Ultimately, we applied this protection-deprotection method to construct novel keto-enamine-linked highly porous organic polymers with a surface area of 1018 m2 g-1 .

Adaptisorption of Nonporous Polymer Crystals

AbstractAlthough our knowledge and understanding of adsorptions in natural and artificial systems has increased dramatically during the past century, adsorption associated with nonporous polymers remains something of a mystery, hampering applications. Here we demonstrate a model system for adaptisorption of nonporous polymers, wherein dative B−N bonds and host‐guest binding units act as the kinetic and thermodynamic components, respectively. The coupling of these two components enables nonporous polymer crystals to adsorb molecules from solution and undergo recrystallization as thermodynamically favored crystals. Adaptisorption of nonporous polymer crystals not only extends the types of adsorption in which the sorbate molecules are integrated in a precise and orderly manner in the sorbent systems, but also provides a facile and accurate approach to the construction of polymeric materials with precise architectures and integrated functions.

Adaptisorption of Nonporous Polymer Crystals.

Although our knowledge and understanding of adsorptions in natural and artificial systems has increased dramatically during the past century, adsorption associated with nonporous polymers remains something of a mystery, hampering applications. Here we demonstrate a model system for adaptisorption of nonporous polymers, wherein dative B-N bonds and host-guest binding units act as the kinetic and thermodynamic components, respectively. The coupling of these two components enables nonporous polymer crystals to adsorb molecules from solution and undergo recrystallization as thermodynamically favored crystals. Adaptisorption of nonporous polymer crystals not only extends the types of adsorption in which the sorbate molecules are integrated in a precise and orderly manner in the sorbent systems, but also provides a facile and accurate approach to the construction of polymeric materials with precise architectures and integrated functions.

Utilizing Plastic Waste with Ecobricks: Creative Solutions for A Healthy and Waste-Free Life

Indonesia ranks second as the largest producer of plastic waste in the world. Plastic waste takes about 1000 years to decompose. Cleaning up plastic waste is very difficult, because plastic waste has non-porous polymer properties, plastic can also cause temperatures to increase day by day. Plastic waste has a negative impact on the environment, such as environmental pollution due to the accumulation of waste. Anticipatory and preventive actions are needed to overcome this problem. The purpose of this research is to increase public awareness of the ecobrick method to utilize waste as an environmentally friendly material that has economic value. The research method used is a systematic literature review method, or called Systematic Literature Review (SLR) with results using an online article database

Therapeutic coordination polymers: tailoring drug release through metal-ligand interactions.

Developing tunable materials which exhibit sustained drug release is a considerable challenge. Herein, we report the concept of Therapeutic Coordination Polymers (TCPs); non-porous coordination polymers constructed from biocompatible components which demonstrate tunable zero-order drug release kinetics upon degradation of metal-ligand bonds. TCPs were constructed from three principal components: (i) a cationic metal center (M = Mg2+, Mn2+, Zn2+, or Cu2+); (ii) an anionic drug (Diclofenac); and (iii) an alkyl bis-imidazole organic ligand which behaves as a "linker" between metal centers. Most drug-release materials, such as amorphous polymer dispersions, or metal-organic frameworks rely on a diffusion-based mechanism for drug release, but the degradation-controlled release of drugs from non-porous one-periodic coordination polymers has been largely unexplored. TCPs described herein exhibit a high wt% of pharmaceutical (>62%), tailorable zero-order drug release rate kinetics which span over three orders of magnitude, and stimuli-responsive drug release behavior making them well suited for extended drug-release applications.

High-Capacity Iodine Adsorption and Nonporous to Porous Structural Transformation in an Originally Nonporous Coordination Polymer

A rare example of the high-capacity uptake of iodine guest molecules by nonporous CP is reported. Moreover, the release of iodine from the iodine loaded framework induces the CP change from nonporous to porous stage.

DEVELOPMENT OF THE METHOD OF DESIGNING THE MICRO SCREW EXTRUDER OF A 3D PRINTER

The article deals with the development of a design method for a 3D printer extruder screw. The key aspects that must be applied during design are described. The main mechanical properties that should be taken into account when designing the screw element of the extruder are given. Various designs of screws, their advantages and disadvantages are considered. A single-screw extruder was selected for a 3D printer, which uses granules, crushed waste polymer materials as raw materials. It is proposed to use a three-zone cylindrical one-way screw with a constant pitch and without a degassing zone of the screw for processing granules or crushed polymer particles. Recommended for screw extruders that do not require high dosing pressure of molten polymer material and that process non-porous homogeneous polymer materials, single-zone screws with a constant pitch and depth of screw cutting. Their use in the processing of cut strips from plastic waste is proposed. The main geometric parameters of the screw with a constant pitch and a variable depth of the screw channel were determined for designing. The diameter for the 3D printer extruder has been selected. Dependencies are given for determining the length of the screw, the pitch of the screw thread, the width of the crest of the turn, the angle of elevation of the screw line of the screw thread, and the depth of the screw channel of the screw. Dependencies are given for determining the boundaries of feeding, plasticizing, and dosing zones. The degree of screw compression was determined for the main polymer materials used in 3D printing. The geometry of screws depending on the degree of compression for different materials is given. A formula is presented for determining the volume performance of a 3D printer extruder depending on the design of the dosing zone and nozzle resistance. The formulas for determining the forward flow constant, the reverse flow constant and the flow constant of the flowing material and the dependence of the coefficients characterizing the design of the auger with a variable cutting depth are presented. The geometric parameters of screws with a constant pitch and depth of screw cutting and expressions for their determination are described.

Sequential Water Sorption/Desorption of a Nonporous Adaptive Organic Ligand Bridged Coordination Polymer for Atmospheric Moisture Harvesting.

Moisture harvesters with favourable attributes such as easy synthetic availability and good processability as alternatives for atmospheric moisture harvesting (AWH) are desirable. This study reports a novel nonporous anionic coordination polymer (CP) of uranyl squarate with methyl viologen (MV2+ ) as charge balancing ions (named U-Squ-CP) which displays intriguing sequential water sorption/desorption behavior as the relative humidity (RH) changes gradually. The evaluation of AWH performance of U-Squ-CP shows that it can absorb water vapor under air atmosphere at a low RH of 20 % typical of the levels found in most dry regions of the world, and have good cycling durability, thus demonstrating the capability as a potential moisture harvester for AWH. To the authors' knowledge, this is the first report on non-porous organic ligand bridged CP materials for AWH. Moreover, a stepwise water-filling mechanism for the water sorption/desorption process is deciphered by comprehensive characterizations combining single-crystal diffraction, which provides a reasonable explanation for the special moisture harvesting behaviour of this non-porous crystalline material.

Formation of Porosity toward Acetylene upon Vitrification of Non-porous Photochromic Coordination Polymer Crystals

Designing permanent microporosity in a glassy state of coordination polymer (CP) and metal–organic framework (MOF) has been challenging due to densification of the structures upon vitrification. Here, we propose a new approach to create porosity in CP/MOF glasses derived from nonporous 1D crystal structures. Glassy states of two dense 1D crystal structures [Ag2(cis-dbe) (CF3SO3)2] and [Ag2(cis-dbe) (CF3CO2)2], where cis-dbe = cis-1,2-dicyano-1,2-bis(2,4,5-trimethyl-3-thienyl)ethene, were prepared by ball milling. Glass structures and dynamics were characterized by synchrotron X-ray, solid-state NMR, and thermal analyses. Loosened assembly of 1D chains through glass formation enabled representation of permanent microporosity and resulted in selective gas sorption behaviors of acetylene over CO2. It elucidated that the property of gas uptake is affected by the glass dynamics and interaction with anions. Reversible photochromism of cis-dbe is preserved in the glasses, leading to multi-functional glass materials.

Non-porous covalent organic polymers enable ultrafast removal of cationic dyes via carbonyl/hydroxyl-synergetic electrostatic adsorption

Rapid and highly efficient removal of organic dyes from polluted water is of great significance for environmental protection and water resources management. Herein, an anionic covalent organic polymer (COP), denominated as COPOH+CO, with the fastest cationic dye adsorption kinetics so far was prepared and packed into solid phase extraction cartridges for rapid and automatic water treatment. As-prepared COPOH+CO contains abundant hydroxyl and carbonyl groups. Compared to COPOH and COPCO, other two COPs containing only hydroxyl and carbonyl, respectively, COPOH+CO gives a maximum adsorption capacity of 813 mg·g−1 towards cationic dye methylene blue (MB), which is about 4.6 times the sum of those of COPOH (42.4 mg·g−1) and COPCO (135 mg·g−1), suggesting the existence of 1 + 1 > 2 synergy between carbonyl and hydroxyl groups. Such a synergy is well demonstrated by theoretical calculation, which shows that the mutual penetration distance of electrostatic potentials in MB/COPOH+CO complex (4.722 Å) is much larger than those in MB/COPOH (0.443 Å) and MB/COPCO (1.602 Å). Although the rapid synthesis endows COPOH+CO with very poor porosity, the resulted surface adsorption avoids the long-term mass transfer, thus giving an ultra-fast adsorption kinetics with a so far fastest adsorption rate constant of 0.17 g·mg−1·s−1. This work demonstrates that by using the synergetic effect of surface functional groups, rapidly synthesized non-porous COPs may work as promising adsorbents for fast adsorption of targets.

An Ultrathin Nonporous Polymer Separator Regulates Na Transfer Toward Dendrite-Free Sodium Storage Batteries.

Sodium storage batteries are one of the ever-increasing next-generation large-scale energy storage systems owing to the abundant resources and low cost. However, their viability is severely hampered by dendrite-related hazards on anodes. Herein, a novel ultrathin (8 µm) exterior-nonporous separator composed of honeycomb-structured fibers is prepared for homogeneous Na deposition and suppressed dendrite penetration. The unhindered ion transmission greatly benefitsfrom honeycomb-structured fibers with huge electrolyte uptake (376.7%) and the polymer's inherent transport ability. Additionally, polar polymer chains consisting of polyethersulfone and polyvinylidene customize the highly aggregated solvation structure of electrolytes via substantial solvent immobilization, facilitating ion-conductivity-enhanced inorganic-rich solid-electrolyte interphase with remarkable interface endurance. With the reliable mechanical strength of theseparator, the assembled sodium-ion full cell delivers significantly improved energy density and high safety,enabling stable operation under cutting and rolling. The as-prepared separator can further be generalized to lithium-based batteries for which apparent dendrite inhibition and cyclability are accessible and demonstrates its potential for practical application.

A 3D Coordination Polymer Based on Syn-Anti Bridged [Mn(RCOO)2]n Chains Showing Spin-Canting with High Coercivity and an Ordering Temperature of 14 K

A new 3D manganese(II) coordination polymer, formulated as [Mn3(HL)6] (1) (where H2L = 6-hydroxypicolinic acid), has been hydrothermally synthesized and characterized by single-crystal X-ray crystallographic analysis along with other spectroscopic and magnetic techniques. Structural analysis shows that the compound crystallizes in the monoclinic C2/c space group and is a non-porous 3D coordination polymer formed by three different Mn(II) centres connected by 6-hydroxypicolinic acid ligands in their keto form. Each Mn(II) centre shows a distorted octahedral coordination environment. Neighbouring Mn(II) centres are connected by two different syn-anti bridging carboxylate groups to form regular coordination chains. There are two different [Mn2(RCOO)2] units along the chain, formed by two crystallographically independent Mn centres (Mn1 and Mn2). These chains are further connected by HL− ligands to form a 3D coordination network. Interestingly, both the hydroxy and the carboxylate groups of the ligands are deprotonated and coordinated to the metal centres, whereas the pyridyl group is protonated and uncoordinated, although it participates in strong hydrogen bonding interactions with oxygen atoms of the HL− ligand, as shown by the Hirshfeld surface analysis. Both the absorption and emission spectra of the compound have also been measured. Variable temperature magnetic studies reveal the presence of a spin-canted antiferromagnetic behaviour with a high coercivity of 40 mT at 2 K and an ordering temperature of 14 K.

Economical amidoxime-functionalized non-porous β-cyclodextrin polymer for selective detection and extraction of uranium

Herein, a dual-functional adsorbent (amidoxime-functionalized non-porous β-cyclodextrin polymer (AO-NPCDP)) with simultaneous detection and adsorption of U(VI) is developed. Fascinatingly, the luminescence intensity of AO-NPCDP could be selectively and efficiently quenched by U(VI) with a quenching rate of 80.5 % in 30 s. The adsorption of U(VI) on AO-NPCDP results in fluorescence quenching with an ultra-low detection limit (10.3 nM) in deionized water, which is much lower than the maximum contamination standard in drinking water of the World Health Organization contamination limit for U(VI) in drinking water (63 nM). More importantly, AO-NPCDP exhibits high sensitivity in detecting U(VI) ions in natural water systems such as lake water, seawater and tap water with the calculated detection limits of 63.5 nM, 22.2 nM and 17.6 nM, respectively. Moreover, the AO-NPCDP can be easily regenerated using a gentle washing procedure and maintains a high reusability of 95.8 % after 7 adsorption–desorption cycles. Density functional theory (DFT) calculation shows that the fluorescence mechanism between AO-NPCDP and U(VI) is photo-induced electron transfer. The sensitivity and selectivity as well as the economy and high reusability reveal the promise of AO-NPCDP for on-site, real-time monitoring and adsorption of U(VI).

Composite with a Glassy Nonporous Coordination Polymer Enhances Gas Adsorption Selectivity.

A glass-crystal composite (g-NCP/PCP), comprising a glassy nonporous coordination polymer (g-NCP) and a crystalline porous coordination polymer (PCP)/metal-organic framework, was synthesized by using a melt-quenched method. Compared to that of the PCP itself, g-NCP/PCP has an enhanced gas adsorption selectivity. The results should stimulate further studies of the chemistry of g-NCP/PCP glass-crystal composites.

Nitrogen-containing nanoporous carbons synthesized from direct carbonization of non-porous coordination polymers for CO2 capture

Nitrogen-containing nanoporous carbons synthesized from direct carbonization of non-porous coordination polymers for CO2 capture