Organic-inorganic Polymer Research Articles

Size-Tunable Covalent Organic Framework Nanoparticles for Assembling One-Dimensional Photonic Crystals With Visual Sensing.

One-dimensional photonic crystals (1D PCs) emerged as superb sensing platforms due to their high sensitivity to environmental changes. However, effectively translating the microscopic interactions between covalent organic frameworks (COFs) and analytes into macroscopic optical responses via 1D PCs for intuitive detection presents a significant challenge. Here, we propose a stepwise-induced synthesis strategy that for the first time achieves a size-controlled synthesis of uniform nanoscale COFs (60-80nm), leading to a high-quality COF layer. This advancement enables COF-based 1D PCs to exhibit diverse color variations and controllable saturation. Notably, the excellent compatibility of the COF layer with inorganic oxides, organic polymers, and metal-organic frameworks (MOFs) results in these 1D PCs exhibiting bright colors. Crucially, introducing the mesoporous materials enables 1D PCs to achieve deep integration of adsorption and recognition functions for volatile organic compounds (VOCs). The fabricated COF/MOF 1D PC allows differentiation of 12 VOCs and visually detects VOCs at different concentrations (0-80gm- 3) through color changes, with a response time under 1 s. In particular, COF-based 1D PCs can be transferred to flexible substrates while retaining VOC visual sensing. These attributes highlight the potential of COF-based 1D PCs for real-time VOC monitoring in industrial environments.

Recent advances in optical heavy water sensors.

D2O and H2O, as two important solvents with very similar properties, play a pivotal role in nuclear industrial production, life and scientific research. Unfortunately, D2O and H2O are highly susceptible to contamination by each other, so effective qualitative and quantitative analyses of both are necessary. This review comprehensively discusses the progress in optical sensing for the detection of a trace amount of H2O in heavy water or vice versa, mainly including five types of analytical systems: inorganic nanocrystals, carbon-based nanomaterials, lanthanide complexes, organic polymers, and organic small molecules. The whole article is divided into several sub-sections based on multiple mechanisms underlying the design of heavy water optical sensors, i.e., the difference in binding energy, the difference in quenching efficacy of oscillator types and the difference in acid-base of H2O and D2O. The working mechanism, advantages and disadvantages, analytical performance and applications of the reported sensors in recent years were analyzed in detail, and the future development is envisioned for the optical sensors towards distinguishing D2O and H2O.

Mechanisms for removing phosphorus species through sequential coagulation using inorganic coagulants and organic polymers.

The need for stringent phosphorus removal from domestic wastewater is increasing to mitigate eutrophication, while efficient phosphate reuse is critical due to the global phosphate crisis. Combining aluminum sulfate (ALS) with high molecular weight organic polymers achieved 95-99% removal of particles, turbidity, and phosphates, reducing ALS usage by 40%. We propose mechanisms to explain the enhanced treatment efficiency. Particle and turbidity removal is more influenced by polymer charge density than molecular weight, while orthophosphate (OP) removal is linked to a change in zeta potential from negative to positive, allowing additional OP binding through complex formation with hydrolysis products and polymers. Enhanced phospholipid (PL) removal likely results from adsorption and neutralization of micelle PL charges by intermediate positively charged aluminum hydroxyphosphate ions. Higher PL removal with low ALS doses is attributed to a two-stage dosing process that optimizes coagulant and polymer dosages. The combined removal of OP and PL improves phosphorus bioavailability, increasing the sludge's fertilizer value.

Recent Advancements in Graphene Derivative-Based Nanocomposites: Innovations in Coating and Sensing Technologies

Graphene derivative-based nanocomposites have emerged as innovative solutions to address challenges in corrosion, marine biofouling, and environmental contamination. This review highlights recent advancements in three key areas: (1) dual-barrier and self-healing anti-corrosion materials, (2) eco-friendly anti-biofouling coatings, and (3) high-efficiency electrocatalytic films for electrochemical sensing. We emphasize the critical roles of graphene (Gr) sheets, graphene oxide (GO), and reduced graphene oxide (rGO) in enhancing nanocomposite performance through novel modifications with inorganic materials, organic polymers, and biomolecules. Key insights into advanced modification techniques and their impact on functionality and durability are presented. The review also explores graphene-enabled electrochemical sensors that showed high sensitivity to phenolic compounds in water. Mechanisms accounting for the improved performance of these materials are discussed, along with associated challenges such as scalability, cost-effectiveness, and stability. Future directions are suggested, focusing on sustainable, intelligent coatings and thin-film devices for environmental applications. This work aims to guide researchers, industry professionals, and policymakers in leveraging graphene-based technologies to tackle global issues in corrosion prevention, marine ecology, and environmental monitoring.

Fast Li+ De‐Solvation Kinetics with PDDA Intercalated‐Montmorillonite Hybrid Artificial Interface Layer on Cu Substrate for Lithium Metal Batteries in a Wide Climate Temperature

AbstractThe tolerance requirement of lithium metal batteries in harsh environments presents great challenges to electrode materials and electrolytes because temperature plays a significant effect in electrochemical processes. In this study, a new artificial layer on a copper current collector that boosts the de‐solvation kinetics and provides electrostatic shielding effects is presented to enhance the electrochemical performance of lithium metal batteries. This new artificial layer is constructed with poly(diallyl dimethyl ammonium chloride) (PDDA) and exfoliated montmorillonite (MMT) nanosheets, which combine the advantages of both inorganic clay and organic polymer. Within this protective hybrid layer, the PDDA cations increase the interlayer spacing of MMT, broadening the diffusion pathways of Li+ and accelerating their fast diffusion. Moreover, the PDDA‐MMT protective layer facilitates Li+ de‐solvation at the interface of the Li anode and electrolyte, enabling the rapid and reversible plating/stripping of lithium metal. As a result, the as‐prepared PDDA‐MMT@Cu anode exhibits excellent stability, and good rate performance is achieved in a commercial electrolyte in the temperature range of −20–60 °C. By combining enhanced diffusion kinetics and electrostatic shielding as an artificial protective layer, this clay‐polymer composite provides a synergistic interaction and offers new inspiration for the development of lithium metal batteries.

Design of hybrid multi-crosslinked hydrogel with a combination of high stiffness, elastic applied in high temperature and high salinity reservoirs

The mechanical strength of conventional hydrogels is inadequate for preventing leakage in high-temperature and high-salinity reservoirs, primarily due to the increased mobility of polymer chains and the degradation of crosslinked networks. Herein, we employed the strategy of ’network nesting and layer reinforcement’ to design a hybrid multi-site crosslinked hydrogel. This approach enhances the interconnections between polymer chains and fortifies the crosslinked network. The shear rheological behavior and temperature sensitive characteristics of the profile control working fluids were evaluated based on rheological dynamics. In the high temperature (140 ℃) and high salinity (21.81 × 104 mg/L) preparation environment, the effects of different components to the mechanical strength of the hydrogel were investigated under dynamic shear and uniaxial compression conditions. The incorporation of N-(hydroxymethyl)acrylamide (NMA) in the copolymerization with acrylamide (AM) resulted in an increase in the covalent cross-linking density, leading to a rise in the shear elastic modulus from 105 Pa to 238 Pa. The use of pre-gelatinized cassava starch (PGCM) as the grafting framework enhanced the bonding between the polymer chains, as evidenced by the increase in uniaxial compressive strength from 0.018 MPa to 0.081 MPa and the rise in peak strain from 55.0 % to 72.9 %. Furthermore, the synergistic effect of fumed silica (AEROSIL), which exploits mechanical coupling between inorganic nano-fillers and organic polymers, increased the compressive strength from 0.081 MPa to 0.418 MPa and raised the peak strain from 72.9 % to 81.8 %. It provides an effective approach to enhance the plugging performance of hydrogels in high temperature and high salinity reservoirs.

Ceramic Rich Composite Electrolytes: An Overview of Paradigm Shift toward Solid Electrolytes for High‐Performance Lithium‐Metal Batteries

AbstractExploiting the synergy between organic polymer electrolytes and inorganic electrolytes via the development of composite electrolytes can suggest solutions to the current challenges of next‐generation solid‐state lithium‐metal batteries (SSLMBs). Depending upon a mass fraction of inorganic fillers and organic polymers, composite electrolytes are broadly classified into “ceramic‐in‐polymer” (CIP) and “polymer‐in‐ceramic” (PIC) categories, inheriting distinct structure and electrochemical properties. Since the stability and electrochemical characteristics of the inorganic phase are superior to those of the organic phase for lithium‐ion conduction, applying lithium‐enrich active filler in PIC seems more promising. The inorganic phase preserves the primary migratory channels in the PIC electrolyte, while the viscoelastic properties attempt to be introduced from the organic binder or host. The present work overviews the studies on state‐of‐the‐art PIC electrolytes, the fundamental mechanism of ionic conduction, preparation methods, and current progress in materials development for SSLMBs. In addition, the modification strategies for improving the electrode–electrolyte interface are also emphasized. Moreover, it further prospects the current challenges and effective strategies for the future development of PICs‐based CPEs to accelerate the practical application of SSLMBs. This review examines the progress and outlook of PIC‐based electrolytes for next‐generation lithium batteries.

Hybridization of Polymer-Encapsulated MoS2-ZnO Nanostructures as Organic-Inorganic Polymer Films for Sonocatalytic-Induced Dye Degradation.

The development of environmentally friendly technology is vital to effectively address the issues related to environmental deterioration. This work integrates ZnO-decorated MoS2 (MZ) to create a high-performing PVDF-based PVDF/MoS2-ZnO (PMZ) hybrid polymer composite film for sonocatalytic organic pollutant degradation. An efficient synergistic combination of MZ was identified by altering the ratio, and its influence on PVDF was assessed using diverse structural, morphological, and sonocatalytic performances. The PMZ film demonstrated very effective sonocatalytic characteristics by degrading rhodamine B (RhB) dye with a degradation efficiency of 97.23%, whereas PVDF only degraded 17.7%. Combining MoS2 and ZnO reduces electron-hole recombination and increases the sonocatalytic degradation performance. Moreover, an ideal piezoelectric PVDF polymer with MZ enhances polarization to improve redox processes and dye degradation, ultimately increasing the degradation efficiency. The degradation efficiency of RhB was seen to decrease while employing isopropanol (IPA) and p-benzoquinone (BQ) due to the presence of reactive oxygen species. This suggests that the active species •O2- and •OH are primarily responsible for the degradation of RhB utilizing PMZ2 film. The PMZ film exhibited improved reusability without substantially decreasing its catalytic activity. The superior embellishment of ZnO onto MoS2 and effective integration of MZ into the PVDF polymer film results in improved degrading performance.

Inorganic–organic polymer networks derived from a cyclic siloxane tetrafunctional glycidyl ether resin

AbstractA tetrafunctional glycidyl ether cyclic siloxane epoxy resin (TGTS) has been synthesized, characterized and cured with four aromatic amine hardeners: 1,3‐phenylenediamine (PDA), diethyltoluenediamine (DETDA), 4,4‐diaminodiphenylmethane (DDM) and 1,3‐bis(4‐aminophenoxy)benzene (APB). Each of the cured networks produces transparent and homogeneous networks, although when TGTS is cured with DETDA, reduced compatibility led to lower epoxide consumption, a more heterogenous microstructure and deleterious effects upon properties. Reduced miscibility of DETDA significantly impacts the chemical structure and microstructure of the network, resulting in significant reductions in thermal and mechanical properties but higher UV‐A transmission. The PDA‐, APB‐ and DDM‐cured networks conversely were more miscible and display properties typical of organic–inorganic hybrid networks, such as good mechanical properties at ambient and sub‐ambient temperatures, comparatively high glass transition temperatures, improved resistance to oxidation and lower UV‐A transmission. © 2024 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

“One for two” strategy to construct an organic-inorganic polymer colloid for flame-retardant modification of flax fabric and rigid polyurethane foam

Polymeric materials such as fabric and foam have high flammability which limits their application in the field of fire protection. To this end, an organic-inorganic polymer colloid constructed from carboxymethyl chitosan and ammonium polyphosphate was used to improve the flame retardancy of flax fabric (FF) and rigid polyurethane foam (RPUF) based on a “one for two” strategy. The modification processes of FF and RPUF relied on pad-dry-cure method and UV-curing technology, respectively, and the modified FF and RPUF were severally designated as CMC/APP-FF and RFR-RPUF. Flame retardancy studies showed that CMC/APP-FF and RFR-RPUF exhibited limiting oxygen index values as high as 39.4 % and 42.6 %, respectively, and both achieved self-extinguishing behavior when external ignition source was removed. Thermogravimetric analysis and cone calorimetry test confirmed that CMC/APP-FF and RFR-RPUF had good charring ability and demonstrated reduced peak heat release rate values of 90.1 % and 10.8 %, respectively, distinct from before they were modified. In addition, condensed phase analysis showed that after burning, CMC/APP-FF became an integration char structure, whereas RFR-RPUF turned into a sandwiched char structure. In summary, the “one for two” strategy reported in this work provides a new insight into the economical fabrication of flame-retardant polymeric materials.

Synthesis and Properties of Organic–Inorganic Materials Based on Polyurethane and MQ Resins

Cross-linked polyurethanes (PUs) were obtained by curing with MQ resins bearing oxymethyldimethylsiloxane or oxyethoxymethyldimethylsiloxane groups, their mixtures with 1,4-butanediol, and neat 1,4-butanediol and studied for their physico-mechanical properties. The MQ resins with functional hydroxy groups were found to act as polyols during curing of a urethane prepolymer. The network PU, obtained by curing with the MQ resins, represents a hybrid organic–inorganic polymer with bulk cross-links of inorganic nature, the surface groups of which are chemically bound to the polymer matrix. At a concentration of the MQ resins of 0.5 ppm, the properties of hybrid polyurethanes are comparable to those of the polyurethane obtained using 0.63 ppm of 1,4-butanediol.

In Situ Hybrid Crosslinking Polymerization of Nanoparticles for Composite Polymer Electrolytes to Achieve Highly‐Stable Solid Lithium–Metal Batteries

AbstractThe composite solid electrolyte, which combines the advantages of inorganic conductors and organic polymer electrolytes, has become a crucial strategy for the construction of solid‐state batteries. However, the physical deposition and agglomeration of traditional composite fillers seriously affect their structural uniformity and ion transport performance, and the construction of uniform and stable composite electrolytes is still an insurmountable challenge. Herein, a strategy of in situ hybrid crosslinking polymerization of TiO2 nanoparticles is proposed for highly stable polymer composite electrolytes (NHCPE) with an ultrahigh ionic conductivity of 1.74 × 10−3 S cm−1 at 25 °C, and a high lithium‐ion transference number of 0.725. These properties enable the composed lithium symmetric battery to be stably deposited/plating off at 0.5 mA cm−2 for more than 1000 h. Moreover, the assembled LFP|PDOL@nanoTiO2|Li battery exhibits a superior specific discharge capacity of 142.6 mAh g−1 at 1 C and 25 °C, and an ultrahigh capacity retention rate of 90% after 1000 cycles. The proposed PDOL@nanoTiO2 NHCPE greatly inhibits the defects of easy agglomeration of composite electrolytes, solves the problems of easy decomposition, low thermal stability, and poor safety of polyether electrolytes, and opens up a new way for the design and industrial application of high‐stability composite polymer electrolytes.

An Evolutionary Review of Hemoperfusion Adsorbents: Materials, Preparation, Functionalization, and Outlook.

Accumulation of pathogenic factors in the blood may cause irreversible damage and may even be life-threatening. Hemoperfusion is an effective technique for eliminating pathogenic factors, which is widely used in the treatment of various diseases including liver failure, renal failure, sepsis, and others. Hemoperfusion adsorbents are crucial in this process as they specifically bind and remove the target pathogenic factors. This review describes the development of hemoperfusion adsorbents, detailing the different properties exhibited by inorganic materials, organic polymers, and new materials. Advances in natural and synthetic polymers and novel materials manufacturing techniques have driven the expansion of hemoperfusion adsorbents in clinical applications. Stimuli-responsive (smart responsive) adsorbents with controllable molecular binding properties have many promising and environmentally friendly biomedical applications. Knowledge gaps, future research directions, and prospects for hemoperfusion adsorbents are discussed.

Direct Evidence of π–π Interactions in Transparent Organic–Inorganic Polymer Hybrids of Polystyrene and Silica Gel

Polystyrene and silica gel polymer hybrids derived from polystyrene and phenyltrimethoxysilane via π–π interactions were synthesized by a slight modification of the previous method. Spectroscopic evidence of the π–π interaction is provided. The obtained polymer hybrids were optically transparent, and no phase separation was observed by scanning electron microscopy measurements. In the FT-IR spectrum of the resulting polymer hybrids, the absorption peaks corresponding to C–H wagging vibration shifted to a lower wavenumber range as the content of silica in the hybrids increased. A UV–vis spectrum of the polystyrene and silica gel polymer hybrids showed a shoulder peak at around 260 nm that shifted toward longer wavenumbers side as the content of silica increased. These results clearly indicate that π–π interactions contribute to the formation of these transparent hybrids.

Li6.28La3Zr2Al0.24O12-reinforced Single-ion Conducting Composite Polymer Electrolyte for Room-Temperature Li-Metal Batteries

Composite polymer electrolytes composed of inorganic fillers and organic polymers are promising electrolyte candidates for Li metal batteries, with benefits of improved safety and suppressed lithium dendrite growth. However, a severe concentration polarization effect often occurs when using conventional dual-ion electrolytes, and the increase in internal impedance during cycling results in decreased lifespan of the battery. To address this challenge, a plasticized single-ion conducting composite polymer electrolyte (SICE) was designed and fabricated by polymerizing the monomers of lithium (4-styrenesulfonyl) (trifluoromethanesulfonyl) imide (LiSTFSI) and poly(ethylene glycol) methyl ether acrylate (PEGMEA), crosslinker poly(ethylene glycol) diacrylate (PEGDA), silane-modified Li6.28La3Al0.24Zr2O12 nanofibers (s@LLAZO NFs), along with a PEG-based plasticizer tetraethylene glycol dimethyl ether (TEGDME), by heat-initiation. The anions were restrained and delocalized so that only Li cation migration occurred during the charging/discharging process, leading to a superior lithium-ion transference number. The s@LLAZO NFs enabled direct monomer grafting with the polymer matrix, resulting in controlled formation of an organic-inorganic network with increased filler content and improved filler distribution in the SICE system. The SICE membrane exhibited high ionic conductivity at room temperature, reduced activation energy and excellent oxidation stability. Most importantly, the all-solid-state Li-metal batteries assembled with the fabricated SICE demonstrated stable long-term cycling performance and remarkable rate capability at room temperature.

Metal ions and organic molecule co-intercalated vanadium oxide cathode for high-performance zinc-ion batteries

Vanadium oxide is a highly promising cathode material for zinc-ion batteries due to its unique layered structure and high theoretical capacity. However, the material dissolution and structural collapse severely limit the development of zinc-ion batteries. Herein, inorganic metal ions (Mg2+) and organic polymer molecules (PANI) were introduced into the hydrated vanadium oxide interlayer in this paper. Mg2+ ions enhance the conductivity of the cathode and widen the interlayer spacing. Meanwhile, PANI serves to cushion the structural expansion resulting from ion embedding and stabilize the layered structure. Additionally, PANI actively participates in the charging and discharging process, thereby enhancing the diffusion rate of Zn2+. Thanks to the synergistic effect of Mg2+ and PANI, the MgVOH/PANI cathode exhibits a discharge capacity of 412 mAh·g−1 at 0.1 A g−1 and retains 93% of its capacity after 1000 cycles at a current density of 2A·g−1. This synergistic strategy of combining organic molecules and inorganic ions can provide a reference for improving the kinetic and structural stability of other aqueous battery cathodes.

The Preparation and Performance Study of Polyamide Film Based on PDA@MWCNTs/PVDF Porous Support Layer.

It is urgent to develop a polyamide (PA) thin-film composite (TFC) membrane with a new method in this study by designing and constructing a new nanomaterial support layer instead of the conventional support layer. Polydopamine-wrapped single-walled carbon nanotubes (PDA@MWCNTs) as the place of the polymerization reaction can optimize the PA film structure and performance. The resulting composite membrane presents a higher water flux of 15.8 L·m-2·h-1·bar-1 and a rejection rate of 97% to Na2SO4, simultaneously maintaining this high separation performance in 300 min. It is a new ideal to construct novel support layer by using inorganic nanoparticles and organic polymer nanofiber membranes.

A two-dimensional coordination polymer bearing an Evans-Showell-type polyoxometalate: Synthesis, structure and biological insight†

An Evans-Showell-type polyoxometalate (POM) based coordination polymer (CP), [H2(Co2Mo10H4O38)2(Co3(L)3(HL)2(H2O)6)(HL)2]·14H2O (1), {L = 4,4′-bipyridine}, was synthesized under hydrothermal conditions and structurally characterized by infrared spectroscopy (IR), elemental analysis, powder X-ray diffraction (PXRD), diffuse reflectance spectroscopy (DRS) and single crystal X-ray diffraction methods. In 1, two [Co2Mo10H4O38]6− POMs are joined together via two Co-O interactions to form a dimer which is centrosymmetric. Here, the dimers act as repeating units and are expanded by another crystallographically independent Co ion in the structure. Binding of the cations to the O atoms of the POM and the N atoms of organic ligand resulted in the formation of a 2D CP structure. Compound 1 is the first example of an inorganic-organic polymer architecture constructed from Evans-Showell-type POM in which Co cations act as metal nodes. The topology of 1 can be rationalized as a 2D square lattice (sql) coordination network with point symbol {44.62} in which [Co2Mo10H4O38]6− and 4,4′-bipyridine units act as linkers and the Co cations as nodes. The cytotoxicity effects of the POM were evaluated on the cancer CT26 and normal L929 cell lines by an MTT assay from which an IC50 value of cancer CT26 cells of approximately 366 ppm was obtained, but normal L929 cells did not show significant toxicity.

Field-Induced Antiferroelectric-Ferroelectric Transformation in Organometallic Perovskite Displaying Giant Negative Electrocaloric Effect.

Antiferroelectric materials with an electrocaloric effect (ECE) have been developed as promising candidates for solid-state refrigeration. Despite the great advances in positive ECE, reports on negative ECE remain quite scarce because of its elusive physical mechanism. Here, a giant negative ECE (maximum ΔS ∼ -33.3 J kg-1 K-1 with ΔT ∼ -11.7 K) is demonstrated near room temperature in organometallic perovskite, iBA2EA2Pb3I10 (1, where iBA = isobutylammonium and EA = ethylammonium), which is comparable to the greatest ECE effects reported so far. Moreover, the ECE efficiency ΔS/ΔE (∼1.85 J cm kg-1 K-1 kV-1) and ΔT/ΔE (∼0.65 K cm kV-1) are almost 2 orders of magnitude higher than those of classical inorganic ceramic ferroelectrics and organic polymers, such as BaTiO3, SrBi2Ta2O9, Hf1/2Zr1/2O2, and P(VDF-TrFE). As far as we know, this is the first report on negative ECE in organometallic hybrid perovskite ferroelectric. Our experimental measurement combined with the first-principles calculations reveals that electric field-induced antipolar to polar structural transformation results in a large change in dipolar ordering (from 6.5 to 45 μC/cm2 under the ΔE of 18 kV/cm) that is closely related to the entropy change, which plays a key role in generating such giant negative ECE. This discovery of field-induced negative ECE is unprecedented in organometallic perovskite, which sheds light on the exploration of next-generation refrigeration devices with high cooling efficiency.

Development of a Polymer-Based Silicon-NMC Solid-State Cell

Solid-state batteries are seen as the next generation of battery technology with the promise of high energy density and improved safety as compared to conventional lithium-ion batteries. To achieve these goals, high-capacity negative electrodes, e.g., silicon or lithium, need to be combined with high capacity and high voltage positive electrodes, e.g., Ni-rich NMC. This combination of active materials provides a number of significant challenges for the solid-state electrolyte. If silicon is used as the anode active material, significant volume changes during lithiation/delithiation occur. These volume changes lead to a variety of problems including irreversible loss of lithium and eventual disintegration of the electrodes, resulting in capacity fade. Therefore, the electrolyte must be sufficiently elastic to buffer these changes. If Ni-rich NMC is used as a cathode active material, then the electrolyte must be stable at voltages up to at least 4.2 V. There are currently few, if any, electrolyte solutions that can address these challenges simultaneously.In the ASTRABAT project, a silicon-NMC solid-state cell has been developed based on two tailored polymer electrolytes, which allows the specific challenges of each cell compartment to be addressed separately. A vinylidene fluoride copolymer-based electrolyte has been developed for use as a catholyte and a hybrid inorganic-organic polymer electrolyte as the anolyte. This work will report a characterization of both electrolytes, along with their electrochemical performance in solid-state half-cells and full-cells.