Cyclic Absorption Research Articles

A novel approach in wood waste utilization for manufacturing of catalyst-free polyurethane-wood composites (PU-WC)

In recent decades, due to the increase in environmental awareness and noticeable environmental degradation, the area of wood waste management has attracted increasing attention. The purpose of this study is to develop a new type of highly filled polyurethane wood-composite (PU-WC) by the utilization of large amount of wood wastes without addition of a catalyst. Although wood-plastic composites (WPCs) are widely known, there is still a lack of knowledge about WPCs with a polyurethane matrix. Obtained results showed that composites with a wood content of up to 80% show mechanical properties to commonly used MDF boards. This may be caused proper adhesion between polyurethane matrix and the wooden filler which was confirmed by scanning electron microscopy. The flexural strength of the manufactured composites varied between 19.25 and 25.11 MPa, while the flexural modulus varied between 966 and 1255 MPa. Dynamic mechanical analysis (DMA) of the composites showed a shift of Tgβ (from −70.3 to −52.3 °C) and Tgα (from 94.9 to 117.8 °C) to higher temperatures with increasing filler amount. The observed shift could be interpreted as a reduction of polymer chain mobility and an increase in cross-linking density of composites with a higher amount of wood. This is caused by chemical reactions between isocyanates and reactive hydroxyl groups on the wood surface. Thermogravimetric analysis has shown that PU-WC degrades in one step with Tmax at around 360 °C and T2% significantly reduce with greater addition of wood. Water absorption tests that water absorption strongly depends on wood content and varies between 13 and 80%. Moreover, cyclic water absorption tests showed no considerable difference between the water adsorption of samples after each cycle. Our work suggests that PU-WC can be used successfully as a potential substitute for wood or different types of wood-plastic composites (WPC).

Reduction of energy consumption in post-combustion carbon capture process via amine-functionalized metal-organic frameworks

In this study, CO2 capture performance of ethylenediamine-functionalized Mg-MOF-74 (EDMOF-74) suspended in 30 wt% monoethanolamine (MEA) aqueous solution is analyzed. A CO2 absorption experiment was performed in a bubble column reactor based on EDMOF-74 concentrations of 0.005, 0.01, 0.05, and 0.1 wt% for different ethylenediamine loadings. It shows that EDMOF-74/30 wt% MEA mixtures improve CO2 absorption performance by a maximum of 7.18 % as compared with the base fluid. Subsequent experiment based on large-volume feed gas reveals a less volatile CO2 absorption rate. By adding EDMOF-74 to the 30 wt% MEA aqueous solution in a cyclic CO2 absorption experiment to evaluate its industrial application, an increase in durability is indicated, which implies a reduction in energy consumption during CO2 regeneration. A feasibility study on the reduction of CO2 regeneration energy was investigated in terms of the results of cyclic experiment and the facility status of Boryeong power plant. The CO2 regeneration energy can be reduced by 13.64 %, which corresponds to a decrease of 484,233 MWht/year for 1 unit of the Boryeong power plant. The abovementioned approach is expected to compensate for the disadvantages of MEA in the industrial CO2 capture process, i.e., low CO2 capacity and high CO2 regeneration energy input.

Tailoring surface features and pore structure by carbon spiral fibers to construct the high-strength carbon foams for the fast and cyclic photo-thermal oil absorption

Two key limitations affecting the commercial application of carbon foams for fast clean-up of varied oils are the complex synthesis process and poor mechanical stability. In this work, an effective method is reported to fabricate the efficient oil-absorbing materials (CSF@MCF) of carbon spiral fibers (CSFs) anchored on melamine carbon foam (MCF) with superior mechanical properties and excellent photothermal conversion. The interwoven CSFs can not only provide extra rigidity but also reduce the stress concentration of the carbon skeleton, which greatly improves the mechanical properties with 6.3 times maximum compression stress and 4.5 times ultimate tensile strength than MCF. In addition, the pure carbon component can reduce the interface resistance and excite the free electrons more easily, thus realizing high-efficiency photothermal conversion in a wide range of wavelengths. Under light irradiation, the CSF@MCF can be quickly heated up to 70 °C and achieve ultra-high absorption of crude oil, up to 62 g g−1, due to its low density and large absorption volume. Meanwhile, the CSF@MCF exhibits impressive absorption stability with persistent superhydrophobicity and a high recovery efficiency of over 85%. Superadding its simple preparation process, low production cost, and excellent acid-alkali resistance, the CSF@MCF shows great commercial potential for effectively absorbing varied oils.

Synthesis, Optical Properties, and Fluorescence Cell Imaging of Novel Mixed Fluorinated Subphthalocyanines.

Subphthalocyanines (SubPcs) are a kind of tripyrrolic macrocycle with a boron atom at their core. Incorporating different units onto the SubPc periphery can endow them with various unique properties. Herein, a series of novel fluorinated low-symmetry SubPc derivatives containing chlorine groups (F8-Cl4-SubPc, F4-Cl8-SubPc) and methoxy groups (F8-(OCH3)2-SubPc) were synthesized and characterized by spectral methods (MS, FT-IR, 1H, 13C, 11B, and 19F NMR spectroscopy), and the effect of the peripheral substituents on their electronic structure of low-symmetry macrocycle was investigated by cyclic voltammetry, theoretical calculation, electronic absorption, and emission spectroscopy. In contrast to perfluorinated SubPcs, these low-symmetry SubPcs revealed non-degenerate LUMO and LUMO + 1 orbitals, especially F8-(OCH3)2-SubPc, which was consistent with the split Q-band absorptions. The cyclic voltammetry revealed that these SubPcs exhibited two or three reduction waves and one oxidation wave, which is consistent with the reported SubPcs. Finally, an intracellular fluorescence imaging study of these compounds revealed that these compounds could enter cancer cells and be entrapped in the lysosomes, which provides a possibility of future applications in lysosome fluorescence imaging and targeting.

Study on Hydrogen Storage Properties, Anti-Oxide Ability and Rate Limiting Step of ZrCr-Based Alloy after Introducing Cobalt as Additive

In this work, the microstructure, hydrogen storage properties, anti-oxide ability and rate limiting step of Zr(Cr1−xCox)2 (x = 0, 0.2, 0.4 and 0.6) alloys have been investigated. After studying the crystal structure, we found that all alloy samples could show C14-type phase but the alloy sample x = 0 could also show a small amount of Cr phase. Rietveld fitting showed that lattice parameter and unit cell volume of C14-type phase decreased with increasing x. After further research, it was clear that the first hydrogen absorption capacity decreased with increasing x. But introducing more Co content had a positive influence on the effective hydrogen storage capacity and cyclic hydrogen absorption and desorption properties of the alloy sample. We also found that adding Co to ZrCr2 alloy could improve its anti-oxide ability. In addition to this, the rate limiting step model was also studied.

TiN/BN composite with excellent thermal stability for efficiency microwave absorption in wide temperature spectrum

• The TiN/BN composite has been constructed via the in-situ synthesis method. • The stable dielectric loss ensures that TiN/BN composite exhibits robust high-temperature absorption properties at X-band. • The stable cyclic microwave absorption properties of TiN/BN composites provide a reliable guarantee for practical applications. High-efficiency and temperature-insensitive microwave absorbing materials (MAMs) are ideal for high-temperature electromagnetic attenuation. Herein, the titanium nitride/boron nitride (TiN/BN) composite with TiN as the loss unit and BN as the impedance matching unit has been constructed by the in-situ synthesis method. The insulating BN not only effectively regulates and optimizes the conductivity and impedance matching of the material but also imparts steady cyclic microwave absorption properties. The steady dielectric loss ensures that TiN/BN composite has robust high-temperature absorption properties at X-band, with a minimum reflection loss (RL min ) of −16.74 dB at 873 K and an effective absorption bandwidth (EAB) of 3.26 GHz in the temperature range of 293–873 K. Compared with the TiN/SiO 2 absorbers with a single system, the TiN/BN/SiO 2 composite keeps reliable high temperature absorbing properties at 873 K. This work confirms that wave-transparent materials for dielectric property modulation can resolve poor temperature stability of effective absorption and non-reusability for high-temperature absorbing materials, providing inspirations for designing efficiency high-temperature microwave absorbers.

Effect of cyclic aging on mode I fracture energy of dissimilar metal/composite DCB adhesive joints

In some industrial applications, adhesive joints are cyclically exposed to a moist environment, where cyclic moisture absorption and desorption can significantly alter the fracture energy of the bonded joints. Most previous studies are based on monotonic aging conditions, while the performance of bonded joints under cyclic aging is not well explored The aim of the current study is to investigate the effect of cyclic aging on mode I fracture energy of dissimilar DCB (double cantilever beam) adhesive joints. Accordingly, bulk adhesive plates were manufactured and exposed to 4 aging cycles. After the aging process, at different exposure times, the aged adhesive plates were used to bond dissimilar Al/GFRP substrates using a secondary adhesive. Then the prepared DCBs were tested and subsequently the mode I fracture energy of the adhesive was determined. Meanwhile, using gravimetrical tests and numerical simulation, moisture diffusion of the adhesive layer in different exposure times was analysed. Using experimental and numerical results, the variation of fracture energy as a function of moisture uptake was studied. In addition, glass transition temperature (Tg) and chemical bonding of the aged adhesive were analysed in different aging cycles. The results showed that by increasing the number of aging cycles, the reduction rate of mode I fracture energy between the aging cycles decreases.

Assessment of cyclic behavior and performance of hybrid linked-column steel plate shear wall system

An innovative hybrid linked columns steel plate shear wall (HLCS) system provided, and its cyclic behavior and energy absorption are investigated by finite element method in this study. The objective of the designed HLCS system was to reduce or possibly prevent damage to the SPSW at low and medium seismic levels by focusing the seismic damage to interchangeable link beams (the energy dissipation components of the presented HLCS system). In this study, the cyclic behavior and energy dissipation of HLCS systems were investigated using numerical methods. To evaluate the hysteresis behavior and energy absorption of the proposed HLCS system, parametric studies were performed. Also, the accuracy of finite element models was evaluated by comparing test results that showed the good accuracy of finite element models in predicting the specimens' hysteresis behavior and failure modes. Due to the failure mechanisms, the coupling ratio amounts meaningfully affect the onset of the first surrender mechanism between the infill steel plate and link beams. In general, by increasing the number of link beams in the floor, the ultimate shear force to the weight ratio of the structure was increased. Also, the type of beam in terms of flexural and shear behavior did not significantly affect the ratio of base shear force to the structure weight. The proposed HLCS system has increased the ratio of base shear force to the weight by an average of 4%–27%, indicating that this system is economically comparable to the SPSW systems. Moreover, the energy dissipation in the HLCS system exhibited a 14%–91% enhancement compared to the SPSW system.

Consecutive Three‐Component Synthesis of Phenothiazine‐Based Merocyanines – Bayesian Optimization, Electronic properties, and DSSC Characteristics**

AbstractA consecutive three‐component Heck‐Knoevenagel synthesis of phenothiazinyl merocyanines was developed by statistical design of experiments (DoE) and Bayesian optimization furnishing nine red orange dyes starting from heteroaryl halides, acrolein and ethyl cyanoacetate. Besides scrutinizing the electronic properties of these merocyanines by cyclic voltammetry, absorption and emission spectroscopy, and (TD)DFT calculations their saponified carboxylic acids were employed in dye‐sensitized solar cell (DSSC) experiments showing promising solar cell performances with relative efficiencies of up to 93 % compared to the standard ruthenium dye N3.

Long-term moisture penetration in concrete exposed to marine tidal conditions

The depth of concrete influenced by seawater penetration plays a vital role in many durability processes affecting reinforced concrete structures in the marine tidal zone. In this study, a phenomenological moisture transport model in concrete is developed and is validated with numerous experimental results reported in the literature. The boundary conditions for cyclic wetting–drying in the tidal zone are formulated based on a novel superimposed tide model that more accurately represents real-time tides. The moisture profiles over a large number of wet–dry cycles are evaluated in the tidal zone using the developed models. The long-term moisture penetration characterised by (i) the influential depth of moisture transport (IMDT) and (ii) the cyclic water absorption amount (CWAA) is compared at various locations along the entire tidal zone. Sensitivity analysis was carried out to estimate the influence of material properties and environmental conditions on the IDMTs and CWAAs. The results of the study revealed that the IDMTs and CWAAs predicted by the realistic superimposed tide model are about 3.5 times greater than those predicted by conventional diurnal tide models. This substantial difference justifies the importance of the correct choice of tide model for durability studies in the tidal zone.

Multiobjective Evaluation of Amine-Based Absorbents for SO2 Capture Process Using the pK a Mathematical Model.

The screening of high-efficiency and low-energy consumption absorbents is critical for capturing SO2. In this study, absorbents with better performance are screened based on mechanism, model, calculation, verification, and analysis methods. The acidity coefficient (pKa) values of ethylenediamine (EDA), piperazine (PZ), 1-(2-hydroxyethyl)piperazine (HEP), 1,4-bis(2-hydroxyethyl)piperazine (DIHEP), and 1-(2-hydroxyethyl)-4-(2-hydroxypropyl)piperazine (HEHPP) are calculated by quantum chemical methods. A mathematical model of the SO2 cyclic absorption capacity per amine (αc) in the amine-based SO2 capture process is built based on the electroneutrality of the solution. Another model of desorption reaction heat (Qdes) is also built based on the van’t Hoff equation. Correspondingly, αc and Qdes of the above five diamines are calculated and verified with the experimental data. The results show that αc of the diamine changes with the increase in the pKa value, and the increase in the pKa value directly leads to changes in Qdes. The order of αc of the above five diamines is EDA > PZ > HEHPP > HEP > DIHEP, and the order of Qdes is EDA > PZ > HEHPP > DIHEP > HEP. The multiobjective analysis between αc and Qdes suggests that it is not advisable to simply pursue a higher αc while ignoring Qdes. The compound quaternary system absorbent has a wider range of αc than the single ternary absorbent, which is the direction of absorbent development. This study is expected to strengthen absorbent screening for the amine-based SO2 capture process from flue gas.

Effect of arylamino-carbazole containing hole transport materials on the device performance and lifetime of OLED

We synthesized four hyper-conjugated aromatic hole transporting materials with different molecular geometry and energy levels by attaching arylamino moiety attached to the carbazole core. A brominated carbazole moiety reacted with an arylamino moiety using a Buchwald-Hartwig reaction. The characteristics of these hole transporting materials were investigated using TGA, DSC, UV–Vis and luminescence spectroscopy. The energy levels of all materials used in this study were estimated from cyclic voltammograms and absorption spectra. The hole transporting properties of the synthesized molecules were measured using single-carrier devices. All four hole transporting materials showed similar hole mobility. The effectiveness of hole transporting materials was compared by fabricating green-emitting organic light emitting diode (OLED) devices. It turned out that the device performances were critically dependent on the relative energy levels of the hole transporting layer and emission layer. However, the molecular geometry greatly influenced the device lifetime, determining thermally induced crystallization by the heat produced during device operation. • Hole transporting materials with different molecular symmetry were synthesized. • Hole transporting materials profoundly affect device performances and lifetime. • Device performances were affected by the energy level relative to the emission layer. • Device lifetime is affected by the molecular geometry of hole transporting materials.

High-efficiency and durable removal of water-in-heavy oil emulsions enabled by delignified and carboxylated basswood with zwitterionic nanohydrogel coatings

HypothesisIt is hypothesized that grafting zwitterionic nanohydrogel (ZNG) helps to achieve anti-asphaltene properties on cellulosic substrates, thus overcoming the fouling issue of natural cellulosic materials for treating oily emulsions. It is also hypothesized that ZNG coatings enhance the water-binding affinity of the substrates, resulting in an outstanding water-removal performance on asphaltene-stabilized emulsions with long-term stability. ExperimentsA cellulosic substrate was derived from nature basswood via a sequence of delignification and carboxylation processes. The ZNG-DBS composite was then developed by esterification to covalently graft ZNGs on the inner channels of the substrate. The water-binding affinity, wettability, water-removal performance for treating water in asphaltene-stabilized emulsions were evaluated via characterizing the filtration/absorption, and anti-fouling mechanism of the ZNG-DBS. FindingsZNG coatings enhance the hydration capability of the basswood substrate, allowing it to absorb water emulsion droplets protected by asphaltenes in the oil medium without being contaminated. Moreover, superior and stable removal capabilities were achieved by using this unique material to treat asphaltenes-stabilized water-in-oil emulsions with the water residue content of <1.0 and ∼0.065 wt% via cyclic filtration and absorption tests, respectively. Our results demonstrate the successful conversion of widely accessible wood resources to functional materials with great potential in the practical treatment of oily wastewater.

Physicochemical characterization of the performance of acidified modified eggshell cyclic adsorption of CO2

The CO2 calcium based adsorbent was prepared by using citric acid monohydrate, L(+)-tartaric acid, glacial acetic acid and L(-)-malic acid modified eggshell. The cyclic calcination/carbonation reaction of the adsorbent before and after modification was carried out by thermogravimetric analyzer to investigate the attenuation characteristics of the cyclic CO2 absorption performance of the calcium-based adsorbent after modification. XRD, N2 adsorption analysis and other methods were used for physical and chemical characterization. The phase composition, morphology, specific surface area and porosity of the acidified calcium based adsorbent were investigated. The results showed that: during 20 cycles of calcination/carbonation after 900°C pre-calcination, the maximum carbonation conversion of CIES900 modified with citric acid is significantly higher than that of the previous adsorbent, and its maximum carbonation conversion is 90.7%. The L(-)-malic acid modified adsorbent MAES900 significantly enhanced the carbonation cycle stability of the adsorbent before modification, and the cycle stability reached 92.9%.

Simultaneous removal of NO, SO2 and Hg0 with the WDRMRS

ABSTRACT Micro-nanobubbles can spontaneously generate hydroxyl free radicals (OH). Urea is a cheap reductant and can react with NOx species, and their products are nontoxic and harmless N2, CO2 and H2O. In this study, a Wet Direct Recycling Micro-nanobubble Flue Gas Multi-pollutants Removal System (WDRMRS) was developed for the simultaneous removal of NO, SO2 and Hg0. In this system, a micro-nanobubble generator (MNBG) was used to produce a micro-nanobubble gas–liquid dispersion system (MNBGLS) through recycling the urea solution from the reactor and the simulated flue gas composed of N2, NO, SO2 and Hg0. The MNBGLS, which has a large gas–liquid dispersion interface, was recycled continuously from the MNBG to the reactor, thus achieving cyclic absorption of various pollutants. All of the investigated parameters, including the initial pH and temperature of the absorbent as well as the concentrations of urea, NO and SO2 had significant effects on the NO removal efficiency but did not significantly affect the SO2 removal efficiency, whereas only the initial solution pH and NO concentration affected the Hg0 removal efficiency. The analysis results of the reaction mechanism showed that ·OH played a critical role in the removal of various pollutants. After the treatment by this system, the main removal products were Hg0 sediment, and NH4+ which could be easily recycled. The use of this system (MNBGLS) for the simultaneous removal of NO, SO2 and Hg0 is a new technology application and research. Recycling process based on MNBGLS succeeded in simultaneously removing NO, SO2 and Hg0. The system (MNBGLS) can provide a reference for commercial applications. The removal products are relatively simple and beneficial to recycling, which can reduce the cost of waste gas treatment.

Amine infused hydrogel-based CO2 gas storage technology for CO2 hydrate-based cold thermal energy storage

Carbon dioxide (CO2) hydrate-based cold thermal energy storage (CTES) is a promising method for load shifting and demand management of cooling systems and for CO2 utilisation. A challenge of CO2 hydrate-based CTES is to find a compatible CO2 gas storage, the CO2 regeneration and absorption conditions of which can be coupled with the charging and discharging conditions of the CTES, respectively. Amine diethanolamine infused hydrogels (DEAIHs) can be an effective CO2 absorber as the gas–DEA surface contact area is greatly enlarged by infusing the solution into a hydrogel. However, the influencing factors of the CO2 absorption and regeneration performance of DEAIHs are unknown. This paper investigates the performance of DEAIHs and explores the possibility of applying them in cyclic CO2 gas storage for CTES. The effects of pressure, temperature, DEAIH sample mass and amine diethanolamine (DEA) mass fraction on CO2 absorption and absorption rate are investigated. It was found that a higher pressure prompted CO2 absorption while a temperature of 12℃ resulted in the highest CO2 absorption rate. The average CO2 absorption rates in the first 100 min were 0.250, 0.228, 0.155 and 0.033 mmol min–1 for 20-g DEAIH sample with 30-wt% DEA and 60-g DEAIH sample with 30, 47 and 89-wt% DEA, respectively. CO2 regeneration from DEAIH under zero and non-zero gauge pressures are studied. Under non-zero gauge pressures, a pressure rise followed by a pressure drop caused by CO2 re-absorption appeared in the CO2 regeneration from DEAIH. It was found for the first time that the system passed through a meta-equilibrium state before it reached an equilibrium pressure. Cyclic absorption and regeneration at 110℃ under zero gauge pressure showed that the CO2 absorption decreased dramatically after the third cycle due to the volatility of amine. Operating a coupled CO2 hydrate-based CTES and CO2 gas storage system demonstrated the possibility of DEAIH material for CO2 gas storage in CTES systems.

Permeation Characteristics and Surface Accumulation of Chloride in Different Zones of Concrete along Altitude in Marine Environments

The accumulation characteristics of surface chloride in concrete in different zones are different in the marine environment. A series of laboratory experiments were conducted to investigate the surface chloride and permeation characteristics of concrete in a simulated marine environment. The experimental results indicated that the surface chloride and chloride profiles of concrete in different zones of marine environment decreased in the following order: tidal zone &gt; splash zone &gt; submerged zone &gt; atmospheric zone. The width of the ascent zone of Cl− concentration at tidal and splash zones was far less than that of the influential depth of moisture transport (IDMT), and the range of convection zone was dependent on the IDMT. Cl− at splash and tidal zones penetrated into concrete as a bulk liquid by non-saturated permeation driven by a humidity gradient. The change of chloride profiles in concrete along the altitudinal gradient was consistent with that of the cyclic water absorption amount (CWAA). The transport rate of chloride was the highest at the highest point of the tide.

Effect of fiber size, cyclic moisture absorption and fungal decay on the durability of natural fiber composites

This research investigated the effect of different lignocellulosic fiber sizes and additives on the durability of wood plastic composites (WPCs) after water absorption/desorption. WPCs were prepared by blending wood flour (20, 80, 120 mesh) with polypropylene (PP). Polypropylene grafted maleic anhydride (MA) and zinc borate (ZB) were added in the formulation to improve the properties of the WPCs. Our results show that the fiber size significantly affects moisture absorption and that the damage accumulates during the cyclic absorption tests and affects the mechanical properties. WPCs with finer wood particulates absorbed less moisture. Adding MA helped maintain the modulus and reduced the moisture absorption of the WPCs during cyclic moisture absorption tests. Because ZB may dissolve in water during the moisture absorption experiment, the addition of ZB did not retard a fungal attack. Although cyclic moisture absorption reduced the mechanical properties, it did not enhance the fungal attack.

Experimental studies on CO2 absorption and solvent recovery in aqueous blends of monoethanolamine and tetrabutylammonium hydroxide

Solvent-based post-combustion CO2 capture process is recently carried out using chemical absorption with aqueous blends of Monoethanolamine (MEA) and Ionic Liquids (IL) as promising solvents. In the present work, the blends of MEA and TetraButylAmmonium Hydroxide [TBA][OH] have been used for CO2 absorption and desorption process. The solubility of CO2 is investigated with aqueous mixtures for various carbon loading time by varying compositions of MEA and [TBA][OH] as 30 wt%, 28 wt%, 25 wt%, 20 wt% and 0 wt%, 2 wt%, 5 wt%, 10 wt% respectively. It increases with increasing IL concentration for all the aqueous mixtures. The solvent regeneration was also studied at different temperatures in order to recover and reuse the solvent for cyclic absorption. The slight decrease in CO2 solubility was noted for 20 wt% MEA +10 wt% [TBA][OH] mixture. However, this mixture exhibits higher absorption/desorption rate and regeneration efficiency than other mixtures. The regeneration energy of this mixture was also calculated as 28.6 kJ/mol of CO2, which is 32% less than that of baseline 30 wt% MEA. Furthermore, the physicochemical properties such as density, viscosity and surface tension for all the solvent blends were studied experimentally.

Electrochemical Synthesis of Conducting Polyporphyrin Films based on 5,10,15,20-Tetrakis(4-hydroxyphenyl)porphyrin

A hydroxy-substituted tetraphenylporphyrin was oxidatively electropolymerized from its solutions in ethanol by cyclic voltammetry. The electropolymerization process is investigated using cyclic voltammetry, absorption spectroscopy, and electrochemical quartz crystal microbalance. The results of IR and electronic absorption spectroscopy studies show that, in deposition from ethanol, the polymerization occurs via the O−H group of the phenyl substituent, which results in the formation of C−O−C bonds. The mechanism of polyporphyrin formation is similar to polymerization of simple organic compounds. The deposited polyporphyrin film (thickness of 80 nm) has a smooth surface. Using the Mott−Schottky approach, it was establish that the films have hole conductivity (i.e., they are a p-type semiconductor). The flat band potential of the poly-5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin is 0.33 V. The film is further oxidized in a supporting electrolyte solution by applying positive potentials, with anions of the supporting electrolyte incorporating into the polyporphyrin.