Nonpolar Adsorbates Research Articles

COMPARATIVE ANALYSIS OF EFFECTIVENESS OF POLVAK 15/72 AS A COAGULANT FOR DRINKING WATER PRODUCTION

New coagulant Polvak 15/72 consisting of aluminum hydroxychloride with a pure Al2O3 content of at least 15.3 wt % was investigated as a possible highly effective agent for discoloration, clarification, and cleaning the natural freshwater to produce high-quality drinking water. Water was taken from the river of Dnipro during the winter-summer period of 2022. A 20 mg dm-3 coagulant concentration showed sufficient water cleaning effectiveness, and brought its chromaticity, turbidity, permanganate oxidizability, aluminum and iron contents within the sanitary limits. This result has been achieved using a coagulant that does not consist of Fe (for which the toxicity is higher than that of Al) and less Al than in the widely used Polvak-68. The effectiveness of removing trihalomethanes (THM, mostly chloroform) by Polvak 15/72 is insufficient, and additional non-polar adsorbent or the use of a chlorine-free water disinfection technology is required to keep the content of THM within the sanitary limits.

Utilization of Ketapang Seed Shells in Reducing Pb(NO<sub>3</sub>)<sub>2</sub> Metal Levels by Adsorption Process

Industrial wastes such as lead metal can cause serious problems because of their toxic nature and can pollute the environment. To reduce levels of lead metal, you can use a natural adsorbent from activated charcoal on the outer shell of ketapang seeds. The ketapang tree is a type of plant that is often found in the surrounding environment because it is used as a shade for the many falling ketapang seeds making waste in the environment to reduce environmental pollution from the falling ketapang can be used as an adsorbent because it contains cellulose and carbon elements. One alternative to reduce lead levels using adsorbents is through the adsorption process which is the process of adsorption of a solid or liquid that involves physical, chemical and electrostatic interactions between the adsorbate and the adsorbent on the surface of the adsorbent. The adsorption process using activated charcoal adsorbent is one of the most frequently used non-polar adsorbents because it has better adsorption power and surface area than other types of adsorbents. This study aims to determine the influencing variables and the optimum condition of the natural adsorbent from the activated charcoal of the outer shell of ketapang seeds on decreasing levels of metal Pb (NO3)2. The research method used is an experimental method with a two-level factorial design. The results showed that the adsorption temperature was the most influential variable in this study with an optimum yield presentation of 66.77%. The activated charcoal produced has a water content of 8%, ash content of 5.2% and an absorption capacity of methylene blue of 698 mg/g.

Optimizing solid phase extraction and HPLC-MS/MS parameters for reliable quantification of COVID-19 pharmaceuticals in Mexico City’s wastewater: A design of experiments approach

Through the COVID-19 health crisis, a plethora of new medications, along with some discontinued pharmaceuticals, were directly tested on population to assess their efficacy in symptom management. Consequently, residues from these treatments were systematically disposed into sewage systems, presenting a novel contamination challenge in urban centers. To effectively address this issue by environmental authorities, the presence of these pollutants in wastewater must be accurately quantified. Herein, we conducted a meticulous study to validate an analytical method based on solid-phase extraction (SPE) and high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) to detect six pharmaceuticals (metformin, famotidine, indomethacin, dexamethasone, azithromycin, and ivermectin) in wastewater. Using a Plackett-Burman design (PBD), the eight parameters significantly impacting on the HPLC-MS/MS technique were established based on the analytical signal of the six analytes. Subsequently, in conjunction with a Box-Behnken design (BBD), optimal analysis conditions were determined as follows: injection volume: 10 µL, column temperature: 20 °C, capillary voltage: 4100 V, drying gas temperature and flow rate of 350 °C and 7 L min−1 respectively, nebulizer pressure: 15 psi, concentration of formic acid and ammonium acetate in the mobile phase of 0.1 % and 10 mmol/L, respectively. SPE was optimized through a univariable experimental design. OASIS HLB cartridges exhibited the highest extraction efficiency compared to highly polar and non-polar adsorbents. The optimal sample loading conditions were set as 250.0 mL of water sample at pH = 9.0. The washing conditions were 5.0 mL of a 95:5 water:methanol solution, while elution conditions were optimal using 6.0 mL of a 98:2 methanol:formic acid solution. After evaporating the eluate to dryness and reconstituting in 1.0 mL of a 98:2 methanol:formic acid solution, a concentration factor of 250 was achieved. The analytical method was validated using for matrices, namely, raw and treated wastewater, wastewater percolated through soil and groundwater. Acceptable levels of precision and accuracy were achieved for all analytes in the tested matrices. Using the validated method, the six pharmaceuticals were quantified in environmental samples, revealing high levels of metformin, dexamethasone, and azithromycin in Mexico City’s sewage. Highly polar compounds displayed mobility through environment as they were present in effluent samples, percolated wastewater, and groundwater.

Decoding wettability in coal-water-CO2 system for enhanced sequestration security

The injection of CO2 into deep unminable coal seam is a most promising carbon storage method that can simultaneously achieve the dual objectives of mitigating CO2 emission and enhancing coalbed methane recovery. In this context, the wettability of the coal-water-CO2 system plays an important role in the CO2 injection rate, storage capacity, and sequestration security. However, the factors affecting wettability alternation in the coal-water-CO2 system are still unclear until now. In this study, the sessile drop method was used to measure the contact angle (CA) in the coal-water-CO2 system under different pressures (3 – 8 MPa) and temperatures of (40–70 °C) with four different rank coals. Results indicate that with increasing pressure, the CA shows a steady increase below 5 MPa followed by a rapid increase at 5 – 8 MPa. The CA decreases with increasing temperature and coal rank. The CA is negatively correlated with the mes- and macro-pores, but positively correlated with micropores. It was found that these relationships are attributed to the CO2 density and CO2 adsorption capacity of coal. As the CO2 density increases, the coal-CO2 interaction force intensifies, leading to a tendency towards CO2 wetting for the coal-water-CO2 system. The adsorption capacity illustrates the strength of the coal-CO2 interaction, where the affinity of polar adsorption sites for CO2 molecules exceeds that of nonpolar adsorption sites. Finally, we conducted a comprehensive assessment of the wettability of the coal-water-CO2 system as it varies with burial depth by developing an integrated model that considers four influential factors, including pressure, temperature, coal rank, and pore structure. The findings of this study can be utilized to determine the optimal CO2 injection pressure in CO2-ECBM projects and enhance sequestration safety.

In English

Features of interfacial adsorbate/adsorbent phenomena depend on several factors: particulate morphology, texture, and structure of adsorbents, molecular weight, shape, and polarity of adsorbates; as well as prehistory of adsorbents pretreated under different conditions. All these factors could affect the efficiency of practical applications of not only adsorbents but also polymer fillers, carriers, catalysts, etc. Interactions of nonpolar nitrogen, hexane, benzene, weakly polar acetonitrile, and polar diethylamine, triethylamine, and water with individual (silica, alumina), binary (silica/alumina (SA)) and ternary (alumina/silica/titania, AST) nanooxides were studied using experimental and theoretical methods to elucidate the influence of the morphological and textural characteristics and surface composition of the materials on the adsorption phenomena. The specific surface area SX / ratio (X is an adsorbate) changes from 0.7 for hexane adsorbed onto amorphous silica/alumina SA8 with 8 wt. % Al2O3 (degassed at 200 °C) to 1.9 for acetonitrile adsorbed onto pure fumed alumina (treated at 900 °C). These changes are relatively large because of variations in orientation, lateral interactions, and adsorption compressing of organic molecules interacting with surfaces characterized by certain set and amounts of various active sites, as well as due to changes in the accessibility of pore surface for probe molecules of different sizes. Larger SX / > 1 values are observed for complex fumed oxides with larger primary nanoparticles, greater surface roughness, hydrophilicity, and Brønsted and Lewis acidity of a surface. Both polar and nonpolar adsorbates can change the morphology and texture of aggregates of oxide nanoparticles, e.g., swelling of structures, compacted during various pretreatments, upon the adsorption of liquids. The studied effects should be considered upon practical applications of adsorbents, especially “soft” fumed oxides.

Investigation of the adsorption of nonpolar adsorbate molecules on the illite surface

Investigation of the adsorption of nonpolar adsorbate molecules on the illite surface

Adsorption of naphthalene and its derivatives onto high-density polyethylene microplastic: Computational, isotherm, thermodynamic, and kinetic study

Microplastics (MP) have received great attention due to the mass-produced residues discharged into the environment. MP are ideal for adhering to organic pollutants that can be easily dispersed, thus posing risks to human health. Furthermore, little has been reported on how different functional groups in polycyclic aromatic hydrocarbons (PAH) derivatives influence the adsorption behavior on MP. To better understand this process, groups methyl (–CH3) and hydroxyl (–OH) were selected and commercial and waste high-density polyethylene (HDPE, ≤ 1 mm) were used as adsorbents, and Naphthalene (Nap), 1-Methyl-Naphthalene (Me-Nap) and α-Naphthol as adsorbates. The results showed different behaviors for nonpolar and polar adsorbates. Dispersion forces were the main type of interaction between HDPE and Nap/Me-Nap, while dipole-induced dipole forces and H-bonding were the chief interactions involving MP and polar compounds. Regardless the HDPE source, Nap and Me-Nap have a Type III isotherm, and α-Naphthol presents a Type II isotherm. Nap and Me-Nap fitted to Freundlich isotherm of an unfavorable process (n = 2.12 and 1.11; 1.87 and 1.31, respectively), with positive values of ΔH° (50 and 77.17; 66 and 64.63 kJ mol−1) and ΔS° (0.070 and 0.0145; 0.122 and 0.103 kJ mol−1) for commercial and waste MP, respectively. Besides, the adsorption isotherm of α-Naphthol on commercial and waste HDPE fitted to the Langmuir model (Qmax = 42.5 and 27.2 μmol g−1, respectively), presenting negative values of ΔH° (−43.71 and −44.10 kJ mol−1) and ΔS° (−0.037 and −0.025 kJ mol−1). The adsorption kinetic study presents a nonlinear pseudo-second-order model for all cases. The K2 values follow the order Me-Nap > Nap >α-Naphthol in both MP. Therefore, this experimental study provides new insights into the affinity of PAH derivatives for a specific class of MP, helping to understand the environmental fate of residual MP and organic pollutants.

Mn-CUK-1: A Flexible MOF for SO2, H2O, and H2S Capture.

The environmentally benign metal-organic framework (MOF) CUK-1 based on 2,4-pyridine dicarboxylate has been prepared for the first time using Mn(II) as the inorganic node and water as the only solvent. Mn-CUK-1 shows reversible and efficient capture of H2O, SO2, and H2S. Compared to previously studied Co(II) and Mg(II) versions of the same MOF, Mn-CUK-1 also exhibited unique temperature-induced structural flexibility due to organic linker torsion, as detailed by variable-temperature single-crystal X-ray diffraction studies. Owing to this inherent solid-state flexibility, Mn-CUK-1 showed stepwise adsorption for polar gases, which induce structural deformations upon adsorption, while the nonpolar guest adsorbates were reversibly sorbed in a more classical manner. Notably, Mn-CUK-1 demonstrates the highest reported H2S capacity-to-surface area ratio among MOFs that are chemically stable toward this reactive acidic molecule. Moreover, Mn-CUK-1 displays exceptional structural stability in the presence of high relative humidity and corrosive gases and shows soft crystalline behavior triggered by changes in both the adsorption temperature and guest molecule identity.

Thermal desorption characteristics of the adsorbate in activated carbon based on a two-dimensional heat and mass transfer model

• A multiphase model of heat and mass transfer in porous media is established. • The multiphase model is validated to simulate the thermal desorption behavior of activated carbon adsorption. • A simplified evaporation rate formula is proposed, and the agreement between the model and the experimental results are verified. • The effect of high thermal conductivity activated carbon on thermal regeneration time is analyzed. • The effects of polar and non-polar adsorbates on model accuracy are analyzed. Thermal desorption of adsorbate in activated carbon is the main part in the thermal regeneration process of spent activated carbon, and previous studies have carried out a series of numerical simulations on it. However, since activated carbon is a porous medium, the heat and mass transfer in activated carbon is different from that in solid. In this paper, a multiphase model of heat and mass transfer in porous media was constructed to study the thermal desorption characteristics of adsorbate in spent activated carbon. In addition, a simplified evaporation rate formula is proposed in this paper, and the agreement between the simulation and the experimental results is verified. When the surroundingtemperature is less than 673.15 K, increasing the surrounding temperature has a significant effect on reducing the thermal desorption time of the adsorbate. Using activated carbon with a thermal conductivity of 5 W / m ∙ K can save about 40% of energy consumption. The model established in this paper can accurately simulate the thermal desorption of adsorbate in activated carbon, which is helpful to deeply understand the mechanism of activated carbon thermal regeneration. In engineering practice, the model can provide technical support for optimizing the thermal regeneration process of spent activated carbon and reducing energy consumption in a targeted manner.

Elaborate interface design of CoS2/Fe7S8/NG heterojunctions modified on a polypropylene separator for efficient lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries are considered as the most promising energy storage system due to their high specific capacity and resource abundance. However, the low electronic conductivity of S8 and Li2S, shuttle effects of lithium polysulfides (LiPSs), and sluggish reaction kinetics hinder the advance of Li-S batteries. The key to addressing the issues mentioned above is to improve the electrical conductivity of the cathode, enhance the absorption of LiPSs and accelerate the conversion. Nevertheless, it is a great challenge to simultaneously optimize them all. In this study, by incorporating the virtues of the large lamellar structure and strong nonpolar adsorption of reducedgrapheneoxide (rGO), strong polar polysulfide adsorption of Fe7S8 and excellent catalytic polysulfide activity of CoS2, a CoS2/Fe7S8 heterostructure grown on the nitrogen-doped rGO (CoS2/Fe7S8/NG) was prepared. Besides, the experiments demonstrate that the designed CoS2/Fe7S8/NG possesses strong absorption and superior catalytic ability towards LiPSs. Subsequently, when applied as a modification layer for the polypropylene (PP) separator, the CoS2/Fe7S8/NG-PP coupled with CNT/S cathode exhibits a high initial discharge capacity (1459 mAh g−1 at 0.1 A g−1), a reversible capacity of 731 mAh g−1 after 100 cycles at 0.2 A g−1, and a robust cycling stability (0.058 % flowing rate at 1.0 A g−1). Moreover, the cathode with a high sulfur mass loading of ∼ 3.8 mg cm−2 can still display a reversible capacity of 663 mAh g−1 after 100 cycles at 0.2 A g−1. More importantly, the study shown herein shed light for the design of heterojunction to improve the electrochemical performance of Li-S batteries.

In English

Interfacial phenomena at a surface of porous and highly disperse adsorbents in the systems containing strongly and weakly bound and unbound liquids depend strongly on the confined space effects. These effects as well as the temperature behavior of liquids located in pores or voids between nanoparticles depend on many factors. They are the pore size distributions, pore volume, specific surface area, surface chemistry of adsorbents, chemical structure and molecular sizes of adsorbates, accessibility of pores vs. probe molecule sizes, as well as textural instability of adsorbents. This instability can appear, e.g., as compaction of fumed oxides under action of liquid adsorbates, especially water, or due to mechanochemical activation. The aim of this study is to analyze features of the interfacial phenomena upon interactions of fumed oxides (silica, alumina, alumina/silica/titania) and porous silicas (silica gels and precipitated silica) with polar (water, dimethyl sulfoxide), weakly polar (chloroform), and nonpolar (n-decane, aromatic benzene and toluene) liquid adsorbates depending on the morphological and textural characteristics of the adsorbents, various adsorbate characteristics, and temperature. The observed effects as well as related phenomena are important because they can differently influence the efficiency of practical applications of adsorbents under various conditions (temperature, pressure, concentrations) depending on the characteristics of adsorbents and adsorbates (liquids, solvents and solutes).

Purge gas humidity improves microwave-assisted regeneration of polymeric and zeolite adsorbents

Microwave (MW) heating can be an effective method for adsorbent regeneration; however, it is limited to adsorbents with high MW absorption ability. In this study, two low MW absorption adsorbents (a beta type zeolite and a hyper-crosslinked polystyrene resin) were regenerated using MW heating to study the effect of purge gas humidity on MW absorption. Water saturation of the purge gas used during MW heating enhanced MW absorption by the adsorbent bed. The zeolite, a hydrophilic adsorbent, showed higher interaction with water molecules in the MW field than the resin, a hydrophobic adsorbent. The interaction of water molecules with the adsorbent surface and the water vapor concentration in the purge gas were found to be the main factors governing the extent of MW heating in the studied adsorbents. MW heating using both dry and humid purge gases was utilized to desorb model polar and non-polar adsorbates (isopropanol and cyclohexane) from the adsorbents. Using water-saturated purge gas reduced the MW energy needed for the complete desorption of cyclohexane and isopropanol on the zeolite by 73 % and 61 %, respectively, and on the resin by 33 % and 25 %, respectively. Nitrogen adsorption analysis showed that BET surface area and total pore volume of adsorbents before and after MW-assisted regeneration were comparable. This study shows that using water-saturated purge gas enhances the MW regeneration of adsorbents with poor dielectric properties.

A Study Into the Alteration of Physical and Chemical Characteristics of Activated Carbon Surface for Purifying Water

The most common applications of activated carbon in today’s world are process water treatment, commercial and industrial wastewater treatment, and air/odour abatement. When transformed to activated carbons, carbonaceous source materials have the potential to efficiently cleanse and eliminate a wide range of pollutants from water and wastewater streams. With over 1,000 recognized uses, activated carbon’s potential is limitless. AC may be tailored to satisfy a wide range of unique purposes, from gold mining to water purification, and food manufacturing. Non-polar adsorbents like activated carbon work well. It may be used with a range of substances to adsorb diverse qualities of wastewater due to its large specific surface area and micropore, high adsorption performance, and recycling. This research aimed to look into the influence of chemical surface features on activated carbons’ application in water purification.

Hydrophobic Modification Experiment and Characterization of FDU-15 with Different Pore Diameter

Three ordered mesoporous carbon materials FDU-15 with different pore diameter were used.The pore size of FDU-15 can be achieved by changing the temperature and calcination atmosphere during template removal calcination.There are more polar functional groups on the inner and outer surfaces of FDU-15 pores. As a highly hydrophilic group, hydroxyl will make FDU-15 adsorb more water molecules. In practical application, water molecules and PAHs (polycyclic aromatic hydrocarbons) will produce competitive adsorption. At the same time, PAHs are mainly non-polar compounds, so non-polar adsorbents are more conducive to the adsorption of PAHs.In conclusion, the nonpolar functional groups on the surface of FDU-15 will reduce the adsorption of PAHs, which is also caused by the poor thermal and hydrothermal stability of FDU-15 material, which limits the application of FDU-15.Therefore, hydrophobic modification of FDU-15 can reduce the number of hydroxyl functional groups on its surface, adjust the surface hydrophobicity, enhance the hydrothermal stability and improve the adsorption performance of FDU-15 for PAHs. The silylation hydrophobic modification of adsorbent is studied, and the FDU-15 with different pore diameter is hydrophobically modified. It is expected to obtain a modified FDU-15 with the best pore size by comparing its adsorption isotherm, which can be put into practical use. The hydrophobic modification in this study adopts post transplantation method, and the modified samples are characterized by FT-IR to test the modification effect.

Influence of physical structures and chemical modification on VOCs adsorption characteristics of molecular sieves

The adsorption method using molecular sieves as adsorbent is one of the effective ways to control the emission of volatile organic compounds (VOCs), while the unclear adsorption mechanism between different molecular sieves and VOCs blocks its industrial application. The effects of physical structure and chemical modification of molecular sieves on the adsorption of VOCs were studied by computer simulation and adsorption experiment. Grand Classical Monte Carlo (GCMC) simulation was employed to investigate the adsorption behaviors of VOCs in a variety of pure silica molecular sieves with different physical structures, including aldehydes, ketones and benzenes. Further, combined with density functional theory (DFT) calculations, the influences of chemical modification on the adsorption of VOCs were investigated. Finally, the theoretical results were verified through adsorption experiments. The results revealed that the molecular sieve topology, the pore diameter of the molecular sieve, and the molecular kinetic diameters of VOCs all markedly influenced the adsorption of VOCs. Pure silica molecular sieves exhibited considerable adsorption ability for polar adsorbates. For nonpolar adsorbates, the adsorption ability decreased as the molecular volume increased. The DFT results indicated that the adsorption of VOCs is stronger at Cu2+ site than [Cu-OH]+ site in modified MFI. The experimental results of toluene adsorption for MFI, BEA, and Y-type zeolites strongly supported the theoretical results.

Competitive and Synergistic Adsorption of Mixtures of Polar and Nonpolar Gases in Carbonaceous Nanopores.

Most adsorption applications involve mixtures, yet accurate predictions of the adsorption of mixtures remain challenging, in part due to the inability to account for the interplay between adsorbate-adsorbate and adsorbate-adsorbent interactions. This study involves a comprehensive Monte Carlo simulation of the adsorption of two groups of mixtures (namely, supercritical and subcritical ones) in carbon nanopores and quantifies Henry's constants, isotherms, energetics, and density distributions in the pores. When interadsorbate interactions are negligible (e.g., in supercritical mixtures such as mixtures of nonpolar gases), adsorbates behave like ideal gases and the adsorption isotherm can be predicted with the ideal adsorbed solution theory (IAST). However, when interadsorbate interactions become significant, IAST fails. This study reveals that (1) in mixtures of polar and nonpolar gases, the stronger intermolecular interaction for the polar constituent leads to synergistic adsorption that causes the nonpolar adsorbate to desorb and (2) for mixtures of polar gases, such as ethanol and water, the adsorbate-adsorbate interactions are so dominant that the unfavorable adsorbate-adsorbent interactions are overcome, such that water adsorbs onto the hydrophobic adsorbent. The competitive and synergistic interactions highlighted here are expected to be valuable in enhancing gas separations.

Effects of external electric field on the sensing property of volatile organic compounds over Janus MoSSe monolayer: a first-principles investigation.

Janus 2D transition metal dichalcogenide (TMD) is a new generation 2D material with a unique asymmetric structure. This asymmetric structure (or out-off plane symmetric geometry) of Janus 2D TMD has been reported to yield tunable electronic properties through strain and electric field, which can also be applied in gas sensing. In this work, we performed DFT calculations to investigate the gas sensing property of cyclohexane and acetone on MoS2 and Janus MoSSe monolayers under external electric fields. Our results show that cyclohexane possesses slightly larger adsorption energy on pristine MoS2 and Janus MoSSe monolayers than acetone without external electric fields. After applying the external electric fields, the adsorption energy for cyclohexane on MoS2 shows no enhancement. However, the adsorption energy of acetone shows the most substantial enhancement on the Janus MoSSe monolayer. We found that the dipole moment orientations of adsorbates and the monolayer can strongly interact with the external electric fields. Hence, the combination of polar adsorbate and polar material, i.e., acetone and Janus MoSSe, demonstrates the most vital sensitivity under the applied bias. On the other hand, the non-polar adsorbate and non-polar material combination show a negligible effect on external bias. These findings can be applied to the design of gas sensors in the future through polar materials.

Sulfonyl PIM‐1: A diverse separation membrane with dilation resistance

AbstractA sulfone modified variant (soPIM‐1) of the first polymer of intrinsic microporosity has been studied through molecular simulations to analyze its applicability for adsorption‐based separations of diverse nonpolar, quadrupolar, and dipolar adsorbate species. Single component gas phase adsorption isotherms of each adsorbate are provided. The adsorptive properties of soPIM‐1 are reported from the application of two methods: (a) traditional grand canonical Monte Carlo (GCMC) simulations and (b) a combination of Monte Carlo and molecular dynamics (GCMC/MD) techniques, which accounts for sorption‐induced polymer dynamics. The calculated isosteric heats of adsorption are compared to those from the parent PIM‐1 structure and reveals increased CO2 affinity with relatively no change in hydrocarbon affinity. Moreover, to quantify soPIM‐1's resistance to dilation the evolution of the microporous structure across the adsorption isotherm loading pressures has been evaluated. Relatedly, nonequilibrium MD simulations have been utilized to determine that soPIM‐1 is approximately twice as stiff as PIM‐1.

The role of surface functionality of sustainable mesoporous materials Starbon® on the adsorption of toxic ammonia and sulphur gasses

The interest in adsorbing toxic gases nowadays is primarily due to their short- and long-term adverse health effects. It is generally accepted that the pore morphology and the surface nature play key roles in the adsorption mechanism of any molecules. The interactions between the adsorbate and adsorbent are affected by their polarity, where nonpolar surfaces would be attracted to a non-polar adsorbate, while polar surfaces have a higher affinity for polar molecules. The primary issue is access to a controllable set of materials with multiple functionalities that provide both polar and nonpolar surfaces for adsorption, which would present an advantage over single-phase adsorbents. Recently this has become available thanks to a novel class of bio-based carbonaceous materials (Starbon®). The functionality of these materials can be easily controlled by their temperature of preparation. The present work studies the nature of the surface chemistry and porosity of bio-based mesoporous materials Starbon and the role this plays in the adsorption of toxic volatile molecules such as ammonia, as a basic adsorptive and two acidic gasses (hydrogen sulphide and sulphur dioxide) using an InfraSorp optical calorimeter. Both hydrogen sulphide and sulphur dioxide adsorb better onto a hydrophobic surface, while ammonia adsorbs best onto a hydrophilic surface. The results showed that in both cases, Starbon significantly outperformed the industrially available powdered Norit® activated carbon (AC) and reacted chemically with the gasses to some extent.

Preparation and application of PGMA-DVB microspheres via surface-modification with quaternary and phenylboronic acid moiety

Porous cross-linked poly (glycidyl methacrylate-divinylbenzene) (PGMA-DVB) particles (7.42 ± 0.24 μm in diameter) were prepared by an improved two-step seed swelling polymerization method. The PGMA-DVB particles were further modified with poly (allylamine hydrochloride) (PAH) and 4-(bromomethyl) phenylboronic acid (BPA), which were used as high performance liquid chromatography (HPLC) filler for nucleotides separation. The liquid chromatographic column packing materials successfully achieved complete separation of nucleotides mixture or deoxynucleotides mixture based on non-polar adsorption, hydrogen bonding interaction and electrostatic adsorption. Reckoning on the chemical structure of BPA, nucleotides and deoxynucleotides with same base group were also separated. The column packing materials were durable after over 100 time running or 7 days. It presents a kind of new notion for the separation of nucleotides by HPLC.