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A particular attention should be paid to isolation, characterization, and assessment of bioactive flavonoids, especially for anti-arthritic activity. The slurry of adsorbent (silica gel; 60–120 lattice) was blended in n-hexane to form a uniform slurry, and this was then employed as a fixed-stage adsorbent. Butanolic solution (10 g) was dissolved in the minimum volume of butanol, and then adsorbed on silica gel (60–120 mesh) while still wet. The wet powder was then dried, and the separated liquid phase was collected and applied to the column to try to isolate possible phytoconstituents. A whole plate full of fractions was monitored simultaneously on a TLC plate with a mixture of chloroform:methanol:water (68:30:02) as the solvent system. Six fractions (F1-F6) were generated after the colours of F1 and F2 were mixed next to each other, and after Rf was discovered in F3. A separate group of six animals was created for the survey, which was made up of five treatment groups and one control group. It was concluded that yellow crystalline solid luteolin was obtained as a result, with the Shinoda test confirming that it was a flavonoid. The absorption of luteolin was discovered to be in an aqueous alkaline solution. There were five different resonances, occurring at different frequencies, in the 400 MHz 1H NMR spectrum: 7.00 (d, J = 13.5 Hz, 2H), 6.73 (s, 1H), 6.56 (s, 1H), 6.18 (s, 1H), 6.05 (s, 1H), 4.78 (s, 1H), 4.24 (s, 1H), 3.81 (s, 1H) (s, 1H). Inhibiting arthritic inflammation at doses of 40 mg/kg (luteolin) was significant (P

We describe a novel strategy to increase the unit-time-productivity of flow synthesis by using hierarchical bimodal porous silica gel (HBPSG) supported palladium column reactors. Because HBPSG has a significantly large surface area, the column reactors have low pressure drop, enabling high-volume production. We demonstrated flow synthesis of the precursor of adapalene, a pharmaceutical compound, at 5 g/h which is over 10-fold greater productivity than previous approaches.

Heat-treated porous silica gel (HT silica gel) previously developed by our group has selectively adsorbed cationic peptides at a pH of 7. Therefore, we focused on the use of antimicrobial peptides (AMPs) as bioactive peptides (BPs). First, 32 AMPs and 32 randomly designed peptides were generated using Fmoc solid synthesis, and their adsorption ratio to HT-silica gel was investigated. Thirty two AMPs showed a relatively higher adsorption ratio of 58.8% compared to that of randomly designed peptides, which was 35.3%. Desorption conditions were investigated using Amyl-1-18 antimicrobial peptides. Next, pepsin hydrolysate from rice endosperm protein (REP) powder was prepared by ourselves. The REP hydrolysate containing dry matter (7.5 mg) was applied to the adsorption/desorption (AD) procedure using HT silica gel to obtain 1.6 mg of AD hydrolysate. When the two hydrolysates were subjected to mass spectrometry, 305 concentrated peptides were obtained. In total, 26 peptides with high content and high enrichment ratios were listed and synthesized. When the antimicrobial activity of these 26 peptides was evaluated using Cutibacterium acnes, five peptides consisting of 12-27 amino acids were identified as novel AMPs. Two of these peptides, which were derived from rice glutelin, showed antimicrobial activity against all four microbes, including Porphyromonas gingivalis, Escherichia coli, and Streptococcus mutans. In the present study, we showed that AMPs could be easily enriched from protein hydrolysate using HT silica gel. The adsorption/desorption procedure using HT silica gel was confirmed to be a useful tool for convenient BP separation.

As the bearer of wet load, the desiccant wheel determines the performance of the rotary wheel dehumidification system. In this study, a novel metal organic framework composite adsorbent desiccant wheel (MOF DW) was prepared by impregnating–spraying method. The complete rotary wheel dehumidification system was built to compare the dehumidification performance of MOF DW and commercially silica gel desiccant wheel (SG DW). The experimental results showed that increasing the rotation speed appropriately improves the utilization ratio of regenerative energy and dehumidification capacity of MOF DW at high ambient humidity ratio. The temperature rise at the inlet and outlet of MOF DW is lower than that of SG DW at low ambient humidity ratios, and the opposite is true at high ambient humidity ratios. In addition, the dehumidification capacity and coefficient of performance of the MOF DW increase by 40%–48% and 13%–19%, respectively, compared with those of the SG DW at the regeneration temperature of 50°C.

An HPTLC technique for simultaneous estimation of Valsartan and Hydrochlorothiazide in a pharmaceutical combination dose form must be verified for stability indication. For the separation of VAL and HTZ using TLC plates coated with aluminium supported silica gel 60 F254, a high-performance thin layer chromatographic (HPTLC) technique has been devised. For the separation of two medicines, a variety of mobile phases were tried and tested. It was decided to use chloroform: ethyl acetate: ethanol/tetrahydrofuran as the final mobile phase for analysis. 247 nm was chosen as the detecting wavelength for both compounds since it exhibited highest absorption. As per the ICH recommendations, the devised technique was validated. Under varied stress settings, medicines were forced to degrade, and the stability of pharmaceuticals was assessed using the HPTLC technique. The separation of VAL and HTZ using HPTLC was a great success. A low percent RSD was determined by testing a variety of factors, and the stability experiments showed that the medicines and degraded products could be separated with an acceptable percent drug recovery profile. Rapid, accurate, and reproducible are some of the characteristics of the devised technique, which proves its appropriateness for valsartan and hydrochlorothiazide stability assessment.

Novel HPLC method was developed for enantioresolution of tyrosine kinase inhibitor drug Ibrutinib (IBT). Separation and identification of IBT enantiomers was investigated using cellulose tris (3,5-dichlorophenylcarbamate) immobilized on silica gel (Chiral-pack-IC). Good baseline enantioseparation was achieved on Chiral-pack-IC under normal-phase condition composed of n-Hexane, ethanol in a ratio of 55 and 45 (%v/v) with 0.1% Diethyl amine and 0.3% Trifluoro acetic acid. Resolution between IBT and its enantiomer was above 4. The flow rate and column oven temperature were 0.9 mL/min and 30 °C respectively. Detection was carried out at 260 nm. Injection volume optimized was 10 µL. Developed method was validated in accordance with ICH guide lines for specificity, limit of detection, limit of quantification, linearity, accuracy, precision, ruggedness and robustness.

The current global concern related to ground water contamination especially fluoride (F- contamination has ascended in an increased exigence for effective adsorbents. In this study, we have used a surface altered pectin biopolymer with silica–gel (SG), and incorporation of cerium oxide (Ce@SG-Pec) for the application of F- adsorption studies from the aqueous systems. The temperature, contact time, absorbent dosage, pH, coexisting anions, and initial F- concentration are discussed. The isothermal and kinetic data were fitted to Temkin and pseudo-second-order model, respectively. Analysis of adsorptive thermodynamics showed that the adsorption process was endothermic, spontaneous, feasible, and chemisorption type of adsorption mechanism. The good adsorption is attributed to chemical adsorption through strong surface complexation of cerium and silicon with F- as well as the special structure of adsorbent. The surface analyses (BET and FESEM) had shown the decrease in pore size after the F- adsorption. Additionally, FTIR analyses supported the substantial role of ion–exchange and electrostatic interaction in the adsorption mechanism.

Indoor air humidity plays a vital role in determining occupants’ health and industrial product quality. Removing excess humidity by adsorption dehumidification is still facing a challenge in finding a suitable material with high adsorption capacity and low regeneration temperature. In this study, the theoretical dehumidification capacity of prepared acorn nutshell-based activated carbons was calculated and compared with silica gel type RD and RD-2060. The calculation was based on the outdoor air condition in two Asian capital cities: Jakarta and Tokyo. The theoretical study found that prepared activated carbon has better dehumidification performance under Jakarta conditions using regeneration temperatures of less than 60°C. Under Tokyo conditions, activated carbon shows auspicious performance during the summer season. Compared with silica gels, acorn nutshell-based activated carbon has a better dehumidification capacity to process high humidity ambient air with a lower regeneration temperature.

Formaldehyde is a dangerous chemical present in many industrial waste gases. It can be recovered via catalytic processes; however, many of these require costly precious metals operating under limited reaction temperatures, making their industrialization difficult. This paper proposes a novel method of formaldehyde recovery. A sulfonation catalyst is used to promote a condensation reaction of methanol and formaldehyde to form methylal. Hence, a valuable chemical product is obtained while removing formaldehyde. A series of Al2O3-xSO3H catalysts were designed and the effects of surface acidity and hydroxyl groups on catalytic activity were explored by varying the activation temperature and sulfonation ratio. At an activation temperature of 60 °C, the yield of formaldehyde reaches 78.62% and the selectivity to methylal reaches 80.11%. This recovery rate is much higher than those reported in other studies. Through a series of characterizations, it was found that when the content of –SO3H groups is low, the hydroxyl content increases, which provides more activation centers for the formation of by-product formic acid from formaldehyde, and for the dehydration and condensation of formic acid and methanol to form methyl formate. At the same time, when the content of –SO3H groups is too high, side reactions of methanol and formaldehyde occur preferentially. Therefore, the synergistic effect of the contents of –SO3H and hydroxyl groups is the fundamental cause of the excellent catalytic performance. Based on in-situ infrared research, a possible mechanism of the reaction between methanol and formaldehyde on sulfonated silica gel is proposed, which also verifies the characterization of the catalyst. This research presents new possibilities for solving the problem of formaldehyde pollution.

The demand for dehumidification in tropical regions contributes to a significant portion of the building energy consumption. Desiccant dehumidification can mitigate energy consumption by recovering the exergy potential from the waste heat and renewable energy sources. Material development is the bottleneck in realizing the full potential of desiccant dehumidification systems beyond conventional adsorbents such as silica gel and zeolite. Therefore, it is necessary to develop novel materials that can be regenerated using the heat source under 70°C. In this study, we developed activated carbons (ACs) as the desiccant materials derived from waste biomass. The ability of activated carbon (AC) to remove the moisture was controlled by carefully preparing the material using several conditions to achieve the right operation window for optimum moisture sorption processes. The porous and surface characteristics of the newly-prepared AC were analyzed and compared with those of silica gel. The adsorption isotherm measurements were conducted, and the data were fitted with Henry-Sips and Do-Do isotherm models. The current AC exhibited an excellent water adsorption capacity (up to 0.41 g/g). The efficacy of the ACs for dehumidification applications was assessed using the weather data from several regions of Indonesia, from North Sumatera to Papua. The results revealed that under the studied conditions, the new desiccant material showed a better dehumidification capacity than silica gel. Moreover, the reported AC can be regenerated using temperatures as low as 40°C, which is readily available from waste heat, including the heat rejection from the condenser of any air-conditioning unit.

As an effective way to improve the performance of heat and mass transfer, Composite adsorbent used in adsorption refrigeration has attracted increasing research attention. The aim of the research is to reveal composite theory of silica gel composite adsorbent and to understand adsorption refrigeration system mechanism running by above composite adsorbent. Coarse porous silica gel with different particle diameters was selected as the matrix of composite adsorbent and calcium chloride was selected as additive. The results showed that composite adsorbent's thermal conductivity and adsorption capacity increased significantly compared with pure silica gel. The thermal conductivity could be increased by 58.2%, and the adsorption capacity could be increased by 4-10 times. Finally, the adsorption refrigeration system using silica gel-calcium chloride composite adsorbent was studied. A two-bed adsorption refrigeration cycle running by above composite adsorbent was adopted. The experimental results the optimal values of system cooling capacity and COP were not at the same time. The system cooling capacity reached its maximum at 1500s and the system COP reached its maximum at 1200s. The best heat recovery time was 20s. The SCP of the system was up to 288.1W kg−1, which could reduce the volume of the adsorption refrigeration system effectively.

Four hitherto unreported cycloartane-type triterpenes (1-4) with C-28/C-30 oxidized methyl groups together with two known compounds (5-6) have been obtained from the leaves and twigs of Caloncoba dusenii Gilg. The compounds were isolated through extraction and silica gel column chromatography. Their structures and relative stereochemistry were determined by extensive use of spectroscopic techniques including IR, 1D and 2D-NMR as well as mass spectrometry. This is the first report of C-28/C-30 oxidized positions in cycloartanes from nature.

The acid leaching process is believed to increase the silica extracted from rice husk ash (RHA). This study intended to investigate the influence of acid leaching sequences in RHA extraction on green silica purity and surface area. The sequences were RHA leaching (T1), aged gel leaching (T2), dried product leaching (T3), and without leaching as a control. The T1 sequence has been proven to improve the green silica purity and surface area reaching 96.44% and 400.69 m2/g, respectively. For T2 and T3 sequences, the green silica has a much lower surface area and purity compared to T1. The values were 87.69% and 55.49 m2/g for T2 as well as 62.46% and 11.40 m2/g for T3. Without acid leaching, the purity and surface area of green silica significantly reduced to 56.94% and 5.72 m2/g. This study concludes that green silica from T1 sequence has successfully obtained high purity, high surface area, and indicates an amorphous and mesoporous particle. It is suitable to be utilized as an industrial silica gel for moisture adsorber which more sustainable and greener process.

Here, a novel adsorbent for selective separation and recovery of In(III) ions from the real wastewater was fabricated using ion imprinting technique with graphene oxide composite as the host materials. Several techniques, including Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Thermogravimetry (TGA) and Brunauer–Emmett–Teller (BET)were used to characterize the silica gel/graphene oxide based ion-imprinted composites (SG/GOIIC) and the obtained experimental results were combined with the Density Functional Theory (DFT) theoretical calculations to reveal the adsorption mechanism. The adsorption behaviors of SG/GOIIC towards In(III) ions was evaluated using both batch and fixed-bed experiments. The results shown that the adsorption ability of In(III) ions onto SG/GOIIC increased with the increase of pH range from 1.5 to 3.0, and that the adsorption equilibrium was reached within 50 min. The maximum uptake of SG/GOIIC calculated using Langmuir isotherm was estimated to 147.1 mg/g. Kinetics studies revealed that the pseudo-second-order was a better choice to describe the whole absorption process, while the isotherms of In(III) ions adsorption followed the Langmuir model. In addition, SG/GOIIC exhibited excellent affinity towards In(III) ions in water even in the presence of Sn(II), Cu(II), Zn(II), Al(III) and Fe(III) ions and the corresponding selectivity coefficients of SG/GOIIC for In/Sn, In/Cu, In/Zn, In/Al and In/Fe were 18.47, 22.99, 35.31, 16.67 and 8.52, respectively. The SG/GOIIC possessed good stability with adsorption rate maintained at 94.36% even after five cycles. More importantly, the SG/GOIIC composite was able to separate and to recover indium from real wastewater through fix-bed adsorption. This study proposed a new method to prepare adsorbent with excellent selectivity towards targeted ions and to figure out the difficulty of graphene oxide in separation from water.

Two 20 wt.% Co/SiO2 catalysts have been prepared using silica gel as a support and cobalt acetate or nitrate as precursors. They were characterized before and after reaction using XRD, skeletal IR and DR-UV–vis-NIR spectroscopies and FE-SEM microscopy. Fresh catalysts are active in CO2 methanation at atmospheric pressure but rapidly deactivate at 623–673 K, due to formation of encapsulating carbon. However, they retain a more stable activity in producing CO by the reverse water gas shift (rWGS) reaction. Methanation and rWGS appear to occur on independent sites. The Co/SiO2 catalyst produced from Co-acetate precursor shows stable activity in Ethanol Steam Reforming (ESR) at 873−973 K, producing also carbon whiskers (nanotubes) that, however, do not cause catalyst deactivation at the laboratory conditions and timescale. The catalyst produced starting with Co-nitrate is even more active in ESR but it deactivates fast. At lower temperature or when deactivated with respect to ESR, both catalysts shift to high activity in ethanol dehydrogenation to acetaldehyde, showing that the ability to activate water is mostly lost. The differences observed among catalysts produced from cobalt acetate and cobalt nitrate precursors can be associated to the different pH of the impregnating solution. The higher pH of cobalt acetate solution results in surface dissolution / hydrolysis of silica and this may be at the origin of the formation of cobalt silicate surface species, which can also stabilize the support against high temperature reactivity. This might favor larger Co particles formation, less active, but also giving rise to inert cobalt species.

The petroleum ether extract from leaves of Erythroxylum monogynum when subjected to phytochemical analysis and chromatographic purification, resulted in the isolation of two new sterols namely 4-methyl ergosta-7, 23‑dien‑3β-ol and 4-methyl ergosta-7, 24 (28)‑dien‑3β-ol. Their structure was elucidated by NMR and Mass Spectrometry. The two sterols were separated on a silica gel 60F254 HPTLC plates impregnated with AgNO3 using dichloromethane: methanol (9:1 v/v) as a mobile phase. Upon densitometric scanning at 254 nm in a reflectance mode, the two sterols separated as sharp and compact bands with Rf of 0.47±0.02 and 0.52±0.01 respectively for 4-methyl ergosta-7, 23‑dien‑3β-ol and 4-methyl ergosta-7, 24 (28)‑dien‑3β-ol. Linear regression and calibration plots constructed (n = 6) showed excellent linearity at 100–500 ng per spot with a correlation coefficient, r = 0.9979±0.0004 and 0.9974±0.0007 for 4-methyl ergosta-7,23‑dien‑3β-ol and 4-methyl ergosta-7,24 (28)‑dien‑3β-ol, respectively. The Limits of detection and quantification were found to be 21.07 ng and 57.23 ng/band for 4-methyl ergosta-7,23‑dien‑3β-ol and 25.18 ng and 63.86 ng/band for 4-methyl ergosta-7,24 (28)‑dien‑3β-ol, respectively. Both the sterols demonstrated good anti-oxidant and anti-glycation activities where, the IC50 values obtained were comparable with the positive control compounds, ascorbic acid and aminoguanidine. The 4-methyl ergosta-7,23‑dien‑3β-ol displayed 100% anti-oxidant activity at 100 µg/ml for both DPPH and H2O2 scavenging assays. In addition, both the sterols presented more than 90% inhibition of Advanced Glycation End products at 100 µg/ml concentration. The results obtained are remarkable indicating that these plant extracts could serve as a natural alternative to the conventional oral hypoglycemic molecules.

Two new oleanane-type triterpene glycosides, 3-O-β- d -glucuronopyranosyl -echinocystic acid-28-O-β- d -apiofuranosyl-(1→3)[O-β- d -xylopyranosyl)(1→4)]-O- α- l -rhamnopyranosyl-(1→2)-β- l -arabinopranoside (1) and 3-O-β- d -glucurono pyranosyl-echinocystic acid-28-O-β- d -apiofuranosyl-(1→3)[O-β- d -xylopyranosyl -(1→4)]-O-α- l -rhamnopyranosyl-(1→2)-β- d -xylopyranoside (2) along with two known compounds impatienoside G (3) and scaberoside A2 (4), were isolated from an n-butanol fraction of the 50 % aqueous ethanol extract of the rhizome of Impatiens pritzellii var. hupehensis. The compounds were separated by silica gel column chromatography and RP-HPLC. Their structures were elucidated through the analysis of 1D and 2D NMR spectra and HRESIMS data. The T-lymphocyte proliferation activity of the isolated terpenoid saponins was evaluated by using the CCK-8 colorimetric method.

Food, especially animal origin food is the main source of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and dioxin-like polychlorinated biphenyls (dl-PCBs) for human exposure. So, a simple, rapid and cheap bioassay method is needed for determination of dioxins in food samples. In this study, we used a new highly sensitive reporter cell line to determine the concentration of dioxins in 33 fish and seafood samples. The samples were extracted by shaking with water/isopropanol (1:1 v/v) and hexane and cleaned-up by a multi layered silica gel column and an alumina column, then analyzed using CBG 2.8D cell line. We compared the results obtained from the CBG 2.8D cell assay to those obtained from conventional High-Resolution Gas Chromatography-High Resolution Mass Spectrometry (HRGC-HRMS) analysis. Good correlations were observed between these two methods (r2=0.93). While the slope of regression line was 1.76, the bioanalytical equivalent (BEQ) values were 1.76 folds higher than WHO-TEQ values and the conversion coefficient was 0.568 (the reciprocal of 1.76). In conclusion, CBG 2.8D cell assay was an applicable method to determine dioxins levels in fish and sea food samples.

Processing 3D SiC objects by thermal oxidation is cumbersome due to poor oxygen diffusion in SiC and the limited thickness of the silica layer at the interface between particles. In the present study we treated SiC particles with NaOH to create a silica gel layer. The surface modified particles were pressed manually at 0.47 MPa into discs and subjected to thermal treatment in the temperature range 500-1000 oC. FTIR confirmed the presence of the characteristic peaks for Si-O and Si-O-Si on the surface of the discs confirming the formation of a silica gel layer that bonded the particles at room temperature. SEM-EDX analysis demonstrated the growth of silica nanowires that bridged the walls of the pores during heat treatment. XRD showed the phase transformation of the silica gel into quartz and then cristobalite solid solution at higher temperature. In conjunction with the increased growth of the silica nano wires, the strength, toughness, and percent weight gain increased significantly without any measurable change in the dimensions of the discs. FTIR analysis of the condensed volatile species released from SiC discs during heating revealed the involvement of SiO gas in the mechanism of nanowires growth. Preliminary thermal shock resistance tests showed stability of the mechanical properties after water quenching of samples treated at 900-1000 oC. The new mechanism of SiC densification by silica nanowires growth while maintaining dimensional stability opens the door for new SiC manufacturing technology.

In this paper, a solar driven winter air-conditioning system comprising desiccant coated concentric tube heat exchanger (DCCTHE) is analysed experimentally. The setup consists of concentric tube heat exchanger with saturated desiccant coating to achieve continuous humidification of the dry air. Silica gel, activated alumina and combination of these with activated clay are used as desiccant materials in concentric tube heat exchanger alternately. Parabolic trough type solar air heater is used to supply hot air to regenerate the desiccant. The performance of the system shows the capability to provide continuous heating and humidification in the dry and cold winter weather of North India. The experimental unit performance is measured in the form of humidification factor, maximum outlet temperature and coefficient of performance. The maximum temperature of conditioned air achieved is 43.1⁰C with multiple desiccants whereas the dehumidification rate was minimum. The desiccant material with lowest regeneration temperature i.e. silica gel achieved maximum humidification factor of 6.7 g/kg. The COP of the system is maximum i.e. 0.74 for silica gel as desiccant, while for activated alumina and multiple desiccants, it is 0.62 and 0.6 respectively.

In this study, the catalytic potential of a novel heterogeneous catalyst-sulphuric acid supported on silica gel (H2SO4-SiO2) has been assessed for the one-pot cyclo condensation reaction of aromatic aldehydes, 4-nitrophenylacetonitrile, ethyl acetoacetate and hydrazine/phenyl hydrazine to furnish poly functionalized pyrano[2,3-c]pyrazol-amine scaffolds under ultrasonication. Notably, within the framework of green chemistry, this divergent and step-economic approach has many benefits such as (i) use of water as solvent in the reaction, (ii) creation of up to five bonds in one sequence, (iii) avail of US irradiation as an efficient source of energy, (iv) application of nontoxic and reusable catalyst. Besides these, simple workup procedure, low catalyst loadings, shorter reaction time, high functional group compatibility, readily accessible starting materials and excellent yields without column chromatography render this protocol novel and greener towards the synthesis of poly functionalized pyrano[2,3-c]pyrazol-amines.

A dual-reflux pressure swing adsorption (DR-PSA) process was proposed and simulated to initially separate the blue coal gas, aiming to capture carbon dioxide (CO2) and enrich hydrogen (H2), simultaneously. With a feed flow rate of 7.290 slpm, a light product reflux flow rate of 0.505 slpm and the heavy product reflux flow rate of 3.68 slpm, the developed DR-PSA process could capture CO2 up to 64.01% with a recovery of 99.60% and enrich H2 up to 34.66% with a recovery of 97.63% from the blue coal gas (36.2% N2/28.5% H2/13.9% CO/12.7% CO2/8.7% CH4). In addition, in order to optimize the process, the effects of various operating parameters on the DR-PSA process performance in terms of product purity and recovery were discussed in detail, including the feed position, the light product reflux ratio and the heavy product reflux ratio. Moreover, the dynamic distribution behaviors of pressure, temperature and gas-solid concentration were presented to explain and evaluate the process separation performance in depth under different operating conditions.

In this work the possibility of producing a CO2 hardened concrete where the binder is a calcium silicate hydrate instead of anhydrous silicates was investigated and the technological parameters for obtaining calcite based products, combining Ca2(HSiO4)(OH) (α-C2SH) hydrothermal synthesis and accelerated carbonation curing were presented. α-C2SH was synthesized in a stirred suspension (water to solid ratio 10, 100 rpm) after 16 h at 200 °C from lime-opoka (silica-calcite sedimentary rock) mixture with molar ratio CaO/SiO2 = 2.0. Pressed cylindrical samples from synthesized binder and its mixtures with sand were carbonated in the CO2 environment at 1.5 MPa and at 45 °C from 8 to 48 h. It was shown that α-C2SH is, in fact, a binder that hardens in a carbon dioxide atmosphere. Compressive strength of the samples carbonated for 8 h was ~10 MPa and with extended curing, reached ~35 MPa and ~60 MPa after 24 and 48 h, respectively. By XRD and STA it was found that most of the α-C2SH sample carbonates within the first 8 h of curing. Amount of CaCO3 continues to grow gradually but steadily for up to 48 h. SEM and 29Si MAS NMR indicated that the compressive strength development is rather more reliant on the calcite crystal growth than silica gel polymerization. Concrete products from binder/sand mixture (1:3 by mass) with a compressive strength of ~25 MPa can be produced when carbonation is performed at 1.5 MPa CO2 pressure, 45 °C, and 24 h duration. α-C2SH binder, compared to Ordinary Portland cement, has a significantly lower negative impact on the environment due to lower amounts of calcareous raw materials and the elimination of high-temperature combustion.

The purpose of this study was to prepare a proof-of-concept CO2 adsorbing material based on a new amine grafted silica aerogel microsphere (AGSAM) that could be used on both fixed and fluidized beds. A low-cost water glass and environment-friendly water were used as precursor and solvent of the silica aerogel, respectively. The silica aerogel microsphere (SAM) was prepared by dropping the siliceous solution into hot oil bath. The effect of the pH value of the siliceous solution, stirring speed and stirring paddle position on the sphericity and size of the SAM was investigated. The SAM with good sphericity was obtained when the pH value was 5.69–5.79. The mean diameter of the SAM decreased from 5 to 1 mm when the stirring speed increased from 1000 to 2000 rpm. The SAM with excellent sphericity was prepared when the paddle was placed on the top of the oil bath. When the paddle was placed at the middle and bottom of the oil bath, some liquid drops aggregated together and formed large aggregations. AGSAM was obtained by grafting the amine groups onto the framework of the silica gel microsphere. The CO2 adsorption capacity of the AGSAM was 1.04 mmol g-1 with 1% CO2 at 300 mL min-1. The AGSAM with 4, 3.2, 2 and 1 mm in diameters had the fluidizing velocities of 0.531, 0.425, 0.265 and 0.159 m s-1, respectively. The AGSAM with different sizes met different fluidizing conditions.

The aim of this research paper was the preparation of aluminum chloride bonded to silica gel catalyst and its application in the modification of steroidal molecules. Steroidal oxazolidinethiones were prepared using silica-supported aluminum chloride (SiO2-AlCl3) under Microwave irradiation, which is common in organic synthesis to achieve high yields in shorter reaction times. The advantage of this method is that the usual procedure can be carried out without tiring and without a secondary product at the end of the reaction. Physicochemical techniques were used to identify the chemical structure of the prepared oxazolidinethiones. A rationalization of the conversion pathways from steroidal epoxides to oxazolidinethiones is sketched on the basis of current and previous results. Antioxidant activities i.e. DPPH assay, total antioxidant capacity and total reductive capability were performed for steroidal compounds, including reactants, and the results indicated that steroidal oxazolidinethione with acetoxy group had a promising activity among the tested steroids. In correlation with antioxidant activity, a promising steroid derivative was subjected to a molecular docking study for binding to tyrosine kinases, the target protein and showed a negative binding energy −7.8 Kcal/mol suggesting good affinity to the active pocket and can be considered as a better antioxidant in the biological system.

MoSi2 has been regarded as one of the most promising structural materials, due to its excellent high-temperature oxidation resistance and high emissivity. However, as the most commonly used emittance agent in high emissivity coatings, it can be easily oxidized when the operating temperature is below 600 °C. To address this issue, the silica-coated MoSi2 powders with good low-temperature (400–600 °C) oxidation resistance were fabricated by a sol-gel method followed by a preoxidation process. Here in, by the combination of the non-isothermal and cyclic-isothermal oxidation analysis, we demonstrate that the silica gel film coated on MoSi2 can prevent oxidation to some extent, but the preoxidation treatment plays a more critical role in improving its oxidation resistance at low temperature. Both the sol-gel and preoxidation processes enable the integrated and compact encapsulation of the silica coating. The synthesized silica-coated MoSi2 exhibits excellent oxidation resistance with slightly weight gains (

In this study, adsorption characteristics of water vapor onto several silica gel-based composites have been investigated experimentally. Adsorbent samples under investigation are silica gel powder (SGP), 98wt% SGP with 2wt% Polyvinylpyrrolidone (PVP) binder, 93wt% SGP, 2wt% PVP binder with 5wt% EG500 and 93wt% SGP, 2wt% PVP binder with 5wt% EG100. The three composite samples have been named as (S1-PVP), (S2-EG500) and (S3-EG100), respectively. Porous properties and thermal conductivity of S2-EG500 and S3-EG100 have been measured and compared with that of SGP. Experimental results showed that S2-EG500 has higher effect on enhancing the thermal conductivity of the composites where its thermal conductivity reached about 2.8 times that of SGP whilst thermal conductivity of S3-EGP100 is found to be about 2.3 times that of SGP. Adsorption isotherms of composite samples/water pairs have been measured gravimetrically at 30, 50 and 70 °C. The Toth and Dubinin-Astakhov (D-A) equations have been used to fit adsorption uptake measurements, Toth equation shows a better fitting. Isosteric heat of adsorption of the studied pairs have been extracted from the experimental measurements using Clausius-Clapeyron equation. The Linear Driving Force (LDF) model is found to be able to present adsorption kinetics of the studied pairs through a good agreement with the experimental data.

The sol-gel route via sodium silicate precursor is known as a practical synthesis method to prepare silica gels in a cost effective way. In the current research, rheological properties of the synthesized silica gels were investigated at different pH values. The gelation time (tgel) was determined from the rheological measurements at different frequencies of 0.1, 0.3 and 0.5 Hz. The results were analyzed using rheological equations of state and the concept of the gelation point was discussed. The results revealed that tgel increases by increasing the pH value. Moreover, it was proved that the fractal value (df) is dependent on the pH value. The relaxation exponent (Δ) value was measured as 0

Five new and one unsual known bioactive compounds have been isolated from the methanol extract of Kuji amber which was subjected to silica gel column chromatography in order to yield lipophilic compounds. A new clerodane derivative, named Kujione A (15-nor-2-oxo-3-cleroden-13-ol), was isolated from the medium polar fractions. This was done using Kujione A’s growth-restoring activity against a mutant Saccharomyces cerevisiae strain (zds1Δ erg3Δ pdr1/3Δ) that is hypersensitive with respect to Ca²+-signal transduction. The structure was elucidated by spectroscopic data, HREIMS, along with 1D- and 2D-NMR, among others. 15-norclerodane has been categorized as a new and distinct compound because it has a conjugated carbonyl functional group; it has not been found in isolated constituents from Kuji amber.

Colloidal silica as nanostructured binder for refractory castables has attracted many attentions in recent years. In the present study, phase composition, microstructure and reactivity evolution of silica gel at different heating conditions were investigated to find suitable system for colloidal silica application. The results showed that atmosphere and carbon slightly affected phase composition of the silica gel at elevated temperatures, and the crystalline phases were composed of major α-cristobalite and minor α-tridymite. The morphology and particle size of the silica gel were greatly affected by atmosphere and carbon during heating. The spherical nano-silica particles with sizes of 40–50 nm rapidly grew into macroscale rod-like particles with temperature increasing from 800-1000 °C to above 1200 °C in air, and sintering of silica particles was observed. However, the size and morphology of the spherical nano-silica particles retained at high temperature in a reducing atmosphere, and many well developed columnar mullite crystals and some SiC whiskers formed on heating silica gel, alumina fines and carbon at 1500 °C, which was due to carbon inclusions retarding the growth of nano-silica particles and the nano silica remained high reactivity at high temperature. Thus, colloidal silica was suitable for application in carbon-containing refractory castables.

This study was performed in order to investigate the adsorption of siloxane for biogas treatment using a novel SiO2-based adsorbent and its regeneration. The siloxane adsorption capacity of the NaOH-modified SiO2 was significantly increased. At low temperature (25–50 °C), the siloxane (D5) adsorption capacity of the novel SiO2 adsorbent was 200 mg per g of adsorbent, which is approximately four times than that observed for silica gel or SiO2 prior to treatment with NaOH. The siloxane retention mechanism of silica particles is the influence of the hydrogen bonds formed between the Si–O–Si groups on the siloxane surface and the OH groups on the silica surface. Therefore, increasing the concentration of NaOH used in the reforming step will increase the density of OH group density increased proportionally and siloxane adsorption capacity also increased. The number of OH groups, determined based on the TGA analysis, was increased to 4.7 OH/nm2 using 3 M NaOH from 1.3 OH/nm2 of pure SiO2. This also supports the hypothesis that the concentration of OH groups on the SiO2 is proportional to the NaOH concentration.

Atmospheric plasma spraying (APS) of silicon carbide (SiC) is a challenging task due to the severe decomposition behaviour of the SiC. Previous studies, which utilized APS technique, mixed SiC powder with metals and/or metal oxides to prepare SiC coating. None of them sprayed silica gel-coated SiC and examined the characteristics of the coatings. In this work, silica gel-coated SiC, sodium dodecyl sulfate (SDS) enhanced silica gel-coated SiC, and the combination of alumina (Al2O3) and SiC were prepared and then deposited onto a titanium (Ti) plate by APS. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), adhesion and acid resistance test were performed to analyse the characteristics of modified powders and coatings. We found that compared to Commercial-SiC coatings, all the modified SiC coatings not only increase the coating thickness but also enhance the adhesion force between the coating and substrate; furthermore, the SDS-modified sample exhibits good sulfuric acid (H2SO4) resistance. On the other hand, samples containing Al2O3 showed a significant increase in coating thickness and adhesion force, despite a bit lower acid resistance. In sum, we believe that compared to silica-gel coated samples, Al2O3 contained samples are more suitable for industrial application.

A successful immobilization of 1-octyl-3-methylimidazolium tetrachloroferrates ([Omim][FeCl4]) thin films on a silica gel while remaining its mesoporousity, was accomplished in this work. The developed catalyst was highly active and cost-effective for deep oxidative desulfurization of refractory thiophenic compounds at room temperature utilizing H2O2 oxidation agent. The reaction products were well separated from fuel by the catalyst itself under a beneficial solvent-free condition. The catalyst was characterized applying different analyses of FT-IR, TGA, XRD, SEM, EDS, AFM, N2 adsorption desorption, BET, and BJH. A sufficiently large pore diameter (∼6.2 nm) and high surface area (∼490 m2/g) of the silica gel for supporting the Lewis acidic [Omim][FeCl4] having a proper anion and cation structure, synergistically enabled a high efficient and selective catalyst for removal of refractory thiophenes. The influences of reaction temperature and time, loading amount of ionic liquid (IL), catalyst and oxidant amount as crucial reaction factors were evaluated in order to have a maximum desulfurization yield. Impressively, only a very low IL loading of 5 wt.% on the silica gel support achieved complete elimination of dibenzothiophene at the optimal mild conditions and room temperature. In the presence of a non-sulfur aromatic hydrocarbon beside different thiophenic models, the desulfurization selectivity of [Omim][FeCl4] increased from 0.92 to 0.95 via immobilization on the silica gel support. A significant decline in the IL consumption was verified as another beneficial effect of this immobilization. The catalyst could be easily separated having a capability for 100 % removal of dibenzothiophene after recycling four times. Meanwhile, GC–MS analysis was employed for further founding of the desulfurization pathway.

Objective To study the antipyretic and anti-inflammatory constituents from the active fraction of Reduning (RDN) Injection. Methods In this study, the active fraction of RDN Injection was screened by the LPS-induced mouse endotoxin shock model. The chemical constituents were isolated by chromatography on HP-20 macroporous adsorptive resins, silica gel, ODS columns and reverse phase MPLC and HPLC repeatedly, and their structures were elucidated based on spectroscopic analysis (HR-ESI-MS, NMR, ECD) and chemical methods. Meanwhile, we evaluated the anti-inflammatory activities of the isolates by measuring their inhibitory effects on TNF-α production in LPS stimulated RAW 264.7 macrophages. Results The 95% ethanol eluate of RDN Injection by the macroporous adsorption resin column was proved to be the antipyretic and anti-inflammatory active fraction of this injection. A novel iridoid, named jasminoide A (1), and a new guaiane sesquiterpenoid, named (1R,7R,8S,10R)-7,8,11-trihydroxy-4-guaien-3-one (2), were isolated from Reduning injection, and compound 2 can inhibit TNF-α production with IC50 values of 72.24 µmol/L. Conclusion In this study, two new terpenoids were isolated from Reduning Injection, and compound 2 showed inhibitory activity against LPS-activated TNF-α production in RAW 264.7 cells in vitro.

An open reading frame of sleh1, a gene encoding for a novel epoxide hydrolase from Solanum lycopersicum (SlEH1), was amplified by RT-PCR and expressed in E. coli BL21(DE3). The substrate spectrum assay showed that E. coli/sleh1 had EH activities towards all tested substrates except for racemic (rac-) 5a, and the highest enantiomeric ratio (E > 200) towards rac-2a, retaining (R)-2a with 99.1% ees and 49.2% yields and affording (R)-2b with 89.8% eep and 46.7% yieldp. Besides, E. coli/sleh1 also hydrolyzed of rac-7a–9a with moderate regioselectivities, producing (S)- or (R)-7b–9b with 40.5–51.3% eep and 69.4–75.2% yieldp. The pH optimum and stability of the purified SlEH1 were 7.5 and at a range of 6.5–8.5, and it was thermostable at or below 40 °C. Its catalytic efficiency (kcatS/KmS = 7.49 mM−1 s−1) for (S)-2a was much higher than that for (R)-2a. The gram-scale kinetic resolution of 150 mM rac-2a was carried out by E. coli/sleh1 at 20 °C for 8 h, producing (R)-2a with 98.2% ees and 45.3% overall yields after purification by silica gel column chromatography. Furthermore, the source of extremely high enantioselectivity of SlEH1 towards rac-2a was analyzed by molecular docking simulations.

Porous silica gel (SG) has been extensively used as an adsorbent in adsorption cooling, dehumidification, and desalination applications. Specific heat capacity (Cp) of SG with temperature variation is not experimentally investigated yet. Therefore, this study focuses on the experimental investigation of Cp along with the porous properties of six types of different particle size silica gels. Adsorbed phase Cp of SG is also determined with 10% and 20% water uptake. The experimental Cp is measured within 30 to 100 °C, and the Cp values vary from 0.8 to 1.10 kJ kg–1 K–1 in the measurement temperature range. RD silica gel of the smallest particle size shows the highest Cp values, whereas indicator type silica gel shows the lowest Cp. The Green-Perry model fits well with the experimental Cp data. The porosity analysis shows that RD silica gels of large particle size (D > 0.7 mm) possess the highest surface area (≈ 770 m2/g), and type B silica gels have the largest pore volume (≈ 0.8 cm3/g) along with larger mesopores. A relationship between pore volume and Cp is also reported. The measured data are novel and essential for rigorous performance prediction of adsorption cooling, dehumidification, and desalination systems.

Boron carbide (B4C), silicon carbide (SiC) and silicon nitride (Si3N4) can achieve low coefficient of friction (Cof) under high relative humidity condition. Therefore, B4C/SiC and B4C/Si3N4 tribo-pairs may exhibit outstanding tribological behaviors, while the tribological investigation is poor. In present investigation, we performed the friction tests of the B4C/SiC and B4C/Si3N4 tribo-pairs under various relative humidity conditions, and revealed that the B4C/SiC tribo-pair is a promising candidate for high relative humidity engineering applications. Surprisingly, the B4C/SiC tribo-pair exhibited much better tribological behaviors than the B4C/Si3N4 tribo-pair with the same test condition and tribochemical products. This is mainly attributed to less wear debris on the SiC ball and the formation of a stable tribochemical film containing boric acid and silica gel.

Solid wastes, such as polystyrene foam waste and silica gel waste which are ubiquitous products have caused serious environmental issues, such as “white pollution”, threatening the health of humans and animals. As such, the need to recycle and re-use of solid wastes has attracted increasing attention in the last few years. In this work, a self-healing superhydrophobic coating is successfully fabricated by blending polystyrene foam waste with fluorinated silica gel waste (F-silica gel waste), octadecyltrimethoxysilane (OTMS) modified silica particles (OTMS-silica particles), and near-infrared (NIR) light responsive microcapsules. The F-silica gel waste and OTMS-silica nanoparticles act as hydrophobic fillers meanwhile the polystyrene foam waste acts as a coating binder. The NIR-responsive microcapsules are obtained by the electrostatic adsorption of carbon nanoparticles onto the surface of microcapsules loaded with 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane. The superhydrophobic property of the coating can be healed after 10 minutes of NIR irradiation. Additionally, the as-prepared coating can be coated on several different substrates, similar to commercial coatings, and it is seen that its excellent superhydrophobic property is durable and is maintained even when the coating is subjected to a sand-drop test. The self-healing mechanism of the superhydrophobic coatings is also investigated.

ɤ-Irradiation induces electrical conductivity (RIC) in water. But, the RIC values of water can be more than twofold higher in the presence of silica gel (SG) with particle size in the range >0.16–0...

Carbon-silica materials with hierarchical pores consisting of micropores and mesopores were prepared by introducing nanocarbon microspheres derived from biomass sugar into silica gel channels in a hydrothermal environment. The physicochemical properties of the materials were characterized by nitrogen physical adsorption (BET), scanning electron microscopy (SEM), and thermogravimetric (TG), and the adsorption properties of various organic waste gases were investigated. The results showed that microporous carbon materials were introduced successfully into the silica gel channels, thus showing the high adsorption capacity of activated carbon in high humidity organic waste gas, and the high stability and mechanical strength of the silica gel. The dynamic adsorption behavior confirmed that the carbon-silica material had excellent adsorption capacity for different volatile organic compounds (VOCs). Furthermore, the carbon-silica material exhibited excellent desorption characteristics: adsorbed toluene was completely desorbed at 150°C, thereby showing superior regeneration characteristics. Both features were attributed to the formation of hierarchical pores.

The synthesis of heterogeneous supported sensitizers has gained much attention in recent times and has found various applications in areas including photosensitized disinfection of waste water, taking into account their advantages over the homogeneous photosensitizers. Among the heterogeneous sensitizers, silica gel supported organic dyes have received great attention. In this paper we report the synthesis of heterogeneous supported sensitizers in which triazatriangulenium cation is covalently anchored on silica. The singlet oxygen sensitization capability of the triazatriangulenium-silica composites was monitored using the singlet oxygen probe disodium-9, 10-anthracenedipropionic acid (ADPA). The study of disinfection of water containing pathogenic bacteria was also carried out to determine the effectiveness of the prepared triazatriangulenium-silica composites for the waste water treatment. All the four types of synthesized triazatriangulenium-silica composites produced singlet oxygen, as it is evident from the photobleaching of singlet oxygen probe ADPA. The results of the disinfection studies using the four types of prepared triazatriangulenium-silica composites shows that these materials are effective in the killing of bacterial pathogens when used with light.

This paper aims to develop new thermochemical materials (TCM) for low-grade thermochemical heat storage. Silica gel as a host material was impregnated with 30 wt% of MgSO4·7H2O, CuSO4·5H2O, and Al2(SO4)3·18H2O using the cyclic wetness impregnation method. The SEM analysis, XRD and Raman Spectroscopy have revealed the good dispersion of hydrated salt into the matrix without any undesirable reactions. The spontaneous thermal analyzer (STA) measurements of water desorption heat have proved good cycling stability of the composites with a high storage density of 792.7, 580.5, and 712.6 J/g for SG-MgS, SG-Al2S, and SG-CuS respectively confirming the great potential of these materials as promising TCM.

This paper reviews the work done previously on the self-healing of cracks in concrete, through the addition of different bacteria to the concrete mixture. The effect of four different bacteria on the mechanical properties of concrete were compiled. The bacteria were added to the concrete either by direct addition or by encapsulation of bacteria, using different materials like Polyurethane, Silica gel, Hydrogel, Diatomaceous earth, Melamine based capsules, Light weight aggregates and Graphite Nanoparticles. Generally, Bacillus Subtilis bacteria were used by many researchers to develop the self-healing concrete. This bacterium based self-healing concrete demonstrates promising future in the field of concrete.

Polyurethane foams (PU), are found in various industrial and domestic applications due to their high energy absorption and sound absorption properties, especially in shock absorbers and noise control problems. This study investigates the effect of silica gel as additive filler in castor oil-based PU foam and its mechanical and acoustical properties are evaluated. Three different loading of 5%, 10%, and 15% silica gel is used as filler. For mechanical properties, the compression test is carried out. As the percentage of filler increases, the rigidity of the foam increases. The acoustical properties of the sample are tested using the two-microphone impedance tube method. Raw PU foams are seen to exhibit a reasonable sound absorption only in higher frequencies. The results show that the sound absorption coefficient of 10% filler PU foam has comparatively better sound absorption capabilities throughout all frequencies, ranging from 200 Hz to 4000 Hz, that it is exposed to. This can be attributed to the optimum number of voids present, compared to the highest number in 15% (high porosity) and lowest in 5%. The results show that the addition of silica gel up to a certain extent enhances both, the mechanical as well as acoustic properties.

High-performance thin-layer chromatography (HPTLC) combined with 1H nuclear magnetic resonance (NMR) spectroscopy has only been demonstrated over a small spectral range so far. The self-printing of chromatographic plates with a modified 3D slurry printer allowed the operator to influence the composition of the adsorbent slurry and thus the purity of the adsorbent layer. The combination of such self-printed, binder-free HPTLC plates with inkjet-driven sample application made possible submicromole-scaled analytical 1H NMR spectroscopy. This was proven using pure HPTLC adsorbents. For comparison, commercial silica gel HPTLC plates were purified by pre-development with solvents for spectroscopy, whereas commercial silica gel HPTLC particles were self-printed on the glass plate after purification under solvent pressure in a recycled HPLC cartridge. Evaluating the signals from different treatments, seven background signals disappeared in the proton spectra and three were reduced to a minimum by use of pre-developed commercial HPTLC plates. In the case of the self-printed, binder-free HPTLC plates made of purified adsorbent, most of the spectral background signals were reduced to a minimum, thus these spectra showed the highest cleanness and most pure analyte proton spectra. For the first time, the full 1H NMR spectroscopy range was made available after an HPTLC separation. This proof of principle opens the avenue for submicromole-scaled analytical 1H NMR spectroscopy.

Two simple, specific, sensitive, accurate and precise stability indicating methods were described for quantitative determination of the anthelmintics drug Niclosamide. The first method was high performance liquid chromatographic with the use of a reversed phase hibarR C-18 column (250 mm × 4.66 mm, 5 μm) and mobile phase of methanol: 1 mM ammonium phosphate buffer (85:15 v/v) at a flow rate of 1.2 mL/min. The retention time of drug was found to be 6.45 ± 0.02 min. Quantification of drug was achieved with diode array detection (DAD) at 332 nm. Linear calibration curve was obtained in concentration range 0.01–100 μg/mL with r2 value of 0.999. The limit of detection and limit of quantification were found to be 0.048 μg/mL and 0.01 μg/ml respectively. The second method involved a high performance thin layer liquid chromatographic. Chromatographic separation was carried out with precoated silica gel G60 F254 aluminum sheets using toluene:ethyl acetate (7:3% v/v) as a mobile phase. Linearity of proposed method was found to be 200–700 ng/band at 332 nm with retention factor of 0.59 and r2 value of 0.998. The limit of detection and limit of quantification were found to be 36.21 ng/band and 109.7 ng/band respectively. Both the developed methods were successfully validated as per International Conference on Harmonization guideline (ICH). Niclosamide was subjected to different stress conditions. The degraded product peaks were well resolved from the pure drug peak with significant difference in their retention time. Stress samples were successfully assayed by developed high performance liquid chromatographic and high performance thin layer liquid chromatographic method. Statistically analysis proves that there were no statistical significant differences between two developed methods. Keywords: RP-HPLC, HPTLC, Niclosamide, Stability indicating, Validation, Statistical comparisons

The aim of the present study was to investigate the ability of natural materials, such as dried cow dung, cocopeat, and sawdust to be used as a desiccant in the evaporative cooling system to reduce the inlet air humidity. Moisture sorption and desorption characteristics of these natural materials were found out and also compared with that of silica gel. These materials were tested in different air conditions to know the sorption (28° C-85% RH, 28° C-60% RH, 33° C-60% RH) and desorption characteristics (50° C-10% RH). The materials' behavior in different humidity with the same temperature; and the same humidity with different temperature was also studied. These natural materials were studied to replace costly chemical desiccants, such as silica gel, zeolites, etc. Experimental results confirmed that cocopeat and dried cow dung have the potential to replace the chemical desiccants based on their sorption and desorption characteristics while sawdust was not found to have the desired characteristics of good desiccant. These natural materials (considered as waste) are cheap, and their reutilization will also be helpful to minimize the waste management problem.

Due to the significant increase in the global temperature, the demand for cooling is dramatically rising. Most of this demand is met by conventional systems driven by electricity generated using fossil fuels contributing in the global warming phenomenon. The adsorption system is a sustainable system being driven by waste or low-grade heat sources such as solar energy. MIL-101(Cr) is a metal–organic framework (MOF) material with exceptional properties and high-water uptake. Nevertheless, it is not suitable for adsorption cooling application as the high capacity is taking place only at high relative pressure range (>0.5). The water adsorption characteristics of MIL-101(Cr) were significantly enhanced through incorporating the material with calcium chloride. Results showed that at a desorption temperature of 90 °C and a chilled water inlet temperature of 10 °C, the SCP increased from 168 for the neat MIL-101(Cr) to 248 and 388 W kg‒1 for Comp_1:5 and Comp_1:8 CaCl2 composites, respectively outperforming the long dominating silica gel.

Separation and purification of secondary metabolites from wild microorganisms remains a challenge due to the analogues existing in the fermentation broth. In this study, a three-liquid-phase salting-out extraction system (TLP-SOES) coupled with column chromatography was developed to purify wortmannilactone F and its dehydrated derivative wortmannilactone L. The TLP-SOES composed of 25.5% petroleum ether/20.0% ethanol/12.9% ammonium sulfate (w/w) at pH 5.6 and room temperature was found to separate wortmannilactone F in the middle (ethanol-rich) phase and wortmannilactone L in the top (petroleum ether-rich) phase with the recovery rates of 88.9% and 83.3%, respectively. The two compounds were further purified by ODS column and semi-preparative HPLC. The total recovery rates of the two compounds were over 2-fold higher than that of the conventional method, which included ethyl acetate/hexane extraction and silica gel column chromatography. Additionally, the calculated logP (ClogP) value of wortmannilactones showed a good linear correlation with their natural logarithm of partition coefficient according to the tie line length (TLL), and that the critical ClogP value might be useful for the selection of TLL or the composition of the extraction system. In summary, our study provided an effective approach for the separation and purification of analogues of natural products.

Co-sensitized photoanode with nitrogen doped graphene particles (NGPs) and CdS capable of harvesting light efficiently in the visible region is combined with a poly(3,4-ethylenedioxypyrrole) (PEDOP)@carbon(C)-cloth based counter electrode (CE) for the first time. The conduction band of NGPs is wedged between that of CdS and TiO2, and charge separation is improved in TiO2/NGPs/CdS compared to TiO2/CdS, thus resulting in a power conversion efficiency (PCE), greater by 37% and 305% in comparison to TiO2/CdS and TiO2/NGPs cells. The electrolyte is a polysulfide/silica gel modified with a polyanionic additive of sodium poly(4-styrenesulfonate) (NaPSS). NaPSS polymer chains serve as a passivating layer at the photoanode/electrolyte interface and reduce back electron transfer, while simultaneously allowing efficient hole transfer to the electrolyte. An optimal NaPSS content is ascertained from the highest PCE, conductivity and longest photovoltage decay time achieved for the electrolyte with 5 wt% NaPSS, compared to electrolytes with lower and higher NaPSS contents. The efficacy of PEDOP@C-cloth as a CE for the solar cell is confirmed from a lower charge transfer resistance and a higher diffusion current density for polysulfide reduction at the CE/electrolyte interface compared to sole C-cloth. This amplified solar cell performance is attained owing to the synergy of all the three components: NGPs at the photoanode, NaPSS in the electrolyte and PEDOP at the CE thus manifesting in a PCE of 7.7% for the TiO2/NGPs/CdS/polysulfide/silica/NaPSS gel/PEDOP@C-cloth cell relative to 3.5% attained for the TiO2/CdS/polysulfide/silica gel/C-cloth cell.