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1.
Data Brief ; 55: 110623, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38993226

ABSTRACT

The high volatility of the terpenes contained in flavour-containing terpene (FCT) products causes the loss of these contents during product storage; thus, measuring the loss of FCT content during storage is important to estimate the final content. This work provides data on the reduction in FCT content of infused pre-rolled paper cones after 1 to 7 days of storage. Determination of FCT content was based on the formation of a reddish-brown precipitate resulting from the reaction of terpene moiety in FCT with sulphuric acid. Then, the absorbance of the precipitate was analysed using the UV-Vis Spectrophotometric method at a visible wavelength of 538 nm. A calibration standard curve was prepared concerning the concentration of the original FCT sample and used to determine the FCT content in infused pre-rolled paper. The FCT content on the first day of storage decreased and increased again after seven days of storage due to condensation. The data on the FCT content reduction as the effect of additive added was also evaluated.

2.
Int J Biol Macromol ; 257(Pt 1): 128502, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38040139

ABSTRACT

As a natural raw material to replace synthetic chemicals, cellulose and its derivatives are the most popular choices in the pharmaceutical industry. For drug delivery applications, cellulose is usually used as a cellulose nanocrystal (CNC). CNC-based hydrogels are widely utilized for drug delivery because drug molecules can be encapsulated in their pore-like structures. This study aims to develop CNC hydrogels for the delivery of doripenem antibiotics. CNC was obtained from jackfruit peel extraction, and alginate was used as a network polymer to produce hydrogels. Ionotropic gelation was used in the synthesis of CNC-alginate hydrogel composites. The maximum adsorption of doripenem by CNC was 65.7 mg/g, while the maximum adsorption by CNC-alginate was 98.4 mg/g. One of the most challenging aspects of drug delivery is predicting drug release from a solid matrix using simple and complex mathematical equations. The sigmoidal equation could represent the doripenem release from CNC, while the Ritger-Peppas equation could describe the doripenem release from CNC-Alginate. The biocompatibility testing of CNC and CNC-alginate against a 7F2 cell line indicates that both materials were non-toxic.


Subject(s)
Artocarpus , Nanoparticles , Hydrogels/chemistry , Cellulose/chemistry , Doripenem , Alginates/chemistry , Adsorption , Nanoparticles/chemistry
3.
Int J Biol Macromol ; 253(Pt 4): 127020, 2023 Dec 31.
Article in English | MEDLINE | ID: mdl-37741484

ABSTRACT

For the drug delivery system, drug carriers' selection is critical to the drug's success in reaching the desired target. Drug carriers from natural biopolymers are preferred over synthetic materials due to their biocompatibility. The use of polysaccharide gums in the drug delivery system has received considerable attention in recent years. Polysaccharide gums are renewable resources and abundantly found in nature. They could be isolated from marine algae, microorganisms, and higher plants. In terms of carbohydrates, the gums are water-soluble, non-starch polysaccharides with high commercial value. Polysaccharide gums are widely used for controlled-release products, capsules, medicinal binders, wound healing agents, capsules, and tablet excipients. One of the essential applications of polysaccharide gum is drug delivery systems. The various kinds of polysaccharide gums obtained from different plants, marine algae, and microorganisms for the drug delivery system application are discussed comprehensively in this review paper.


Subject(s)
Drug Delivery Systems , Polysaccharides , Drug Carriers , Excipients , Plant Gums
4.
Data Brief ; 48: 109159, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37168600

ABSTRACT

The dataset reported in this article describes the adsorption isotherms of amoxicillin, ampicillin, and doripenem onto bentonite. Batch adsorption experiments were carried out on single antibiotic solutions with various dosage of bentonite across temperatures from 30 to 50 °C. The adsorbent loading dataset was later obtained by measuring the concentration of antibiotic solution at adsorption equilibrium via UV-Vis spectrophotometer. The dataset was also fitted using various isotherm models including Freundlich, Langmuir, Toth, Hill, and Dubinin-Radushkevich models to further analyze the adsorption behavior. On top of that, orthogonal regression was applied to avoid fitting biasness, whereby the fitting results revealed the highest adsorption capacities of 82.259 mg g-1 for amoxicillin, 78.851 mg g-1 for ampicillin, and 93.278 mg g-1 for doripenem using Langmuir model, which gave an accurate representation of the adsorption isotherm dataset that was consistent with the results of Toth and Hill model.

5.
Biomater Adv ; 146: 213269, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36696782

ABSTRACT

Tuberculosis (TB) is a disease caused by the M. tuberculosis bacteria infection and is listed as one of the deadliest diseases to date. Despite the development of antituberculosis drugs, the need for long-term drug consumption and low patient commitment are obstacles to the success of TB treatment. A continuous drug delivery system that has a long-term effect is needed to reduce routine drug consumption intervals, suppress infection, and prevent the emergence of drug-resistant strains of M. tuberculosis. For this reason, biomolecule metal-organic framework (BioMOF) with good biocompatibility, nontoxicity, bioactivity, and high stability are becoming potential drug carriers. This study used a bioactive protocatechuic acid (PCA) as organic linker to prepare copper-based BioMOF Cu-PCA under base-modulated conditions. Detailed crystal analysis by the powder X-ray diffraction demonstrated that the Cu-PCA, with a chemical formula of C14H16O13Cu3, crystalizes as triclinic in space group P1. Comprehensive physicochemical characterizations were provided using FTIR, SEM, XPS, TGA, EA, and N2 sorption. As a drug carrier, Cu-PCA showed a high maximum rifampicin (RIF) drug loading of 443.01 mg/g. Upon resuspension in PBS, the RIF and linkers release profile exhibited two-stage release kinetic profiles, which are well described by the Biphasic Dose Response (BiDoseResp) model. A complete release of these compounds (RIF and PCA) was achieved after ~9 h of mixing in PBS. Cu-PCA and RIF@Cu-PCA possessed antibacterial activity against Escherichia coli, and good biocompatibility is evidenced by the high viability of MH-S mice alveolar macrophage cells upon supplementations.


Subject(s)
Metal-Organic Frameworks , Mycobacterium tuberculosis , Tuberculosis , Mice , Animals , Rifampin/pharmacology , Rifampin/therapeutic use , Metal-Organic Frameworks/chemistry , Metal-Organic Frameworks/pharmacology , Metal-Organic Frameworks/therapeutic use , Copper/pharmacology , Antitubercular Agents/pharmacology , Antitubercular Agents/therapeutic use , Tuberculosis/drug therapy , Drug Carriers/chemistry
6.
Polymers (Basel) ; 14(23)2022 Nov 29.
Article in English | MEDLINE | ID: mdl-36501594

ABSTRACT

In this study, CNCs were extracted from durian rind. Modification to CNCs with saponin was conducted at 50 °C for one h. CNCs and CNCs-saponin were employed as dexamethasone carriers. Modification to CNCs using saponin did not change the relative crystallinity of CNCs. CNCs' molecular structure and surface chemistry did not alter significantly after modification. Both nanoparticles have surface charges independently of pH. Dexamethasone-released kinetics were studied at two different pH (7.4 and 5.8). Higuchi, Ritger-Peppas, first-order kinetic and sigmoidal equations were used to represent the released kinetic data. The sigmoidal equation was found to be superior to other models. The CNCs and CNCs-saponin showed burst release at 30 min. The study indicated that cell viability decreased by 30% after modification with saponin.

7.
Polymers (Basel) ; 14(22)2022 Nov 18.
Article in English | MEDLINE | ID: mdl-36433118

ABSTRACT

This study developed a novel composite material containing cellulose nanocrystals (CNCs) and HKUST-1. Here, the addition of CNCs was used to enhance the characteristics of HKUST-1 in terms of surface area, adsorption ability, and functional groups. Here, the fabrication of CNCs@HKUST-1 composites was carried out by adding CNCs into the fabrication process of HKUST-1. The addition of CNCs provides additional functional groups on the surface of composite material which can be used to attach other organic compounds, such as in waste management and drug delivery systems. Here, CNCs@HKUST-1 composites were tested as a material for crystal violet (CV) removal and doxorubicin (DOX) loading. The removal capacity of CNCs@HKUST-1 composite towards CV molecules reached 1182.25 ± 27.74 mg/g, while the loading capacity for DOX drugs was around 1514.94 ± 11.67 mg/g. Both applications showed that CNCs@HKUST-1 composite had higher adsorption capacity and ability compared to its precursor materials, i.e., CNCs and HKUST-1.

8.
ACS Omega ; 7(27): 23009-23026, 2022 Jul 12.
Article in English | MEDLINE | ID: mdl-35847319

ABSTRACT

A molecularly imprinted affinity membrane (MIAM) can perform separation with high selectivity due to its unique molecular recognition introduced from the molecular-printing technique. In this way, a MIAM is able to separate a specific or targeted molecule from a mixture. In addition, it is possible to achieve high selectivity while maintaining membrane permeability. Various methods have been developed to produce a MIAM with high selectivity and productivity, with their respective advantages and disadvantages. In this paper, the MIAM is reviewed comprehensively, from the fundamentals of the affinity membrane to its applications. First, the development of a MIAM and various preparation methods are presented. Then, applications of MIAMs in sensor, metal ion separation, and organic compound separation are discussed. The last part of the review discusses the outlook of MIAMs for future development.

9.
Nanomaterials (Basel) ; 12(2)2022 Jan 13.
Article in English | MEDLINE | ID: mdl-35055261

ABSTRACT

The fast depletion of fossil fuels has attracted researchers worldwide to explore alternative biofuels, such as biodiesel. In general, the production of biodiesel is carried out via transesterification processes of vegetable oil with the presence of a suitable catalyst. A mixed metal oxide has shown to be a very attractive heterogeneous catalyst with a high performance. Most of the mixed metal oxide is made by using the general wetness impregnation method. A simple route to synthesize silane-modified mixed metal oxide (CaO-CuO/C6) catalysts has been successfully developed. A fluorocarbon surfactant and triblock copolymers (EO)106(PO)70(EO)106 were used to prevent the crystal agglomeration of carbonate salts (CaCO3-CuCO3) as the precursor to form CaO-CuO with a definite size and morphology. The materials show high potency as a catalyst in the transesterification process to produce biodiesel. The calcined co-precipitation product has a high crystallinity form, as confirmed by the XRD analysis. The synthesized catalyst was characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX). The mechanism of surface modification and the effects of the catalytic activity were also discussed. The biodiesel purity of the final product was analyzed by gas chromatography. The optimum biodiesel yield was 90.17% using the modified mixed metal oxide CaO-CuO/C6.

10.
Environ Res ; 207: 112162, 2022 05 01.
Article in English | MEDLINE | ID: mdl-34610325

ABSTRACT

The removal of persistent antibiotics from the water bodies can be quite challenging. The present study deals with the removal of doripenem, one of the most stable and persistent antibiotics, from aqueous solution via adsorption technique using the low-cost structured alginate-immobilized bentonite (Alg@iB) beads which can be easily recovered after the process. Alg@iB possesses a porous interior and higher basal spacing compared with the acid-activated bentonite (iB). Its adsorption/desorption isotherm corresponds to type IV IUPAC classification and H4-type hysteresis loops, implying the presence of slit- or plane-shaped pores. The influences of four independent adsorption parameters, e.g., pH, initial doripenem concentrations (md), temperature (T), and Alg@iB loading (mc), on the removal rate of doripenem (Yd) are investigated. The maximum Yd (95.8% w/w) is obtained at pH = 5, mc = 1.4% w/v, T = 50 °C, and md = 250 mg/l. The study suggests that the adsorption of doripenem is spontaneous and endothermic. Further analysis using the multi-linear intra-particle diffusion (IPD) model indicates that the rate-governing step in this adsorption process is the physical diffusion from the bulk solution to the boundary layer of Alg@iB. However, the mechanism study also considers the chemical hydrogen binding between the hydronium ions of Alg@iB and hydroxyl groups of doripenem as one of the driving forces that promote adsorption. Alg@iB shows good reusability with Yd > 90% w/w up to five adsorption cycles. Based on the study, the Alg@iB beads exhibit excellent affinity to doripenem, indicating that an effective doripenem removal can be achieved using this sorbent material.


Subject(s)
Bentonite , Water Pollutants, Chemical , Adsorption , Alginates , Anti-Bacterial Agents/analysis , Hydrogen-Ion Concentration , Kinetics , Water , Water Pollutants, Chemical/analysis
11.
Molecules ; 26(21)2021 Oct 25.
Article in English | MEDLINE | ID: mdl-34770838

ABSTRACT

Due to its excellency and versatility, many synthesis methods and conditions were developed to produce HKUST-1 ([Cu3(BTC)2(H2O)3]n). However, the diversity of HKUST-1 was actually generated both in terms of characteristics and morphologies. Hence, the consistency of HKUST-1 characteristics and morphologies needs to be maintained. The statistical analysis and optimization provide features to determine the best synthesis condition. Here, a room-temperature coordination modulation method was proposed to maintain the morphology of HKUST-1 while reducing energy consumption. In addition, response surface methodology (RSM) was used to demonstrate the statistical analysis and optimization of the synthesis of HKUST-1. The molar ratio of ligand to metal, reaction time, and acetic acid concentration were studied to determine their effects on HKUST-1. The optimum HKUST-1 was obtained by the synthesis with a molar ratio of ligand to metal of 0.4703 for 27.2 h using 5% v/v acetic acid concentration. The statistical analysis performed a good agreement with the experimental data and showed the significance of three desired parameters on HKUST-1. The optimum HKUST-1 had the adsorption capacity of 1005.22 mg/g with a removal efficiency of 92.31% towards CV dye. It could be reused up to 5 cycles with insignificant decrease in performance.

12.
Int J Biol Macromol ; 193(Pt A): 721-733, 2021 Dec 15.
Article in English | MEDLINE | ID: mdl-34655594

ABSTRACT

The development of porous adsorbent materials from renewable resources for water and wastewater treatment has received considerable interest from academia and industry. This work aims to synthesize composite hydrogel from the combination of guar gum (a neutral galactomannan polysaccharide) and TiO2. The TiO2-embedded guar gum hydrogel (TiO2@GGH) was utilized to remove methylene blue through adsorption and photodegradation. The presence of TiO2 particles in the hydrogel matrix (TiO2@GGH) was confirmed by scanning electron microscopy-energy dispersive X-ray and X-ray photoelectron spectroscopy analysis. The mercury intrusion and N2 sorption isotherm indicate the macroporous structure of the TiO2@GGH composite, showing the presence of pore sizes ~420 µm. The dye removal efficiency of the GGH and TiO2@GGH was evaluated in batch mode at ambient temperature under varying pH. The effect of UV radiation on the dye removal efficiency was also assessed. The results demonstrated that the highest dye removal was recorded at pH 10, with the equilibrium condition achieved within 5 h. UV radiation was shown to enhance dye removal. The maximum adsorption capacity of TiO2@GGH is 198.61 mg g-1, while GGH sorbent is 188.53 mg g-1. The results imply that UV radiation gives rise to the photodegradation effect.


Subject(s)
Galactans/chemistry , Hydrogels/chemistry , Mannans/chemistry , Methylene Blue/chemistry , Nanocomposites/chemistry , Photolysis , Plant Gums/chemistry , Titanium/chemistry , Adsorption , Galactose/analogs & derivatives , Microscopy, Electron, Scanning , Ultraviolet Rays , Water Purification/methods
13.
Molecules ; 26(15)2021 Jul 21.
Article in English | MEDLINE | ID: mdl-34361568

ABSTRACT

Due to its excellent characteristics, zeolitic imidazole framework-L (ZIF-L) is widely used in various applications, such as drug delivery, wastewater treatments and energy storage. In the synthesis of ZIF-L, the molar ratio of ligand to metal, the reaction time and the temperature are essential parameters to produce excellent ZIF-L. In this work, ZIF-L was synthesized using a facile and green synthesis method. It was statistically investigated and optimized to obtain the best operating conditions. The optimization was carried out toward the amount of adsorbed crystal violet (CV) dye (q) as the response in the statistics. The optimal ZIF-L was obtained using a molar ratio of ligand to metal of 8.2220 for 97 min at 29 °C, where the q value of the CV adsorption onto this optimal ZIF-L reached 823.02 mg/g. The obtained ZIF-L was characterized using SEM, XRD, FTIR and TGA analyses to ensure its excellent characteristics.

14.
Polymers (Basel) ; 13(13)2021 Jun 23.
Article in English | MEDLINE | ID: mdl-34201884

ABSTRACT

The 'Back-to-nature' concept has currently been adopted intensively in various industries, especially the pharmaceutical industry. In the past few decades, the overuse of synthetic chemicals has caused severe damage to the environment and ecosystem. One class of natural materials developed to substitute artificial chemicals in the pharmaceutical industries is the natural polymers, including cellulose and its derivatives. The development of nanocelluloses as nanocarriers in drug delivery systems has reached an advanced stage. Cellulose nanofiber (CNF), nanocrystal cellulose (NCC), and bacterial nanocellulose (BC) are the most common nanocellulose used as nanocarriers in drug delivery systems. Modification and functionalization using various processes and chemicals have been carried out to increase the adsorption and drug delivery performance of nanocellulose. Nanocellulose may be attached to the drug by physical interaction or chemical functionalization for covalent drug binding. Current development of nanocarrier formulations such as surfactant nanocellulose, ultra-lightweight porous materials, hydrogel, polyelectrolytes, and inorganic hybridizations has advanced to enable the construction of stimuli-responsive and specific recognition characteristics. Thus, an opportunity has emerged to develop a new generation of nanocellulose-based carriers that can modulate the drug conveyance for diverse drug characteristics. This review provides insights into selecting appropriate nanocellulose-based hybrid materials and the available modification routes to achieve satisfactory carrier performance and briefly discusses the essential criteria to achieve high-quality nanocellulose.

15.
ACS Omega ; 6(3): 1834-1845, 2021 Jan 26.
Article in English | MEDLINE | ID: mdl-33521424

ABSTRACT

In this study, a metal-organic framework, namely, Zn3(BTC)2 (BTC = 1,3,5-benzenetricaboxylic acid), was solvothermally synthesized and employed as a catalyst for biodiesel production from degummed vegetable oil via a one-step transesterification and esterification reaction. The resulting Zn3(BTC)2 particles exhibit a well-defined triclinic structure with an average size of about 1.2 µm, high specific surface area of 1176 m2/g, and thermal stability up to 300 °C. The response surface methodology-Box-Behnken design (RSM-BBD) was employed to identify the optimal reaction conditions and to model the biodiesel yield in relation to three important parameters, namely, the methanol/oil molar ratio (4:1-8:1), temperature (45-65 °C), and time (1.5-4.5 h). Under the optimized reaction conditions (i.e., 6:1 methanol/oil molar ratio, 65 °C, 4.5 h), the maximum biodiesel yield reached 89.89% in a 1 wt % catalyst, which agreed very well with the quadratic polynomial model's prediction (89.96%). The intrinsic catalytic activity of Zn3(BTC)2, expressed as the turnover frequency, was found to be superior to that of other MOF catalysts applied in the transesterification and esterification reactions. The reusability study showed that the as-synthesized Zn3(BTC)2 catalyst exhibited good stability upon three consecutive reuses without a noticeable decrease in the methyl ester yield (∼4%) and any appreciable metal leaching (<5%). Furthermore, a preliminary technoeconomic analysis showed that the total direct operating cost for the kilogram-scale production of Zn3(BTC)2 is estimated to be US$50, which may sound economically attractive.

16.
Molecules ; 26(3)2021 Jan 28.
Article in English | MEDLINE | ID: mdl-33525445

ABSTRACT

Due to their biocompatibility, biodegradability, and non-toxicity, lignocellulosic-derived nanoparticles are very potential materials for drug carriers in drug delivery applications. There are three main lignocellulosic-derived nanoparticles discussed in this review. First, lignin nanoparticles (LNPs) are an amphiphilic nanoparticle which has versatile interactions toward hydrophilic or hydrophobic drugs. The synthesis methods of LNPs play an important role in this amphiphilic characteristic. Second, xylan nanoparticles (XNPs) are a hemicellulose-derived nanoparticle, where additional pretreatment is needed to obtain a high purity xylan before the synthesis of XNPs. This process is quite long and challenging, but XNPs have a lot of potential as a drug carrier due to their stronger interactions with various drugs. Third, cellulose nanocrystals (CNCs) are a widely exploited nanoparticle, especially in drug delivery applications. CNCs have low cytotoxicity, therefore they are suitable for use as a drug carrier. The research possibilities for these three nanoparticles are still wide and there is potential in drug delivery applications, especially for enhancing their characteristics with further surface modifications adjusted to the drugs.


Subject(s)
Cellulose/chemistry , Lignin/chemistry , Nanoparticles/chemistry , Pharmaceutical Preparations/chemistry , Xylans/chemistry , Animals , Drug Delivery Systems/methods , Humans
17.
Mater Sci Eng C Mater Biol Appl ; 118: 111542, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33255094

ABSTRACT

Bacterial contamination on external wounds is known to be a factor that prevents wound healing and triggers tissue damage. Hydrogel-dressings with antibacterial activity is a useful medical device to avoid this contamination, wherein the antibacterial activity can be provided via incorporation of silver nanoparticles (AgNPs). Contrary to the conventional two-step preparation of an AgNPs-loaded hydrogel (AgNPs@hydrogel), this work aims to establish a new and facile synthesis method employing the adsorption principle. Once AgNO3 adsorbed into active sites of the hydrogels, in situ reductions using NaBH4 was employed to produce AgNPs@hydrogel. The effect of surfactant addition on the AgNO3 loading and the antibacterial activity of the resulting hydrogel dressing was investigated. The outcome of this work indicates that the addition of rarasaponin not only can increase the loading of AgNPs on cellulose carbamate hydrogel (CCH) but also significantly enhance the antibacterial activity of the resulted hydrogel-dressing. Superior to the other studied surfactant, the loading capacity (LC) of AgNPs is found to be 10.15, 9.94, and 7.53 mg/g for CCH modified with rarasaponin, CTAB, and Tween80, respectively. These findings conclude that the addition of surfactant, especially rarasaponin, can effectively improve the loading of AgNPs onto hydrogel-dressing via adsorption and promote the antibacterial activity. Furthermore, the cytotoxic test shows that the hydrogel-dressings have good biocompatibility toward skin fibroblast cells.


Subject(s)
Metal Nanoparticles , Silver , Adsorption , Anti-Bacterial Agents/pharmacology , Bandages , Carbamates , Cellulose , Hydrogels , Surface-Active Agents
18.
ACS Omega ; 5(44): 28673-28683, 2020 Nov 10.
Article in English | MEDLINE | ID: mdl-33195920

ABSTRACT

Oil palm trunk (OPT) represents one of the five main oil palm biomass wastes with high carbon content that can be economically converted to a large surface area, porous activated carbon (AC) adsorbent to treat palm oil mill effluent wastewater in Indonesia and Malaysia. In the first portion of this work, the design of the experiment was used to determine the optimum set of synthesis parameters required to maximize the iodine number of AC [i.e., Brunauer-Emmett-Teller (BET) specific surface area indicator] prepared from OPT via chemical activation route using H3PO4. The iodine numbers of AC and AC yield were probed as the impregnation ratio, the activation time, and the activation temperature were varied in the range of 0.28-3.47, 5.68-69.32 min, and 379-521 °C, respectively. An impregnation ratio of 2.29, an activation time of 6 min, and an activation temperature of 450 °C were identified as the optimum set of synthesis parameters. In the second portion of the work, the AC synthesized using the optimum parameters were then characterized and tested as an adsorbent for tannin. N2 sorption results revealed that the AC exhibits type IV isotherm, that is, contains micropores and mesopores and displays a relatively high BET specific surface area of 1657 m2 g-1. Adsorption equilibria isotherms for tannin adsorption onto the AC were collected at three different pH of 2, 4, and 6 and were nonlinearly fitted using Langmuir and Freundlich isotherm models, where the Langmuir isotherm gave better fitting than Freundlich. The higher adsorption capacity at lower pH can be explained in terms of the absence of electrostatic repulsion interaction between the AC surface and the tannic acid species as suggested by the point of zero charges (pHpzc) of 4.8 and an increasing ionization of tannic acid with pH rise between 4 and 7. Adsorption kinetics data were also obtained at four different pH of 2, 4, 6, and 8 where the nonlinear pseudo-first-order model best fitted the kinetic at pH of 2 and the nonlinear pseudo-second-order model represented the kinetic best at the remaining higher pH, which suggests that tannin adsorption onto AC occurred by physisorption at pH of 2 and by chemisorption at pH of 4, 6, and 8.

19.
ACS Omega ; 5(44): 28844-28855, 2020 Nov 10.
Article in English | MEDLINE | ID: mdl-33195937

ABSTRACT

To promote a minimal use of acid in the activation of bentonite and to maintain oil quality during refinery and storage, a new class of bleaching agent, cetyltrimethylammonium bromide (CTAB)-pillared bentonite (CTAB@Bent), is fabricated. The influences of three independent intercalation variables, including temperature T (40, 50, and 60 °C), time t (2, 4, and 6 h), and CTAB loading m c (0.2, 0.25, 0.33, 0.50, and 1.00%, w/w), on the ß-carotene removal rate are studied. The multilevel factorial design combined with the response surface methodology and three-way analysis of variance is employed to design and optimize experiments in regard to the three independent variables. Based on the optimization results, the highest ß-carotene removal rate is monitored at 71.04% (w/w) using CTAB@Bent obtained at optimum intercalation conditions (CTAB@Ben-Opt): T = 40 °C, t = 3.2 h, m c = 1.00% (w/w). The mechanism study shows that the adsorption of ß-carotene onto CTAB@Bent-Opt is spontaneous and endothermic, with the governing steps of physical interaction and ion exchange between ß-carotene and the cationic head of CTAB. CTAB@Bent-Opt also exhibits characteristics superior to those of commercial raw bentonite and acid-activated bentonite, indicating that a more efficient ß-carotene removal can be achieved using this new bleaching agent.

20.
Sci Rep ; 10(1): 19212, 2020 Nov 05.
Article in English | MEDLINE | ID: mdl-33154425

ABSTRACT

A greener route to synthesize mesoporous copper-gallic acid metal-organic framework (CuGA MOF) than the conventional method using harmful DMF solvent was proposed in this study. Various synthesis attempts were conducted by modifying the synthesis conditions to produce CuGA MOF with comparable physical properties to a reference material (DMF-synthesized CuGA NMOF). The independent variables investigated include the molar ratio of NaOH to GA (1.1 to 4.4) and the synthesis temperature (30, 60, 90 °C). It was found that proper NaOH addition was crucial for suppressing the generation of copper oxide while maximizing the formation of CuGA MOF. On the other hand, the reaction temperature mainly affected the stability and adsorption potential of CuGA MOF. Reacting Cu, GA, and NaOH at a molar ratio of 1:1:2.2 and a temperature of 90 °C, produced mesoporous MOF (CuGA 90-2.2) with a surface area of 198.22 m2/g, a pore diameter of 8.6 nm, and a thermal stability of 219 °C. This MOF exhibited an excellent adsorption capacity for the removal of methylene blue (124.64 mg/g) and congo red (344.54 mg/g). The potential usage of CuGA 90-2.2 as a reusable adsorbent was demonstrated by its high adsorption efficiency (> 90%) after 5 adsorption-desorption cycles.

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