scholarly journals Hydrophilic and Hydrophobic Mesoporous Silica Derived from Rice Husk Ash as a Potential Drug Carrier

2018 ◽  
Author(s):  
Supakij Suttiruengwong ◽  
Metta Chareonpanich ◽  
Sommai Pivsa-Art
Keyword(s):  
Mesoporous Silica ◽  
Surface Area ◽  
Rice Husk ◽  
Release Rate ◽  
Pore Diameter ◽  
Rice Husk Ash ◽  
Release Kinetics ◽  
Drug Carrier ◽  
Bet Surface Area ◽  
Hydrophobic Nature

This work describes the preparation of mesoporous silica by the green reaction of rice husk ash (RHA) with glycerol, followed by the modification and the potential use as a drug carrier. The reaction was carried out at 215 °C for 2 h. The solution was further hydrolyzed with deionized water and aged for various times (24, 48, 120, 360, 528 and 672 h) before calcinations at 500 oC for 24 h. Further treatment of prepared mesoporous silica was performed using trimethylmethoxysilane (TMMS) to obtain hydrophobic Mesoporous silica. For all synthesized silica, silica contents were as high as 95%wt, whereas organic residues were less than 3%wt. RHA-glycerol showed the highest specific surface area with smallest pore diameter (205.70 m2/g, 7.46 nm) when aged for 48 h. The optimal hydrolysis-ageing period of 120 h resulted in 500.7 m2/g BET surface area, 0.655 cm3/g pore volume and 5.23 nm pore diameter. The surface modification of RHA-glycerol was succeeded through the reaction with TMMS as confirmed by FTIR. Ibuprofen was selected as a model drug for the adsorption experiments. The adsorption under supercritical CO2 was carried out at isothermal temperature of 40 ˚C and 100 bar, % ibuprofen loading of TMMS modified mesoporous silica (TMMS-g-MS) was 6 times less than mesoporous silica aged for 24 h (MS-24h) due to the hydrophobic nature of modified mesoporous silica, not surface and pore characteristics. The release kinetics of ibuprofen-loaded mesoporous silicas were also investigated in vitro. The release rate of ibuprofen-loaded MS-24h was much faster than that of ibuprofen-loaded TMMS-g-MS, but comparable to the crystalline ibuprofen. The slower release rate was attributed to the diffusion control and the stability of hydrophobic nature of modified silica. This would allow the design for the controlled release drug delivery system.

scholarly journals Development of a Hydrophobicity-Controlled Delivery System Containing Levodopa Methyl Ester Hydrochloride Loaded into a Mesoporous Silica

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1039
Author(s):  
Tamás Kiss ◽  
Gábor Katona ◽  
László Mérai ◽  
László Janovák ◽  
Ágota Deák ◽  
...  
Keyword(s):  
Methyl Ester ◽  
Drug Release ◽  
Mesoporous Silica ◽  
Surface Area ◽  
Release Rate ◽  
Release Kinetics ◽  
Amorphous State ◽  
Ester Hydrochloride ◽  
Methyl Ester Hydrochloride ◽  
Levodopa Methyl Ester

Background: The drug release of antiparkinsonian drugs is an important issue during the formulation process because proper release kinetics can help to reduce the off periods of Parkinson’s disease. A 2-factor, 3-level (32) full-factorial design was conducted to evaluate statistically the influence of the hydrophobicity of mesoporous silica on drug release. Methods: Hydrophobization was evaluated by different methods, such as contact angle measurement, infrared spectroscopy and charge titration. After loading the drug (levodopa methyl ester hydrochloride, melevodopa hydrochloride, LDME) into the mesopores, drug content, particle size, specific surface area and homogeneity of the products were also analyzed. The amorphous state of LDME was verified by X-ray diffractometry and differential scanning calorimetry. Results: Drug release was characterized by a model-independent method using the so-called initial release rate parameter, as detailed in the article. The adaptability of this method was verified; the model fitted closely to the actual release results according to the similarity factor, independently of the release kinetics. Conclusions: The API was successfully loaded into the silica, resulting in a reduced surface area. The release studies indicated that the release rate significantly decreased (p < 0.05) with increasing hydrophobicity. The products with controlled release can reduce the off period frequency.

Synthesis of MCM-41 from Rice Husk Ash and its Utilization for Lipase Immobilization

2014 ◽  
Vol 925 ◽  
pp. 23-27
Author(s):  
Nurhadijah Zainalabidin ◽  
Noor Hasyierah Mohd Salleh ◽  
Dachyar Arbain
Keyword(s):  
Surface Area ◽  
Mesoporous Materials ◽  
Rice Husk ◽  
Fine Particles ◽  
Rice Husk Ash ◽  
Enzyme Stability ◽  
Solid Particles ◽  
Bet Surface Area ◽  
Time Range ◽  
Mcm 41

Mesoporous materials are favorable for enzyme immobilization due to their unique properties of large surface area, uniform pore system and functionalizable surfaces. Immobilization on these materials enhances enzyme stability, activity and resistance towards harsh environmental conditions such as temperature and pH. The present study deals with synthesis of mesoporous materials namely MCM-41. For that purpose, the MCM-41 was synthesized using cetyltrimethylammonium bromide (CTAB) as a template and extractable silica from rice husk ash as a silica source. The synthesis was performed under alkaline conditions to produce white fine solid particles, followed by grafting with 3-aminopropyltriethoxysilane and activation with carbodiimide before it was immobilized with lipase. Characterization of those fine particles using Nitrogen physisorption gives BET surface area, as BET, and the pore diameterto be 1184 m²/g and 2.58 nm respectively. Fourier Transform Infrared spectra show peak of SiO2, NH2 and COOH functional group which confirms the existence of those compounds in covalent bonding formation between amine-grafted MCM-41 and lipase enzyme. Immobilized enzyme shows an increase in pH stability when compared to free enzyme at fixed temperature of 20°C in time range from 30 to 180 minutes.

scholarly journals Effect of CTAB Ratio to the Characters of Mesoporous Silica Prepared from Rice Husk Ash in the Pyrolysis of a–cellulose

2021 ◽  
Vol 16 (3) ◽  
pp. 632-640
Author(s):  
Nia Meisa Wulandari ◽  
Lisna Efiyanti ◽  
Wega Trisunaryanti ◽  
Haryo Satriya Oktaviano ◽  
Syaiful Bahri ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Surface Area ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Agricultural Waste ◽  
Cost Effective ◽  
Mesoporous Structure ◽  
Chemical Production ◽  
Sem Images ◽  
Strong Base

Due to its wide application, synthesizing silica through a cost-effective process becomes an attractive subject to be studied today. In this work, mesoporous silica (MS) was prepared from the highly available agricultural waste, rice husk ash (RHA), to be used as catalyst in the pyrolysis of a-cellulose. Silica was extracted from RHA through a reflux process in a strong base solution and arranged into a mesoporous structure by using cetyltrimethylammonium bromide (CTAB). To find a condition that produces a mesoporous support with the highest surface area and catalytic activity, the mole ratios of CTAB:SiO2 used during the preparation of MS were varied; 0.05:1; 0.1:1; 0.2:1. Afterwards, all prepared MS were characterized using Fourier Transform Infra Red (FTIR), Scanning Electron Microscope (SEM), and Surface Area Analyzer (SAA). Through he surface area analysis, it was found that MS materials possessed surface area, pore diameter, and pore volume that range from 600–970 m2.g−1, 3.5–4.7 nm, 0.7–1 cm3.g−1, respectively. The highest surface area, with over 970.80 m2.g−1, was obtained in MS support prepared by using CTAB:SiO2 mole ratio of 0.1:1. SEM images showed a coral reef-like surface morphology for all MS. In the pyrolysis of a-cellulose evaluated by Py-GCMS, aside from producing biofuel compounds, the use of MS was able to generate two-fold furan production, which is considered as a valuable compound in many chemical syntheses. This result highlights the potential of MS prepared from RHA to be used as a catalysis support material that is more economical for biofuel and other chemical production. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

scholarly journals Hydrophilic and Hydrophobic Mesoporous Silica Derived from Rice Husk Ash as a Potential Drug Carrier

Materials ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1142 ◽  
Author(s):  
Supakij Suttiruengwong ◽  
Sommai Pivsa-Art ◽  
Metta Chareonpanich
Keyword(s):  
Mesoporous Silica ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Drug Carrier ◽  
Potential Drug

Hydrothermal Synthesis of Nanorods/Nanoparticles TiO2 for Photocatalytic Activity and Dye-sensitized Solar Cell Applications

2006 ◽  
Vol 951 ◽  
Author(s):  
Sorapong Pavasupree ◽  
Supachai Ngamsinlapasathian ◽  
Yoshikazu Suzuki ◽  
Susumu Yoshikawa
Keyword(s):  
Photocatalytic Activity ◽  
Surface Area ◽  
Pore Diameter ◽  
Mesoporous Structure ◽  
Energy Conversion Efficiency ◽  
Bet Surface Area ◽  
Average Pore ◽  
Dye Sensitized ◽  
Prepared Material ◽  
20 Nm

ABSTRACTNanorods/nanoparticles TiO2 with mesoporous structure were synthesized by hydrothermal method at 150 °C for 20 h. The samples characterized by XRD, SEM, TEM, SAED, HRTEM, and BET surface area. The nanorods had diameter about 10-20 nm and the lengths of 100-200 nm, the nanoparticles had diameter about 5-10 nm. The prepared material had average pore diameter about 7-12 nm. The BET surface area and pore volume of the sample are about 203 m2/g and 0.655 cm3/g, respectively. The nanorods/nanoparticles TiO2 with mesoporous structure showed higher photocatalytic activity (I3− concentration) than the nanorods TiO2, nanofibers TiO2, mesoporous TiO2, and commercial TiO2 (ST-01, P-25, JRC-01, and JRC-03). The solar energy conversion efficiency (η) of the cell using nanorods/nanoparticles TiO2 with mesoporous structure was about 7.12 % with Jsc of 13.97 mA/cm2, Voc of 0.73 V and ff of 0.70; while η of the cell using P-25 reached 5.82 % with Jsc of 12.74 mA/cm2, Voc of 0.704 V and ff of 0.649.

Mesoporous Silica Sol-Gel as Catalyst for the Synthesis of Alkylpolyglucosides

2012 ◽  
Vol 620 ◽  
pp. 446-452 ◽  
Author(s):  
Izazi Azzahidah Amin ◽  
Mohd Ambar Yarmo ◽  
Nik Idris Nik Yusoff ◽  
Mohd Zahid Yusoff ◽  
Alifee Ayatillah
Keyword(s):  
Binding Energy ◽  
Mesoporous Silica ◽  
Surface Area ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Silica Sol ◽  
Area Measurement ◽  
Bet Surface Area ◽  
Solid Catalyst ◽  
Positive Mode

The synthesis of alkylpolyglucosides involves condensation of decanol with dextrose in the presence of mesoporous silica sol-gel as a catalyst. In this study, mesoporous silica was produced using sol-gel technique by converting tetraethyl orthosilicate (TEOS) into silica. The mesoporous silica was characterized using BET surface area measurement and X-ray Photoelectron Spectroscopy surface analysis. The specific BET surface area was 794m2/g. From the XPS analysis, the Si2p binding energy is 103.7 eV while the O1s binding energy is 532.8eV indicating the formation of Si-O-Si bond which attributed to SiO2. Mesoporous silica has been found efficient to be solid catalyst for synthesis alkylpolyglucosides and easy to be separated. The reaction was carried out 8 hours at 110°C-120°C under vacuum condition. The mass determination of alkylpoluglucosides has been achieved by ESI LC-MS/MS (ToF) positive-mode giving a mass peak at m/z = 343.21 corresponding to [M++ of alkylmonoglucoside peak at retention time 11.0 min.

scholarly journals Preparation of Alpinia galangaStem Based Activated Carbon via Single-step Microwave Irradiation for Cationic Dye Removal

2021 ◽  
Vol 50 (8) ◽  
pp. 2251-2269
Author(s):  
N.A. Ahammad ◽  
M.F.M. Yusop ◽  
A.T. Mohd Din ◽  
M.A. Ahmad
Keyword(s):  
Activated Carbon ◽  
Microwave Irradiation ◽  
Surface Area ◽  
Dye Removal ◽  
Pore Diameter ◽  
Focal Point ◽  
Radiation Power ◽  
Single Step ◽  
Bet Surface Area ◽  
Cationic Dye

The focal point of this study is to synthesis Alpinia galanga Stem-based activated carbon (AGSAC) by using single-step microwave irradiation and testing it for the removal of cationic dye, methylene blue (MB) from aqueous solution. AGSAC was prepared under the flow of carbon dioxide (CO2) for the gasification effect. The factors of contact time (from 0 to 24 h) and initial concentration (25-300 mg/L) on the adsorption performance of AGSAC were studied. With the aid of response surface methodology (RSM) via face-centered composite design (FCD), optimum preparation conditions for AGSAC were found to be 400 W for radiation power and 4 min for activation time, respectively, which resulted in 95.67% of MB dye removal. The optimized AGSAC has a Bruneaur-Emmet-Teller (BET) surface area of 172.19 m2/g, mesopore surface area of 103.32 m2/g, a total pore volume of 0.1077 cm3/g, and fixed carbon content of 47.63%. The pore diameter of AGSAC was found to be a mesoporous type with a pore diameter of 2.50 nm. Freundlich isotherm and pseudo-second-order were found as the best-fitted model for MB adsorption equilibrium and kinetic respectively onto prepared AGSAC. Intraparticle diffusion was found to be the rate-limiting step.

scholarly journals PHYSICOCHEMICAL PROPERTIES AND POZZOLANIC PERFORMANCE OF ULTRAFINE TREATED RICE HUSK ASH (UFTRHA) AS ADDITIVE IN CONCRETE

2018 ◽  
Vol 16 ◽  
Author(s):  
Siti Asmahani Saad ◽  
Nasir Shafiq ◽  
Maisarah Ali
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Rice Husk ◽  
Amorphous Silica ◽  
Rice Husk Ash ◽  
High Energy ◽  
Size Analysis ◽  
Pre Treatment

Rice husk ash (RHA) contains high amount of amorphous silica that is ubiquitous in the pozzolanic reaction of SCM in concrete. However, usage of conventional RHA is currently unfavourable in concrete industry due to its properties inconsistency. In this regard, improvement on the RHA properties by introduction of thermochemical pre-treatment prior to burning procedure is seen as an excellent way to reach the goal. In this paper, raw rice husk was pre-treated using 0.1N hydrochloric acid (HCl) and heated at 80oC. It was then mechanically activated by high energy planetary ball mill for 15 minutes at speed of 300rpmand ball-to-powder ratio (BPR) of 15:1. The chemical composition, mineralogical properties, particle size analysis, specific surface area as well as microstructure properties of ultrafine treated rice husk ash (UFTRHA) were determined accordingly. As for amorphous silica content of the optimum sample was recorded as 98.60% incinerated at 600oC with four hours of pre-treatment soaking duration. In terms of particle size and specific surface, it was also observed that, burning temperature of 600oC, pre-treated at four hours were recorded to produce finest size of UFTRHA where d(0.1), d(0.5) and d(0.9) were obtained as 1.416?m, 4.364 ?m and 14.043 ?m respectively. Largest specific surface area value was obtained at 219.58 m2/g with the similar pre-treatment conditions. Meanwhile, the strength activity of UFTRHA from the optimum pre-treatment process was measured by testing the compressive strength of mortars. The highest compression value obtained was 50.17MPa with 3% UFTRHA replacement at 28 days.

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