scholarly journals Zn2+-Loaded Cellulose Beads Stabilized by Chitosan and Prepared via Freeze-Drying for Removing Human Testosterone in Plasma

2018 ◽  
Author(s):  
Huibin Yu ◽  
Hongqin Ke ◽  
Tu Chen ◽  
Xing Li ◽  
Shenglong Tan ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Surface Area ◽  
Metal Ion ◽  
Freeze Drying ◽  
Chitosan Solution ◽  
Drying Method ◽  
Total Proteins ◽  
Adsorption Ability ◽  
Factors Affecting ◽  
Affinity Adsorbent

Immobilized metal ion affinity adsorbents have been widely used in separation technique to purify proteins. Due to the leakage of metal ion from the adsorbents, there is no metal ion affinity adsorbent for hemoperfusion has been applied to clinical trial. In this study, in order to prevent the leakage of Zn2+ loaded from cellulose beads based adsorbent, improve its stability and adsorption capacity for testosterone, Freeze-drying method was used to enhance the porosity of cellulose beads, improve the surface area of the cellulose beads and adsorption capacity for testosterone. Chitosan was used to coat the adsorbents for preventing the leakage of Zn2+ loaded and improve the adsorbent’s stability. Moreover, the factors affecting adsorption ability and some components in plasma were also investigated. The results indicate the adsorption ability of the adsorbent can be significantly improved by freeze-drying. After the adsorbent was coated with 0.02% chitosan solution, the highest adsorption percentage reached 48%. During adsorption, the Zn2+ concentration in plasma did not rise. In addition, the adsorption percentage for total proteins was below 15%. The results may be caused by the pore size and surface area of the adsorbent enlarged via freeze-drying, and the chitosan solution went into the pores and coated the outer and inner surface of the adsorbent. The adsorbent has a potential clinical application to remove testosterone in patients with recurrent and metastatic prostate cancer.

Development and Characterization of Amine-Clay Hybrid Adsorbents for CO2 Capture

2016 ◽  
Vol 1133 ◽  
pp. 547-551 ◽  
Author(s):  
Ali E.I. Elkhalifah ◽  
Mohammad Azmi Bustam ◽  
Azmi Mohd Shariff ◽  
Sami Ullah ◽  
Nadia Riaz ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Surface Area ◽  
Surface Properties ◽  
Molar Mass ◽  
Adsorption Ability ◽  
Stepwise Increase ◽  
Inverse Effect ◽  
Bet Method ◽  
Sodium Form

The present work aims at a better understanding of the influences of the intercalated mono-, di- and triethanolamines on the characteristics and CO2 adsorption ability of sodium form of bentonite (Na-bentonite). The results revealed that the molar mass of intercalated amines significantly influenced the structural and surface properties as well as the CO2 adsorption capacity of Na-bentonite. In this respect, a stepwise increase in the d-spacing of Na-bentonite with the molar mass of amine was recorded by XRD technique. However, an inverse effect of the molar mass of amine on the surface area was confirmed by BET method. CO2 adsorption experiments on amine-bentonite hybrid adsorbents showed that the CO2 adsorption capacity inversly related to the molar mass of amine at 25 ͦC and 101 kPa. Accordingly, Na-bentonite modified by monoethanolammonium cations adsorbed as high as 0.475 mmol CO2/g compared to 0.148 and 0.087 mmol CO2/g for that one treated with di- and triethanolammonium cations, respectively.

scholarly journals Fabrication and Characterization of Cellulose Nanofiber Aerogels Prepared via Two Different Drying Techniques

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2583 ◽  
Author(s):  
Zhe Wang ◽  
Wenkai Zhu ◽  
Runzhou Huang ◽  
Yang Zhang ◽  
Chong Jia ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Liquid Nitrogen ◽  
Compression Strength ◽  
Pore Volume ◽  
Supercritical Co2 ◽  
Freeze Drying ◽  
Drying Method ◽  
Drying Techniques ◽  
Supercritical Co2 Drying

Studies on the influence of drying processes on cellulose nanofiber (CNF) aerogel performance has always been a great challenge. In this study, CNF aerogels were prepared via two different drying techniques. The CNF solution was prepared via existing chemical methods, and the resultant aerogel was fabricated through supercritical CO2 drying and liquid nitrogen freeze-drying techniques. The microstructure, shrinkage, specific surface area, pore volume, density, compression strength, and isothermal desorption curves of CNF aerogel were characterized. The aerogel obtained from the liquid nitrogen freeze-drying method showed a relatively higher shrinkage, higher compression strength, lower specific surface area, higher pore volume, and higher density. The N2 adsorption capacity and pore diameter of the aerogel obtained via the liquid nitrogen freeze-drying method were lower than the aerogel that underwent supercritical CO2 drying. However, the structures of CNF aerogels obtained from these two drying methods were extremely similar.

Preparation of a Novel Cation Exchange Resin PSSS-g-CD301 and its Adsorption Properties towards Metal Ion

2014 ◽  
Vol 1053 ◽  
pp. 216-223 ◽  
Author(s):  
Wei Guang Ping ◽  
Tuo Ping Hu ◽  
Jian Feng Gao ◽  
Xi Chen ◽  
Wen Xia Zhou
Keyword(s):  
Adsorption Capacity ◽  
Metal Ion ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Gravimetric Method ◽  
Amino Groups ◽  
Adsorption Ability ◽  
Isothermal Adsorption ◽  
Sodium Styrene Sulfonate ◽  
Strong Adsorption

Resin D301 was surface-carbonized to obtain the surface charring materials (CD301). Using redox initiating system constituted by the amino groups of CD301 particles and persulfate in the solution, the poly (sodium styrene sulfonate) (PSSS) was grafted onto the surface of CD301, obtaining the grafted material PSSS-g-CD301, and the degree of grafting can reach 17.7% under suitable conditions. PSSS-g-CD301 was characterized by infrared spectrum (FTIR), and the degree of grafting was measured by gravimetric method. The adsorption character of PSSS-g-CD301 towards Al3+, Fe3+ and Cu2+ were mainly examined and investigated. PSSS-g-CD301 possesses strong adsorption ability towards Al3+, Fe3+and Cu2+. The adsorption capacity can get up to 13.285mg·g-1, 14.864mg·g-1, and 15.10mg·g-1, respectively. The data of isothermal adsorption matched well with Langmuir equation. The adsorption capacity increased with the increase of temperature and the value of pH. The adsorption capacity of PSSS-g-CD301 towards Fe3+ changed little after use them six times.

Freeze-Drying Graphene Aerogels and their Adsorption Ability towards Organic Reagents

2017 ◽  
Vol 898 ◽  
pp. 1923-1928 ◽  
Author(s):  
Hai Kun Wu ◽  
Xiao Min Li ◽  
Wen Zhao ◽  
Zhe Meng ◽  
Wen Jin Zhang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Freeze Drying ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Adsorption Ability ◽  
Organic Reagents ◽  
X Ray ◽  
Relative Standard ◽  
Cyclic Adsorption

Graphene (GR) aerogels with three-dimensional interconnected network were prepared from freeze drying graphene oxide (GO) dispersions for adsorbing organic reagents. Microstructures of GR aerogels were observed by field-emission scanning electron microscopy, and the components were analyzed by X-ray photoelectron spectroscopy and X-ray diffraction. Their adsorption abilities and recycling performances for organic reagents were investigated in detail. The results showed that the adsorption capacity of GR aerogels was dependent on the concentration of GO dispersion. For example, the adsorption capacity of ethanol increased from 7.04 to 32 g/g when the GO concentration changed from 5 to 10 mg/ml. The GR aerogels also exhibited good adsorption performance for other organic reagents, reaching 44.78, 93.41 and 56.56 g/g for cyclohexane, acetone and methanol, respectively. Moreover, the 7GR had good cyclic adsorption capacity for cyclohexane, acetone and methanol, and the relative standard deviation was 3.7%, 4.3%, 3%, respectively.

Removal of Fe (II) from Aqueous Solution by Chitosan Activated Carbon Composite Beads

2020 ◽  
Vol 898 ◽  
pp. 3-8
Author(s):  
Putri Wulan ◽  
Yuni Kusumastuti ◽  
Agus Prasetya
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Adsorption Capacity ◽  
Metal Ion ◽  
Adsorption Process ◽  
Chitosan Solution ◽  
Carbon Composite ◽  
Composite Beads ◽  
Naoh Solution ◽  
Adsorbent Dose

The high levels of Fe2+ metal ion in water can be reduced by adsorption process. The adsorbent used is a composite of chitosan activated carbon. The composites were prepared by adding 1.5 g of activated carbon into chitosan solution 1.5% (w/v). The gels of chitosan activated carbon were then dropped into a 2.8% NaOH solution mixture to produce composite beads. The beads were neutralized using aquadest and dried in an oven at 50oC for 2 hours. The dried bead was used as adsorbent. The adsorption process was carried out with erlenmeyer in shaker bath with 0.5 g, 1 g, and 1.5 g at 25oC, 35oC and 45oC in 50 mL solution of Fe2+ metal ion having concentration of 10 ppm. Sample were taken in 5, 10, 20, 40 60, 80 and 120 min. Adsorbent were characterized by SEM and EDX. The composite beads adsorbent was analyzed by SEM and EDX. SEM results show that chitosan was successfully coated on activated carbon with a porous surface structure. The EDX results show that chitosan activated carbon composite beads can absorb Fe2+ metal ions, with an adsorption capacity of 88.3% at 60 min in 1.5 g adsorbent dose.

A study of the freeze-drying process and quality evaluation of Angelica sinensis

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Zhang Haizhu ◽  
Luyao Zheng ◽  
Xingying Zhang ◽  
Xiuming Cui ◽  
Chengxiao Wang ◽  
...  
Keyword(s):  
Ferulic Acid ◽  
Freeze Drying ◽  
Chemical Constituents ◽  
Angelica Sinensis ◽  
Slice Thickness ◽  
Drying Method ◽  
Drying Process ◽  
Characteristic Structure ◽  
Factors Affecting

Abstract The freeze-drying process of Angelica sinensis (Oliv.) Diels was studied and evaluated. Using a single factor investigation, drying temperature and pressure were determined as the main factors affecting the drying process. The central composite design (CCD) combined with response surface method was employed to optimize the drying process. Optimal conditions were determined to be 52 Pa, 63 °C, and a slice thickness of 5 mm. Subsequently, samples were compared in terms of chemical constituents, microstructure, and in vitro absorption profiles under different drying operations. The freeze-drying process was effective for the preservation of ferulic acid (1.82 mg/g), Z-ligustilide (13.91 mg/g), and other compositions. The porous and loose characteristic structure enabled rapid release of ferulic acid (71%, 60 min) and Z-ligustilide (32%, 60 min). Therefore, the freeze-drying method is a reasonable and efficient drying method for the dehydration of A. sinensis.

scholarly journals Evaluation of Innovative Dried Purée from Jerusalem Artichoke—In Vitro Studies of Its Physicochemical and Health-Promoting Properties

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2644
Author(s):  
Jan Oszmiański ◽  
Sabina Lachowicz ◽  
Paulina Nowicka ◽  
Paweł Rubiński ◽  
Tomasz Cebulak
Keyword(s):  
Freeze Drying ◽  
Jerusalem Artichoke ◽  
Polyphenolic Compounds ◽  
Raw Material ◽  
Vacuum Drying ◽  
Drying Methods ◽  
Drying Method ◽  
Activity Inhibition ◽  
Health Promoting

The present study aimed to evaluate the effect of Jerusalem artichoke processing methods and drying methods (freeze drying, sublimation drying, vacuum drying) on the basic physicochemical parameters, profiles and contents of sugars and polyphenolic compounds, and health-promoting properties (antioxidant activity, inhibition of the activities of α-amylase, α-glucosidase, and pancreatic lipase) of the produced purée. A total of 25 polyphenolic compounds belonging to hydroxycinnamic phenolic acids (LC-PDA-MS-QTof) were detected in Jerusalem artichoke purée. Their average content in the raw material was at 820 mg/100 g dm (UPLC-PDA-FL) and was 2.7 times higher than in the cooked material. The chemical composition and the health-promoting value of the purées were affected by the drying method, with the most beneficial values of the evaluated parameters obtained upon freeze drying. Vacuum drying could offer an alternative to freeze drying, as both methods ensured relatively comparable values of the assessed parameters.

scholarly journals Environmentally Friendly and Multifunctional Shaddock Peel-Based Carbon Aerogel for Thermal-Insulation and Microwave Absorption

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Weihua Gu ◽  
Jiaqi Sheng ◽  
Qianqian Huang ◽  
Gehuan Wang ◽  
Jiabin Chen ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Thermal Insulation ◽  
Freeze Drying ◽  
Thermal Infrared ◽  
Carbon Aerogel ◽  
Carbon Aerogels ◽  
List Type ◽  
Drying Method ◽  
Cross Sectional ◽  
Compression Resistance

Highlights The eco-friendly shaddock peel-derived carbon aerogels were prepared by a freeze-drying method. Multiple functions such as thermal insulation, compression resistance and microwave absorption can be integrated into one material-carbon aerogel. Novel computer simulation technology strategy was selected to simulate significant radar cross-sectional reduction values under real far field condition. . Abstract Eco-friendly electromagnetic wave absorbing materials with excellent thermal infrared stealth property, heat-insulating ability and compression resistance are highly attractive in practical applications. Meeting the aforesaid requirements simultaneously is a formidable challenge. Herein, ultra-light carbon aerogels were fabricated via fresh shaddock peel by facile freeze-drying method and calcination process, forming porous network architecture. With the heating platform temperature of 70 °C, the upper surface temperatures of the as-prepared carbon aerogel present a slow upward trend. The color of the sample surface in thermal infrared images is similar to that of the surroundings. With the maximum compressive stress of 2.435 kPa, the carbon aerogels can provide favorable endurance. The shaddock peel-based carbon aerogels possess the minimum reflection loss value (RLmin) of − 29.50 dB in X band. Meanwhile, the effective absorption bandwidth covers 5.80 GHz at a relatively thin thickness of only 1.7 mm. With the detection theta of 0°, the maximum radar cross-sectional (RCS) reduction values of 16.28 dB m2 can be achieved. Theoretical simulations of RCS have aroused extensive interest owing to their ingenious design and time-saving feature. This work paves the way for preparing multi-functional microwave absorbers derived from biomass raw materials under the guidance of RCS simulations.

scholarly journals Effective Poly (Cyclotriphosphazene-Co-4,4′-Sulfonyldiphenol)@rGO Sheets for Tetracycline Adsorption: Fabrication, Characterization, Adsorption Kinetics and Thermodynamics

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1540
Author(s):  
Muhammad Ahmad ◽  
Tehseen Nawaz ◽  
Mohammad Mujahid Alam ◽  
Yasir Abbas ◽  
Shafqat Ali ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
High Adsorption ◽  
Clean Environment ◽  
Equilibrium Data ◽  
Langmuir Isotherm Model ◽  
High Adsorption Capacity ◽  
Adsorption Equilibrium Data

The development of excellent drug adsorbents and clarifying the interaction mechanisms between adsorbents and adsorbates are greatly desired for a clean environment. Herein, we report that a reduced graphene oxide modified sheeted polyphosphazene (rGO/poly (cyclotriphosphazene-co-4,4′-sulfonyldiphenol)) defined as PZS on rGO was used to remove the tetracycline (TC) drug from an aqueous solution. Compared to PZS microspheres, the adsorption capacity of sheeted PZS@rGO exhibited a high adsorption capacity of 496 mg/g. The adsorption equilibrium data well obeyed the Langmuir isotherm model, and the kinetics isotherm was fitted to the pseudo-second-order model. Thermodynamic analysis showed that the adsorption of TC was an exothermic, spontaneous process. Furthermore, we highlighted the importance of the surface modification of PZS by the introduction of rGO, which tremendously increased the surface area necessary for high adsorption. Along with high surface area, electrostatic attractions, H-bonding, π-π stacking and Lewis acid-base interactions were involved in the high adsorption capacity of PZS@rGO. Furthermore, we also proposed the mechanism of TC adsorption via PZS@rGO.

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