Effect of pH and temperature on swelling Behaviour of tamarind gum

Author(s):  
Braja B. Panda ◽  
Rudra N. Sahoo ◽  
Nilamadhab Nayak ◽  
Subrata Mallick

Natural gum tamarind is a plant polysaccharide extracted from seeds endosperm of the plant, Tamarindus indica Linn. Thin film of the gum was prepared by direct compression method. The prepared film was investigated for the effect of pH and temperature on solvent uptake property of film by gravimetric method. Different swelling parameters such as mass swelling ratio (MSR), equilibrium swelling ratio (ESR), equilibrium swelling ratio (ESw) and the equilibrium water content (EWC) were studied. It was found that swelling parameters were influenced by different pH and temperature conditions. The results suggested that the water content in equilibrium state was similar to body fluid. The gum converted to a high viscous gel of pseudo plastic characteristics in different pH conditions and the mechanism of continuous diffusion of solvent molecules into tablet during swelling was a non fickian and followed a second order kinetics.

2009 ◽  
Vol 79-82 ◽  
pp. 1999-2002
Author(s):  
Yu Hua Xue ◽  
Wen Yuan Zhao ◽  
Shou Feng Sun ◽  
Hu Yu

In this study, macroporous, pH sensitive polyacrylic acid hydrogels were prepared by using different concentration of aqueous NaCl solutions as the polymerization medium. The optical photos showed that the pore morphologies of the hydrogels were dependent on the concentration of NaCl. Swelling studies showed an increase in equilibrium swelling ratio as the NaCl concentration in the polymerization medium increased from 0 to 0.7mol/L. The hydrogels exhibited stronger sensitivity to pH changes, and showed much faster reswelling and deswelling response rates with the NaCl concentration increasing in the polymerization medium.


2012 ◽  
Vol 601 ◽  
pp. 12-15 ◽  
Author(s):  
Tong Wan ◽  
Li Ying Liu ◽  
Wei Zeng ◽  
Yong Zhu

Bacterial Cellulose (BC) consisting of hydrophobic ultra-fine fibers was produced by Acetobacter xylinum. Hydroxypropyl bacterial celluloses (HPBC) were synthesized by surface modification of nano-fibrils via hydroxypropylation using two modifier systems, sodium hydroxide/ propylene oxide as system (I) and sodium hydroxide/urea/propylene oxide as system (II) respectively. The equilibrium swelling ratio (ESR) of HPBC was studied. ESR of HPBC obtained from system (I) was significantly higher than that obtained from system (II). The maximum ESR of HPBC was nearly 70 times larger than that of air dried BC and 10 times larger than that of freeze dried BC.


2012 ◽  
Vol 2 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Asefe Mousavi Moghadam ◽  
Mohsen Vafaie Sefti ◽  
Mahsa Baghban Salehi ◽  
Ahmad Dadvand Koohi

2010 ◽  
Vol 8 (2) ◽  
pp. 426-433 ◽  
Author(s):  
Yueqin Yu ◽  
Yanshun Li ◽  
Chunjing Zhu ◽  
Lingxiu Liu

AbstractBased on a biodegradable cross-linker, N-maleyl chitosan (N-MACH), a series of Poly(N-isopropylacrylamide) (PNIPAAm) and Poly(N-isopropylacrylamide-co-acrylamide) [P(NIPAAm-co-Am)] hydrogels were prepared, and their lower critical solution temperature (LCST), swelling kinetics, equilibrium swelling ratio in NaCl solution, and enzymatic degradation behavior in simulated gastric fluids (SGF) were discussed. The LCST did not change with different cross-linker contents. By altering the NIPAAm/Am molar ratio of P(NIPAAm-co-Am) hydrogels, the LCST could be increased to 39°C. The LCST of the hydrogel was significantly influenced by the monomer ratio of the NIPAAm/Am but not by the cross-linker content. In the swelling kinetics, all the dry hydrogels exhibited fast swelling behavior, and the swelling ratios were influenced by the cross-linker content and NIPAAm/Am molar ratios. Equilibrium swelling ratio of all the hydrogels decreased with increasing NaCl solution concentration. In enzymatic degradation tests, the weight loss of hydrogels was dependent on the cross-linker contents and the enzyme concentration.


2013 ◽  
Vol 774-776 ◽  
pp. 544-547
Author(s):  
Wei Han ◽  
You Hong Tang

A series of water-swelling rubbers (WSR) were prepared by directly mixing room temperature vulcanization-2 components silicone rubber (RTV-2 SR) with superabsorbent polymer (SAP) and nanofiller (s) (halloysite nanotube or/and CaCO3). The effects of component on its mechanical behaviours and water-absorbent properties such as degree of swelling, swelling ratio, and weight loss ratio were investigated. The equilibrium swelling ratio increased with increasing amounts of water-absorbent resin. Well-dispersed nanofiller (s) increased the mechanical properties of WSR and prevented SAP breaking off from the elastomer network to effectively enhance the water-swelling durability of WSR.


2013 ◽  
Vol 448-453 ◽  
pp. 3993-3997
Author(s):  
Yu Lou ◽  
Wei Yao Zhu ◽  
Xue Ling Zhang ◽  
Yun Qian Long

Nano/micro polymer particles of acrylamide (AM), acrylic acid (AA), methyl methacrylate (MMA) are used to enhance oil recovery. Swelling kinetics of nano/micro polymer particles were investigated through experimental analysis and statistical analysis. The effect of salinity and temperature on swelling behavior over time is studied experimentally. The swelling kinetics of nano/micro polymer particle was described by second order kinetics. Equilibrium swelling ratio and swelling rate were obtained through nonlinear regression. The quantitative relationships between equilibrium swelling ratio and salinity, temperature were presented. Results show that the swelling ratio increases with increasing temperature or decreasing salt concentration. The study provides a direct perspective of swelling characteristics of nano/micro polymer particles for oil recovery enhancement.


2012 ◽  
Vol 535-537 ◽  
pp. 2296-2300 ◽  
Author(s):  
Yong Hui Wang ◽  
Chen Hui Zhu ◽  
Yu Mi ◽  
Dai Di Fan ◽  
Li Jun Zhang

Hydrogels were prepared from carboxymethyl chitosan (CMCS)/Human-like collagen(HLC) by S-acetylmercaptosuccinic anhydride(SAMSA) crosslinker. Fourier transform infrared (FTIR) spectroscopy indicated that there exactly existed interaction HLC, carboxymethyl chitosan and SAMSA. The morphology of the hydrogels was observed by scanning electron microscope (SEM). The equilibrium swelling ratio was also evaluated. Cell culture results showed that these hydrogels were good in promoting the cell attachment and proliferation. The hydrogels are promised for the applications in the biomaterials area.


2011 ◽  
Vol 311-313 ◽  
pp. 2084-2088 ◽  
Author(s):  
Kun Yuan ◽  
Xiao Fang Wang ◽  
Yuan Cheng Zhu ◽  
Guo Fang Zuo

A novel thermo-responsive microsphere-sized poly(N-isopropylacrylamide) (PNIPAm) composite hydrogels were prepared by gelation of poly(vinyl alcohol) (PVA) solution containing ultra-fine CaCO3, then treated with 2wt% glutaraldehyde solution, sequencely with HCl acid, and PVA matrix with microsphere-sized pores obtained. The internal pores of the dry PVA matrix were filled with PNIPAm hydrogels to give a thermo-responsive composite hydrogels for drug carrier. The composite hydrogel was characterized via scanning electron microscopy (SEM), temperature dependence of equilibrium swelling ratio in water of the composite hydrogels was also investigated. Rhodamine B (RB) was loaded to the composite hydrogels for release study.


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