Terephthalaldehyde as better crosslinking agent in crosslinked chitosan hydrogel for selective removal of anionic dyes

2021 ◽  
Author(s):  
Madhvi Garg ◽  
Navneet Bhullar ◽  
Bharat Bajaj ◽  
Dhiraj Sud

The present manuscript reports the ultrasound radiation induced synthesis of grafted chitosan hydrogels (CAAT and CAAG) using terephthalaldehyde/glutaraldehyde as crosslinking agents and its application for removal of synthetic dyes from...

2017 ◽  
Vol 2 (2) ◽  
pp. 77
Author(s):  
Bambang Piluharto ◽  
A Sjaifullah ◽  
I Rahmawati ◽  
Erix Nurharianto

AbstrakMembran blend biodegradabel dengan kestabilan termal dan mekanik yang berasal dari gabungan kitosan dan PVA telah dihasilkan melalui dua tahapan. Pada tahap pertama dilakukan proses pelarutan kitosan dan poli vinil alkohol dan selanjutnya pencampuran kitosan/PVA dan asam oksalat sebagai agen pengikat silang. Asam asetat dan air dipilih sebagai pelarut untuk kitosan dan PVA. Beberapa variasi dalam proses seperti perbandingan konsentrasi kitosan:PVA, konsentrasi agen pengikat silang dan pH buffer, dijadikan sebagai parameter pada penelitian ini. Kerapatan hidrogel dan kuat tarik mengalami kenaikan seiring dengan peningkatan konsentrasi agen pengikat silang dan PVA dengan konsentrasi kitosan paling rendah. Namun derajat swelling memiliki trend yang berbeda dimana naiknya derajat swelling diperoleh seiring dengan peningkatan konsentrasi kitosan dengan kondisi konsentrasi agen pengikat silang dan PVA paling rendah. Keberhasilan proses blending  dan ikat silang ditunjukkan dari hasil spektra infra merah dimana analisa spektrum infra merah dari hidrogel kitosan murni dan hidrogel kitosan/PVA menunjukkan kenaikan intensitas serapan pada daerah amida (1600 cm-1 sampai 1670 cm-1), hal ini menguatkan dugaan terbentuknya ikatan silang antara asam oksalat sebagai crosslinker dengan kitosan. Kata kunci: membran blend, kitosan/PVA, asam oksalat, pengikat silang. AbstractBiodegradable blend membranes with thermal and mechanical stability based on combination of chitosan and PVA have been produced through two stages. In the first stage, chitosan and PVA are dissolved and further mixing chitosan/polyvinyl alcohol with oxalic acid as crosslinking agents. Acetic acid and water are selected as solvents for chitosan and PVA. Some variations in the process such as comparison of chitosan:PVA concentration, concentration of crosslinking agent and pH of buffer, are used as parameters in this study. The hydrogel density and tensile strength increased with increasing concentration of crosslinking agent and PVA with the lowest concentration of chitosan. However, the degree of swelling has a distinct trend in which the increase of degree of swelling is obtained along with the increase of chitosan concentration with the lowest concentration of crosslinking agent and PVA. The success of the blending and crosslinking process is shown by the results of infrared spectra where infrared spectrum analyzes from purified chitosan hydrogels and chitosan/chloride hydrogels show an increase in absorption intensity in the amide area (1600 cm-1 to 1670 cm-1), this reinforces the alleged crosslinking formation between oxalic acid as crosslinker and chitosan. Keywords: blend membrane, chitosan: PVA, crosslinker.


2021 ◽  
Vol 183 ◽  
pp. 2293-2304
Author(s):  
Nahum Andrés Medellín-Castillo ◽  
Elizabeth Diane Isaacs-Páez ◽  
Itzia Rodríguez-Méndez ◽  
Raul González-García ◽  
Gladis Judith Labrada-Delgado ◽  
...  

RSC Advances ◽  
2020 ◽  
Vol 10 (71) ◽  
pp. 43904-43914
Author(s):  
Deola Majhi ◽  
Braja N. Patra

Polyaniline and sodium alginate nanocomposite was synthesized and it was used for selective removal of both cationic and anionic dyes from water at different pH.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1388
Author(s):  
Kathryn E. O’Harra ◽  
Emily M. DeVriese ◽  
Erika M. Turflinger ◽  
Danielle M. Noll ◽  
Jason E. Bara

This work introduces a series of vinyl-imidazolium-based polyelectrolyte composites, which were structurally modified via impregnation with multivalent imidazolium-benzene ionic liquids (ILs) or crosslinked with novel cationic crosslinkers which possess internal imidazolium cations and vinylimidazolium cations at the periphery. A set of eight [C4vim][Tf2N]-based membranes were prepared via UV-initiated free radical polymerization, including four composites containing di-, tri-, tetra-, and hexa-imidazolium benzene ILs and four crosslinked derivatives which utilized tri- and tetra- vinylimidazolium benzene crosslinking agents. Structural and functional characterizations were performed, and pure gas permeation data were collected to better understand the effects of “free” ILs dispersed in the polymeric matrix versus integrated ionic crosslinks on the transport behaviors of these thin films. These imidazolium PIL:IL composites exhibited moderately high CO2 permeabilities (~20–40 Barrer), a 4–7× increase relative to corresponding neat PIL, with excellent selectivities against N2 or CH4. The addition of imidazolium-benzene fillers with increased imidazolium content were shown to correspondingly enhance CO2 solubility (di- < tri- < tetra- < hexa-), with the [C4vim][Tf2N]: [Hexa(Im+)Benz ][Tf2N] composite showing the highest CO2 permeability (PCO2 = 38.4 Barrer), while maintaining modest selectivities (αCO2/CH4 = 20.2, αCO2/N2 = 23.6). Additionally, these metrics were similarly improved with the integration of more ionic content bonded to the polymeric matrix; increased PCO2 with increased wt% of the tri- and tetra-vinylimidazolium benzene crosslinking agent was observed. This study demonstrates the intriguing interactions and effects of ionic additives or crosslinkers within a PIL matrix, revealing the potential for the tuning of the properties and transport behaviors of ionic polymers using ionic liquid-inspired small molecules.


2003 ◽  
Vol 21 (5) ◽  
pp. 439-449 ◽  
Author(s):  
Yoshiaki Shimizu ◽  
Atsushi Taga ◽  
Hitoshi Yamaoka

Novel chitosan-based adsorbent materials with a higher fatty diacid diglycidyl as the crosslinking agent were synthesized and the adsorption abilities of the resulting polymers evaluated towards typical acid dyes. The successful formation of a crosslinked structure was confirmed via infrared spectroscopic measurements and the solubility of the polymer towards 10% aqueous solutions of acetic and formic acids determined. At higher dye concentrations, the adsorption abilities of the crosslinked chitosan towards hydrophilic CI Acid Orange 7 and CI Acid Red 1 increased with decreasing degree of substitution. However, at lower dye concentrations, the crosslinked chitosan with the lowest degree of substitution exhibited the lowest adsorption capability. With such hydrophilic acid dyes, the extent of adsorption decreased significantly as the pH of the solution increased. On the other hand, CI Acid Red 138, which contains a dodecyl group in the chemical structure, was adsorbed to a considerable extent even at higher pH values, suggesting hydrophobic interaction between the alkyl group in the dye molecule and the hydrophobic crosslinker.


Author(s):  
Qiong Jiang ◽  
Wei zhou ◽  
Jun Wang ◽  
Rupei Tang ◽  
Di Zhang ◽  
...  

Author(s):  
Guo-Xiang Cheng ◽  
Jing Liu ◽  
Ren-Zhe Zhao ◽  
Kang-De Yao ◽  
Ping-Chuan Sun ◽  
...  

2019 ◽  
Vol 8 (1) ◽  
pp. 645-660 ◽  
Author(s):  
Yu Miao ◽  
Jiawei Lu ◽  
Junhui Yin ◽  
Changchun Zhou ◽  
Yaping Guo ◽  
...  

AbstractMelanoma is the most lethal dermal tumor, and a high recurrence rate and skin defects are two main serious problems. An antimelanoma material,which effectively inhibits tumor recurrence and possesses excellent biocompatibility, is urgently needed to treat melanoma. In this study, we developed a novel antitumor Yb3+ [Yb(NO3)3]containing chitosan hydrogel (Yb-CS hydrogel) by dissolving Yb(NO3)3 and chitosan in acetic acid solution and forming composite hydrogels by a freeze-drying process after adding NaOH to the mixed solution. In vitro studies demonstrated that the Yb3+ produces effect of inducing cell death in Yb-CS hydrogel. Moreover, we found that the Yb-CS hydrogel inhibited a focal adhesion kinase (FAK)-dependent signaling pathway and induced B-16 cell anoikis. However, the Yb-CS hydrogel was less effective on L929 normal mouse dermal cells. In vivo studies showed that the Yb-CS hydrogel inhibited the recurrence of melanoma in a mouse bare xenograft tumor model. We concluded that the Yb-CS hydrogel could potentially be used in the antimelanoma field, especially in the inhibition of melanoma recurrence.


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