poly acrylic acid
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Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 469
Tannaz Soltanolzakerin Sorkhabi ◽  
Mehrab Fallahi Samberan ◽  
Krzysztof Adam Ostrowski ◽  
Tomasz M. Majka

The effect of SiO2 nanoparticles on the formation of PAA (poly acrylic acid) gel structure was investigated with seeded emulsion polymerization method used to prepare SiO2/PAA nanoparticles. The morphologies of the nanocomposite nanoparticles were studied by transmission electron microscopy (TEM). Fourier-transform infrared (FTIR) spectroscopy results indicated that the PAA was chemically bonded to the surface of the SiO2 nanoparticles. Additionally, the resulting morphology of the nanocomposite nanoparticles confirmed the co-crosslinking role of the SiO2 nanoparticles in the formation of the 3D structure and hydrogel of PAA. SiO2/PAA nanocomposite hydrogels were synthesized by in situ solution polymerization with and without toluene. The morphology studies by field emission scanning electron microscopy (FESEM) showed that when the toluene was used as a pore forming agent in the polymerization process, a macroporous hydrogel structure was achieved. The pH-sensitive swelling behaviors of the nanocomposite hydrogels showed that the formation of pores in the gels structure was a dominant factor on the water absorption capacity. In the current research the absorption capacity was changed from about 500 to 4000 g water/g dry hydrogel. Finally, the macroporous nanocomposite hydrogel sample was tested as an amoxicillin release system in buffer solutions with pHs of 3, 7.2, and 9 at 37 °C. The results showed that the percentage cumulative release of amoxicillin from the hydrogels was higher in neutral and basic mediums than in the acidic medium and the amoxicillin release rate was decreased with increasing pH. Additionally, the release results were very similar to swelling results and hence amoxicillin release was a swelling controlled-release system.

2022 ◽  
pp. 52091
Giorgio Marques Milani ◽  
Isabela Trindade Coutinho ◽  
Felipe Nogueira Ambrosio ◽  
Mônica Helena Monteiro do Nascimento ◽  
Christiane Bertachini Lombello ◽  

Chemosphere ◽  
2022 ◽  
pp. 133487
Alexander W. Jackson ◽  
Srinivasa Reddy Mothe ◽  
Pancy Ang ◽  
Lohitha Rao Chennamaneni ◽  
Alexander M.V. Herk ◽  

CrystEngComm ◽  
2022 ◽  
Hong Lyun Kim ◽  
Yu Seob Shin ◽  
Sung Ho Yang

In a biological system, biomineral is regulated by a controlled mass transfer as well as an assistance of soluble and insoluble macromolecules. Inspired by biomineralization, calcium carbonate morphologies were controlled...

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 115
Silvia Franco ◽  
Elena Buratti ◽  
Valentina Nigro ◽  
Monica Bertoldo ◽  
Barbara Ruzicka ◽  

Stimuli-responsive microgels have recently attracted great attention in fundamental research as their soft particles can be deformed and compressed at high packing fractions resulting in singular phase behaviours. Moreover, they are also well suited for a wide variety of applications such as drug delivery, tissue engineering, organ-on-chip devices, microlenses fabrication and cultural heritage. Here, thermoresponsive and pH-sensitive cross-linked microgels, composed of interpenetrating polymer networks of poly(N-isopropylacrylamide) (PNIPAM) and poly(acrylic acid) (PAAc), are synthesized by a precipitation polymerization method in water and investigated through differential scanning calorimetry in a temperature range across the volume phase transition temperature of PNIPAM microgels. The phase behaviour is studied as a function of heating/cooling rate, concentration, pH and PAAc content. At low concentrations and PAAc contents, the network interpenetration does not affect the transition temperature typical of PNIPAM microgel in agreement with previous studies; on the contrary, we show that it induces a marked decrease at higher concentrations. DSC analysis also reveals an increase of the overall calorimetric enthalpy with increasing concentration and a decrease with increasing PAAc content. These findings are discussed and explained as related to emerging aggregation processes that can be finely controlled by properly changing concentration, PAAc content an pH. A deep analysis of the thermodynamic parameters allows to draw a temperature– concentration state diagram in the investigated concentration range.

2021 ◽  
Nan Zhang ◽  
Zhensheng Tian ◽  
Yuanyuan Yu ◽  
Ping Wang ◽  
Man Zhou ◽  

2021 ◽  
Vol 0 (0) ◽  
Ely Cheikh S’Id ◽  
Mohamed Degué ◽  
Chlouma Khalifa ◽  
Chamekh M’Bareck

Abstract The current investigation is focused on the removal of crystal violet (CV) from water by adsorption process (bach method). To achieve this purpose, specific membranes were prepared from poly acrylonitrile-co-sodium methallyl sulfonate (AN69) and poly acrylic acid (PAA) blends. The adsorption of CV onto AN69/PAA membranes was studied under various conditions: membrane composition, pH, contact time, initial concentration and temperature. To understand the effect of membrane morphology on adsorption process, scanning electronic microscopy (SEM) was employed to determine the features of section and membrane’s surface. From isotherm results, it was found that: the maximum adsorption capacity Q m was 1250 mg g−1, the Langmuir separation factor R L was lying between 0.33 and 0.76, the Freundlich intensity was higher than Unit (n = 1.25) and the adsorption process follows preferentially the Langmuir model (correlation constant R 2 = 0.99). The mechanism of adsorption is perfectly fitted by pseudo second order. The obtained results tend to confirm that the removal of dye molecules is due to the establishment of strong electrostatic interactions between cationic dye molecules and anionic membrane groups. The high adsorption capacity (1250 mg g−1) for the small dye molecules may open wide opportunities to apply these membranes in the removal of various hazardous pollutants commonly present in water.

2021 ◽  
Vol 9 (6) ◽  
pp. 106346
Bo Gao ◽  
Hairong Yu ◽  
Jingya Wen ◽  
Hongju Zeng ◽  
Ting Liang ◽  

Xiumei Zhang ◽  
Huining Wan ◽  
Weiwei Lan ◽  
Fenyan Miao ◽  
Miao Qin ◽  

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