scholarly journals An Active Absorbent for Cleanup of High-Concentration Strong Acid and Base Solutions

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3389
Author(s):  
Nara Han ◽  
Sol Park ◽  
Byung Kwon Kaang ◽  
Wooree Jang ◽  
Hye Young Koo ◽  
...  

There is significant interest in developing novel absorbents for hazardous material cleanup. Iron oxide-coated melamine formaldehyde sponge (MFS/IO) absorbents with various IO layer thicknesses were synthesized. Various other absorbents were also synthesized and compared to evaluate the absorption capability of the MFS/IO absorbents for strong acid (15%, v/v) and base (50%, m/m) solutions. Specifically, absorbent and solution drop tests, dust tests, and droplet fragment tests were performed. Among the various absorbents, MFS/IO absorbents possessing a needlelike surface morphology showed several unique characteristics not observed in other absorbents. The MFS/IO absorbents naturally absorbed a strong base solution (absorption time: 0.71–0.5 s, absorption capacity: 10,000–34,000%) without an additional external force and immediately absorbed a strong acid solution (0.31–0.43 s, 9830–10,810%) without absorption delay/overflow during absorbent and solution drop tests, respectively. The MFS/IO absorbents were also demonstrated to be ideal absorbents that generated fewer dust particles (semiclass 1 (ISO 3) level of 280 piece/L) than the level of a clean room (class 100). Furthermore, the MFS/IO absorbents were able to prevent the formation of droplet fragments and solution overflow during the solution drop test due to their unique surface morphology and extremely high absorption speed/capacity, respectively.

2018 ◽  
Vol 206 ◽  
pp. 353-364 ◽  
Author(s):  
Muhammed Shah Miran ◽  
Tomohiro Yasuda ◽  
Ryoichi Tatara ◽  
Md. Abu Bin Hasan Susan ◽  
Masayoshi Watanabe

Amphoteric water was mixed with equimolar amounts of a super-strong acid, trifluoromethanesulfonic acid (TfOH), and a super-strong base, 1,8-diazabicyclo-[5.4.0]-7-undecene (DBU) to explore the properties as fuel cell electrolytes.


Substantia ◽  
2021 ◽  
pp. 39-48
Author(s):  
Tanita Gettongsong ◽  
Mojtaba Taseidifar ◽  
Richard M. Pashley ◽  
Barry W. Ninham

This paper reports the synthesis and properties of new polymer resins containing strong acid and base groups for optimising applications in desalination. Several polyampholytic gels were synthesised with a ratio of 1:1 of strong acid (sulphonate) and strong base (quaternary ammonium) groups and a zwitterionic resin with a 1:1 strong acid and base ratio. The physico-chemical properties of these highly charged resins were studied in electrolyte solutions over a range of pH values, in particular: effects of chemical cross-linking, water and electrolyte swelling; bulk electrical conductivities and surface charging properties in different pH values. The results from absorption of NaCl showed that the resins have considerable potential for more effective desalination than other resin-based techniques.


1993 ◽  
Vol 328 ◽  
Author(s):  
Leonard J. Buckley

ABSTRACTChemically synthesized polyaniline films were studied during the doping and dedoping process by imaging the polymer surface using in-situ Atomic Force Microscopy (AFM). The polymer, which was initially in the base non-conducting form was doped using aqueous acidic solutions of both tosylic (pH=0.2) and HCl (pH of 0.2 and 1.0). Dedoping was accomplished by exposing the same doped polymer surface to NH4OH (pH=12) base solution. AFM images showed that it was necessary to cycle the polymer surface 3 times between acid and base before a reproducible surface morphology was established between the doped and dedoped states. For the case of doping with tosylic acid AFM images showed that the polyaniline surface was immediately roughened. In addition there appeared to be an increase in the size of surface channels and cracks. When doping with HC1 (pH=1.0), no change in surface morphology was observed; however, noticeable surface roughening occurred over 10 Minutes for the case of the lower pH=0.2 solution. The complex permittivity and DC conductivity was measured to estimate the level of protonation in the AFM samples.


2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
N. Kapilraj ◽  
S. Keerthanan ◽  
M. Sithambaresan

Commonly used indicators for acid-base titrations are synthetic, and this work was focused to identify the eco-friendly natural indicators and to determine their pKa values. The analytical potential of the flower extracts is very promising as seen in its application in acid-base titrimetry. These selected flower extracts were found to perform well in titrating strong acid-strong base than in weak acid-strong base. We have obtained a sharp and clear colour change from red to brownish yellow for the Bougainvillea glabra extract, from red to yellow for the Bauhinia purpurea extract, and from red to brownish yellow for the Impatiens balsamina extract. All the three flower extracts gave clear colour change with acids and bases, and the colour change was maintained with different acids and bases. The sharp contrast between their colours in acid and base made the pigment suitable for use as acid-base indicators. As these flower extracts have very simple,cost-effective, environment friendly extraction procedure and excellent performance with sharp colour change in end points of the titrations, it would be possible to replace the standard indicators being used in conventional laboratories with natural flower indicators.


Author(s):  
Janusz Krawczyk ◽  
Wieslaw Szatko ◽  
Irina Postnikova ◽  
Valerian Blinichev

High efficiency of intensive work of wet scrubbers is the result of simultaneous formation of different collectors - dust collectors. Under the collectors it can understand the drops of the sprayed liquid, the bubbles generated in the conditions of intense bubbling, the liquid surface and the wet surface. All collectors are formed during the operation of the circulation unit, the features of which were considered in a previous article by the same authors. This article discusses the laboratory installation to assess the impact of various factors on the efficiency of collectors. The first device consists of three chambers in which the dust separation with a varying concentration of the suspension was analyzed independently in the drop area, under bubbling conditions, as well as upon impact on the wetted surface. To estimate the fractional effectiveness a multi-stage cascade impact mechanisms was used. A significant part of the second test bench was the dust collecting chamber, which provides a cross-flow of the suspension with respect to the dust gas acting on the surface of the liquid. A number of general efficiency tests were carried out at the stand under varying conditions of the impact of the outflow of dusty air on the surface of the liquid with constant dust dosing into the system. Dust removal efficiency was evaluated by measuring the mass of dust supplied to the system compared to the dust held by the filter on the outflow pipeline. The physical model of the phenomenon was developed on the basis of the hypothesis that the efficiency of dust particles capture by wet scrubbers depends on the absorption capacity of the liquid and, therefore, is associated with the concentration of the suspension.  A high concentration of a suspension may prevent the penetration of particles in the reservoirs and not disclose them to the surface for further collisions of the dust particles.


Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2535
Author(s):  
Ji-Bong Choi ◽  
Yu-Kyoung Kim ◽  
Seon-Mi Byeon ◽  
Jung-Eun Park ◽  
Tae-Sung Bae ◽  
...  

In this study, a hydrogel using single and double crosslinking was prepared using GelMA, a natural polymer, and the effect was evaluated when the double crosslinked hydrogel and tannic acid were treated. The resulting hydrogel was subjected to physicochemical property evaluation, biocompatibility evaluation, and animal testing. The free radicals generated through APS/TEMED have a scaffold form with a porous structure in the hydrogel, and have a more stable structure through photo crosslinking. The double crosslinked hydrogel had improved mechanical strength and better results in cell compatibility tests than the single crosslinked group. Moreover, in the hydrogel transplanted into the femur of a rat, the double crosslinked group showed an osteoinductive response due to the attachment of bone minerals after 4 and 8 weeks, but the single crosslinked group did not show an osteoinductive response due to rapid degradation. Treatment with a high concentration of tannic acid showed significantly improved mechanical strength through H-bonding. However, cell adhesion and proliferation were limited compared to the untreated group due to the limitation of water absorption capacity, and no osteoinduction reaction was observed. As a result, it was confirmed that the treatment of high-concentration tannic acid significantly improved mechanical strength, but it was not a suitable method for improving bone induction due to the limitation of water absorption.


Proceedings ◽  
2020 ◽  
Vol 69 (1) ◽  
pp. 38
Author(s):  
Celia Idres ◽  
Mustapha Kaci ◽  
Nadjet Dehouche ◽  
Idris Zembouai ◽  
Stéphane Bruzaud

This paper aims to investigate the effect of different chemical modifications of biocomposites based on poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) and aloe vera bio-fibers incorporated at 20 wt%. The fiber surface was modified with alkaline, organosilanes, and combined alkaline/organosilanes. Surface morphology, thermal stability, water absorption capacity, and rheological behavior of the modified biocomposite materials were studied, and the results compared to both unmodified biocomposites and neat PHBH. The study showed that the modified biocomposites with both alkaline and organosilanes exhibited an improved surface morphology, resulting in a good fiber/matrix interfacial adhesion. As a result, increases in complex viscosity, storage modulus, and loss modulus were observed, whereas water absorption was reduced. Thermal stability remained almost unchanged, with the exception of the biocomposite treated with alkaline, where this property decreased significantly. Finally, the coupling of alkaline and organosilane modification is an efficient route to enhance the properties of PHBH biocomposites.


RSC Advances ◽  
2021 ◽  
Vol 11 (21) ◽  
pp. 12703-12709
Author(s):  
Huijun Li ◽  
Bin Wang ◽  
Yueli Wen ◽  
Chunyao Hao ◽  
Yuhua Liu ◽  
...  

For the side chain alkylation of toluene with methanol, middle base sites can improve the selectivity of styrene and ethylbenzene. With enough middle base sites on the catalysts, strong base sites benefit the selectivity of styrene.


RSC Advances ◽  
2013 ◽  
Vol 3 (48) ◽  
pp. 25944 ◽  
Author(s):  
Hyunjoo Lee ◽  
Young Mee Jung ◽  
Keun Im Lee ◽  
Hoon Sik Kim ◽  
Ho Seok Park

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1268
Author(s):  
Yan Wang ◽  
Shuhang Ren ◽  
Yucui Hou ◽  
Weize Wu

Up to now, many kinds of deep eutectic solvents (DESs) were investigated for the capture of acidic gases from flue gases. In this review, non-functionalized and functionalized DESs, including binary and ternary DESs, for SO2, CO2 and NO capture, are summarized based on the mechanism of absorption, physical interaction or chemical reaction. New strategies for improving the absorption capacity are introduced in this review. For example, a third component can be introduced to form a ternary DES to suppress the increase in viscosity and improve the CO2 absorption capacity. DESs, synthesized with halogen salt hydrogen bond acceptors (HBAs) and functionalized hydrogen bond donors (HBDs), can be used for the absorption of SO2 and NO with high absorption capacities and low viscosities after absorption, due to physicochemical interaction between gases and DESs. Emphasis is given to introducing the absorption capacities of acidic gases in these DESs, the mechanism of the absorption, and the ways to enhance the absorption capacity.


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