Multi‐instrument characterization of poly(divinylbenzene) microspheres for use in liquid chromatography: as received, air oxidized, carbonized, and acid treated

Hung, Chuan-Hsi; Singh, Bhupinder; Landowski, Michael G.; Ibrahim, Mohammed; Miles, Andrew J.; Jensen, David S.; Vail, Michael A.; Dadson, Andrew E.; Smith, Stacey J.; Linford, Matthew R.

doi:10.1002/sia.5778

Cited by 6 publications

(7 citation statements)

References 59 publications

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“…Figure e reveals diffused peaks appearing at the 2θ degree of about 13° and 22° which are ascribed to amorphous silica and crystalline Si, respectively. , These peaks were still evident in the XRD spectra of SiO 2 /DVB in Figure f; however, a broad peak at 2θ = 18° caused an overlap with the other peak of SiO 2 . According to Hung et al, this peak corresponds to DVB, which confirms the result of DVB being incorporated onto the pores of SiO 2 .…”

Section: Resultssupporting

confidence: 63%

“…33,34 These peaks were still evident in the XRD spectra of SiO 2 /DVB in Figure 1f; however, a broad peak at 2θ = 18°c aused an overlap with the other peak of SiO 2 . According to Hung et al, this peak corresponds to DVB, 19 which confirms the result of DVB being incorporated onto the pores of SiO 2 .…”

Section: Resultssupporting

confidence: 58%

“…One of the features of the Langmuir isotherm is the dimensionless constant called the separation factor, R l , which is used to evaluate the effectiveness of adsorption, and is defined by eq where the value of R l indicates the shape of the isotherms to be either irreversible ( R l = 0), favorable (0 < R l < 1), linear ( R l = 1), or unfavorable ( R l > 1) …”

Section: Methodsmentioning

confidence: 99%

“…where the value of R l indicates the shape of the isotherms to be either irreversible (R l = 0), favorable (0 < R l < 1), linear (R l = 1), or unfavorable (R l > 1). 19 The Freundlich model is based on an empirical equation that assumes the occurrence of a heterogeneous adsorption surface having unequally available sites with different energies of adsorption. 20 The linearized Freundlich equation is given by eq 4…”

Section: Energy and Fuelsmentioning

confidence: 99%

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Applicability of Composite Silica–Divinylbenzene in Bioethanol Dehydration: Equilibrium, Kinetic, Thermodynamic, and Regeneration Analysis

Luna

Divinagracia

Choi³

et al. 2019

Energy Fuels

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A composite silica–divinylbenzene (SiO2/DVB) adsorbent was prepared for the adsorption of ethanol from the ethanol–water mixture. Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and a Brunauer, Emmett and Teller surface area analyzer were utilized for the characterization analysis of the adsorbents. Batch experiments were executed at different initial ethanol concentrations (10–95 vol %), contact times (1–24 h), and temperatures (10–40 °C). The equilibrium studies indicated a favorable adsorption of ethanol on SiO2/DVB because of a separation factor R l of 0.18 from the Langmuir model. Moreover, Freundlich parameter constant n was found to be 2.37. This implies that the adsorption is governed by a physical process. Results in the experimental data best-fitted the pseudo-second-order kinetic model (R 2 ≥ 0.98 and RMSE ≤ 1.26), which suggests chemisorption as the rate-limiting step of the adsorption system. Based on the Weber–Morris kinetic analysis, intraparticle diffusion occurred after the outer surface of the SiO2/DVB became saturated by ethanol molecules. Approximately 99.2 ± 0.4% (20 °C) and 99.8 ± 0.2% (30 °C) of the ethanol were adsorbed onto the SiO2/DVB adsorbent. Furthermore, thermodynamic parameters indicated a nonspontaneous and exothermic reaction in the adsorption process. It was revealed that the reusability profile of SiO2/DVB showed a 5.3% reduction in terms of the adsorption capacity after the first cycle and 8.3% reduction after four cycles.

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Section: Resultssupporting

confidence: 63%

Section: Resultssupporting

confidence: 58%

Section: Methodsmentioning

confidence: 99%

Section: Energy and Fuelsmentioning

confidence: 99%

See 2 more Smart Citations

Applicability of Composite Silica–Divinylbenzene in Bioethanol Dehydration: Equilibrium, Kinetic, Thermodynamic, and Regeneration Analysis

Luna

Divinagracia

Choi³

et al. 2019

Energy Fuels

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show abstract

“…Nevertheless, ToF-SIMS provides more chemical information. ToF-SIMS does not give chemical state information about elements other than the hydrogen atom, and XPS is not sensitive to hydrogen . In addition, these techniques allow for the characterization of the changes in the contents of various functional groups immobilized onto the silica surface, which are associated with the method of silica fabrication, thermal history, or surface treatment …”

Section: Fundamentals Of High-performance Liquid Chromatographymentioning

confidence: 99%

Column Characterization and Selection Systems in Reversed-Phase High-Performance Liquid Chromatography

et al. 2019

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Reversed-phase high-performance liquid chromatography (RP-HPLC) is the most popular chromatographic mode, accounting for more than 90% of all separations. HPLC itself owes its immense popularity to it being relatively simple and inexpensive, with the equipment being reliable and easy to operate. Due to extensive automation, it can be run virtually unattended with multiple samples at various separation conditions, even by relatively low-skilled personnel. Currently, there are >600 RP-HPLC columns available to end users for purchase, some of which exhibit very large differences in selectivity and production quality. Often, two similar RP-HPLC columns are not equally suitable for the requisite separation, and to date, there is no universal RP-HPLC column covering a variety of analytes. This forces analytical laboratories to keep a multitude of diverse columns. Therefore, column selection is a crucial segment of RP-HPLC method development, especially since sample complexity is constantly increasing. Rationally choosing an appropriate column is complicated. In addition to the differences in the primary intermolecular interactions with analytes of the dispersive (London) type, individual columns can also exhibit a unique character owing to specific polar, hydrogen bond, and electron pair donor–acceptor interactions. They can also vary depending on the type of packing, amount and type of residual silanols, “end-capping”, bonding density of ligands, and pore size, among others. Consequently, the chromatographic performance of RP-HPLC systems is often considerably altered depending on the selected column. Although a wide spectrum of knowledge is available on this important subject, there is still a lack of a comprehensive review for an objective comparison and/or selection of chromatographic columns. We aim for this review to be a comprehensive, authoritative, critical, and easily readable monograph of the most relevant publications regarding column selection and characterization in RP-HPLC covering the past four decades. Future perspectives, which involve the integration of state-of-the-art molecular simulations (molecular dynamics or Monte Carlo) with minimal experiments, aimed at nearly “experiment-free” column selection methodology, are proposed.

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Investigations of the carbonization process of hybrid polymer microspheres using the TGA-EGA method: assessment of the impact of sulphanilic acid on the process

Sobiesiak,

Podkościelna,

Mazur

2024

J Therm Anal Calorim

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The TGA-EGA technique was used to study the influence of sulphanilic acid (SA) on the carbonisation process of the hybrid terpolymeric precursors composed of methacrylamide, divinylbenzene, and trimethoxyvinylsilane. The pristine polymers were impregnated with saturated solution of SA, dried, and carbonized at 600 °C under N2 atmosphere. The characteristic properties of both the pristine hybrid polymers and the resulting carbons were based on FTIR, Raman, and PXRD analyses, which revealed the materials were composed of amorphous polymeric or carbon phase interpenetrated by silica/silicate disordered network. The porosimetric analysis showed the resulted carbons possessed homogeneous supermicropores with the average pore width of 0.7 nm and reduced number of mesopores compared to pristine precursors. From the TGA results, it was followed that impregnated polymers decomposed in two stages, instead of one like pristine precursors did. Moreover, IDT of impregnated polymers was reduced by about 100 °C, and their Tmax was increased by 2–5.5 °C. Their decomposition proceeded slower by 22–37% that caused increase in efficiency of the process by 10–48%. The EGA showed the decomposition of the impregnated precursors started from the degradation of the amide groups, then SA destruction took place, followed by further decomposition of the polymer. The studies led to the conclusion that SA had the protective effect on the surface of the carbonized polymers. During impregnation and thermal treatment, SA produced a deposit in pores of the precursors. This resulted in narrowing of the pore width, delaying and slowing down the polymer thermal decomposition process, as well as increasing its efficiency.

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Multi‐instrument characterization of poly(divinylbenzene) microspheres for use in liquid chromatography: as received, air oxidized, carbonized, and acid treated

Cited by 6 publications

References 59 publications

Applicability of Composite Silica–Divinylbenzene in Bioethanol Dehydration: Equilibrium, Kinetic, Thermodynamic, and Regeneration Analysis

Applicability of Composite Silica–Divinylbenzene in Bioethanol Dehydration: Equilibrium, Kinetic, Thermodynamic, and Regeneration Analysis

Column Characterization and Selection Systems in Reversed-Phase High-Performance Liquid Chromatography

Investigations of the carbonization process of hybrid polymer microspheres using the TGA-EGA method: assessment of the impact of sulphanilic acid on the process

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