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Dong, Y., Laaksonen, A., Cao, W., Ji, X. & Lu, X. (2019). AFM Study of pH-Dependent Adhesion of Single Protein to TiO2 Surface. Advanced Materials Interfaces, 6(14), Article ID 1900411.
Open this publication in new window or tab >>AFM Study of pH-Dependent Adhesion of Single Protein to TiO2 Surface
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2019 (English)In: Advanced Materials Interfaces, ISSN 2196-7350, Vol. 6, no 14, article id 1900411Article in journal (Refereed) Published
Abstract [en]

The effect of pH-induced electrostatic conditions on the molecular interaction force of a single lysozyme molecule with TiO2 is investigated using atomic force microscopy (AFM). The force between the charged or neutral lysozyme molecule and the TiO2 surface is measured at different pH from 3.6 to 10.8. It is found to be directly proportional to the contact area, given by an effective diameter of the lysozyme molecule, and is further qualitatively verified by the AFM-measured friction coefficients. The results of the Derjaguin–Landau–Verwey–Overbeek theory show that the pH can change the surface charge densities of both lysozyme and TiO2, but the molecular interaction force at different pH is only dependent on the pH-induced effective diameter of lysozyme. The molecular interaction forces, quantified at the nanoscale, can be directly used to design high-performance liquid chromatography measurements at macroscale by tuning the retention time of a protein under varied pH conditions. They can also be applied to develop a model for predicting and controlling the chromatographic separations of proteins.

Place, publisher, year, edition, pages
John Wiley & Sons, 2019
Keywords
AFM, DLVO theory, electrostatic conditions, HPLC, molecular interaction force
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-74601 (URN)10.1002/admi.201900411 (DOI)000478624200016 ()2-s2.0-85067084518 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-08-21 (johcin)

Available from: 2019-06-17 Created: 2019-06-17 Last updated: 2019-08-21Bibliographically approved
Liu, Y., Nie, Y., Lu, X., Zhang, X., He, H., Pan, F., . . . Zhang, S. (2019). Cascade utilization of lignocellulosic biomass to high-value products. Green Chemistry, 21(13), 3499-3535
Open this publication in new window or tab >>Cascade utilization of lignocellulosic biomass to high-value products
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2019 (English)In: Green Chemistry, ISSN 1463-9262, E-ISSN 1463-9270, Vol. 21, no 13, p. 3499-3535Article in journal (Refereed) Published
Abstract [en]

Lignocellulosic biomass is a potential sustainable feedstock to replace fossil fuels. However, the complex structure of biomass makes it difficult to convert into high-value products. Utilization of lignocellulosic biomass in a green and effective way is of great significance for sustainable development. Based on the analysis of different options, we proposed that cascade utilization according to its composition, characteristics, and nature is the best way to utilize the lignocellulosic biomass. To promote the cascade utilization of lignocellulosic biomass, this article provides a review of the latest research results from the aspect of cascade utilization of lignocellulosic biomass covering the whole chain from pretreatment to high-value products, and the research on the non-conventional pretreatments including microwave irradiation, supercritical fluids, ultrasonic irradiation, electric field, hydrodynamic cavitation, and ionic liquids are presented in detail and evaluated by 4 proposed levels, and the newly developed high-value applications were further overviewed for lignin (carbon/graphene/carbon nano-tubes, dye dispersants, bioplastics, and aerogels), cellulose (cellulose-based ionic liquids, functional composites, adsorbent materials, carbon, and aerogels), and hemicellulose (films and pharmaceutical carriers), respectively. Finally, perspectives on the future research on the cascade utilization of lignocellulosic biomass are highlighted.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2019
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-75207 (URN)10.1039/c9gc00473d (DOI)000474622600002 ()
Note

Validerad;2019;Nivå 2;2019-07-04 (svasva)

Available from: 2019-07-04 Created: 2019-07-04 Last updated: 2019-08-22Bibliographically approved
Dong, Y., Ji, X., Laaksonen, A., Cao, W., An, R., Lu, L. & Lu, X. (2019). Determination of the small amount of proteins interacting with TiO2 nanotubes by AFM-measurement. Biomaterials, 192, 368-376
Open this publication in new window or tab >>Determination of the small amount of proteins interacting with TiO2 nanotubes by AFM-measurement
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2019 (English)In: Biomaterials, ISSN 0142-9612, E-ISSN 1878-5905, Vol. 192, p. 368-376Article in journal (Refereed) Published
Abstract [en]

Detecting the small amounts of proteins interacting effectively with the solid film electrodes surface still remains a challenge. To address this, in this work, a new approach was proposed by the combination of the adhesion forces and the molecular interaction measured with AFM. Cytochrome c (Cyt C) interacting effectively with TiO2 nanotube arrays (TNAs) was chosen as a probe. The amounts of Cyt C molecules interacting effectively on TNAs surface (CTNA) range from 5.5×10-12 to 7.0×10-12 mol/cm2 (68.2-86.8 ng/cm2) and they are comparable with the values obtained by the electrochemistry method in the literature, in evidence of the accuracy of this AFM-based approach. The reliability of the proposed approach was further verified by conducting Surface Enhanced Raman Scattering (SERS) measurements and estimating the enhancement factor (EF). This interaction-based AFM approach can be used to accurately obtain the small amounts of adsorbed substances on the solid film electrodes surface in the applications such as biosensors, biocatalysis, and drug delivery, etc.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
TiO2, nanotubes, Adsorption amount, AFM, Molecular interaction, Adhesion force, SERS
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-71860 (URN)10.1016/j.biomaterials.2018.11.013 (DOI)000456902000030 ()30476718 (PubMedID)2-s2.0-85059333773 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-12-03 (johcin)

Available from: 2018-12-03 Created: 2018-12-03 Last updated: 2019-03-27Bibliographically approved
Ma, C., Liu, C., Lu, X. & Ji, X. (2019). Erratum: Techno-economic analysis and performance comparison of aqueous deep eutectic solvent and other physical absorbents for biogas upgrading [Letter to the editor]. Applied Energy, 235, 1669-1670
Open this publication in new window or tab >>Erratum: Techno-economic analysis and performance comparison of aqueous deep eutectic solvent and other physical absorbents for biogas upgrading
2019 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 235, p. 1669-1670Article in journal, Letter (Refereed) Published
Abstract [en]

The authors regret to inform that there are errors in the vertical axis of Figs. 4 and 5 as well as corresponding text. The corrected versions are given below. (Figure presented.) Fig. 4b: the left y-axis should read “$·Nm-3 CH4” instead of “k$·Nm-3 CH4”; The corrected version of Fig. 5 is shown below. Abstract: The text at the end of Abstract: ‘For the case with …respectively’ should read: “…with AQ50wt.%DESand PC decrease by…” instead of “…with PC and AQ50wt.%DES decrease by…” Section 3.3.2: The text at the end of paragraph 5: ‘The results of specific TAC of using…than that using water, respectively. ’ should read: “…using AQ50wt.%DES and PC decrease by ….” instead of “…using PC and AQDES decrease by…” “…using AQ50wt.%DES and PC increase up to…” instead of “…using PC and AQ50wt.%DESincrease up to…” The text at the end of paragraph 6: ‘While, using…raw biogas capacity. ’ should read: “…and 25% than water…” instead of “…and 50% than water…” Conclusion: The text at the end of paragraph 2: ‘The results of specific TAC of using PC …than PC should be developed.’ should read: “…using AQ50wt.%DES and PC decrease by…” instead of “…using PC and AQ50wt.%DES decrease by…” “…using AQ50wt.%DES and PC treated with…” instead of “…using PC and AQ50wt.%DES treated with…” The above errors do not reflect any calculations errors and do not compromise the findings of the paper. The authors would like to apologize for any inconvenience caused. 

Place, publisher, year, edition, pages
Elsevier, 2019
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-72798 (URN)10.1016/j.apenergy.2018.09.218 (DOI)000458942800133 ()2-s2.0-85060587157 (Scopus ID)
Note

Erratum in: Energy, Vol. 225, s. 437-447, DOI: 10.1016/j.apenergy.2018.04.112

Available from: 2019-02-06 Created: 2019-02-06 Last updated: 2019-03-27Bibliographically approved
Li, Z., Ji, X., Yang, Z. & Lu, X. (2019). Experimental studies of air-blast atomization on the CO2 capture with aqueous alkali solutions. Chinese Journal of Chemical Engineering
Open this publication in new window or tab >>Experimental studies of air-blast atomization on the CO2 capture with aqueous alkali solutions
2019 (English)In: Chinese Journal of Chemical Engineering, ISSN 1004-9541, E-ISSN 2210-321XArticle in journal (Refereed) Epub ahead of print
Abstract [en]

In this work, an air-blast atomizing column was used to study the CO2 capture performance with aqueous MEA (mono-ethanol-amine) and NaOH solutions. The effects of gas flow rate, the liquid to gas ratio (L/G), the CO2 concentration on the CO2 removal efficiency (η) and the volumetric overall mass transfer coefficient (KGav) were investigated. The air-blast atomizing column was also compared with the pressure spray tower on the studies of the CO2 capture performance. For the aqueous MEA and NaOH solutions, the experimental results show that the ηdecreases with increasing gas flow rate and CO2 concentration while it increases with increasing L/G. The effects on KGav are more complicated than those for η. When the CO2 concentration is low (3 v/v%), KGav increases with increasing gas flow rate while decreases with increasing L/G. However, when the CO2 concentration is high (9.5 v/v%), as the gas flow rate and L/G increases, KGav increases first and then decreases. The aqueous MEA solution achieves higher η and KGav than the aqueous NaOH solution. The air-blast atomizing column shows a good performance on CO2 capture.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Air-blast atomizer, CO2 capture, Aqueous alkali solutions
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-73068 (URN)10.1016/j.cjche.2019.01.021 (DOI)
Available from: 2019-02-28 Created: 2019-02-28 Last updated: 2019-02-28
Han, J., Bai, L., Yang, B., Bai, Y., Luo, S., Zeng, S., . . . Zhang, X. (2019). Highly Selective Oxygen/Nitrogen Separation Membrane Engineered Using a Porphyrin-Based Oxygen Carrier. Membranes, 9(9), Article ID 115.
Open this publication in new window or tab >>Highly Selective Oxygen/Nitrogen Separation Membrane Engineered Using a Porphyrin-Based Oxygen Carrier
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2019 (English)In: Membranes, ISSN 2077-0375, E-ISSN 2077-0375, Vol. 9, no 9, article id 115Article in journal (Refereed) Published
Abstract [en]

Air separation is very important from the viewpoint of the economic and environmental advantages. In this work, defect-free facilitated transport membranes based on poly(amide-12-b-ethylene oxide) (Pebax-2533) and tetra(p-methoxylphenyl)porphyrin cobalt chloride (T(p-OCH3)PPCoCl) were fabricated in systematically varied compositions for O2/N2 separation. T(p-OCH3)PPCoCl was introduced as carriers that selectively and reversibly interacted with O2 and facilitated O2 transport in the membrane. The T(p-OCH3)PPCoCl had good compatibility with the Pebax-2533 via the hydrogen bond interaction and formed a uniform and thin selective layer on the substrate. The O2 separation performance of the thin film composite (TFC) membranes was improved by adding a small amount of the T(p-OCH3)PPCoCl and decreasing the feed pressure. At the pressure of 0.035 MPa, the O2 permeability and O2/N2 selectivity of the 0.6 wt % T(p-OCH3)PPCoCl/Pebax-2533 was more than 3.5 times that of the Pebax-2533 TFC membrane, which reached the 2008 Robeson upper bound. It provides a candidate membrane material for O2/N2 efficient separation in moderate conditions

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
facilitated transport membranes, cobalt porphyrin, oxygen/nitrogen separation, mixed matrix membrane, selectivity
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-75963 (URN)10.3390/membranes9090115 (DOI)000487746100017 ()31484439 (PubMedID)
Note

Validerad;2019;Nivå 2;2019-09-11 (johcin)

Available from: 2019-09-11 Created: 2019-09-11 Last updated: 2019-10-18Bibliographically approved
Liu, S., Li, H., Chen, Y., Yang, Z., Wang, H., Ji, X. & Lu, X. (2019). Improved CO2 separation performance of aqueous choline-glycine solution by partially replacing water with polyethylene glycol. Fluid Phase Equilibria, 495, 12-20
Open this publication in new window or tab >>Improved CO2 separation performance of aqueous choline-glycine solution by partially replacing water with polyethylene glycol
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2019 (English)In: Fluid Phase Equilibria, ISSN 0378-3812, E-ISSN 1879-0224, Vol. 495, p. 12-20Article in journal (Refereed) Published
Abstract [en]

Aqueous choline-glycine ([Cho][Gly]) solution is a potential candidate for CO2separation owing to its excellent absorption performance and biodegradability. Moreover, the aqueous solution is easy to volatilize at high temperatures. In this work, H2O was partially replaced with polyethylene glycol (PEG200) and the effect of PEG200 on the CO2 separation performance in [Cho][Gly])/H2O was investigated. The viscosity of [Cho][Gly]/H2O/PEG200 and CO2 solubility in the solution were determined experimentally in the temperature range 308.15–338.15 K at pressures ≤6.5 bar. Further, the measured CO2 solubility was fitted with the reaction equilibrium thermodynamic model and the CO2 desorption enthalpy was estimated. The regeneration performance of [Cho][Gly]/H2O/PEG200 was also evaluated. The results revealed that [Cho][Gly]/H2O/PEG200 has a low CO2desorption enthalpy and high regeneration efficiency. Particularly, [Cho][Gly]/H2O/PEG200 with 30 wt% PEG200 has a high regeneration efficiency of 95%. Owing to its physical-chemical properties and CO2 separation performance, [Cho][Gly]/H2O/PEG200 shows great potential as an absorbent for CO2 separation.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Ionic liquids, Carbon dioxide, Solubility, Reaction equilibrium thermodynamic model, Regeneration
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-73942 (URN)10.1016/j.fluid.2019.05.006 (DOI)000473379400002 ()2-s2.0-85065612653 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-06-11 (oliekm)

Available from: 2019-05-15 Created: 2019-05-15 Last updated: 2019-08-15Bibliographically approved
Bülow, M., Ji, X. & Held, C. (2019). Incorporating a concentration-dependent dielectric constant into ePC-SAFT. An application to binary mixtures containing ionic liquids. Fluid Phase Equilibria, 492, 26-33
Open this publication in new window or tab >>Incorporating a concentration-dependent dielectric constant into ePC-SAFT. An application to binary mixtures containing ionic liquids
2019 (English)In: Fluid Phase Equilibria, ISSN 0378-3812, E-ISSN 1879-0224, Vol. 492, p. 26-33Article in journal (Refereed) Published
Abstract [en]

Primitive thermodynamic models for electrolyte solutions require the dielectric constant ε. This property strongly depends on the concentration of the electrolytes in the mixture. Neglecting this dependency might be reasonable for modeling solutions at low electrolyte concentrations. However, in solutions containing ionic liquids (ILs) and especially for the calculation of liquid-liquid equilibria (LLE) of systems with ILs, liquid phases often contain high IL concentrations. At such conditions, neglecting the influence of concentration on ε is an oversimplification. In this work, an approach to account for the concentration-dependent dielectric constant within the Debye-Hückel theory was implemented into electrolyte Perturbed-Chain Statistical Associating Fluid Theory (original ePC-SAFT). This new approach was then applied to model LLE of binary mixtures containing water and commonly used hydrophobic ILs. These common ILs are comprised of the IL-cations [C n mim] + , [C n py] + , [C n mpy] + , [C n mpyr] + , [C 4 m 4 py] + and the IL-anions [BF 4 ] - , [NTf 2 ] - , [PF 6 ] - , [TFO] - . The LLE of binary mixtures water + IL were modeled at ambient pressure and different temperatures with the new ePC-SAFT and with the original ePC-SAFT [Ji et al. DOI: 10.1016/j.fluid.2012.05.029] without the concentration-dependent ε. Overall, the new approach within ePC-SAFT shows superior modeling as well as correlation capability compared to original ePC-SAFT, which was concluded by comparing both models with LLE data from literature. 

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Electrolytes, Liquid-liquid equilibria, Prediction, Thermodynamics
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-73437 (URN)10.1016/j.fluid.2019.03.010 (DOI)000469151600003 ()
Note

Validerad;2019;Nivå 2;2019-04-05 (svasva)

Available from: 2019-04-05 Created: 2019-04-05 Last updated: 2019-06-19Bibliographically approved
Huangfu, C., Dong, Y., Ji, X., Wu, N. & Lu, X. (2019). Mechanistic Study of Protein Adsorption on Mesoporous TiO2 in Aqueous Buffer Solutions. Langmuir, 35(34), 11037-11047
Open this publication in new window or tab >>Mechanistic Study of Protein Adsorption on Mesoporous TiOin Aqueous Buffer Solutions
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2019 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 35, no 34, p. 11037-11047Article in journal (Refereed) Published
Abstract [en]

Protein adsorption is of fundamental importance for bioseparation engineering applications. In this work, a series of mesoporous TiO2 with various geometric structures and different aqueous buffer solutions were prepared as platforms to investigate the effects of the surface geometry and ionic strength on the protein adsorptive behavior. The surface geometry of the TiO2 was found to play a dominant role in the protein adsorption capacity when the ionic strength of buffer solutions is very low. With the increase in ionic strength, the effect of the geometric structure on the protein adsorption capacity reduced greatly. The change of ionic strength has the highest significant effect on the mesoporous TiO2 with large pore size compared with that with small pore size. The interaction between the protein and TiO2 measured with atomic force microscopy further demonstrated that the adhesion force induced by the surface geometry reduced with the increase in the ionic strength. These findings were used to guide the detection of the retention behavior of protein by high-performance liquid chromatography, providing a step forward toward understanding the protein adsorption for predicting and controlling the chromatographic separation of proteins.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2019
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-76106 (URN)10.1021/acs.langmuir.9b01354 (DOI)000483439400005 ()
Note

Validerad;2019;Nivå 2;2019-09-24 (johcin)

Available from: 2019-09-24 Created: 2019-09-24 Last updated: 2019-09-24Bibliographically approved
Sun, Y., Schemann, A., Held, C., Lu, X., Shen, G. & Ji, X. (2019). Modeling Thermodynamic Derivative Properties and Gas Solubility of Ionic Liquids with ePC-SAFT. Industrial & Engineering Chemistry Research, 58(19), 8401-8417
Open this publication in new window or tab >>Modeling Thermodynamic Derivative Properties and Gas Solubility of Ionic Liquids with ePC-SAFT
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2019 (English)In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 58, no 19, p. 8401-8417Article in journal (Refereed) Published
Abstract [en]

In this work, the ion-specific electrolyte perturbed-chain statistical associating fluid theory (ePC-SAFT) was extended to predict the second-order thermodynamic derivative properties and gas solubility of the ionic liquids (ILs) containing one of the IL cations ([Cnmim]+, [Cnpy]+, [Cnmpy]+, [Cnmpyr]+, and [THTDP]+) and one of the IL anions ([Tf2N], [PF6], [BF4], [tfo], [DCA], [SCN], [C1SO4], [C2SO4], [eFAP], Cl, [Ac], and Br). The ideal-gas isobaric heat capacities of ILs were estimated by the group contribution method for obtaining the heat capacity. The model prediction results were compared with the available experimental data, and the comparison shows that the ePC-SAFT prediction is reliable for most ILs. Furthermore, one adjustable ion-specific binary interaction parameter between the IL ion and CO2 can be used to further improve the model prediction performance for the CO2 solubility in ILs.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2019
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-74685 (URN)10.1021/acs.iecr.9b00254 (DOI)000468368100074 ()2-s2.0-85065545825 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-06-18 (johcin)

Available from: 2019-06-18 Created: 2019-06-18 Last updated: 2019-06-18Bibliographically approved
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