@article{wege_kim_paunov_zhong_velev_2008, title={Long-term stabilization of foams and emulsions with in-situ formed microparticles from hydrophobic cellulose}, volume={24}, ISSN={["0743-7463"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-51449120260&partnerID=MN8TOARS}, DOI={10.1021/la801634j}, abstractNote={We report a simple method to produce foams and emulsions of extraordinary stability by using hydrophobic cellulose microparticles, which are formed in situ by a liquid-liquid dispersion technique. The hydrophobic cellulose derivative, hypromellose phthalate (HP), was initially dissolved in water-miscible solvents such as acetone and ethanol/water mixtures. As these HP stock solutions were sheared in aqueous media, micron sized cellulose particles formed by the solvent attrition. We also designed and investigated an effective and simple process for making HP particles without any organic solvents, where both the solvent and antisolvent were aqueous buffer solutions at different pH. Consequently, the HP particles adsorbed onto the water/air or water/oil interfaces created during shear blending, resulting in highly stable foams or foam/emulsions. The formation of HP particles and their ability for short-term and long-term stabilization of interfaces strongly depended on the HP concentration in stock solutions, as well as the solvent chemistry of both stock solutions and continuous phase media. Some foams and emulsion samples formed in the presence of ca. 1 wt% HP were stable for months. This new class of nontoxic inexpensive cellulose-based particle stabilizers has the potential to substitute conventional synthetic surfactants, especially in edible, pharmaceutical and biodegradable products.}, number={17}, journal={LANGMUIR}, author={Wege, Hartmut A. and Kim, Sejong and Paunov, Vesselin N. and Zhong, Qixin and Velev, Orlin D.}, year={2008}, month={Sep}, pages={9245–9253} }
 @article{zhong_daubert_velev_2004, title={Cooling effects on a model rennet casein gel system: Part II. Permeability and microscopy}, volume={20}, ISSN={["0743-7463"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-4444266641&partnerID=MN8TOARS}, DOI={10.1021/la036148o}, abstractNote={Microscopy and permeability studies were performed to further illustrate the cooling effects on rennet casein gel structure and help interpret the rheological observations in the first part of this paper. Samples of gels cooled from 80 to 5 degrees C at four rates (0.5, 0.1, 0.05, and 0.025 degrees C/min) were studied with a confocal laser scanning microscope. A larger number of smaller flocs were generated at slower cooling rates, creating more cross-links within a network and corresponding to a stronger gel. Formation of a larger number of smaller flocs was hypothesized to result from a greater degree of doublet formation because the system spent more time within the temperature region where doublet formation is favored when cooled at slower rates. The doublets represent sites available for floc growth, similar to nucleation sites for crystal growth. Microscopy results further substantiated that the cooling effects were different from the aging effects because cooling affected floc size, and aging enabled the addition of idle flocs into the casein network. The conclusions for the cooling effects on floc size were further supported by permeability tests. A smaller permeability coefficient resulted from smaller flocs obtained with a slower cooling schedule. This study showed the importance of controlling floc numbers to modulate the strength of a gel, and cooling rates provide an approach of modulating functional properties when the chemical composition of a system is fixed.}, number={18}, journal={LANGMUIR}, author={Zhong, QX and Daubert, CR and Velev, OD}, year={2004}, month={Aug}, pages={7406–7411} }
 @article{zhong_daubert_velev_2004, title={Cooling effects on a model rennet casein gel system: part I. Rheological characterization}, volume={20}, ISSN={["0743-7463"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-4444224511&partnerID=MN8TOARS}, DOI={10.1021/la036147w}, abstractNote={The gelation of a model rennet casein system was studied during cooling at different rates. During cooling, casein network structure development was proposed to evolve over a few steps at different length scales: molecules, particles, flocs, or network. Rennet casein flocs are fractal in nature, and fractal dimension and floc size are two variables affecting the rheology and microstructure of a rennet casein gel. Casein structure formation during cooling from 80 to 5 degrees C at four different rates (0.5, 0.1, 0.05, and 0.025 degrees C/min) was monitored by dynamic rheological tests, and a stronger gel developed at a slower cooling rate. During different cooling schedules, similar fractal dimensions were observed due to a lack of difference in the colloidal interactions. Differences among rheological data were possibly caused by variability in floc size, as observed in the second part of this paper. A larger number of smaller-sized flocs enabled gelation at a higher temperature and created a stronger network at a slower cooling rate. Controlling cooling schemes thus provides an approach for manipulating casein gelation and the microstructure for a system of fixed chemical compositions.}, number={18}, journal={LANGMUIR}, author={Zhong, QX and Daubert, CR and Velev, OD}, year={2004}, month={Aug}, pages={7399–7405} }
 @article{zhong_daubert_farkas_2004, title={Cooling effects on processed cheese functionality}, volume={27}, ISSN={["1745-4530"]}, DOI={10.1111/j.1745-4530.2004.00390.x}, abstractNote={ABSTRACT}, number={5}, journal={JOURNAL OF FOOD PROCESS ENGINEERING}, author={Zhong, QX and Daubert, CR and Farkas, BE}, year={2004}, pages={392–412} }
 @article{zhong_daubert_2004, title={Kinetics of rennet casein gelation at different cooling rates}, volume={279}, ISSN={["1095-7103"]}, DOI={10.1016/j.jcis.2004.06.059}, abstractNote={A mathematical model was developed to quantitatively analyze the rheological data of rennet casein gelation at different cooling rates. Kinetic parameters were estimated and correlated with the microstructure development of the protein network. The kinetic model identified structure development upon cooling to be first order, and the network forming energies were estimated for four protein concentrations cooled at four rates. A lower energy for network formation was observed for a slower cooling rate and a higher protein concentration. This observation resulted from the availability of more flocs at a slower cooling rate and a higher casein concentration, simplifying floc cross-linking. By analyzing the kinetics during the aging process of casein gels, no difference in the reaction mechanism was observed. This study illustrated that structure formation resulted from the addition of flocs into the protein network: not all flocs were part of the network at a defined gel point. The incubation period following cooling integrated idle flocs into the network, thereby strengthening the gel. By understanding the gelation mechanism during cooling of rennet casein gels, the structure and thus quality of dairy products, such as processed cheese, may be better controlled.}, number={1}, journal={JOURNAL OF COLLOID AND INTERFACE SCIENCE}, author={Zhong, Q and Daubert, CR}, year={2004}, month={Nov}, pages={88–94} }
 @article{zhong_sandeep_swartzel_2003, title={Continuous flow radio frequency heating of water and carboxymethylcellulose solutions}, volume={68}, ISSN={["0022-1147"]}, DOI={10.1111/j.1365-2621.2003.tb14142.x}, abstractNote={ABSTRACT}, number={1}, journal={JOURNAL OF FOOD SCIENCE}, author={Zhong, Q and Sandeep, KP and Swartzel, KR}, year={2003}, pages={217–223} }