Acoustic - Electroacoustic Spectrometer (AES) for colloids characterization

所要求的声-电-声光谱仪主要用于测定悬浮液和乳状液中颗粒和液滴的大小和电荷。在决定悬浮液和乳液的稳定性时，电荷和尺寸是重要的。有几种方法来测量胶体的尺寸和电荷，其中大多数使用颗粒和液滴与光的相互作用（光散射）。然而，当悬浮液是深色或浑浊时（如在沥青乳液和颗粒的浓缩悬浮液的情况下），这些技术是不合适的。在这些情况下，电声光谱是最好的选择，因为它使用不同频率的声波衰减来确定颗粒的大小和电荷。这种方法的另一个优点是，它最适合相对浓缩的悬浮液（体积分数为0.1%至40%），这意味着不需要稀释样品。 在多伦多大学和其他大学的许多实验室中常见的其他方法需要将样品在水或其他合适的溶剂中稀释。必要的取样和稀释方法会干扰悬浮液或乳液本身的稳定性，从而在测量中产生系统误差。申请人充分意识到这些限制，因为在先前对沥青乳液稳定性、粘土和富含粘土的材料的稳定性、矿物悬浮液的稳定性、在纸浆和造纸工业中使用的牛皮纸化学品回收循环中携带的颗粒的稳定性的研究中已经变得清楚。获得确定胶体的尺寸和电荷的适当方法将帮助申请人和其他同事改进矿物提取工业中常用的沉降池中的颗粒去稳定化方法，改进原油加工中的油-颗粒-水分离方法，改进化学回收循环的效率，以及用于环境和能源相关应用的纳米颗粒的设计，了解和改进霜剂和其他局部产品的配方，以及乳液为基础的食品和水提取油从种子和其他生物质。

The requested acoustic-electroacoustic spectrometer (AES) is an instrument that will be primarily utilized in determining the size and charge of particles and drops in suspensions and emulsions. Charge and size are important at the time of determining the estability of suspensions and emulsions. There are several methods to measure size and charge of colloids, most of them use the interaction of particles and drops with light (light scattering). However, these techniques are not suitable when the suspension is dark or turbit (as in the case of bitumen emulsions and concentrated suspensions of particles). In those cases, electroacoustic spectroscopy is the best option as it uses the attenuation of sound waves at different frequencies to determine the size and charge of particles. An additional advantage of this method is that it works best with relatively concentrated suspensions (volume fractions from 0.1 to 40%), which means that it is not necessary to dilute the sample. Other methods, common in a number of laboratories at the University of Toronto and other Universities, require the sample to be diluted in water or other suitable solvent. The necessary sampling and dilution methods interfere with the stability of the suspension or emulsion itself, thus creating systematic errors in the measurement. The applicants are well aware of these limitations as it has become clear in previous studies of bitumen emulsion stability, stability of clays and clay-rich material, stability of mineral suspensions, stability of particles carried over in kraft chemical recovery cycles used in the pulp and paper industry. Having access to a proper methodolgy of determining the size and charge of colloids will help the applicants and other colleagues improve methods of particle destabilization in settling ponds commonly used in the mineral extraction industry, improve methods of oil-particle-water separation in the processing of crude oils, improve the efficiency of chemical recovery cycles, and the design of nanoparticles for environmental and energy-related applications, understand and improve the formulation of creams and other topical products as well as emulsion-based food products and aqueous extraction of oils from seeds and other biomass.