Influence of the magnetic force on the van der Waals force of superparamagnetic composite particles

Knoll, Johannes; Nirschl, Hermann

doi:10.1016/j.powtec.2014.03.050

Cited by 10 publications

(2 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The former is based on the sum of the individual interactions between molecules [83] and the latter is based on the quantum field theory and considers the interacting molecules as continuous macroscopic materials [84]. In DEM simulation, van der Waals force (FvdW) is commonly calculated based on the Hamaker-based theory approach, which is defined by the following equation [15,85]:FvdW=HR6h2 where h is the separation distance between spherical particles; H is the Hamaker constant; R is the radius of the spherical particle. The Equation (15) indicates that van der Waals force becomes infinite when the spherical particle contact ( h = 0), which can be caused a significant problem in DEM simulation.…”

Section: Comprehensive Theory Of Discrete Element Methodsmentioning

confidence: 99%

Application of the Discrete Element Method for Manufacturing Process Simulation in the Pharmaceutical Industry

Yeom

Kim

et al. 2019

Pharmaceutics

View full text Add to dashboard Cite

Process simulation using mathematical modeling tools is becoming more common in the pharmaceutical industry. A mechanistic model is a mathematical modeling tool that can enhance process understanding, reduce experimentation cost and improve product quality. A commonly used mechanistic modeling approach for powder is the discrete element method (DEM). Most pharmaceutical materials have powder or granular material. Therefore, DEM might be widely applied in the pharmaceutical industry. This review focused on the basic elements of DEM and its implementations in pharmaceutical manufacturing simulation. Contact models and input parameters are essential elements in DEM simulation. Contact models computed contact forces acting on the particle-particle and particle-geometry interactions. Input parameters were divided into two types—material properties and interaction parameters. Various calibration methods were presented to define the interaction parameters of pharmaceutical materials. Several applications of DEM simulation in pharmaceutical manufacturing processes, such as milling, blending, granulation and coating, were categorized and summarized. Based on this review, DEM simulation might provide a systematic process understanding and process control to ensure the quality of a drug product.

show abstract

Section: Comprehensive Theory Of Discrete Element Methodsmentioning

confidence: 99%

Application of the Discrete Element Method for Manufacturing Process Simulation in the Pharmaceutical Industry

Yeom

Kim

et al. 2019

Pharmaceutics

View full text Add to dashboard Cite

show abstract

“…The experimental materials are dried at 105°C for 3 h prior to each use and stored in a desiccator after using. The physical properties of the above granular materials are listed in Table , including the actual density, Sauter mean size, and Hamaker constant …”

Section: Methodsmentioning

confidence: 99%

Gravitational discharge of fine dry powders with asperities from a conical hopper

Zhong

Cao

et al. 2017

AIChE Journal

View full text Add to dashboard Cite

The effects of particle properties, especially the surface roughness and particle type, on the gravity discharge rate and flow behavior of fine dry powders from a conical hopper are studied in detail. The van der Waals force is considered to dominate the discharge of small particles, while the empty annulus effect dominates the discharge of large particles. To predict the van der Waals force between two rough spherical particles, a model based on Rumpf theory is adopted. The effect of surface roughness can be reflected by Bond number Bo g which is correlated with discharge rate. By modifying the powder bed porosity and Beverloo constant, the discharge rates of fine dry powders can be well predicted by an empirical correlation. Finally, not only the ratio of hopper outlet size to particle size D 0 /d p but also the Bond number Bo g is found to be an important indicator to determine the powder flowability.

show abstract

Determination of the Adhesion Forces of Magnetic Composite Particles

Knoll

Rhein

Nirschl

2019

Particles in Contact

View full text Add to dashboard Cite

Influence of the magnetic force on the van der Waals force of superparamagnetic composite particles

Cited by 10 publications

References 11 publications

Application of the Discrete Element Method for Manufacturing Process Simulation in the Pharmaceutical Industry

Application of the Discrete Element Method for Manufacturing Process Simulation in the Pharmaceutical Industry

Gravitational discharge of fine dry powders with asperities from a conical hopper

Determination of the Adhesion Forces of Magnetic Composite Particles

Contact Info

Product

Resources

About