In household products, specific chemical ingredients are used to satisfy the desired target properties as required by the consumers. However, some of these ingredients may result in safety risks and adverse health effects. Early consideration of safety and health aspects during product design is vital to minimize the impact on consumers. Safety and health aspects have not been strongly emphasized before in many product design methodologies. Therefore, a systematic methodology is proposed to assess the safety and health effects of the potential ingredients, before they are used in the product formulation. The chemical ingredient candidate may be a novel ingredient or a typical ingredient used in formulated product design. In this work, a computer-aided molecular design (CAMD) technique was used to design the novel ingredient candidates with the integration of safety and health aspects. Then, the safety and health performance of the ingredient candidates were assessed by inherent safety and health sub-indexes. Each safety or health parameter was assigned with a score, based on the degree of the potential hazards. A higher score was given to the ingredients with higher safety risk or more severe health effect, and vice versa. The result of the safety and health assessment based on the score allocation had contributed to the selection of chemical ingredient. This new approach ensures that the selected ingredient possesses desirable properties as well as low safety and health effects. A case study on surfactant design is presented to illustrate the incorporation of safety and health aspects into product design methodologies.
Atomic force microscopy (AFM) has a wide range of applications and is rapidly growing in research and development. This powerful technique has been used to visualize surfaces both in liquid or gas media. It has been considered as an effective tool to investigate the surface structure for its ability to generate high-resolution 3D images at a subnanometer range without sample pretreatment. In this paper, the use of AFM to characterize the membrane roughness is presented for commercial and self-prepared membranes for specific applications. Surface roughness has been regarded as one of the most important surface properties, and has significant effect in membrane permeability and fouling behaviour. Several scan areas were used to compare surface roughness for different membrane samples. Characterization of the surfaces was achieved by measuring the average roughness (Ra) and root mean square roughness (Rrms) of the membrane. AFM image shows that the membrane surface was composed entirely of peaks and valleys. Surface roughness is substantially greater for commercial available hydrophobic membranes, in contrast to self-prepared membranes. This study also shows that foulants deposited on membrane surface would increase the membrane roughness.