Vicki L Baliga

Physical characterization of the cigarette coal: part 1—smolder burn

Abstract The morphology of the coal from the smoldering cigarette was characterized using light microscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), inductively coupled plasma spectroscopy, and image analysis. The coal of the smoked cigarette was divided into four regions: the char positioned at and behind the char line of the cigarette paper, the coal base located just in front of the char line, the coal tip located in front of the coal base, and the ash that surrounded the exterior surface of the coal cone. The morphology of the char behind the coal consisted of tobacco shreds that transitioned from yellow to brown to black with changes in morphology from minimal surface damage to cuticle separation. The blackened area of the coal base contained shreds that exhibited vesicle formation to carbonized shells to inorganic encrustation of the shreds, all of which are characteristic morphologies of pyrolysis. Shreds within the coal tip region exhibited morphologies similar to those found in the coal base as well as progressive cell wall degradation through etching, morphology that is characteristic of oxidative pyrolysis. Shred structures from the ash region consisted of inorganic replicas of the tobacco shreds to materials that consisted of melts of inorganic components. Some of the potassium, sulfur, and sodium from the tobacco migrated into the gas stream.

Design of a Polymer Blend for One-Step Porous Fiber Fabrication

We demonstrate a novel polymer blend derived from a hydrophobic poly(vinyl acetate) (PVAC) and a hydrophilic poly(acrylic acid) (PAA) that forms a porous fiber in a single step by melt spinning. Polymer fibers of PAA, PVAC, and fibers made of 40:60, 50:50 and 60:40 PVAC/PAA blends were melt-spun and examined with the use of transmitted light microscopy and environmental scanning electron microscopy. The morphology of melt-spun fibers made from PAA and from PVAC were solid fibers. Fibers melt-spun from the polymer blends of 40%, 50% and 60% PVAC with PAA making the remainder of 100% consisted of a honeycombed, porous fiber structure with some internal cell to cell interconnectivity. It is also noteworthy to mention that fibers melt-spun from PAA only and from PVAC only were very fragile and were difficult to make. However, fibers from the novel blend of PAA and PVAC were spinnable and formed porous fibers that maintained their fiber integrity.