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The purpose of this project is to explore the adsorption rates of different dye methods (direct, reactive, acidic, disperse, azo dyes) in three shapes of chitosan materials (film, microsphere, and scaffold) which were formed by 88% deacetylation degree of chitosan. Results of this research suggest that the samples with larger specific surface areas tend to have shorter adsorption times. Among the three samples, the chitosan scaffold reached the adsorptive saturation on the third day, showing the shortest adsorption time of the direct, reactive, acidic, dispersive and azo dyes, whereas the chitosan film reached the adsorptive saturation on the eighth day, giving it the longest adsorption time of the dyes.

We have prepared anisotropic chitosan gels with birefringence by immersing a sandwiched chitosan in aqueous acetic acid into aqueous sodium hydroxide. The gel forming process was traced under observation with crossed nicols and open nicols with and without litmus agent. The time courses of the gel front, the birefringent layer and the pH-change layer agreed with each other fairly well. The early stage of the dynamics was expressed by a theory with an assumption of an OH − diffusion-limited process, whereas the behavior in the late stage deviated from the theoretical one. The deviation results from the effect of the outflow of protons, and the crossover of the two behaviors is attributed to the relaxation to the thermal equilibrium.

This study discusses poly(3-hydroxybutyrate- co -4-hydroxybutyrate) that is produced by Delftia acidovorans bacteria in fed-batch cultures from various carbon sources. The experimentally determined optimal fed-batch culture conditions are as follows: pH: 7.0, incubation temperature: 26 °C, incubation time: 72 h, and concentration of carbon source: 10 g/L. The maximum 4HB unit composition of P(3HB- co -4HB) obtained using the fed-batch culture with a cell concentration of about 2.5 g/L was 94 mol% although the P(3HB- co -4HB) content remained low, at around 13 wt%. The extent of the enzymatic degradation of P(3HB- co -4HB) was determined by involved PHB depolymerase and lipase. The tensile strength of P(3HB- co -4HB) markedly decreased during 2 h of degradation by PHB depolymerase, whereas that of P(3HB- co -4HB) degraded by lipase for 50 h was at least 3 MPa.

This research studies the morphology and characterization of three-dimensional (3D) micro-porous structures produced from biodegradable chitosan for use as scaffolds for cells culture. The chitosan 3D micro-porous structures were produced by a simple liquid hardening method, which includes the processes of foaming by mechanical stirring without any chemical foaming agent added, and hardening by NaOH cross linking. The pore size and porosity were controlled with mechanical stirring strength. This study includes the morphology of chitosan scaffolds, the characterization of mechanical properties, water absorption properties and in vitro enzymatic degradation of the 3D micro-porous structures. The results show that chitosan 3D micro-porous structures were successfully produced. Better formation samples were obtained when chitosan concentration is at 1-3%, and concentration of NaOH is at 5%. Faster stirring rate would produce samples of smaller pore diameter, but when rotation speed reaches 4000 rpm and higher the changes in pore size is minimal. Water absorption would reduce along with the decrease of chitosan scaffolds' pore diameter. From stress-strain analysis, chitosan scaffolds' mechanical properties are improved when it has smaller pore diameter. From in vitro enzymatic degradation results, it shows that the disintegration rate of chitosan scaffolds would increase along with the processing time increase, but approaching equilibrium when the disintegration rate reaches about 20%.

This research uses three kinds of recycled synthetic fibers that all possess excellent thermal plasticity property as raw material to develop a new firm cultivation media: polyethylene terephthalate, polyamide and polypropylene. One can not only freely control plants cultivation growing condition by changing bulk density of the media, but also solve disposal problem after usage by applying thermal oxidative treatment during manufacturing processes. The water content, air permeability and formation conditions of these fiber growing media that are required in plants growing habitat were discussed, and compared the fallout with rockwool (RW) growing media that is commonly used at present days. The results indicated that the polyethylene terephthalate fiber media could attain best formation characteristics among these fibers at the same bulk density range. Furthermore, the fiber media that were thermo-oxidative treated at 240–260 °C could obtained above 90% total porosity, 23–49% air capacity and 48–68% water availability, water contents raised from 1735–1094 to 2145–1156% under bulk densities of 0.03–0.09 g/cm3, which conforms to the common plant growing habitat conditions. Its performance well surpasses the rockwool growing media. We also discovered that the thermo-oxidative treated polyethylene terephthalate (PET) fiber media could be easily broken down and become powdery by exerting pressure, thus greatly reduce its volume and effectively improve disposal processes that are difficult presently for the huge refuse create by rockwool.

Solution-grown single crystals of poly(ethylene succinate-co-trimethylene succinate)s (PETSA) were hydrolyzed by polyhydroxybutyrate (PHB) depolymerase from Ralstonia pickettii T1. Enzymatic degradation proceeded from the edges of the lamellar crystals, yielding serrated contours and small crystal fragments. On the other hand, single PETSA crystals were aminolyzed in 20 % aqueous methylamine solution to remove the folded chain regions, and enzymatically degraded using PHB depolymerase to remove poly(trimethylene succinate)—PTSA—components at the surfaces of single aminolyzed crystals. It was found that a small amount of PTSA component could be incorporated into the poly(ethylene succinate)—PESA—mother crystal lattice irrespective of the PTSA content.

This research uses modified orifice method to prepare the O/W type Chitosan encapsulated volatile Citronella Oil microcapsules. In this article, we investigated the forming condition of microcapsules and the influence to sustained release effect of volatile Citronella Oil by applying thermal pretreatment to microcapsules. The results suggest that the forming of microcapsules should be processed under the fundamental conditions of: (1) the concentration of Chitosan is at least 0.2wt%, (2) NaOH is greater than 0.1wt%, and (3) with the additive of coconut oil as natural surfactant, so that we could obtain final product of microcapsules with better formation and dispersion. The changes in concentration of Chitosan will affect the encapsulation efficiency of the volatile Citronella Oil. When the concentrations of Chitosan are 0.5%, 1.0% and 1.5%, the encapsulation efficiencies are 98.2%, 95.8% and 94.7%, respectively. The particle size of Chitosan microcapsules would decrease as the emulsification stirring speed increases. When the stirring speeds are 400 rpm, 800 rpm, and 1500 rpm, the average particle sizes of microcapsules produced are 225+/-24 microm, 131+/-20 microm, and 11+/-3 microm, respectively. If the microcapsules were thermal pretreated at 80 degrees C, the structure of Chitosan wall membrane would shrink and thus achieve the effect of sustained release. The sustaining effect would increase along with treatment time increases.

The research is to utilize synthetic fibers to manufacture new growing media with uncomplicated adjustment of water availability and air capacity. Using polyethylene terephthalate (PET), polyamide (Nylon66) and polypropylene (PP) as the raw materials; utilizing their excellent thermo-plasticity to cure above the glass-transition temperature, using different ratio of fibers to produce growing media of different bulk densities. The formation characteristics of these growing media are required in plants cultivation were discussed. Compare the results with rockwool growing media that are commonly used at present days. The results indicated that PET, Nylon66 and PP fibers could obtain good formation characteristics in 0.026–0.076, 0.054–0.162, 0.055–0.157 g/cm 3 , respectively. Among them the culture media that uses PET as raw material, for its excellent stiffness and thermo-plasticity, produces the best formation characteristics. PET under the aforementioned bulk densities could have above 90% total porosity, above 10% air capacity, above 40% water availability and above 1200% water content, which conforms to the common plant culture habitat conditions. Its performance well surpasses the rockwool growing media. If we adjust with different ratio of fine denier fiber in the PET fiber growing media, then the water content of the media may be enhanced up to 20%.

Poly(urea-urethane) microcapsules were prepared by the interfacial polymerization with using mixtures of tri- and di-isocyanate monomers as wall forming materials, and dioctyl phthalate containing an oil-soluble dye as a core material. The time course of the dye release in dispersing tetrahydrofuran was measured as a function of the weight fraction of tri-isocyanate monomer in the total monomer w and the core/wall material-weight ratio g. The dye release curves were well represented by an exponential function C=Ceq(1-e-t/tau), where C is the concentration of the dye in the dispersing medium, Ceq that at equilibrium state, t the elution time and tau is a time constant. tau increased linearly against w at high g, suggesting controllability of the release rate of microcapsules by varying tri-isocyanate/di-isocyanate ratio.

Alginate complex capsules containing eucalyptus oil were prepared by the interfacial insolubilization reaction and its controlled release characteristics were examined. The capsule walls became substantially impermeable to eucalyptus oil by incubating the capsules at 37 °C for 20 min, when the preparation parameters were above the critical values of 1.0 w/v% sodium alginate, 2.0 w/v% calcium chloride and 20 min of the cross-linking time. The maximum oil content in the capsules was 90–92% at this condition. The time course of the oil release from the closed capsules was measured as a function of crashing force. It was confirmed that holding the capsules between fingers could control the oil release.

Transfer of azo-dyes from dioctylphthalate core to binary mixtures of methanol+acetone with different compositions through poly(ureaurethane) (PUU) microcapsule membrane has been measured. The release curves were expressed by an exponential equation C(t)=Ceq(1−exp(−t/τ)) except for pure acetone, where C(t) is the concentration of the dye in the dispersing medium, Ceq that at the equilibrium state, t the elution time and τ a time constant. Ceq and τ are related to the chemical potentials and the diffusion coefficient of the dye, based on a simple theoretical model. The logarithm of τ was roughly proportional to the reciprocal of the absolute temperature, from which the activation energy Ea for the transfer of the dye was estimated. The value of Ea observed using acetone as the dispersing medium was much larger than that observed using methanol. In the curve of τ versus percentage weight of acetone w in the dispersing medium, a minimum was observed around w∼40%. The release curve for pure acetone had multi steps and did not agree with the theoretical prediction. These characteristic permeability properties were attributed to a structural change of the microcapsule membrane surface due to the interaction of the protective colloid and the dispersing medium.

The time course for the transfer of azo dyes from the microcapsule core of dioctylphthalate to the dispersing medium of methanol through a poly(ureaurethane) (PUU) membrane was measured for various average size microcapsules with a size distribution. The dye release curves are represented by a stretched exponential function C ( t )= C eq {1−exp [−( t / τ eff ) α ]}, where C ( t ) is the concentration of the dye in methanol, C eq that at the equilibrium state, and t the time. The exponent α decreased by increasing the variance of the size distribution of microcapsules. The effective time constant τ eff was expressed by τ eff = c 0 〈 R 2 〉/ κ ( α ), where 〈 R 2 〉 and κ ( α ) are the mean square of microcapsule radius and a correction for the size distribution, respectively. The characteristic proportional constant, c 0 , was determined as 2.6±0.2 min/μm 2 . From the value of the constant, the diffusion coefficient of the azo dye in the PUU membrane was evaluated as 2.6×10 −12 cm 2 /s.

We have studied the release curve for microcapsules with size distribution. On the basis of an analogy to the relaxation phenomena with multiple characteristic times, we propose a stretched exponential release curve for the system with size distribution and relate the release curve to the size distribution function of the microcapsule. This method was successfully applied to the transfer of azo-pigments from inner medium of dioctyl phthalate to dispersing medium of methanol through poly(ureaurethane) microcapsule membrane.

A retrospective study of patients' records on reviewing the purpose of venous catheter insertion (chemotherapy, blood transfusion, antibiotics or parenteral nutrition); total period of insertion; reason for catheter removal. 120 admitted patients who received fluoroscopic guide PICC (4-French single lumen silicone rubber catheter) insertions into distal SVC via antecubital region of forearm. We retrospectively review human factors including the patients' laboratory data of pre- and post-insertion, total insertion period and reasons for withdrawal. The important human factors that affect the clinical outcome of PICC were also evaluated. The results indicated that the most common complications were wound oozing, phlebitis, occlusion, infection and leaking. Persistent wound oozing for over 3-day-period is the higher incidence of complication. It also demonstrated a surprisingly high ratio (77%) in those patients with thrombocytopenia and leukemia. In this group, persistent low platelet counts could be noted, the ratio of failure (remove PICC within 3 days) is 10% and there is 40% decrease insertion period (30 days). Prospectively, it is worthwhile to choose new material or new technology of surface coating of PICC, to decrease consumption of platelet thrombogenic proteins and to maintain normal coagulate function of human bodies.