Provided are purification systems and methods of using such systems for purifying various environments, such as indoor air, outdoor air, vehicle emissions, and industrial emissions. A purification system comprises an ionizing purifier having a substrate and an active coating. The active coating comprises a pyroelectric and/or piezoelectric material. During the operation, an incoming stream is directed toward the active coating while controlling the average pressure exerting on the active coating. This contact between the incoming stream and the active coating generates negative ions from components of the incoming stream via change in temperature and pressure/force/vibration, etc. The negative ions then interact with pollutants, transforming them into safe, purified materials of the outgoing stream. Unlike the pollutants in the incoming stream, the purified materials are non-harmful, and/or can be easily removed from the outgoing stream, e.g., by filtering and/or other separation techniques.

Provided are purification systems and methods of using such systems for purifying various environments, such as indoor air, outdoor air, vehicle emissions, and industrial emissions. A purification system comprises an ionizing purifier having a substrate and an active coating. The active coating comprises a pyroelectric and/or piezoelectric material. During the operation, an incoming stream is directed toward the active coating while controlling the average pressure exerting on the active coating. This contact between the incoming stream and the active coating generates negative ions from components of the incoming stream via change in temperature and pressure/force/vibration, etc. The negative ions then interact with pollutants, transforming them into safe, purified materials of the outgoing stream. Unlike the pollutants in the incoming stream, the purified materials are non-harmful, and/or can be easily removed from the outgoing stream, e.g., by filtering and/or other separation techniques.

An air purifier having an electret module for capturing airborne particles, the electret module includes an electret element which generates a static field for capturing airborne particles. The electret module is positioned incorporated into the air purifier such that the static field helps prevent the inhalation of the airborne particles.

An air purifier having an electret module for capturing airborne particles, the electret module includes an electret element which generates a static field for capturing airborne particles. The electret module is positioned incorporated into the air purifier such that the static field helps prevent the inhalation of the airborne particles.

An active field polarized filter includes a scrimless filter media that includes a mixture of polypropylene fibers with polymethaphenylene isophtalamide fibers. This mixture may be in the form of a nonwoven material having a weight ratio of polymethaphenylene isophtalamide fibers to polypropylene fibers ranging between 5:95 and 50:50, and even more preferably between 10:90 and 30:70.

A method of making a fluorinated fibrous web, which method includes providing a nonwoven web 22 that contains polymeric fibers, creating a plasma that contains fluorine atoms at a first location 14, and contacting the nonwoven web with products from the plasma at a second location 26 remote from the first location 14. The method avoids exposure of the web to the plasma and hence expands the manufacturing processing window. Webs so fluorinated have a different C.sub.3F.sub.4H.sup.+ to C.sub.2F.sub.5.sup.+ ratio when compared to locally fluorinated webs having similar levels of surface fluorination. The remote fluorinated webs can be subsequently charged electrically to provide a good performing electret filter 40 suitable for use in an air purifying respirator 30. Webs fluorinated in accordance with this invention also may exhibit good performance even after being aged at high temperatures.

A method of making a fluorinated fibrous web, which method includes providing a nonwoven web 22 that contains polymeric fibers, creating a plasma that contains fluorine atoms at a first location 14, and contacting the nonwoven web with products from the plasma at a second location 26 remote from the first location 14. The method avoids exposure of the web to the plasma and hence expands the manufacturing processing window. Webs so fluorinated have a different C.sub.3F.sub.4H.sup.+ to C.sub.2F.sub.5.sup.+ ratio when compared to locally fluorinated webs having similar levels of surface fluorination. The remote fluorinated webs can be subsequently charged electrically to provide a good performing electret filter 40 suitable for use in an air purifying respirator 30. Webs fluorinated in accordance with this invention also may exhibit good performance even after being aged at high temperatures.

A filtration material of the present invention comprises a bulky fiber sheet layer having a thickness of 0.5 mm or more, and a triboelectrically-charged nonwoven fabric layer in which two or more types of fibers different in constituent resin are mixed, wherein constituent fibers of the triboelectrically-charged nonwoven fabric layer penetrate into the bulky fiber sheet layer. A three-layer filtration material of the present invention comprises bulky fiber sheet layers having a thickness of 0.5 mm or more, and a triboelectrically-charged nonwoven fabric layer, which is located between the bulky fiber sheet layers, wherein the constituent fibers of the triboelectrically-charged nonwoven fabric layer penetrate into the bulky fiber sheet layers, and both bulky fiber sheet layers contain fibers having a limiting oxygen index of 20 or more, and have a mass per unit area 0.5 times or more than that of the triboelectrically-charged nonwoven fabric layer. A filter element of the present invention comprises the filtration material in a pleated state.

A filtration material of the present invention comprises a bulky fiber sheet layer having a thickness of 0.5 mm or more, and a triboelectrically-charged nonwoven fabric layer in which two or more types of fibers different in constituent resin are mixed, wherein constituent fibers of the triboelectrically-charged nonwoven fabric layer penetrate into the bulky fiber sheet layer. A three-layer filtration material of the present invention comprises bulky fiber sheet layers having a thickness of 0.5 mm or more, and a triboelectrically-charged nonwoven fabric layer, which is located between the bulky fiber sheet layers, wherein the constituent fibers of the triboelectrically-charged nonwoven fabric layer penetrate into the bulky fiber sheet layers, and both bulky fiber sheet layers contain fibers having a limiting oxygen index of 20 or more, and have a mass per unit area 0.5 times or more than that of the triboelectrically-charged nonwoven fabric layer. A filter element of the present invention comprises the filtration material in a pleated state.

Provided are purification systems and methods of using such systems for purifying various environments, such as indoor air, outdoor air, vehicle emissions, and industrial emissions. A purification system comprises an ionizing purifier having a substrate and an active coating. The active coating comprises a pyroelectric and/or piezoelectric material. During the operation, an incoming stream is directed toward the active coating while controlling the average pressure exerting on the active coating. This contact between the incoming stream and the active coating generates negative ions from components of the incoming stream via change in temperature and pressure/force/vibration, etc. The negative ions then interact with pollutants, transforming them into safe, purified materials of the outgoing stream. Unlike the pollutants in the incoming stream, the purified materials are non-harmful, and/or can be easily removed from the outgoing stream, e.g., by filtering and/or other separation techniques.